Add vendoring to containerd master

Initial vendor list validated with empty $GOPATH
and only master checked out; followed by `make`
and verified that all binaries build properly.
Updates require github.com/LK4D4/vndr tool.

Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com>
This commit is contained in:
Phil Estes 2016-12-16 12:03:35 -05:00
parent 286ea04591
commit dd9309c15e
No known key found for this signature in database
GPG key ID: 0F386284C03A1162
407 changed files with 113562 additions and 0 deletions

201
vendor/github.com/prometheus/client_golang/LICENSE generated vendored Normal file
View file

@ -0,0 +1,201 @@
Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.
"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
"Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.
2. Grant of Copyright License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.
3. Grant of Patent License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
(b) You must cause any modified files to carry prominent notices
stating that You changed the files; and
(c) You must retain, in the Source form of any Derivative Works
that You distribute, all copyright, patent, trademark, and
attribution notices from the Source form of the Work,
excluding those notices that do not pertain to any part of
the Derivative Works; and
(d) If the Work includes a "NOTICE" text file as part of its
distribution, then any Derivative Works that You distribute must
include a readable copy of the attribution notices contained
within such NOTICE file, excluding those notices that do not
pertain to any part of the Derivative Works, in at least one
of the following places: within a NOTICE text file distributed
as part of the Derivative Works; within the Source form or
documentation, if provided along with the Derivative Works; or,
within a display generated by the Derivative Works, if and
wherever such third-party notices normally appear. The contents
of the NOTICE file are for informational purposes only and
do not modify the License. You may add Your own attribution
notices within Derivative Works that You distribute, alongside
or as an addendum to the NOTICE text from the Work, provided
that such additional attribution notices cannot be construed
as modifying the License.
You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "[]"
replaced with your own identifying information. (Don't include
the brackets!) The text should be enclosed in the appropriate
comment syntax for the file format. We also recommend that a
file or class name and description of purpose be included on the
same "printed page" as the copyright notice for easier
identification within third-party archives.
Copyright [yyyy] [name of copyright owner]
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

23
vendor/github.com/prometheus/client_golang/NOTICE generated vendored Normal file
View file

@ -0,0 +1,23 @@
Prometheus instrumentation library for Go applications
Copyright 2012-2015 The Prometheus Authors
This product includes software developed at
SoundCloud Ltd. (http://soundcloud.com/).
The following components are included in this product:
perks - a fork of https://github.com/bmizerany/perks
https://github.com/beorn7/perks
Copyright 2013-2015 Blake Mizerany, Björn Rabenstein
See https://github.com/beorn7/perks/blob/master/README.md for license details.
Go support for Protocol Buffers - Google's data interchange format
http://github.com/golang/protobuf/
Copyright 2010 The Go Authors
See source code for license details.
Support for streaming Protocol Buffer messages for the Go language (golang).
https://github.com/matttproud/golang_protobuf_extensions
Copyright 2013 Matt T. Proud
Licensed under the Apache License, Version 2.0

View file

@ -0,0 +1,75 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// Collector is the interface implemented by anything that can be used by
// Prometheus to collect metrics. A Collector has to be registered for
// collection. See Registerer.Register.
//
// The stock metrics provided by this package (Gauge, Counter, Summary,
// Histogram, Untyped) are also Collectors (which only ever collect one metric,
// namely itself). An implementer of Collector may, however, collect multiple
// metrics in a coordinated fashion and/or create metrics on the fly. Examples
// for collectors already implemented in this library are the metric vectors
// (i.e. collection of multiple instances of the same Metric but with different
// label values) like GaugeVec or SummaryVec, and the ExpvarCollector.
type Collector interface {
// Describe sends the super-set of all possible descriptors of metrics
// collected by this Collector to the provided channel and returns once
// the last descriptor has been sent. The sent descriptors fulfill the
// consistency and uniqueness requirements described in the Desc
// documentation. (It is valid if one and the same Collector sends
// duplicate descriptors. Those duplicates are simply ignored. However,
// two different Collectors must not send duplicate descriptors.) This
// method idempotently sends the same descriptors throughout the
// lifetime of the Collector. If a Collector encounters an error while
// executing this method, it must send an invalid descriptor (created
// with NewInvalidDesc) to signal the error to the registry.
Describe(chan<- *Desc)
// Collect is called by the Prometheus registry when collecting
// metrics. The implementation sends each collected metric via the
// provided channel and returns once the last metric has been sent. The
// descriptor of each sent metric is one of those returned by
// Describe. Returned metrics that share the same descriptor must differ
// in their variable label values. This method may be called
// concurrently and must therefore be implemented in a concurrency safe
// way. Blocking occurs at the expense of total performance of rendering
// all registered metrics. Ideally, Collector implementations support
// concurrent readers.
Collect(chan<- Metric)
}
// selfCollector implements Collector for a single Metric so that the Metric
// collects itself. Add it as an anonymous field to a struct that implements
// Metric, and call init with the Metric itself as an argument.
type selfCollector struct {
self Metric
}
// init provides the selfCollector with a reference to the metric it is supposed
// to collect. It is usually called within the factory function to create a
// metric. See example.
func (c *selfCollector) init(self Metric) {
c.self = self
}
// Describe implements Collector.
func (c *selfCollector) Describe(ch chan<- *Desc) {
ch <- c.self.Desc()
}
// Collect implements Collector.
func (c *selfCollector) Collect(ch chan<- Metric) {
ch <- c.self
}

View file

@ -0,0 +1,172 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
)
// Counter is a Metric that represents a single numerical value that only ever
// goes up. That implies that it cannot be used to count items whose number can
// also go down, e.g. the number of currently running goroutines. Those
// "counters" are represented by Gauges.
//
// A Counter is typically used to count requests served, tasks completed, errors
// occurred, etc.
//
// To create Counter instances, use NewCounter.
type Counter interface {
Metric
Collector
// Set is used to set the Counter to an arbitrary value. It is only used
// if you have to transfer a value from an external counter into this
// Prometheus metric. Do not use it for regular handling of a
// Prometheus counter (as it can be used to break the contract of
// monotonically increasing values).
//
// Deprecated: Use NewConstMetric to create a counter for an external
// value. A Counter should never be set.
Set(float64)
// Inc increments the counter by 1.
Inc()
// Add adds the given value to the counter. It panics if the value is <
// 0.
Add(float64)
}
// CounterOpts is an alias for Opts. See there for doc comments.
type CounterOpts Opts
// NewCounter creates a new Counter based on the provided CounterOpts.
func NewCounter(opts CounterOpts) Counter {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
)
result := &counter{value: value{desc: desc, valType: CounterValue, labelPairs: desc.constLabelPairs}}
result.init(result) // Init self-collection.
return result
}
type counter struct {
value
}
func (c *counter) Add(v float64) {
if v < 0 {
panic(errors.New("counter cannot decrease in value"))
}
c.value.Add(v)
}
// CounterVec is a Collector that bundles a set of Counters that all share the
// same Desc, but have different values for their variable labels. This is used
// if you want to count the same thing partitioned by various dimensions
// (e.g. number of HTTP requests, partitioned by response code and
// method). Create instances with NewCounterVec.
//
// CounterVec embeds MetricVec. See there for a full list of methods with
// detailed documentation.
type CounterVec struct {
*MetricVec
}
// NewCounterVec creates a new CounterVec based on the provided CounterOpts and
// partitioned by the given label names. At least one label name must be
// provided.
func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &CounterVec{
MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
result := &counter{value: value{
desc: desc,
valType: CounterValue,
labelPairs: makeLabelPairs(desc, lvs),
}}
result.init(result) // Init self-collection.
return result
}),
}
}
// GetMetricWithLabelValues replaces the method of the same name in
// MetricVec. The difference is that this method returns a Counter and not a
// Metric so that no type conversion is required.
func (m *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Counter), err
}
return nil, err
}
// GetMetricWith replaces the method of the same name in MetricVec. The
// difference is that this method returns a Counter and not a Metric so that no
// type conversion is required.
func (m *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
metric, err := m.MetricVec.GetMetricWith(labels)
if metric != nil {
return metric.(Counter), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. By not returning an
// error, WithLabelValues allows shortcuts like
// myVec.WithLabelValues("404", "GET").Add(42)
func (m *CounterVec) WithLabelValues(lvs ...string) Counter {
return m.MetricVec.WithLabelValues(lvs...).(Counter)
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. By not returning an error, With allows shortcuts like
// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
func (m *CounterVec) With(labels Labels) Counter {
return m.MetricVec.With(labels).(Counter)
}
// CounterFunc is a Counter whose value is determined at collect time by calling a
// provided function.
//
// To create CounterFunc instances, use NewCounterFunc.
type CounterFunc interface {
Metric
Collector
}
// NewCounterFunc creates a new CounterFunc based on the provided
// CounterOpts. The value reported is determined by calling the given function
// from within the Write method. Take into account that metric collection may
// happen concurrently. If that results in concurrent calls to Write, like in
// the case where a CounterFunc is directly registered with Prometheus, the
// provided function must be concurrency-safe. The function should also honor
// the contract for a Counter (values only go up, not down), but compliance will
// not be checked.
func NewCounterFunc(opts CounterOpts, function func() float64) CounterFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), CounterValue, function)
}

View file

@ -0,0 +1,205 @@
// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"fmt"
"regexp"
"sort"
"strings"
"github.com/golang/protobuf/proto"
dto "github.com/prometheus/client_model/go"
)
var (
metricNameRE = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_:]*$`)
labelNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
)
// reservedLabelPrefix is a prefix which is not legal in user-supplied
// label names.
const reservedLabelPrefix = "__"
// Labels represents a collection of label name -> value mappings. This type is
// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
// metric vector Collectors, e.g.:
// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
//
// The other use-case is the specification of constant label pairs in Opts or to
// create a Desc.
type Labels map[string]string
// Desc is the descriptor used by every Prometheus Metric. It is essentially
// the immutable meta-data of a Metric. The normal Metric implementations
// included in this package manage their Desc under the hood. Users only have to
// deal with Desc if they use advanced features like the ExpvarCollector or
// custom Collectors and Metrics.
//
// Descriptors registered with the same registry have to fulfill certain
// consistency and uniqueness criteria if they share the same fully-qualified
// name: They must have the same help string and the same label names (aka label
// dimensions) in each, constLabels and variableLabels, but they must differ in
// the values of the constLabels.
//
// Descriptors that share the same fully-qualified names and the same label
// values of their constLabels are considered equal.
//
// Use NewDesc to create new Desc instances.
type Desc struct {
// fqName has been built from Namespace, Subsystem, and Name.
fqName string
// help provides some helpful information about this metric.
help string
// constLabelPairs contains precalculated DTO label pairs based on
// the constant labels.
constLabelPairs []*dto.LabelPair
// VariableLabels contains names of labels for which the metric
// maintains variable values.
variableLabels []string
// id is a hash of the values of the ConstLabels and fqName. This
// must be unique among all registered descriptors and can therefore be
// used as an identifier of the descriptor.
id uint64
// dimHash is a hash of the label names (preset and variable) and the
// Help string. Each Desc with the same fqName must have the same
// dimHash.
dimHash uint64
// err is an error that occured during construction. It is reported on
// registration time.
err error
}
// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
// and will be reported on registration time. variableLabels and constLabels can
// be nil if no such labels should be set. fqName and help must not be empty.
//
// variableLabels only contain the label names. Their label values are variable
// and therefore not part of the Desc. (They are managed within the Metric.)
//
// For constLabels, the label values are constant. Therefore, they are fully
// specified in the Desc. See the Opts documentation for the implications of
// constant labels.
func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc {
d := &Desc{
fqName: fqName,
help: help,
variableLabels: variableLabels,
}
if help == "" {
d.err = errors.New("empty help string")
return d
}
if !metricNameRE.MatchString(fqName) {
d.err = fmt.Errorf("%q is not a valid metric name", fqName)
return d
}
// labelValues contains the label values of const labels (in order of
// their sorted label names) plus the fqName (at position 0).
labelValues := make([]string, 1, len(constLabels)+1)
labelValues[0] = fqName
labelNames := make([]string, 0, len(constLabels)+len(variableLabels))
labelNameSet := map[string]struct{}{}
// First add only the const label names and sort them...
for labelName := range constLabels {
if !checkLabelName(labelName) {
d.err = fmt.Errorf("%q is not a valid label name", labelName)
return d
}
labelNames = append(labelNames, labelName)
labelNameSet[labelName] = struct{}{}
}
sort.Strings(labelNames)
// ... so that we can now add const label values in the order of their names.
for _, labelName := range labelNames {
labelValues = append(labelValues, constLabels[labelName])
}
// Now add the variable label names, but prefix them with something that
// cannot be in a regular label name. That prevents matching the label
// dimension with a different mix between preset and variable labels.
for _, labelName := range variableLabels {
if !checkLabelName(labelName) {
d.err = fmt.Errorf("%q is not a valid label name", labelName)
return d
}
labelNames = append(labelNames, "$"+labelName)
labelNameSet[labelName] = struct{}{}
}
if len(labelNames) != len(labelNameSet) {
d.err = errors.New("duplicate label names")
return d
}
vh := hashNew()
for _, val := range labelValues {
vh = hashAdd(vh, val)
vh = hashAddByte(vh, separatorByte)
}
d.id = vh
// Sort labelNames so that order doesn't matter for the hash.
sort.Strings(labelNames)
// Now hash together (in this order) the help string and the sorted
// label names.
lh := hashNew()
lh = hashAdd(lh, help)
lh = hashAddByte(lh, separatorByte)
for _, labelName := range labelNames {
lh = hashAdd(lh, labelName)
lh = hashAddByte(lh, separatorByte)
}
d.dimHash = lh
d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
for n, v := range constLabels {
d.constLabelPairs = append(d.constLabelPairs, &dto.LabelPair{
Name: proto.String(n),
Value: proto.String(v),
})
}
sort.Sort(LabelPairSorter(d.constLabelPairs))
return d
}
// NewInvalidDesc returns an invalid descriptor, i.e. a descriptor with the
// provided error set. If a collector returning such a descriptor is registered,
// registration will fail with the provided error. NewInvalidDesc can be used by
// a Collector to signal inability to describe itself.
func NewInvalidDesc(err error) *Desc {
return &Desc{
err: err,
}
}
func (d *Desc) String() string {
lpStrings := make([]string, 0, len(d.constLabelPairs))
for _, lp := range d.constLabelPairs {
lpStrings = append(
lpStrings,
fmt.Sprintf("%s=%q", lp.GetName(), lp.GetValue()),
)
}
return fmt.Sprintf(
"Desc{fqName: %q, help: %q, constLabels: {%s}, variableLabels: %v}",
d.fqName,
d.help,
strings.Join(lpStrings, ","),
d.variableLabels,
)
}
func checkLabelName(l string) bool {
return labelNameRE.MatchString(l) &&
!strings.HasPrefix(l, reservedLabelPrefix)
}

View file

@ -0,0 +1,181 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package prometheus provides metrics primitives to instrument code for
// monitoring. It also offers a registry for metrics. Sub-packages allow to
// expose the registered metrics via HTTP (package promhttp) or push them to a
// Pushgateway (package push).
//
// All exported functions and methods are safe to be used concurrently unless
//specified otherwise.
//
// A Basic Example
//
// As a starting point, a very basic usage example:
//
// package main
//
// import (
// "net/http"
//
// "github.com/prometheus/client_golang/prometheus"
// "github.com/prometheus/client_golang/prometheus/promhttp"
// )
//
// var (
// cpuTemp = prometheus.NewGauge(prometheus.GaugeOpts{
// Name: "cpu_temperature_celsius",
// Help: "Current temperature of the CPU.",
// })
// hdFailures = prometheus.NewCounterVec(
// prometheus.CounterOpts{
// Name: "hd_errors_total",
// Help: "Number of hard-disk errors.",
// },
// []string{"device"},
// )
// )
//
// func init() {
// // Metrics have to be registered to be exposed:
// prometheus.MustRegister(cpuTemp)
// prometheus.MustRegister(hdFailures)
// }
//
// func main() {
// cpuTemp.Set(65.3)
// hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc()
//
// // The Handler function provides a default handler to expose metrics
// // via an HTTP server. "/metrics" is the usual endpoint for that.
// http.Handle("/metrics", promhttp.Handler())
// http.ListenAndServe(":8080", nil)
// }
//
//
// This is a complete program that exports two metrics, a Gauge and a Counter,
// the latter with a label attached to turn it into a (one-dimensional) vector.
//
// Metrics
//
// The number of exported identifiers in this package might appear a bit
// overwhelming. Hovever, in addition to the basic plumbing shown in the example
// above, you only need to understand the different metric types and their
// vector versions for basic usage.
//
// Above, you have already touched the Counter and the Gauge. There are two more
// advanced metric types: the Summary and Histogram. A more thorough description
// of those four metric types can be found in the Prometheus docs:
// https://prometheus.io/docs/concepts/metric_types/
//
// A fifth "type" of metric is Untyped. It behaves like a Gauge, but signals the
// Prometheus server not to assume anything about its type.
//
// In addition to the fundamental metric types Gauge, Counter, Summary,
// Histogram, and Untyped, a very important part of the Prometheus data model is
// the partitioning of samples along dimensions called labels, which results in
// metric vectors. The fundamental types are GaugeVec, CounterVec, SummaryVec,
// HistogramVec, and UntypedVec.
//
// While only the fundamental metric types implement the Metric interface, both
// the metrics and their vector versions implement the Collector interface. A
// Collector manages the collection of a number of Metrics, but for convenience,
// a Metric can also “collect itself”. Note that Gauge, Counter, Summary,
// Histogram, and Untyped are interfaces themselves while GaugeVec, CounterVec,
// SummaryVec, HistogramVec, and UntypedVec are not.
//
// To create instances of Metrics and their vector versions, you need a suitable
// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts,
// HistogramOpts, or UntypedOpts.
//
// Custom Collectors and constant Metrics
//
// While you could create your own implementations of Metric, most likely you
// will only ever implement the Collector interface on your own. At a first
// glance, a custom Collector seems handy to bundle Metrics for common
// registration (with the prime example of the different metric vectors above,
// which bundle all the metrics of the same name but with different labels).
//
// There is a more involved use case, too: If you already have metrics
// available, created outside of the Prometheus context, you don't need the
// interface of the various Metric types. You essentially want to mirror the
// existing numbers into Prometheus Metrics during collection. An own
// implementation of the Collector interface is perfect for that. You can create
// Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and
// NewConstSummary (and their respective Must… versions). That will happen in
// the Collect method. The Describe method has to return separate Desc
// instances, representative of the “throw-away” metrics to be created
// later. NewDesc comes in handy to create those Desc instances.
//
// The Collector example illustrates the use case. You can also look at the
// source code of the processCollector (mirroring process metrics), the
// goCollector (mirroring Go metrics), or the expvarCollector (mirroring expvar
// metrics) as examples that are used in this package itself.
//
// If you just need to call a function to get a single float value to collect as
// a metric, GaugeFunc, CounterFunc, or UntypedFunc might be interesting
// shortcuts.
//
// Advanced Uses of the Registry
//
// While MustRegister is the by far most common way of registering a Collector,
// sometimes you might want to handle the errors the registration might
// cause. As suggested by the name, MustRegister panics if an error occurs. With
// the Register function, the error is returned and can be handled.
//
// An error is returned if the registered Collector is incompatible or
// inconsistent with already registered metrics. The registry aims for
// consistency of the collected metrics according to the Prometheus data
// model. Inconsistencies are ideally detected at registration time, not at
// collect time. The former will usually be detected at start-up time of a
// program, while the latter will only happen at scrape time, possibly not even
// on the first scrape if the inconsistency only becomes relevant later. That is
// the main reason why a Collector and a Metric have to describe themselves to
// the registry.
//
// So far, everything we did operated on the so-called default registry, as it
// can be found in the global DefaultRegistry variable. With NewRegistry, you
// can create a custom registry, or you can even implement the Registerer or
// Gatherer interfaces yourself. The methods Register and Unregister work in
// the same way on a custom registry as the global functions Register and
// Unregister on the default registry.
//
// There are a number of uses for custom registries: You can use registries
// with special properties, see NewPedanticRegistry. You can avoid global state,
// as it is imposed by the DefaultRegistry. You can use multiple registries at
// the same time to expose different metrics in different ways. You can use
// separate registries for testing purposes.
//
// Also note that the DefaultRegistry comes registered with a Collector for Go
// runtime metrics (via NewGoCollector) and a Collector for process metrics (via
// NewProcessCollector). With a custom registry, you are in control and decide
// yourself about the Collectors to register.
//
// HTTP Exposition
//
// The Registry implements the Gatherer interface. The caller of the Gather
// method can then expose the gathered metrics in some way. Usually, the metrics
// are served via HTTP on the /metrics endpoint. That's happening in the example
// above. The tools to expose metrics via HTTP are in the promhttp
// sub-package. (The top-level functions in the prometheus package are
// deprecated.)
//
// Pushing to the Pushgateway
//
// Function for pushing to the Pushgateway can be found in the push sub-package.
//
// Other Means of Exposition
//
// More ways of exposing metrics can easily be added. Sending metrics to
// Graphite would be an example that will soon be implemented.
package prometheus

View file

@ -0,0 +1,119 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"encoding/json"
"expvar"
)
type expvarCollector struct {
exports map[string]*Desc
}
// NewExpvarCollector returns a newly allocated expvar Collector that still has
// to be registered with a Prometheus registry.
//
// An expvar Collector collects metrics from the expvar interface. It provides a
// quick way to expose numeric values that are already exported via expvar as
// Prometheus metrics. Note that the data models of expvar and Prometheus are
// fundamentally different, and that the expvar Collector is inherently slower
// than native Prometheus metrics. Thus, the expvar Collector is probably great
// for experiments and prototying, but you should seriously consider a more
// direct implementation of Prometheus metrics for monitoring production
// systems.
//
// The exports map has the following meaning:
//
// The keys in the map correspond to expvar keys, i.e. for every expvar key you
// want to export as Prometheus metric, you need an entry in the exports
// map. The descriptor mapped to each key describes how to export the expvar
// value. It defines the name and the help string of the Prometheus metric
// proxying the expvar value. The type will always be Untyped.
//
// For descriptors without variable labels, the expvar value must be a number or
// a bool. The number is then directly exported as the Prometheus sample
// value. (For a bool, 'false' translates to 0 and 'true' to 1). Expvar values
// that are not numbers or bools are silently ignored.
//
// If the descriptor has one variable label, the expvar value must be an expvar
// map. The keys in the expvar map become the various values of the one
// Prometheus label. The values in the expvar map must be numbers or bools again
// as above.
//
// For descriptors with more than one variable label, the expvar must be a
// nested expvar map, i.e. where the values of the topmost map are maps again
// etc. until a depth is reached that corresponds to the number of labels. The
// leaves of that structure must be numbers or bools as above to serve as the
// sample values.
//
// Anything that does not fit into the scheme above is silently ignored.
func NewExpvarCollector(exports map[string]*Desc) Collector {
return &expvarCollector{
exports: exports,
}
}
// Describe implements Collector.
func (e *expvarCollector) Describe(ch chan<- *Desc) {
for _, desc := range e.exports {
ch <- desc
}
}
// Collect implements Collector.
func (e *expvarCollector) Collect(ch chan<- Metric) {
for name, desc := range e.exports {
var m Metric
expVar := expvar.Get(name)
if expVar == nil {
continue
}
var v interface{}
labels := make([]string, len(desc.variableLabels))
if err := json.Unmarshal([]byte(expVar.String()), &v); err != nil {
ch <- NewInvalidMetric(desc, err)
continue
}
var processValue func(v interface{}, i int)
processValue = func(v interface{}, i int) {
if i >= len(labels) {
copiedLabels := append(make([]string, 0, len(labels)), labels...)
switch v := v.(type) {
case float64:
m = MustNewConstMetric(desc, UntypedValue, v, copiedLabels...)
case bool:
if v {
m = MustNewConstMetric(desc, UntypedValue, 1, copiedLabels...)
} else {
m = MustNewConstMetric(desc, UntypedValue, 0, copiedLabels...)
}
default:
return
}
ch <- m
return
}
vm, ok := v.(map[string]interface{})
if !ok {
return
}
for lv, val := range vm {
labels[i] = lv
processValue(val, i+1)
}
}
processValue(v, 0)
}
}

View file

@ -0,0 +1,29 @@
package prometheus
// Inline and byte-free variant of hash/fnv's fnv64a.
const (
offset64 = 14695981039346656037
prime64 = 1099511628211
)
// hashNew initializies a new fnv64a hash value.
func hashNew() uint64 {
return offset64
}
// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
func hashAdd(h uint64, s string) uint64 {
for i := 0; i < len(s); i++ {
h ^= uint64(s[i])
h *= prime64
}
return h
}
// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
func hashAddByte(h uint64, b byte) uint64 {
h ^= uint64(b)
h *= prime64
return h
}

View file

@ -0,0 +1,140 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// Gauge is a Metric that represents a single numerical value that can
// arbitrarily go up and down.
//
// A Gauge is typically used for measured values like temperatures or current
// memory usage, but also "counts" that can go up and down, like the number of
// running goroutines.
//
// To create Gauge instances, use NewGauge.
type Gauge interface {
Metric
Collector
// Set sets the Gauge to an arbitrary value.
Set(float64)
// Inc increments the Gauge by 1.
Inc()
// Dec decrements the Gauge by 1.
Dec()
// Add adds the given value to the Gauge. (The value can be
// negative, resulting in a decrease of the Gauge.)
Add(float64)
// Sub subtracts the given value from the Gauge. (The value can be
// negative, resulting in an increase of the Gauge.)
Sub(float64)
}
// GaugeOpts is an alias for Opts. See there for doc comments.
type GaugeOpts Opts
// NewGauge creates a new Gauge based on the provided GaugeOpts.
func NewGauge(opts GaugeOpts) Gauge {
return newValue(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), GaugeValue, 0)
}
// GaugeVec is a Collector that bundles a set of Gauges that all share the same
// Desc, but have different values for their variable labels. This is used if
// you want to count the same thing partitioned by various dimensions
// (e.g. number of operations queued, partitioned by user and operation
// type). Create instances with NewGaugeVec.
type GaugeVec struct {
*MetricVec
}
// NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and
// partitioned by the given label names. At least one label name must be
// provided.
func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &GaugeVec{
MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
return newValue(desc, GaugeValue, 0, lvs...)
}),
}
}
// GetMetricWithLabelValues replaces the method of the same name in
// MetricVec. The difference is that this method returns a Gauge and not a
// Metric so that no type conversion is required.
func (m *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Gauge), err
}
return nil, err
}
// GetMetricWith replaces the method of the same name in MetricVec. The
// difference is that this method returns a Gauge and not a Metric so that no
// type conversion is required.
func (m *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
metric, err := m.MetricVec.GetMetricWith(labels)
if metric != nil {
return metric.(Gauge), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. By not returning an
// error, WithLabelValues allows shortcuts like
// myVec.WithLabelValues("404", "GET").Add(42)
func (m *GaugeVec) WithLabelValues(lvs ...string) Gauge {
return m.MetricVec.WithLabelValues(lvs...).(Gauge)
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. By not returning an error, With allows shortcuts like
// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
func (m *GaugeVec) With(labels Labels) Gauge {
return m.MetricVec.With(labels).(Gauge)
}
// GaugeFunc is a Gauge whose value is determined at collect time by calling a
// provided function.
//
// To create GaugeFunc instances, use NewGaugeFunc.
type GaugeFunc interface {
Metric
Collector
}
// NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The
// value reported is determined by calling the given function from within the
// Write method. Take into account that metric collection may happen
// concurrently. If that results in concurrent calls to Write, like in the case
// where a GaugeFunc is directly registered with Prometheus, the provided
// function must be concurrency-safe.
func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), GaugeValue, function)
}

View file

@ -0,0 +1,263 @@
package prometheus
import (
"fmt"
"runtime"
"runtime/debug"
"time"
)
type goCollector struct {
goroutines Gauge
gcDesc *Desc
// metrics to describe and collect
metrics memStatsMetrics
}
// NewGoCollector returns a collector which exports metrics about the current
// go process.
func NewGoCollector() Collector {
return &goCollector{
goroutines: NewGauge(GaugeOpts{
Namespace: "go",
Name: "goroutines",
Help: "Number of goroutines that currently exist.",
}),
gcDesc: NewDesc(
"go_gc_duration_seconds",
"A summary of the GC invocation durations.",
nil, nil),
metrics: memStatsMetrics{
{
desc: NewDesc(
memstatNamespace("alloc_bytes"),
"Number of bytes allocated and still in use.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("alloc_bytes_total"),
"Total number of bytes allocated, even if freed.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("sys_bytes"),
"Number of bytes obtained by system. Sum of all system allocations.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("lookups_total"),
"Total number of pointer lookups.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Lookups) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("mallocs_total"),
"Total number of mallocs.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("frees_total"),
"Total number of frees.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Frees) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("heap_alloc_bytes"),
"Number of heap bytes allocated and still in use.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_sys_bytes"),
"Number of heap bytes obtained from system.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_idle_bytes"),
"Number of heap bytes waiting to be used.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_inuse_bytes"),
"Number of heap bytes that are in use.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_released_bytes_total"),
"Total number of heap bytes released to OS.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("heap_objects"),
"Number of allocated objects.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("stack_inuse_bytes"),
"Number of bytes in use by the stack allocator.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("stack_sys_bytes"),
"Number of bytes obtained from system for stack allocator.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mspan_inuse_bytes"),
"Number of bytes in use by mspan structures.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mspan_sys_bytes"),
"Number of bytes used for mspan structures obtained from system.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mcache_inuse_bytes"),
"Number of bytes in use by mcache structures.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mcache_sys_bytes"),
"Number of bytes used for mcache structures obtained from system.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("buck_hash_sys_bytes"),
"Number of bytes used by the profiling bucket hash table.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("gc_sys_bytes"),
"Number of bytes used for garbage collection system metadata.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("other_sys_bytes"),
"Number of bytes used for other system allocations.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("next_gc_bytes"),
"Number of heap bytes when next garbage collection will take place.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("last_gc_time_seconds"),
"Number of seconds since 1970 of last garbage collection.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.LastGC) / 1e9 },
valType: GaugeValue,
},
},
}
}
func memstatNamespace(s string) string {
return fmt.Sprintf("go_memstats_%s", s)
}
// Describe returns all descriptions of the collector.
func (c *goCollector) Describe(ch chan<- *Desc) {
ch <- c.goroutines.Desc()
ch <- c.gcDesc
for _, i := range c.metrics {
ch <- i.desc
}
}
// Collect returns the current state of all metrics of the collector.
func (c *goCollector) Collect(ch chan<- Metric) {
c.goroutines.Set(float64(runtime.NumGoroutine()))
ch <- c.goroutines
var stats debug.GCStats
stats.PauseQuantiles = make([]time.Duration, 5)
debug.ReadGCStats(&stats)
quantiles := make(map[float64]float64)
for idx, pq := range stats.PauseQuantiles[1:] {
quantiles[float64(idx+1)/float64(len(stats.PauseQuantiles)-1)] = pq.Seconds()
}
quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), float64(stats.PauseTotal.Seconds()), quantiles)
ms := &runtime.MemStats{}
runtime.ReadMemStats(ms)
for _, i := range c.metrics {
ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms))
}
}
// memStatsMetrics provide description, value, and value type for memstat metrics.
type memStatsMetrics []struct {
desc *Desc
eval func(*runtime.MemStats) float64
valType ValueType
}

View file

@ -0,0 +1,444 @@
// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"math"
"sort"
"sync/atomic"
"github.com/golang/protobuf/proto"
dto "github.com/prometheus/client_model/go"
)
// A Histogram counts individual observations from an event or sample stream in
// configurable buckets. Similar to a summary, it also provides a sum of
// observations and an observation count.
//
// On the Prometheus server, quantiles can be calculated from a Histogram using
// the histogram_quantile function in the query language.
//
// Note that Histograms, in contrast to Summaries, can be aggregated with the
// Prometheus query language (see the documentation for detailed
// procedures). However, Histograms require the user to pre-define suitable
// buckets, and they are in general less accurate. The Observe method of a
// Histogram has a very low performance overhead in comparison with the Observe
// method of a Summary.
//
// To create Histogram instances, use NewHistogram.
type Histogram interface {
Metric
Collector
// Observe adds a single observation to the histogram.
Observe(float64)
}
// bucketLabel is used for the label that defines the upper bound of a
// bucket of a histogram ("le" -> "less or equal").
const bucketLabel = "le"
// DefBuckets are the default Histogram buckets. The default buckets are
// tailored to broadly measure the response time (in seconds) of a network
// service. Most likely, however, you will be required to define buckets
// customized to your use case.
var (
DefBuckets = []float64{.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10}
errBucketLabelNotAllowed = fmt.Errorf(
"%q is not allowed as label name in histograms", bucketLabel,
)
)
// LinearBuckets creates 'count' buckets, each 'width' wide, where the lowest
// bucket has an upper bound of 'start'. The final +Inf bucket is not counted
// and not included in the returned slice. The returned slice is meant to be
// used for the Buckets field of HistogramOpts.
//
// The function panics if 'count' is zero or negative.
func LinearBuckets(start, width float64, count int) []float64 {
if count < 1 {
panic("LinearBuckets needs a positive count")
}
buckets := make([]float64, count)
for i := range buckets {
buckets[i] = start
start += width
}
return buckets
}
// ExponentialBuckets creates 'count' buckets, where the lowest bucket has an
// upper bound of 'start' and each following bucket's upper bound is 'factor'
// times the previous bucket's upper bound. The final +Inf bucket is not counted
// and not included in the returned slice. The returned slice is meant to be
// used for the Buckets field of HistogramOpts.
//
// The function panics if 'count' is 0 or negative, if 'start' is 0 or negative,
// or if 'factor' is less than or equal 1.
func ExponentialBuckets(start, factor float64, count int) []float64 {
if count < 1 {
panic("ExponentialBuckets needs a positive count")
}
if start <= 0 {
panic("ExponentialBuckets needs a positive start value")
}
if factor <= 1 {
panic("ExponentialBuckets needs a factor greater than 1")
}
buckets := make([]float64, count)
for i := range buckets {
buckets[i] = start
start *= factor
}
return buckets
}
// HistogramOpts bundles the options for creating a Histogram metric. It is
// mandatory to set Name and Help to a non-empty string. All other fields are
// optional and can safely be left at their zero value.
type HistogramOpts struct {
// Namespace, Subsystem, and Name are components of the fully-qualified
// name of the Histogram (created by joining these components with
// "_"). Only Name is mandatory, the others merely help structuring the
// name. Note that the fully-qualified name of the Histogram must be a
// valid Prometheus metric name.
Namespace string
Subsystem string
Name string
// Help provides information about this Histogram. Mandatory!
//
// Metrics with the same fully-qualified name must have the same Help
// string.
Help string
// ConstLabels are used to attach fixed labels to this
// Histogram. Histograms with the same fully-qualified name must have the
// same label names in their ConstLabels.
//
// Note that in most cases, labels have a value that varies during the
// lifetime of a process. Those labels are usually managed with a
// HistogramVec. ConstLabels serve only special purposes. One is for the
// special case where the value of a label does not change during the
// lifetime of a process, e.g. if the revision of the running binary is
// put into a label. Another, more advanced purpose is if more than one
// Collector needs to collect Histograms with the same fully-qualified
// name. In that case, those Summaries must differ in the values of
// their ConstLabels. See the Collector examples.
//
// If the value of a label never changes (not even between binaries),
// that label most likely should not be a label at all (but part of the
// metric name).
ConstLabels Labels
// Buckets defines the buckets into which observations are counted. Each
// element in the slice is the upper inclusive bound of a bucket. The
// values must be sorted in strictly increasing order. There is no need
// to add a highest bucket with +Inf bound, it will be added
// implicitly. The default value is DefBuckets.
Buckets []float64
}
// NewHistogram creates a new Histogram based on the provided HistogramOpts. It
// panics if the buckets in HistogramOpts are not in strictly increasing order.
func NewHistogram(opts HistogramOpts) Histogram {
return newHistogram(
NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
),
opts,
)
}
func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogram {
if len(desc.variableLabels) != len(labelValues) {
panic(errInconsistentCardinality)
}
for _, n := range desc.variableLabels {
if n == bucketLabel {
panic(errBucketLabelNotAllowed)
}
}
for _, lp := range desc.constLabelPairs {
if lp.GetName() == bucketLabel {
panic(errBucketLabelNotAllowed)
}
}
if len(opts.Buckets) == 0 {
opts.Buckets = DefBuckets
}
h := &histogram{
desc: desc,
upperBounds: opts.Buckets,
labelPairs: makeLabelPairs(desc, labelValues),
}
for i, upperBound := range h.upperBounds {
if i < len(h.upperBounds)-1 {
if upperBound >= h.upperBounds[i+1] {
panic(fmt.Errorf(
"histogram buckets must be in increasing order: %f >= %f",
upperBound, h.upperBounds[i+1],
))
}
} else {
if math.IsInf(upperBound, +1) {
// The +Inf bucket is implicit. Remove it here.
h.upperBounds = h.upperBounds[:i]
}
}
}
// Finally we know the final length of h.upperBounds and can make counts.
h.counts = make([]uint64, len(h.upperBounds))
h.init(h) // Init self-collection.
return h
}
type histogram struct {
// sumBits contains the bits of the float64 representing the sum of all
// observations. sumBits and count have to go first in the struct to
// guarantee alignment for atomic operations.
// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
sumBits uint64
count uint64
selfCollector
// Note that there is no mutex required.
desc *Desc
upperBounds []float64
counts []uint64
labelPairs []*dto.LabelPair
}
func (h *histogram) Desc() *Desc {
return h.desc
}
func (h *histogram) Observe(v float64) {
// TODO(beorn7): For small numbers of buckets (<30), a linear search is
// slightly faster than the binary search. If we really care, we could
// switch from one search strategy to the other depending on the number
// of buckets.
//
// Microbenchmarks (BenchmarkHistogramNoLabels):
// 11 buckets: 38.3 ns/op linear - binary 48.7 ns/op
// 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op
// 300 buckets: 154 ns/op linear - binary 61.6 ns/op
i := sort.SearchFloat64s(h.upperBounds, v)
if i < len(h.counts) {
atomic.AddUint64(&h.counts[i], 1)
}
atomic.AddUint64(&h.count, 1)
for {
oldBits := atomic.LoadUint64(&h.sumBits)
newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
if atomic.CompareAndSwapUint64(&h.sumBits, oldBits, newBits) {
break
}
}
}
func (h *histogram) Write(out *dto.Metric) error {
his := &dto.Histogram{}
buckets := make([]*dto.Bucket, len(h.upperBounds))
his.SampleSum = proto.Float64(math.Float64frombits(atomic.LoadUint64(&h.sumBits)))
his.SampleCount = proto.Uint64(atomic.LoadUint64(&h.count))
var count uint64
for i, upperBound := range h.upperBounds {
count += atomic.LoadUint64(&h.counts[i])
buckets[i] = &dto.Bucket{
CumulativeCount: proto.Uint64(count),
UpperBound: proto.Float64(upperBound),
}
}
his.Bucket = buckets
out.Histogram = his
out.Label = h.labelPairs
return nil
}
// HistogramVec is a Collector that bundles a set of Histograms that all share the
// same Desc, but have different values for their variable labels. This is used
// if you want to count the same thing partitioned by various dimensions
// (e.g. HTTP request latencies, partitioned by status code and method). Create
// instances with NewHistogramVec.
type HistogramVec struct {
*MetricVec
}
// NewHistogramVec creates a new HistogramVec based on the provided HistogramOpts and
// partitioned by the given label names. At least one label name must be
// provided.
func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &HistogramVec{
MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
return newHistogram(desc, opts, lvs...)
}),
}
}
// GetMetricWithLabelValues replaces the method of the same name in
// MetricVec. The difference is that this method returns a Histogram and not a
// Metric so that no type conversion is required.
func (m *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Histogram, error) {
metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Histogram), err
}
return nil, err
}
// GetMetricWith replaces the method of the same name in MetricVec. The
// difference is that this method returns a Histogram and not a Metric so that no
// type conversion is required.
func (m *HistogramVec) GetMetricWith(labels Labels) (Histogram, error) {
metric, err := m.MetricVec.GetMetricWith(labels)
if metric != nil {
return metric.(Histogram), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. By not returning an
// error, WithLabelValues allows shortcuts like
// myVec.WithLabelValues("404", "GET").Observe(42.21)
func (m *HistogramVec) WithLabelValues(lvs ...string) Histogram {
return m.MetricVec.WithLabelValues(lvs...).(Histogram)
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. By not returning an error, With allows shortcuts like
// myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21)
func (m *HistogramVec) With(labels Labels) Histogram {
return m.MetricVec.With(labels).(Histogram)
}
type constHistogram struct {
desc *Desc
count uint64
sum float64
buckets map[float64]uint64
labelPairs []*dto.LabelPair
}
func (h *constHistogram) Desc() *Desc {
return h.desc
}
func (h *constHistogram) Write(out *dto.Metric) error {
his := &dto.Histogram{}
buckets := make([]*dto.Bucket, 0, len(h.buckets))
his.SampleCount = proto.Uint64(h.count)
his.SampleSum = proto.Float64(h.sum)
for upperBound, count := range h.buckets {
buckets = append(buckets, &dto.Bucket{
CumulativeCount: proto.Uint64(count),
UpperBound: proto.Float64(upperBound),
})
}
if len(buckets) > 0 {
sort.Sort(buckSort(buckets))
}
his.Bucket = buckets
out.Histogram = his
out.Label = h.labelPairs
return nil
}
// NewConstHistogram returns a metric representing a Prometheus histogram with
// fixed values for the count, sum, and bucket counts. As those parameters
// cannot be changed, the returned value does not implement the Histogram
// interface (but only the Metric interface). Users of this package will not
// have much use for it in regular operations. However, when implementing custom
// Collectors, it is useful as a throw-away metric that is generated on the fly
// to send it to Prometheus in the Collect method.
//
// buckets is a map of upper bounds to cumulative counts, excluding the +Inf
// bucket.
//
// NewConstHistogram returns an error if the length of labelValues is not
// consistent with the variable labels in Desc.
func NewConstHistogram(
desc *Desc,
count uint64,
sum float64,
buckets map[float64]uint64,
labelValues ...string,
) (Metric, error) {
if len(desc.variableLabels) != len(labelValues) {
return nil, errInconsistentCardinality
}
return &constHistogram{
desc: desc,
count: count,
sum: sum,
buckets: buckets,
labelPairs: makeLabelPairs(desc, labelValues),
}, nil
}
// MustNewConstHistogram is a version of NewConstHistogram that panics where
// NewConstMetric would have returned an error.
func MustNewConstHistogram(
desc *Desc,
count uint64,
sum float64,
buckets map[float64]uint64,
labelValues ...string,
) Metric {
m, err := NewConstHistogram(desc, count, sum, buckets, labelValues...)
if err != nil {
panic(err)
}
return m
}
type buckSort []*dto.Bucket
func (s buckSort) Len() int {
return len(s)
}
func (s buckSort) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s buckSort) Less(i, j int) bool {
return s[i].GetUpperBound() < s[j].GetUpperBound()
}

View file

@ -0,0 +1,490 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"bufio"
"bytes"
"compress/gzip"
"fmt"
"io"
"net"
"net/http"
"strconv"
"strings"
"sync"
"time"
"github.com/prometheus/common/expfmt"
)
// TODO(beorn7): Remove this whole file. It is a partial mirror of
// promhttp/http.go (to avoid circular import chains) where everything HTTP
// related should live. The functions here are just for avoiding
// breakage. Everything is deprecated.
const (
contentTypeHeader = "Content-Type"
contentLengthHeader = "Content-Length"
contentEncodingHeader = "Content-Encoding"
acceptEncodingHeader = "Accept-Encoding"
)
var bufPool sync.Pool
func getBuf() *bytes.Buffer {
buf := bufPool.Get()
if buf == nil {
return &bytes.Buffer{}
}
return buf.(*bytes.Buffer)
}
func giveBuf(buf *bytes.Buffer) {
buf.Reset()
bufPool.Put(buf)
}
// Handler returns an HTTP handler for the DefaultGatherer. It is
// already instrumented with InstrumentHandler (using "prometheus" as handler
// name).
//
// Deprecated: Please note the issues described in the doc comment of
// InstrumentHandler. You might want to consider using promhttp.Handler instead
// (which is non instrumented).
func Handler() http.Handler {
return InstrumentHandler("prometheus", UninstrumentedHandler())
}
// UninstrumentedHandler returns an HTTP handler for the DefaultGatherer.
//
// Deprecated: Use promhttp.Handler instead. See there for further documentation.
func UninstrumentedHandler() http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
mfs, err := DefaultGatherer.Gather()
if err != nil {
http.Error(w, "An error has occurred during metrics collection:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
contentType := expfmt.Negotiate(req.Header)
buf := getBuf()
defer giveBuf(buf)
writer, encoding := decorateWriter(req, buf)
enc := expfmt.NewEncoder(writer, contentType)
var lastErr error
for _, mf := range mfs {
if err := enc.Encode(mf); err != nil {
lastErr = err
http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
}
if closer, ok := writer.(io.Closer); ok {
closer.Close()
}
if lastErr != nil && buf.Len() == 0 {
http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
header := w.Header()
header.Set(contentTypeHeader, string(contentType))
header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
if encoding != "" {
header.Set(contentEncodingHeader, encoding)
}
w.Write(buf.Bytes())
})
}
// decorateWriter wraps a writer to handle gzip compression if requested. It
// returns the decorated writer and the appropriate "Content-Encoding" header
// (which is empty if no compression is enabled).
func decorateWriter(request *http.Request, writer io.Writer) (io.Writer, string) {
header := request.Header.Get(acceptEncodingHeader)
parts := strings.Split(header, ",")
for _, part := range parts {
part := strings.TrimSpace(part)
if part == "gzip" || strings.HasPrefix(part, "gzip;") {
return gzip.NewWriter(writer), "gzip"
}
}
return writer, ""
}
var instLabels = []string{"method", "code"}
type nower interface {
Now() time.Time
}
type nowFunc func() time.Time
func (n nowFunc) Now() time.Time {
return n()
}
var now nower = nowFunc(func() time.Time {
return time.Now()
})
func nowSeries(t ...time.Time) nower {
return nowFunc(func() time.Time {
defer func() {
t = t[1:]
}()
return t[0]
})
}
// InstrumentHandler wraps the given HTTP handler for instrumentation. It
// registers four metric collectors (if not already done) and reports HTTP
// metrics to the (newly or already) registered collectors: http_requests_total
// (CounterVec), http_request_duration_microseconds (Summary),
// http_request_size_bytes (Summary), http_response_size_bytes (Summary). Each
// has a constant label named "handler" with the provided handlerName as
// value. http_requests_total is a metric vector partitioned by HTTP method
// (label name "method") and HTTP status code (label name "code").
//
// Deprecated: InstrumentHandler has several issues:
//
// - It uses Summaries rather than Histograms. Summaries are not useful if
// aggregation across multiple instances is required.
//
// - It uses microseconds as unit, which is deprecated and should be replaced by
// seconds.
//
// - The size of the request is calculated in a separate goroutine. Since this
// calculator requires access to the request header, it creates a race with
// any writes to the header performed during request handling.
// httputil.ReverseProxy is a prominent example for a handler
// performing such writes.
//
// Upcoming versions of this package will provide ways of instrumenting HTTP
// handlers that are more flexible and have fewer issues. Please prefer direct
// instrumentation in the meantime.
func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc {
return InstrumentHandlerFunc(handlerName, handler.ServeHTTP)
}
// InstrumentHandlerFunc wraps the given function for instrumentation. It
// otherwise works in the same way as InstrumentHandler (and shares the same
// issues).
//
// Deprecated: InstrumentHandlerFunc is deprecated for the same reasons as
// InstrumentHandler is.
func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
return InstrumentHandlerFuncWithOpts(
SummaryOpts{
Subsystem: "http",
ConstLabels: Labels{"handler": handlerName},
},
handlerFunc,
)
}
// InstrumentHandlerWithOpts works like InstrumentHandler (and shares the same
// issues) but provides more flexibility (at the cost of a more complex call
// syntax). As InstrumentHandler, this function registers four metric
// collectors, but it uses the provided SummaryOpts to create them. However, the
// fields "Name" and "Help" in the SummaryOpts are ignored. "Name" is replaced
// by "requests_total", "request_duration_microseconds", "request_size_bytes",
// and "response_size_bytes", respectively. "Help" is replaced by an appropriate
// help string. The names of the variable labels of the http_requests_total
// CounterVec are "method" (get, post, etc.), and "code" (HTTP status code).
//
// If InstrumentHandlerWithOpts is called as follows, it mimics exactly the
// behavior of InstrumentHandler:
//
// prometheus.InstrumentHandlerWithOpts(
// prometheus.SummaryOpts{
// Subsystem: "http",
// ConstLabels: prometheus.Labels{"handler": handlerName},
// },
// handler,
// )
//
// Technical detail: "requests_total" is a CounterVec, not a SummaryVec, so it
// cannot use SummaryOpts. Instead, a CounterOpts struct is created internally,
// and all its fields are set to the equally named fields in the provided
// SummaryOpts.
//
// Deprecated: InstrumentHandlerWithOpts is deprecated for the same reasons as
// InstrumentHandler is.
func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc {
return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP)
}
// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc (and shares
// the same issues) but provides more flexibility (at the cost of a more complex
// call syntax). See InstrumentHandlerWithOpts for details how the provided
// SummaryOpts are used.
//
// Deprecated: InstrumentHandlerFuncWithOpts is deprecated for the same reasons
// as InstrumentHandler is.
func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
reqCnt := NewCounterVec(
CounterOpts{
Namespace: opts.Namespace,
Subsystem: opts.Subsystem,
Name: "requests_total",
Help: "Total number of HTTP requests made.",
ConstLabels: opts.ConstLabels,
},
instLabels,
)
opts.Name = "request_duration_microseconds"
opts.Help = "The HTTP request latencies in microseconds."
reqDur := NewSummary(opts)
opts.Name = "request_size_bytes"
opts.Help = "The HTTP request sizes in bytes."
reqSz := NewSummary(opts)
opts.Name = "response_size_bytes"
opts.Help = "The HTTP response sizes in bytes."
resSz := NewSummary(opts)
regReqCnt := MustRegisterOrGet(reqCnt).(*CounterVec)
regReqDur := MustRegisterOrGet(reqDur).(Summary)
regReqSz := MustRegisterOrGet(reqSz).(Summary)
regResSz := MustRegisterOrGet(resSz).(Summary)
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
now := time.Now()
delegate := &responseWriterDelegator{ResponseWriter: w}
out := make(chan int)
urlLen := 0
if r.URL != nil {
urlLen = len(r.URL.String())
}
go computeApproximateRequestSize(r, out, urlLen)
_, cn := w.(http.CloseNotifier)
_, fl := w.(http.Flusher)
_, hj := w.(http.Hijacker)
_, rf := w.(io.ReaderFrom)
var rw http.ResponseWriter
if cn && fl && hj && rf {
rw = &fancyResponseWriterDelegator{delegate}
} else {
rw = delegate
}
handlerFunc(rw, r)
elapsed := float64(time.Since(now)) / float64(time.Microsecond)
method := sanitizeMethod(r.Method)
code := sanitizeCode(delegate.status)
regReqCnt.WithLabelValues(method, code).Inc()
regReqDur.Observe(elapsed)
regResSz.Observe(float64(delegate.written))
regReqSz.Observe(float64(<-out))
})
}
func computeApproximateRequestSize(r *http.Request, out chan int, s int) {
s += len(r.Method)
s += len(r.Proto)
for name, values := range r.Header {
s += len(name)
for _, value := range values {
s += len(value)
}
}
s += len(r.Host)
// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
if r.ContentLength != -1 {
s += int(r.ContentLength)
}
out <- s
}
type responseWriterDelegator struct {
http.ResponseWriter
handler, method string
status int
written int64
wroteHeader bool
}
func (r *responseWriterDelegator) WriteHeader(code int) {
r.status = code
r.wroteHeader = true
r.ResponseWriter.WriteHeader(code)
}
func (r *responseWriterDelegator) Write(b []byte) (int, error) {
if !r.wroteHeader {
r.WriteHeader(http.StatusOK)
}
n, err := r.ResponseWriter.Write(b)
r.written += int64(n)
return n, err
}
type fancyResponseWriterDelegator struct {
*responseWriterDelegator
}
func (f *fancyResponseWriterDelegator) CloseNotify() <-chan bool {
return f.ResponseWriter.(http.CloseNotifier).CloseNotify()
}
func (f *fancyResponseWriterDelegator) Flush() {
f.ResponseWriter.(http.Flusher).Flush()
}
func (f *fancyResponseWriterDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
return f.ResponseWriter.(http.Hijacker).Hijack()
}
func (f *fancyResponseWriterDelegator) ReadFrom(r io.Reader) (int64, error) {
if !f.wroteHeader {
f.WriteHeader(http.StatusOK)
}
n, err := f.ResponseWriter.(io.ReaderFrom).ReadFrom(r)
f.written += n
return n, err
}
func sanitizeMethod(m string) string {
switch m {
case "GET", "get":
return "get"
case "PUT", "put":
return "put"
case "HEAD", "head":
return "head"
case "POST", "post":
return "post"
case "DELETE", "delete":
return "delete"
case "CONNECT", "connect":
return "connect"
case "OPTIONS", "options":
return "options"
case "NOTIFY", "notify":
return "notify"
default:
return strings.ToLower(m)
}
}
func sanitizeCode(s int) string {
switch s {
case 100:
return "100"
case 101:
return "101"
case 200:
return "200"
case 201:
return "201"
case 202:
return "202"
case 203:
return "203"
case 204:
return "204"
case 205:
return "205"
case 206:
return "206"
case 300:
return "300"
case 301:
return "301"
case 302:
return "302"
case 304:
return "304"
case 305:
return "305"
case 307:
return "307"
case 400:
return "400"
case 401:
return "401"
case 402:
return "402"
case 403:
return "403"
case 404:
return "404"
case 405:
return "405"
case 406:
return "406"
case 407:
return "407"
case 408:
return "408"
case 409:
return "409"
case 410:
return "410"
case 411:
return "411"
case 412:
return "412"
case 413:
return "413"
case 414:
return "414"
case 415:
return "415"
case 416:
return "416"
case 417:
return "417"
case 418:
return "418"
case 500:
return "500"
case 501:
return "501"
case 502:
return "502"
case 503:
return "503"
case 504:
return "504"
case 505:
return "505"
case 428:
return "428"
case 429:
return "429"
case 431:
return "431"
case 511:
return "511"
default:
return strconv.Itoa(s)
}
}

View file

@ -0,0 +1,166 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"strings"
dto "github.com/prometheus/client_model/go"
)
const separatorByte byte = 255
// A Metric models a single sample value with its meta data being exported to
// Prometheus. Implementations of Metric in this package are Gauge, Counter,
// Histogram, Summary, and Untyped.
type Metric interface {
// Desc returns the descriptor for the Metric. This method idempotently
// returns the same descriptor throughout the lifetime of the
// Metric. The returned descriptor is immutable by contract. A Metric
// unable to describe itself must return an invalid descriptor (created
// with NewInvalidDesc).
Desc() *Desc
// Write encodes the Metric into a "Metric" Protocol Buffer data
// transmission object.
//
// Metric implementations must observe concurrency safety as reads of
// this metric may occur at any time, and any blocking occurs at the
// expense of total performance of rendering all registered
// metrics. Ideally, Metric implementations should support concurrent
// readers.
//
// While populating dto.Metric, it is the responsibility of the
// implementation to ensure validity of the Metric protobuf (like valid
// UTF-8 strings or syntactically valid metric and label names). It is
// recommended to sort labels lexicographically. (Implementers may find
// LabelPairSorter useful for that.) Callers of Write should still make
// sure of sorting if they depend on it.
Write(*dto.Metric) error
// TODO(beorn7): The original rationale of passing in a pre-allocated
// dto.Metric protobuf to save allocations has disappeared. The
// signature of this method should be changed to "Write() (*dto.Metric,
// error)".
}
// Opts bundles the options for creating most Metric types. Each metric
// implementation XXX has its own XXXOpts type, but in most cases, it is just be
// an alias of this type (which might change when the requirement arises.)
//
// It is mandatory to set Name and Help to a non-empty string. All other fields
// are optional and can safely be left at their zero value.
type Opts struct {
// Namespace, Subsystem, and Name are components of the fully-qualified
// name of the Metric (created by joining these components with
// "_"). Only Name is mandatory, the others merely help structuring the
// name. Note that the fully-qualified name of the metric must be a
// valid Prometheus metric name.
Namespace string
Subsystem string
Name string
// Help provides information about this metric. Mandatory!
//
// Metrics with the same fully-qualified name must have the same Help
// string.
Help string
// ConstLabels are used to attach fixed labels to this metric. Metrics
// with the same fully-qualified name must have the same label names in
// their ConstLabels.
//
// Note that in most cases, labels have a value that varies during the
// lifetime of a process. Those labels are usually managed with a metric
// vector collector (like CounterVec, GaugeVec, UntypedVec). ConstLabels
// serve only special purposes. One is for the special case where the
// value of a label does not change during the lifetime of a process,
// e.g. if the revision of the running binary is put into a
// label. Another, more advanced purpose is if more than one Collector
// needs to collect Metrics with the same fully-qualified name. In that
// case, those Metrics must differ in the values of their
// ConstLabels. See the Collector examples.
//
// If the value of a label never changes (not even between binaries),
// that label most likely should not be a label at all (but part of the
// metric name).
ConstLabels Labels
}
// BuildFQName joins the given three name components by "_". Empty name
// components are ignored. If the name parameter itself is empty, an empty
// string is returned, no matter what. Metric implementations included in this
// library use this function internally to generate the fully-qualified metric
// name from the name component in their Opts. Users of the library will only
// need this function if they implement their own Metric or instantiate a Desc
// (with NewDesc) directly.
func BuildFQName(namespace, subsystem, name string) string {
if name == "" {
return ""
}
switch {
case namespace != "" && subsystem != "":
return strings.Join([]string{namespace, subsystem, name}, "_")
case namespace != "":
return strings.Join([]string{namespace, name}, "_")
case subsystem != "":
return strings.Join([]string{subsystem, name}, "_")
}
return name
}
// LabelPairSorter implements sort.Interface. It is used to sort a slice of
// dto.LabelPair pointers. This is useful for implementing the Write method of
// custom metrics.
type LabelPairSorter []*dto.LabelPair
func (s LabelPairSorter) Len() int {
return len(s)
}
func (s LabelPairSorter) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s LabelPairSorter) Less(i, j int) bool {
return s[i].GetName() < s[j].GetName()
}
type hashSorter []uint64
func (s hashSorter) Len() int {
return len(s)
}
func (s hashSorter) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s hashSorter) Less(i, j int) bool {
return s[i] < s[j]
}
type invalidMetric struct {
desc *Desc
err error
}
// NewInvalidMetric returns a metric whose Write method always returns the
// provided error. It is useful if a Collector finds itself unable to collect
// a metric and wishes to report an error to the registry.
func NewInvalidMetric(desc *Desc, err error) Metric {
return &invalidMetric{desc, err}
}
func (m *invalidMetric) Desc() *Desc { return m.desc }
func (m *invalidMetric) Write(*dto.Metric) error { return m.err }

View file

@ -0,0 +1,142 @@
// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import "github.com/prometheus/procfs"
type processCollector struct {
pid int
collectFn func(chan<- Metric)
pidFn func() (int, error)
cpuTotal Counter
openFDs, maxFDs Gauge
vsize, rss Gauge
startTime Gauge
}
// NewProcessCollector returns a collector which exports the current state of
// process metrics including cpu, memory and file descriptor usage as well as
// the process start time for the given process id under the given namespace.
func NewProcessCollector(pid int, namespace string) Collector {
return NewProcessCollectorPIDFn(
func() (int, error) { return pid, nil },
namespace,
)
}
// NewProcessCollectorPIDFn returns a collector which exports the current state
// of process metrics including cpu, memory and file descriptor usage as well
// as the process start time under the given namespace. The given pidFn is
// called on each collect and is used to determine the process to export
// metrics for.
func NewProcessCollectorPIDFn(
pidFn func() (int, error),
namespace string,
) Collector {
c := processCollector{
pidFn: pidFn,
collectFn: func(chan<- Metric) {},
cpuTotal: NewCounter(CounterOpts{
Namespace: namespace,
Name: "process_cpu_seconds_total",
Help: "Total user and system CPU time spent in seconds.",
}),
openFDs: NewGauge(GaugeOpts{
Namespace: namespace,
Name: "process_open_fds",
Help: "Number of open file descriptors.",
}),
maxFDs: NewGauge(GaugeOpts{
Namespace: namespace,
Name: "process_max_fds",
Help: "Maximum number of open file descriptors.",
}),
vsize: NewGauge(GaugeOpts{
Namespace: namespace,
Name: "process_virtual_memory_bytes",
Help: "Virtual memory size in bytes.",
}),
rss: NewGauge(GaugeOpts{
Namespace: namespace,
Name: "process_resident_memory_bytes",
Help: "Resident memory size in bytes.",
}),
startTime: NewGauge(GaugeOpts{
Namespace: namespace,
Name: "process_start_time_seconds",
Help: "Start time of the process since unix epoch in seconds.",
}),
}
// Set up process metric collection if supported by the runtime.
if _, err := procfs.NewStat(); err == nil {
c.collectFn = c.processCollect
}
return &c
}
// Describe returns all descriptions of the collector.
func (c *processCollector) Describe(ch chan<- *Desc) {
ch <- c.cpuTotal.Desc()
ch <- c.openFDs.Desc()
ch <- c.maxFDs.Desc()
ch <- c.vsize.Desc()
ch <- c.rss.Desc()
ch <- c.startTime.Desc()
}
// Collect returns the current state of all metrics of the collector.
func (c *processCollector) Collect(ch chan<- Metric) {
c.collectFn(ch)
}
// TODO(ts): Bring back error reporting by reverting 7faf9e7 as soon as the
// client allows users to configure the error behavior.
func (c *processCollector) processCollect(ch chan<- Metric) {
pid, err := c.pidFn()
if err != nil {
return
}
p, err := procfs.NewProc(pid)
if err != nil {
return
}
if stat, err := p.NewStat(); err == nil {
c.cpuTotal.Set(stat.CPUTime())
ch <- c.cpuTotal
c.vsize.Set(float64(stat.VirtualMemory()))
ch <- c.vsize
c.rss.Set(float64(stat.ResidentMemory()))
ch <- c.rss
if startTime, err := stat.StartTime(); err == nil {
c.startTime.Set(startTime)
ch <- c.startTime
}
}
if fds, err := p.FileDescriptorsLen(); err == nil {
c.openFDs.Set(float64(fds))
ch <- c.openFDs
}
if limits, err := p.NewLimits(); err == nil {
c.maxFDs.Set(float64(limits.OpenFiles))
ch <- c.maxFDs
}
}

View file

@ -0,0 +1,806 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"bytes"
"errors"
"fmt"
"os"
"sort"
"sync"
"github.com/golang/protobuf/proto"
dto "github.com/prometheus/client_model/go"
)
const (
// Capacity for the channel to collect metrics and descriptors.
capMetricChan = 1000
capDescChan = 10
)
// DefaultRegisterer and DefaultGatherer are the implementations of the
// Registerer and Gatherer interface a number of convenience functions in this
// package act on. Initially, both variables point to the same Registry, which
// has a process collector (see NewProcessCollector) and a Go collector (see
// NewGoCollector) already registered. This approach to keep default instances
// as global state mirrors the approach of other packages in the Go standard
// library. Note that there are caveats. Change the variables with caution and
// only if you understand the consequences. Users who want to avoid global state
// altogether should not use the convenience function and act on custom
// instances instead.
var (
defaultRegistry = NewRegistry()
DefaultRegisterer Registerer = defaultRegistry
DefaultGatherer Gatherer = defaultRegistry
)
func init() {
MustRegister(NewProcessCollector(os.Getpid(), ""))
MustRegister(NewGoCollector())
}
// NewRegistry creates a new vanilla Registry without any Collectors
// pre-registered.
func NewRegistry() *Registry {
return &Registry{
collectorsByID: map[uint64]Collector{},
descIDs: map[uint64]struct{}{},
dimHashesByName: map[string]uint64{},
}
}
// NewPedanticRegistry returns a registry that checks during collection if each
// collected Metric is consistent with its reported Desc, and if the Desc has
// actually been registered with the registry.
//
// Usually, a Registry will be happy as long as the union of all collected
// Metrics is consistent and valid even if some metrics are not consistent with
// their own Desc or a Desc provided by their registered Collector. Well-behaved
// Collectors and Metrics will only provide consistent Descs. This Registry is
// useful to test the implementation of Collectors and Metrics.
func NewPedanticRegistry() *Registry {
r := NewRegistry()
r.pedanticChecksEnabled = true
return r
}
// Registerer is the interface for the part of a registry in charge of
// registering and unregistering. Users of custom registries should use
// Registerer as type for registration purposes (rather then the Registry type
// directly). In that way, they are free to use custom Registerer implementation
// (e.g. for testing purposes).
type Registerer interface {
// Register registers a new Collector to be included in metrics
// collection. It returns an error if the descriptors provided by the
// Collector are invalid or if they — in combination with descriptors of
// already registered Collectors — do not fulfill the consistency and
// uniqueness criteria described in the documentation of metric.Desc.
//
// If the provided Collector is equal to a Collector already registered
// (which includes the case of re-registering the same Collector), the
// returned error is an instance of AlreadyRegisteredError, which
// contains the previously registered Collector.
//
// It is in general not safe to register the same Collector multiple
// times concurrently.
Register(Collector) error
// MustRegister works like Register but registers any number of
// Collectors and panics upon the first registration that causes an
// error.
MustRegister(...Collector)
// Unregister unregisters the Collector that equals the Collector passed
// in as an argument. (Two Collectors are considered equal if their
// Describe method yields the same set of descriptors.) The function
// returns whether a Collector was unregistered.
//
// Note that even after unregistering, it will not be possible to
// register a new Collector that is inconsistent with the unregistered
// Collector, e.g. a Collector collecting metrics with the same name but
// a different help string. The rationale here is that the same registry
// instance must only collect consistent metrics throughout its
// lifetime.
Unregister(Collector) bool
}
// Gatherer is the interface for the part of a registry in charge of gathering
// the collected metrics into a number of MetricFamilies. The Gatherer interface
// comes with the same general implication as described for the Registerer
// interface.
type Gatherer interface {
// Gather calls the Collect method of the registered Collectors and then
// gathers the collected metrics into a lexicographically sorted slice
// of MetricFamily protobufs. Even if an error occurs, Gather attempts
// to gather as many metrics as possible. Hence, if a non-nil error is
// returned, the returned MetricFamily slice could be nil (in case of a
// fatal error that prevented any meaningful metric collection) or
// contain a number of MetricFamily protobufs, some of which might be
// incomplete, and some might be missing altogether. The returned error
// (which might be a MultiError) explains the details. In scenarios
// where complete collection is critical, the returned MetricFamily
// protobufs should be disregarded if the returned error is non-nil.
Gather() ([]*dto.MetricFamily, error)
}
// Register registers the provided Collector with the DefaultRegisterer.
//
// Register is a shortcut for DefaultRegisterer.Register(c). See there for more
// details.
func Register(c Collector) error {
return DefaultRegisterer.Register(c)
}
// MustRegister registers the provided Collectors with the DefaultRegisterer and
// panics if any error occurs.
//
// MustRegister is a shortcut for DefaultRegisterer.MustRegister(cs...). See
// there for more details.
func MustRegister(cs ...Collector) {
DefaultRegisterer.MustRegister(cs...)
}
// RegisterOrGet registers the provided Collector with the DefaultRegisterer and
// returns the Collector, unless an equal Collector was registered before, in
// which case that Collector is returned.
//
// Deprecated: RegisterOrGet is merely a convenience function for the
// implementation as described in the documentation for
// AlreadyRegisteredError. As the use case is relatively rare, this function
// will be removed in a future version of this package to clean up the
// namespace.
func RegisterOrGet(c Collector) (Collector, error) {
if err := Register(c); err != nil {
if are, ok := err.(AlreadyRegisteredError); ok {
return are.ExistingCollector, nil
}
return nil, err
}
return c, nil
}
// MustRegisterOrGet behaves like RegisterOrGet but panics instead of returning
// an error.
//
// Deprecated: This is deprecated for the same reason RegisterOrGet is. See
// there for details.
func MustRegisterOrGet(c Collector) Collector {
c, err := RegisterOrGet(c)
if err != nil {
panic(err)
}
return c
}
// Unregister removes the registration of the provided Collector from the
// DefaultRegisterer.
//
// Unregister is a shortcut for DefaultRegisterer.Unregister(c). See there for
// more details.
func Unregister(c Collector) bool {
return DefaultRegisterer.Unregister(c)
}
// GathererFunc turns a function into a Gatherer.
type GathererFunc func() ([]*dto.MetricFamily, error)
// Gather implements Gatherer.
func (gf GathererFunc) Gather() ([]*dto.MetricFamily, error) {
return gf()
}
// SetMetricFamilyInjectionHook replaces the DefaultGatherer with one that
// gathers from the previous DefaultGatherers but then merges the MetricFamily
// protobufs returned from the provided hook function with the MetricFamily
// protobufs returned from the original DefaultGatherer.
//
// Deprecated: This function manipulates the DefaultGatherer variable. Consider
// the implications, i.e. don't do this concurrently with any uses of the
// DefaultGatherer. In the rare cases where you need to inject MetricFamily
// protobufs directly, it is recommended to use a custom Registry and combine it
// with a custom Gatherer using the Gatherers type (see
// there). SetMetricFamilyInjectionHook only exists for compatibility reasons
// with previous versions of this package.
func SetMetricFamilyInjectionHook(hook func() []*dto.MetricFamily) {
DefaultGatherer = Gatherers{
DefaultGatherer,
GathererFunc(func() ([]*dto.MetricFamily, error) { return hook(), nil }),
}
}
// AlreadyRegisteredError is returned by the Register method if the Collector to
// be registered has already been registered before, or a different Collector
// that collects the same metrics has been registered before. Registration fails
// in that case, but you can detect from the kind of error what has
// happened. The error contains fields for the existing Collector and the
// (rejected) new Collector that equals the existing one. This can be used to
// find out if an equal Collector has been registered before and switch over to
// using the old one, as demonstrated in the example.
type AlreadyRegisteredError struct {
ExistingCollector, NewCollector Collector
}
func (err AlreadyRegisteredError) Error() string {
return "duplicate metrics collector registration attempted"
}
// MultiError is a slice of errors implementing the error interface. It is used
// by a Gatherer to report multiple errors during MetricFamily gathering.
type MultiError []error
func (errs MultiError) Error() string {
if len(errs) == 0 {
return ""
}
buf := &bytes.Buffer{}
fmt.Fprintf(buf, "%d error(s) occurred:", len(errs))
for _, err := range errs {
fmt.Fprintf(buf, "\n* %s", err)
}
return buf.String()
}
// MaybeUnwrap returns nil if len(errs) is 0. It returns the first and only
// contained error as error if len(errs is 1). In all other cases, it returns
// the MultiError directly. This is helpful for returning a MultiError in a way
// that only uses the MultiError if needed.
func (errs MultiError) MaybeUnwrap() error {
switch len(errs) {
case 0:
return nil
case 1:
return errs[0]
default:
return errs
}
}
// Registry registers Prometheus collectors, collects their metrics, and gathers
// them into MetricFamilies for exposition. It implements both Registerer and
// Gatherer. The zero value is not usable. Create instances with NewRegistry or
// NewPedanticRegistry.
type Registry struct {
mtx sync.RWMutex
collectorsByID map[uint64]Collector // ID is a hash of the descIDs.
descIDs map[uint64]struct{}
dimHashesByName map[string]uint64
pedanticChecksEnabled bool
}
// Register implements Registerer.
func (r *Registry) Register(c Collector) error {
var (
descChan = make(chan *Desc, capDescChan)
newDescIDs = map[uint64]struct{}{}
newDimHashesByName = map[string]uint64{}
collectorID uint64 // Just a sum of all desc IDs.
duplicateDescErr error
)
go func() {
c.Describe(descChan)
close(descChan)
}()
r.mtx.Lock()
defer r.mtx.Unlock()
// Coduct various tests...
for desc := range descChan {
// Is the descriptor valid at all?
if desc.err != nil {
return fmt.Errorf("descriptor %s is invalid: %s", desc, desc.err)
}
// Is the descID unique?
// (In other words: Is the fqName + constLabel combination unique?)
if _, exists := r.descIDs[desc.id]; exists {
duplicateDescErr = fmt.Errorf("descriptor %s already exists with the same fully-qualified name and const label values", desc)
}
// If it is not a duplicate desc in this collector, add it to
// the collectorID. (We allow duplicate descs within the same
// collector, but their existence must be a no-op.)
if _, exists := newDescIDs[desc.id]; !exists {
newDescIDs[desc.id] = struct{}{}
collectorID += desc.id
}
// Are all the label names and the help string consistent with
// previous descriptors of the same name?
// First check existing descriptors...
if dimHash, exists := r.dimHashesByName[desc.fqName]; exists {
if dimHash != desc.dimHash {
return fmt.Errorf("a previously registered descriptor with the same fully-qualified name as %s has different label names or a different help string", desc)
}
} else {
// ...then check the new descriptors already seen.
if dimHash, exists := newDimHashesByName[desc.fqName]; exists {
if dimHash != desc.dimHash {
return fmt.Errorf("descriptors reported by collector have inconsistent label names or help strings for the same fully-qualified name, offender is %s", desc)
}
} else {
newDimHashesByName[desc.fqName] = desc.dimHash
}
}
}
// Did anything happen at all?
if len(newDescIDs) == 0 {
return errors.New("collector has no descriptors")
}
if existing, exists := r.collectorsByID[collectorID]; exists {
return AlreadyRegisteredError{
ExistingCollector: existing,
NewCollector: c,
}
}
// If the collectorID is new, but at least one of the descs existed
// before, we are in trouble.
if duplicateDescErr != nil {
return duplicateDescErr
}
// Only after all tests have passed, actually register.
r.collectorsByID[collectorID] = c
for hash := range newDescIDs {
r.descIDs[hash] = struct{}{}
}
for name, dimHash := range newDimHashesByName {
r.dimHashesByName[name] = dimHash
}
return nil
}
// Unregister implements Registerer.
func (r *Registry) Unregister(c Collector) bool {
var (
descChan = make(chan *Desc, capDescChan)
descIDs = map[uint64]struct{}{}
collectorID uint64 // Just a sum of the desc IDs.
)
go func() {
c.Describe(descChan)
close(descChan)
}()
for desc := range descChan {
if _, exists := descIDs[desc.id]; !exists {
collectorID += desc.id
descIDs[desc.id] = struct{}{}
}
}
r.mtx.RLock()
if _, exists := r.collectorsByID[collectorID]; !exists {
r.mtx.RUnlock()
return false
}
r.mtx.RUnlock()
r.mtx.Lock()
defer r.mtx.Unlock()
delete(r.collectorsByID, collectorID)
for id := range descIDs {
delete(r.descIDs, id)
}
// dimHashesByName is left untouched as those must be consistent
// throughout the lifetime of a program.
return true
}
// MustRegister implements Registerer.
func (r *Registry) MustRegister(cs ...Collector) {
for _, c := range cs {
if err := r.Register(c); err != nil {
panic(err)
}
}
}
// Gather implements Gatherer.
func (r *Registry) Gather() ([]*dto.MetricFamily, error) {
var (
metricChan = make(chan Metric, capMetricChan)
metricHashes = map[uint64]struct{}{}
dimHashes = map[string]uint64{}
wg sync.WaitGroup
errs MultiError // The collected errors to return in the end.
registeredDescIDs map[uint64]struct{} // Only used for pedantic checks
)
r.mtx.RLock()
metricFamiliesByName := make(map[string]*dto.MetricFamily, len(r.dimHashesByName))
// Scatter.
// (Collectors could be complex and slow, so we call them all at once.)
wg.Add(len(r.collectorsByID))
go func() {
wg.Wait()
close(metricChan)
}()
for _, collector := range r.collectorsByID {
go func(collector Collector) {
defer wg.Done()
collector.Collect(metricChan)
}(collector)
}
// In case pedantic checks are enabled, we have to copy the map before
// giving up the RLock.
if r.pedanticChecksEnabled {
registeredDescIDs = make(map[uint64]struct{}, len(r.descIDs))
for id := range r.descIDs {
registeredDescIDs[id] = struct{}{}
}
}
r.mtx.RUnlock()
// Drain metricChan in case of premature return.
defer func() {
for _ = range metricChan {
}
}()
// Gather.
for metric := range metricChan {
// This could be done concurrently, too, but it required locking
// of metricFamiliesByName (and of metricHashes if checks are
// enabled). Most likely not worth it.
desc := metric.Desc()
dtoMetric := &dto.Metric{}
if err := metric.Write(dtoMetric); err != nil {
errs = append(errs, fmt.Errorf(
"error collecting metric %v: %s", desc, err,
))
continue
}
metricFamily, ok := metricFamiliesByName[desc.fqName]
if ok {
if metricFamily.GetHelp() != desc.help {
errs = append(errs, fmt.Errorf(
"collected metric %s %s has help %q but should have %q",
desc.fqName, dtoMetric, desc.help, metricFamily.GetHelp(),
))
continue
}
// TODO(beorn7): Simplify switch once Desc has type.
switch metricFamily.GetType() {
case dto.MetricType_COUNTER:
if dtoMetric.Counter == nil {
errs = append(errs, fmt.Errorf(
"collected metric %s %s should be a Counter",
desc.fqName, dtoMetric,
))
continue
}
case dto.MetricType_GAUGE:
if dtoMetric.Gauge == nil {
errs = append(errs, fmt.Errorf(
"collected metric %s %s should be a Gauge",
desc.fqName, dtoMetric,
))
continue
}
case dto.MetricType_SUMMARY:
if dtoMetric.Summary == nil {
errs = append(errs, fmt.Errorf(
"collected metric %s %s should be a Summary",
desc.fqName, dtoMetric,
))
continue
}
case dto.MetricType_UNTYPED:
if dtoMetric.Untyped == nil {
errs = append(errs, fmt.Errorf(
"collected metric %s %s should be Untyped",
desc.fqName, dtoMetric,
))
continue
}
case dto.MetricType_HISTOGRAM:
if dtoMetric.Histogram == nil {
errs = append(errs, fmt.Errorf(
"collected metric %s %s should be a Histogram",
desc.fqName, dtoMetric,
))
continue
}
default:
panic("encountered MetricFamily with invalid type")
}
} else {
metricFamily = &dto.MetricFamily{}
metricFamily.Name = proto.String(desc.fqName)
metricFamily.Help = proto.String(desc.help)
// TODO(beorn7): Simplify switch once Desc has type.
switch {
case dtoMetric.Gauge != nil:
metricFamily.Type = dto.MetricType_GAUGE.Enum()
case dtoMetric.Counter != nil:
metricFamily.Type = dto.MetricType_COUNTER.Enum()
case dtoMetric.Summary != nil:
metricFamily.Type = dto.MetricType_SUMMARY.Enum()
case dtoMetric.Untyped != nil:
metricFamily.Type = dto.MetricType_UNTYPED.Enum()
case dtoMetric.Histogram != nil:
metricFamily.Type = dto.MetricType_HISTOGRAM.Enum()
default:
errs = append(errs, fmt.Errorf(
"empty metric collected: %s", dtoMetric,
))
continue
}
metricFamiliesByName[desc.fqName] = metricFamily
}
if err := checkMetricConsistency(metricFamily, dtoMetric, metricHashes, dimHashes); err != nil {
errs = append(errs, err)
continue
}
if r.pedanticChecksEnabled {
// Is the desc registered at all?
if _, exist := registeredDescIDs[desc.id]; !exist {
errs = append(errs, fmt.Errorf(
"collected metric %s %s with unregistered descriptor %s",
metricFamily.GetName(), dtoMetric, desc,
))
continue
}
if err := checkDescConsistency(metricFamily, dtoMetric, desc); err != nil {
errs = append(errs, err)
continue
}
}
metricFamily.Metric = append(metricFamily.Metric, dtoMetric)
}
return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
}
// Gatherers is a slice of Gatherer instances that implements the Gatherer
// interface itself. Its Gather method calls Gather on all Gatherers in the
// slice in order and returns the merged results. Errors returned from the
// Gather calles are all returned in a flattened MultiError. Duplicate and
// inconsistent Metrics are skipped (first occurrence in slice order wins) and
// reported in the returned error.
//
// Gatherers can be used to merge the Gather results from multiple
// Registries. It also provides a way to directly inject existing MetricFamily
// protobufs into the gathering by creating a custom Gatherer with a Gather
// method that simply returns the existing MetricFamily protobufs. Note that no
// registration is involved (in contrast to Collector registration), so
// obviously registration-time checks cannot happen. Any inconsistencies between
// the gathered MetricFamilies are reported as errors by the Gather method, and
// inconsistent Metrics are dropped. Invalid parts of the MetricFamilies
// (e.g. syntactically invalid metric or label names) will go undetected.
type Gatherers []Gatherer
// Gather implements Gatherer.
func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) {
var (
metricFamiliesByName = map[string]*dto.MetricFamily{}
metricHashes = map[uint64]struct{}{}
dimHashes = map[string]uint64{}
errs MultiError // The collected errors to return in the end.
)
for i, g := range gs {
mfs, err := g.Gather()
if err != nil {
if multiErr, ok := err.(MultiError); ok {
for _, err := range multiErr {
errs = append(errs, fmt.Errorf("[from Gatherer #%d] %s", i+1, err))
}
} else {
errs = append(errs, fmt.Errorf("[from Gatherer #%d] %s", i+1, err))
}
}
for _, mf := range mfs {
existingMF, exists := metricFamiliesByName[mf.GetName()]
if exists {
if existingMF.GetHelp() != mf.GetHelp() {
errs = append(errs, fmt.Errorf(
"gathered metric family %s has help %q but should have %q",
mf.GetName(), mf.GetHelp(), existingMF.GetHelp(),
))
continue
}
if existingMF.GetType() != mf.GetType() {
errs = append(errs, fmt.Errorf(
"gathered metric family %s has type %s but should have %s",
mf.GetName(), mf.GetType(), existingMF.GetType(),
))
continue
}
} else {
existingMF = &dto.MetricFamily{}
existingMF.Name = mf.Name
existingMF.Help = mf.Help
existingMF.Type = mf.Type
metricFamiliesByName[mf.GetName()] = existingMF
}
for _, m := range mf.Metric {
if err := checkMetricConsistency(existingMF, m, metricHashes, dimHashes); err != nil {
errs = append(errs, err)
continue
}
existingMF.Metric = append(existingMF.Metric, m)
}
}
}
return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
}
// metricSorter is a sortable slice of *dto.Metric.
type metricSorter []*dto.Metric
func (s metricSorter) Len() int {
return len(s)
}
func (s metricSorter) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s metricSorter) Less(i, j int) bool {
if len(s[i].Label) != len(s[j].Label) {
// This should not happen. The metrics are
// inconsistent. However, we have to deal with the fact, as
// people might use custom collectors or metric family injection
// to create inconsistent metrics. So let's simply compare the
// number of labels in this case. That will still yield
// reproducible sorting.
return len(s[i].Label) < len(s[j].Label)
}
for n, lp := range s[i].Label {
vi := lp.GetValue()
vj := s[j].Label[n].GetValue()
if vi != vj {
return vi < vj
}
}
// We should never arrive here. Multiple metrics with the same
// label set in the same scrape will lead to undefined ingestion
// behavior. However, as above, we have to provide stable sorting
// here, even for inconsistent metrics. So sort equal metrics
// by their timestamp, with missing timestamps (implying "now")
// coming last.
if s[i].TimestampMs == nil {
return false
}
if s[j].TimestampMs == nil {
return true
}
return s[i].GetTimestampMs() < s[j].GetTimestampMs()
}
// normalizeMetricFamilies returns a MetricFamily slice whith empty
// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
// the slice, with the contained Metrics sorted within each MetricFamily.
func normalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
for _, mf := range metricFamiliesByName {
sort.Sort(metricSorter(mf.Metric))
}
names := make([]string, 0, len(metricFamiliesByName))
for name, mf := range metricFamiliesByName {
if len(mf.Metric) > 0 {
names = append(names, name)
}
}
sort.Strings(names)
result := make([]*dto.MetricFamily, 0, len(names))
for _, name := range names {
result = append(result, metricFamiliesByName[name])
}
return result
}
// checkMetricConsistency checks if the provided Metric is consistent with the
// provided MetricFamily. It also hashed the Metric labels and the MetricFamily
// name. If the resulting hash is alread in the provided metricHashes, an error
// is returned. If not, it is added to metricHashes. The provided dimHashes maps
// MetricFamily names to their dimHash (hashed sorted label names). If dimHashes
// doesn't yet contain a hash for the provided MetricFamily, it is
// added. Otherwise, an error is returned if the existing dimHashes in not equal
// the calculated dimHash.
func checkMetricConsistency(
metricFamily *dto.MetricFamily,
dtoMetric *dto.Metric,
metricHashes map[uint64]struct{},
dimHashes map[string]uint64,
) error {
// Type consistency with metric family.
if metricFamily.GetType() == dto.MetricType_GAUGE && dtoMetric.Gauge == nil ||
metricFamily.GetType() == dto.MetricType_COUNTER && dtoMetric.Counter == nil ||
metricFamily.GetType() == dto.MetricType_SUMMARY && dtoMetric.Summary == nil ||
metricFamily.GetType() == dto.MetricType_HISTOGRAM && dtoMetric.Histogram == nil ||
metricFamily.GetType() == dto.MetricType_UNTYPED && dtoMetric.Untyped == nil {
return fmt.Errorf(
"collected metric %s %s is not a %s",
metricFamily.GetName(), dtoMetric, metricFamily.GetType(),
)
}
// Is the metric unique (i.e. no other metric with the same name and the same label values)?
h := hashNew()
h = hashAdd(h, metricFamily.GetName())
h = hashAddByte(h, separatorByte)
dh := hashNew()
// Make sure label pairs are sorted. We depend on it for the consistency
// check.
sort.Sort(LabelPairSorter(dtoMetric.Label))
for _, lp := range dtoMetric.Label {
h = hashAdd(h, lp.GetValue())
h = hashAddByte(h, separatorByte)
dh = hashAdd(dh, lp.GetName())
dh = hashAddByte(dh, separatorByte)
}
if _, exists := metricHashes[h]; exists {
return fmt.Errorf(
"collected metric %s %s was collected before with the same name and label values",
metricFamily.GetName(), dtoMetric,
)
}
if dimHash, ok := dimHashes[metricFamily.GetName()]; ok {
if dimHash != dh {
return fmt.Errorf(
"collected metric %s %s has label dimensions inconsistent with previously collected metrics in the same metric family",
metricFamily.GetName(), dtoMetric,
)
}
} else {
dimHashes[metricFamily.GetName()] = dh
}
metricHashes[h] = struct{}{}
return nil
}
func checkDescConsistency(
metricFamily *dto.MetricFamily,
dtoMetric *dto.Metric,
desc *Desc,
) error {
// Desc help consistency with metric family help.
if metricFamily.GetHelp() != desc.help {
return fmt.Errorf(
"collected metric %s %s has help %q but should have %q",
metricFamily.GetName(), dtoMetric, metricFamily.GetHelp(), desc.help,
)
}
// Is the desc consistent with the content of the metric?
lpsFromDesc := make([]*dto.LabelPair, 0, len(dtoMetric.Label))
lpsFromDesc = append(lpsFromDesc, desc.constLabelPairs...)
for _, l := range desc.variableLabels {
lpsFromDesc = append(lpsFromDesc, &dto.LabelPair{
Name: proto.String(l),
})
}
if len(lpsFromDesc) != len(dtoMetric.Label) {
return fmt.Errorf(
"labels in collected metric %s %s are inconsistent with descriptor %s",
metricFamily.GetName(), dtoMetric, desc,
)
}
sort.Sort(LabelPairSorter(lpsFromDesc))
for i, lpFromDesc := range lpsFromDesc {
lpFromMetric := dtoMetric.Label[i]
if lpFromDesc.GetName() != lpFromMetric.GetName() ||
lpFromDesc.Value != nil && lpFromDesc.GetValue() != lpFromMetric.GetValue() {
return fmt.Errorf(
"labels in collected metric %s %s are inconsistent with descriptor %s",
metricFamily.GetName(), dtoMetric, desc,
)
}
}
return nil
}

View file

@ -0,0 +1,534 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"math"
"sort"
"sync"
"time"
"github.com/beorn7/perks/quantile"
"github.com/golang/protobuf/proto"
dto "github.com/prometheus/client_model/go"
)
// quantileLabel is used for the label that defines the quantile in a
// summary.
const quantileLabel = "quantile"
// A Summary captures individual observations from an event or sample stream and
// summarizes them in a manner similar to traditional summary statistics: 1. sum
// of observations, 2. observation count, 3. rank estimations.
//
// A typical use-case is the observation of request latencies. By default, a
// Summary provides the median, the 90th and the 99th percentile of the latency
// as rank estimations.
//
// Note that the rank estimations cannot be aggregated in a meaningful way with
// the Prometheus query language (i.e. you cannot average or add them). If you
// need aggregatable quantiles (e.g. you want the 99th percentile latency of all
// queries served across all instances of a service), consider the Histogram
// metric type. See the Prometheus documentation for more details.
//
// To create Summary instances, use NewSummary.
type Summary interface {
Metric
Collector
// Observe adds a single observation to the summary.
Observe(float64)
}
// DefObjectives are the default Summary quantile values.
var (
DefObjectives = map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001}
errQuantileLabelNotAllowed = fmt.Errorf(
"%q is not allowed as label name in summaries", quantileLabel,
)
)
// Default values for SummaryOpts.
const (
// DefMaxAge is the default duration for which observations stay
// relevant.
DefMaxAge time.Duration = 10 * time.Minute
// DefAgeBuckets is the default number of buckets used to calculate the
// age of observations.
DefAgeBuckets = 5
// DefBufCap is the standard buffer size for collecting Summary observations.
DefBufCap = 500
)
// SummaryOpts bundles the options for creating a Summary metric. It is
// mandatory to set Name and Help to a non-empty string. All other fields are
// optional and can safely be left at their zero value.
type SummaryOpts struct {
// Namespace, Subsystem, and Name are components of the fully-qualified
// name of the Summary (created by joining these components with
// "_"). Only Name is mandatory, the others merely help structuring the
// name. Note that the fully-qualified name of the Summary must be a
// valid Prometheus metric name.
Namespace string
Subsystem string
Name string
// Help provides information about this Summary. Mandatory!
//
// Metrics with the same fully-qualified name must have the same Help
// string.
Help string
// ConstLabels are used to attach fixed labels to this
// Summary. Summaries with the same fully-qualified name must have the
// same label names in their ConstLabels.
//
// Note that in most cases, labels have a value that varies during the
// lifetime of a process. Those labels are usually managed with a
// SummaryVec. ConstLabels serve only special purposes. One is for the
// special case where the value of a label does not change during the
// lifetime of a process, e.g. if the revision of the running binary is
// put into a label. Another, more advanced purpose is if more than one
// Collector needs to collect Summaries with the same fully-qualified
// name. In that case, those Summaries must differ in the values of
// their ConstLabels. See the Collector examples.
//
// If the value of a label never changes (not even between binaries),
// that label most likely should not be a label at all (but part of the
// metric name).
ConstLabels Labels
// Objectives defines the quantile rank estimates with their respective
// absolute error. If Objectives[q] = e, then the value reported
// for q will be the φ-quantile value for some φ between q-e and q+e.
// The default value is DefObjectives.
Objectives map[float64]float64
// MaxAge defines the duration for which an observation stays relevant
// for the summary. Must be positive. The default value is DefMaxAge.
MaxAge time.Duration
// AgeBuckets is the number of buckets used to exclude observations that
// are older than MaxAge from the summary. A higher number has a
// resource penalty, so only increase it if the higher resolution is
// really required. For very high observation rates, you might want to
// reduce the number of age buckets. With only one age bucket, you will
// effectively see a complete reset of the summary each time MaxAge has
// passed. The default value is DefAgeBuckets.
AgeBuckets uint32
// BufCap defines the default sample stream buffer size. The default
// value of DefBufCap should suffice for most uses. If there is a need
// to increase the value, a multiple of 500 is recommended (because that
// is the internal buffer size of the underlying package
// "github.com/bmizerany/perks/quantile").
BufCap uint32
}
// Great fuck-up with the sliding-window decay algorithm... The Merge method of
// perk/quantile is actually not working as advertised - and it might be
// unfixable, as the underlying algorithm is apparently not capable of merging
// summaries in the first place. To avoid using Merge, we are currently adding
// observations to _each_ age bucket, i.e. the effort to add a sample is
// essentially multiplied by the number of age buckets. When rotating age
// buckets, we empty the previous head stream. On scrape time, we simply take
// the quantiles from the head stream (no merging required). Result: More effort
// on observation time, less effort on scrape time, which is exactly the
// opposite of what we try to accomplish, but at least the results are correct.
//
// The quite elegant previous contraption to merge the age buckets efficiently
// on scrape time (see code up commit 6b9530d72ea715f0ba612c0120e6e09fbf1d49d0)
// can't be used anymore.
// NewSummary creates a new Summary based on the provided SummaryOpts.
func NewSummary(opts SummaryOpts) Summary {
return newSummary(
NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
),
opts,
)
}
func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
if len(desc.variableLabels) != len(labelValues) {
panic(errInconsistentCardinality)
}
for _, n := range desc.variableLabels {
if n == quantileLabel {
panic(errQuantileLabelNotAllowed)
}
}
for _, lp := range desc.constLabelPairs {
if lp.GetName() == quantileLabel {
panic(errQuantileLabelNotAllowed)
}
}
if len(opts.Objectives) == 0 {
opts.Objectives = DefObjectives
}
if opts.MaxAge < 0 {
panic(fmt.Errorf("illegal max age MaxAge=%v", opts.MaxAge))
}
if opts.MaxAge == 0 {
opts.MaxAge = DefMaxAge
}
if opts.AgeBuckets == 0 {
opts.AgeBuckets = DefAgeBuckets
}
if opts.BufCap == 0 {
opts.BufCap = DefBufCap
}
s := &summary{
desc: desc,
objectives: opts.Objectives,
sortedObjectives: make([]float64, 0, len(opts.Objectives)),
labelPairs: makeLabelPairs(desc, labelValues),
hotBuf: make([]float64, 0, opts.BufCap),
coldBuf: make([]float64, 0, opts.BufCap),
streamDuration: opts.MaxAge / time.Duration(opts.AgeBuckets),
}
s.headStreamExpTime = time.Now().Add(s.streamDuration)
s.hotBufExpTime = s.headStreamExpTime
for i := uint32(0); i < opts.AgeBuckets; i++ {
s.streams = append(s.streams, s.newStream())
}
s.headStream = s.streams[0]
for qu := range s.objectives {
s.sortedObjectives = append(s.sortedObjectives, qu)
}
sort.Float64s(s.sortedObjectives)
s.init(s) // Init self-collection.
return s
}
type summary struct {
selfCollector
bufMtx sync.Mutex // Protects hotBuf and hotBufExpTime.
mtx sync.Mutex // Protects every other moving part.
// Lock bufMtx before mtx if both are needed.
desc *Desc
objectives map[float64]float64
sortedObjectives []float64
labelPairs []*dto.LabelPair
sum float64
cnt uint64
hotBuf, coldBuf []float64
streams []*quantile.Stream
streamDuration time.Duration
headStream *quantile.Stream
headStreamIdx int
headStreamExpTime, hotBufExpTime time.Time
}
func (s *summary) Desc() *Desc {
return s.desc
}
func (s *summary) Observe(v float64) {
s.bufMtx.Lock()
defer s.bufMtx.Unlock()
now := time.Now()
if now.After(s.hotBufExpTime) {
s.asyncFlush(now)
}
s.hotBuf = append(s.hotBuf, v)
if len(s.hotBuf) == cap(s.hotBuf) {
s.asyncFlush(now)
}
}
func (s *summary) Write(out *dto.Metric) error {
sum := &dto.Summary{}
qs := make([]*dto.Quantile, 0, len(s.objectives))
s.bufMtx.Lock()
s.mtx.Lock()
// Swap bufs even if hotBuf is empty to set new hotBufExpTime.
s.swapBufs(time.Now())
s.bufMtx.Unlock()
s.flushColdBuf()
sum.SampleCount = proto.Uint64(s.cnt)
sum.SampleSum = proto.Float64(s.sum)
for _, rank := range s.sortedObjectives {
var q float64
if s.headStream.Count() == 0 {
q = math.NaN()
} else {
q = s.headStream.Query(rank)
}
qs = append(qs, &dto.Quantile{
Quantile: proto.Float64(rank),
Value: proto.Float64(q),
})
}
s.mtx.Unlock()
if len(qs) > 0 {
sort.Sort(quantSort(qs))
}
sum.Quantile = qs
out.Summary = sum
out.Label = s.labelPairs
return nil
}
func (s *summary) newStream() *quantile.Stream {
return quantile.NewTargeted(s.objectives)
}
// asyncFlush needs bufMtx locked.
func (s *summary) asyncFlush(now time.Time) {
s.mtx.Lock()
s.swapBufs(now)
// Unblock the original goroutine that was responsible for the mutation
// that triggered the compaction. But hold onto the global non-buffer
// state mutex until the operation finishes.
go func() {
s.flushColdBuf()
s.mtx.Unlock()
}()
}
// rotateStreams needs mtx AND bufMtx locked.
func (s *summary) maybeRotateStreams() {
for !s.hotBufExpTime.Equal(s.headStreamExpTime) {
s.headStream.Reset()
s.headStreamIdx++
if s.headStreamIdx >= len(s.streams) {
s.headStreamIdx = 0
}
s.headStream = s.streams[s.headStreamIdx]
s.headStreamExpTime = s.headStreamExpTime.Add(s.streamDuration)
}
}
// flushColdBuf needs mtx locked.
func (s *summary) flushColdBuf() {
for _, v := range s.coldBuf {
for _, stream := range s.streams {
stream.Insert(v)
}
s.cnt++
s.sum += v
}
s.coldBuf = s.coldBuf[0:0]
s.maybeRotateStreams()
}
// swapBufs needs mtx AND bufMtx locked, coldBuf must be empty.
func (s *summary) swapBufs(now time.Time) {
if len(s.coldBuf) != 0 {
panic("coldBuf is not empty")
}
s.hotBuf, s.coldBuf = s.coldBuf, s.hotBuf
// hotBuf is now empty and gets new expiration set.
for now.After(s.hotBufExpTime) {
s.hotBufExpTime = s.hotBufExpTime.Add(s.streamDuration)
}
}
type quantSort []*dto.Quantile
func (s quantSort) Len() int {
return len(s)
}
func (s quantSort) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s quantSort) Less(i, j int) bool {
return s[i].GetQuantile() < s[j].GetQuantile()
}
// SummaryVec is a Collector that bundles a set of Summaries that all share the
// same Desc, but have different values for their variable labels. This is used
// if you want to count the same thing partitioned by various dimensions
// (e.g. HTTP request latencies, partitioned by status code and method). Create
// instances with NewSummaryVec.
type SummaryVec struct {
*MetricVec
}
// NewSummaryVec creates a new SummaryVec based on the provided SummaryOpts and
// partitioned by the given label names. At least one label name must be
// provided.
func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &SummaryVec{
MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
return newSummary(desc, opts, lvs...)
}),
}
}
// GetMetricWithLabelValues replaces the method of the same name in
// MetricVec. The difference is that this method returns a Summary and not a
// Metric so that no type conversion is required.
func (m *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Summary, error) {
metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Summary), err
}
return nil, err
}
// GetMetricWith replaces the method of the same name in MetricVec. The
// difference is that this method returns a Summary and not a Metric so that no
// type conversion is required.
func (m *SummaryVec) GetMetricWith(labels Labels) (Summary, error) {
metric, err := m.MetricVec.GetMetricWith(labels)
if metric != nil {
return metric.(Summary), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. By not returning an
// error, WithLabelValues allows shortcuts like
// myVec.WithLabelValues("404", "GET").Observe(42.21)
func (m *SummaryVec) WithLabelValues(lvs ...string) Summary {
return m.MetricVec.WithLabelValues(lvs...).(Summary)
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. By not returning an error, With allows shortcuts like
// myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21)
func (m *SummaryVec) With(labels Labels) Summary {
return m.MetricVec.With(labels).(Summary)
}
type constSummary struct {
desc *Desc
count uint64
sum float64
quantiles map[float64]float64
labelPairs []*dto.LabelPair
}
func (s *constSummary) Desc() *Desc {
return s.desc
}
func (s *constSummary) Write(out *dto.Metric) error {
sum := &dto.Summary{}
qs := make([]*dto.Quantile, 0, len(s.quantiles))
sum.SampleCount = proto.Uint64(s.count)
sum.SampleSum = proto.Float64(s.sum)
for rank, q := range s.quantiles {
qs = append(qs, &dto.Quantile{
Quantile: proto.Float64(rank),
Value: proto.Float64(q),
})
}
if len(qs) > 0 {
sort.Sort(quantSort(qs))
}
sum.Quantile = qs
out.Summary = sum
out.Label = s.labelPairs
return nil
}
// NewConstSummary returns a metric representing a Prometheus summary with fixed
// values for the count, sum, and quantiles. As those parameters cannot be
// changed, the returned value does not implement the Summary interface (but
// only the Metric interface). Users of this package will not have much use for
// it in regular operations. However, when implementing custom Collectors, it is
// useful as a throw-away metric that is generated on the fly to send it to
// Prometheus in the Collect method.
//
// quantiles maps ranks to quantile values. For example, a median latency of
// 0.23s and a 99th percentile latency of 0.56s would be expressed as:
// map[float64]float64{0.5: 0.23, 0.99: 0.56}
//
// NewConstSummary returns an error if the length of labelValues is not
// consistent with the variable labels in Desc.
func NewConstSummary(
desc *Desc,
count uint64,
sum float64,
quantiles map[float64]float64,
labelValues ...string,
) (Metric, error) {
if len(desc.variableLabels) != len(labelValues) {
return nil, errInconsistentCardinality
}
return &constSummary{
desc: desc,
count: count,
sum: sum,
quantiles: quantiles,
labelPairs: makeLabelPairs(desc, labelValues),
}, nil
}
// MustNewConstSummary is a version of NewConstSummary that panics where
// NewConstMetric would have returned an error.
func MustNewConstSummary(
desc *Desc,
count uint64,
sum float64,
quantiles map[float64]float64,
labelValues ...string,
) Metric {
m, err := NewConstSummary(desc, count, sum, quantiles, labelValues...)
if err != nil {
panic(err)
}
return m
}

View file

@ -0,0 +1,138 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// Untyped is a Metric that represents a single numerical value that can
// arbitrarily go up and down.
//
// An Untyped metric works the same as a Gauge. The only difference is that to
// no type information is implied.
//
// To create Untyped instances, use NewUntyped.
type Untyped interface {
Metric
Collector
// Set sets the Untyped metric to an arbitrary value.
Set(float64)
// Inc increments the Untyped metric by 1.
Inc()
// Dec decrements the Untyped metric by 1.
Dec()
// Add adds the given value to the Untyped metric. (The value can be
// negative, resulting in a decrease.)
Add(float64)
// Sub subtracts the given value from the Untyped metric. (The value can
// be negative, resulting in an increase.)
Sub(float64)
}
// UntypedOpts is an alias for Opts. See there for doc comments.
type UntypedOpts Opts
// NewUntyped creates a new Untyped metric from the provided UntypedOpts.
func NewUntyped(opts UntypedOpts) Untyped {
return newValue(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), UntypedValue, 0)
}
// UntypedVec is a Collector that bundles a set of Untyped metrics that all
// share the same Desc, but have different values for their variable
// labels. This is used if you want to count the same thing partitioned by
// various dimensions. Create instances with NewUntypedVec.
type UntypedVec struct {
*MetricVec
}
// NewUntypedVec creates a new UntypedVec based on the provided UntypedOpts and
// partitioned by the given label names. At least one label name must be
// provided.
func NewUntypedVec(opts UntypedOpts, labelNames []string) *UntypedVec {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &UntypedVec{
MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
return newValue(desc, UntypedValue, 0, lvs...)
}),
}
}
// GetMetricWithLabelValues replaces the method of the same name in
// MetricVec. The difference is that this method returns an Untyped and not a
// Metric so that no type conversion is required.
func (m *UntypedVec) GetMetricWithLabelValues(lvs ...string) (Untyped, error) {
metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Untyped), err
}
return nil, err
}
// GetMetricWith replaces the method of the same name in MetricVec. The
// difference is that this method returns an Untyped and not a Metric so that no
// type conversion is required.
func (m *UntypedVec) GetMetricWith(labels Labels) (Untyped, error) {
metric, err := m.MetricVec.GetMetricWith(labels)
if metric != nil {
return metric.(Untyped), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. By not returning an
// error, WithLabelValues allows shortcuts like
// myVec.WithLabelValues("404", "GET").Add(42)
func (m *UntypedVec) WithLabelValues(lvs ...string) Untyped {
return m.MetricVec.WithLabelValues(lvs...).(Untyped)
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. By not returning an error, With allows shortcuts like
// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
func (m *UntypedVec) With(labels Labels) Untyped {
return m.MetricVec.With(labels).(Untyped)
}
// UntypedFunc is an Untyped whose value is determined at collect time by
// calling a provided function.
//
// To create UntypedFunc instances, use NewUntypedFunc.
type UntypedFunc interface {
Metric
Collector
}
// NewUntypedFunc creates a new UntypedFunc based on the provided
// UntypedOpts. The value reported is determined by calling the given function
// from within the Write method. Take into account that metric collection may
// happen concurrently. If that results in concurrent calls to Write, like in
// the case where an UntypedFunc is directly registered with Prometheus, the
// provided function must be concurrency-safe.
func NewUntypedFunc(opts UntypedOpts, function func() float64) UntypedFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), UntypedValue, function)
}

View file

@ -0,0 +1,234 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"fmt"
"math"
"sort"
"sync/atomic"
dto "github.com/prometheus/client_model/go"
"github.com/golang/protobuf/proto"
)
// ValueType is an enumeration of metric types that represent a simple value.
type ValueType int
// Possible values for the ValueType enum.
const (
_ ValueType = iota
CounterValue
GaugeValue
UntypedValue
)
var errInconsistentCardinality = errors.New("inconsistent label cardinality")
// value is a generic metric for simple values. It implements Metric, Collector,
// Counter, Gauge, and Untyped. Its effective type is determined by
// ValueType. This is a low-level building block used by the library to back the
// implementations of Counter, Gauge, and Untyped.
type value struct {
// valBits containst the bits of the represented float64 value. It has
// to go first in the struct to guarantee alignment for atomic
// operations. http://golang.org/pkg/sync/atomic/#pkg-note-BUG
valBits uint64
selfCollector
desc *Desc
valType ValueType
labelPairs []*dto.LabelPair
}
// newValue returns a newly allocated value with the given Desc, ValueType,
// sample value and label values. It panics if the number of label
// values is different from the number of variable labels in Desc.
func newValue(desc *Desc, valueType ValueType, val float64, labelValues ...string) *value {
if len(labelValues) != len(desc.variableLabels) {
panic(errInconsistentCardinality)
}
result := &value{
desc: desc,
valType: valueType,
valBits: math.Float64bits(val),
labelPairs: makeLabelPairs(desc, labelValues),
}
result.init(result)
return result
}
func (v *value) Desc() *Desc {
return v.desc
}
func (v *value) Set(val float64) {
atomic.StoreUint64(&v.valBits, math.Float64bits(val))
}
func (v *value) Inc() {
v.Add(1)
}
func (v *value) Dec() {
v.Add(-1)
}
func (v *value) Add(val float64) {
for {
oldBits := atomic.LoadUint64(&v.valBits)
newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
if atomic.CompareAndSwapUint64(&v.valBits, oldBits, newBits) {
return
}
}
}
func (v *value) Sub(val float64) {
v.Add(val * -1)
}
func (v *value) Write(out *dto.Metric) error {
val := math.Float64frombits(atomic.LoadUint64(&v.valBits))
return populateMetric(v.valType, val, v.labelPairs, out)
}
// valueFunc is a generic metric for simple values retrieved on collect time
// from a function. It implements Metric and Collector. Its effective type is
// determined by ValueType. This is a low-level building block used by the
// library to back the implementations of CounterFunc, GaugeFunc, and
// UntypedFunc.
type valueFunc struct {
selfCollector
desc *Desc
valType ValueType
function func() float64
labelPairs []*dto.LabelPair
}
// newValueFunc returns a newly allocated valueFunc with the given Desc and
// ValueType. The value reported is determined by calling the given function
// from within the Write method. Take into account that metric collection may
// happen concurrently. If that results in concurrent calls to Write, like in
// the case where a valueFunc is directly registered with Prometheus, the
// provided function must be concurrency-safe.
func newValueFunc(desc *Desc, valueType ValueType, function func() float64) *valueFunc {
result := &valueFunc{
desc: desc,
valType: valueType,
function: function,
labelPairs: makeLabelPairs(desc, nil),
}
result.init(result)
return result
}
func (v *valueFunc) Desc() *Desc {
return v.desc
}
func (v *valueFunc) Write(out *dto.Metric) error {
return populateMetric(v.valType, v.function(), v.labelPairs, out)
}
// NewConstMetric returns a metric with one fixed value that cannot be
// changed. Users of this package will not have much use for it in regular
// operations. However, when implementing custom Collectors, it is useful as a
// throw-away metric that is generated on the fly to send it to Prometheus in
// the Collect method. NewConstMetric returns an error if the length of
// labelValues is not consistent with the variable labels in Desc.
func NewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) (Metric, error) {
if len(desc.variableLabels) != len(labelValues) {
return nil, errInconsistentCardinality
}
return &constMetric{
desc: desc,
valType: valueType,
val: value,
labelPairs: makeLabelPairs(desc, labelValues),
}, nil
}
// MustNewConstMetric is a version of NewConstMetric that panics where
// NewConstMetric would have returned an error.
func MustNewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) Metric {
m, err := NewConstMetric(desc, valueType, value, labelValues...)
if err != nil {
panic(err)
}
return m
}
type constMetric struct {
desc *Desc
valType ValueType
val float64
labelPairs []*dto.LabelPair
}
func (m *constMetric) Desc() *Desc {
return m.desc
}
func (m *constMetric) Write(out *dto.Metric) error {
return populateMetric(m.valType, m.val, m.labelPairs, out)
}
func populateMetric(
t ValueType,
v float64,
labelPairs []*dto.LabelPair,
m *dto.Metric,
) error {
m.Label = labelPairs
switch t {
case CounterValue:
m.Counter = &dto.Counter{Value: proto.Float64(v)}
case GaugeValue:
m.Gauge = &dto.Gauge{Value: proto.Float64(v)}
case UntypedValue:
m.Untyped = &dto.Untyped{Value: proto.Float64(v)}
default:
return fmt.Errorf("encountered unknown type %v", t)
}
return nil
}
func makeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair {
totalLen := len(desc.variableLabels) + len(desc.constLabelPairs)
if totalLen == 0 {
// Super fast path.
return nil
}
if len(desc.variableLabels) == 0 {
// Moderately fast path.
return desc.constLabelPairs
}
labelPairs := make([]*dto.LabelPair, 0, totalLen)
for i, n := range desc.variableLabels {
labelPairs = append(labelPairs, &dto.LabelPair{
Name: proto.String(n),
Value: proto.String(labelValues[i]),
})
}
for _, lp := range desc.constLabelPairs {
labelPairs = append(labelPairs, lp)
}
sort.Sort(LabelPairSorter(labelPairs))
return labelPairs
}

View file

@ -0,0 +1,404 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"sync"
"github.com/prometheus/common/model"
)
// MetricVec is a Collector to bundle metrics of the same name that
// differ in their label values. MetricVec is usually not used directly but as a
// building block for implementations of vectors of a given metric
// type. GaugeVec, CounterVec, SummaryVec, and UntypedVec are examples already
// provided in this package.
type MetricVec struct {
mtx sync.RWMutex // Protects the children.
children map[uint64][]metricWithLabelValues
desc *Desc
newMetric func(labelValues ...string) Metric
hashAdd func(h uint64, s string) uint64 // replace hash function for testing collision handling
hashAddByte func(h uint64, b byte) uint64
}
// newMetricVec returns an initialized MetricVec. The concrete value is
// returned for embedding into another struct.
func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *MetricVec {
return &MetricVec{
children: map[uint64][]metricWithLabelValues{},
desc: desc,
newMetric: newMetric,
hashAdd: hashAdd,
hashAddByte: hashAddByte,
}
}
// metricWithLabelValues provides the metric and its label values for
// disambiguation on hash collision.
type metricWithLabelValues struct {
values []string
metric Metric
}
// Describe implements Collector. The length of the returned slice
// is always one.
func (m *MetricVec) Describe(ch chan<- *Desc) {
ch <- m.desc
}
// Collect implements Collector.
func (m *MetricVec) Collect(ch chan<- Metric) {
m.mtx.RLock()
defer m.mtx.RUnlock()
for _, metrics := range m.children {
for _, metric := range metrics {
ch <- metric.metric
}
}
}
// GetMetricWithLabelValues returns the Metric for the given slice of label
// values (same order as the VariableLabels in Desc). If that combination of
// label values is accessed for the first time, a new Metric is created.
//
// It is possible to call this method without using the returned Metric to only
// create the new Metric but leave it at its start value (e.g. a Summary or
// Histogram without any observations). See also the SummaryVec example.
//
// Keeping the Metric for later use is possible (and should be considered if
// performance is critical), but keep in mind that Reset, DeleteLabelValues and
// Delete can be used to delete the Metric from the MetricVec. In that case, the
// Metric will still exist, but it will not be exported anymore, even if a
// Metric with the same label values is created later. See also the CounterVec
// example.
//
// An error is returned if the number of label values is not the same as the
// number of VariableLabels in Desc.
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
// an alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
// See also the GaugeVec example.
func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) {
h, err := m.hashLabelValues(lvs)
if err != nil {
return nil, err
}
return m.getOrCreateMetricWithLabelValues(h, lvs), nil
}
// GetMetricWith returns the Metric for the given Labels map (the label names
// must match those of the VariableLabels in Desc). If that label map is
// accessed for the first time, a new Metric is created. Implications of
// creating a Metric without using it and keeping the Metric for later use are
// the same as for GetMetricWithLabelValues.
//
// An error is returned if the number and names of the Labels are inconsistent
// with those of the VariableLabels in Desc.
//
// This method is used for the same purpose as
// GetMetricWithLabelValues(...string). See there for pros and cons of the two
// methods.
func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) {
h, err := m.hashLabels(labels)
if err != nil {
return nil, err
}
return m.getOrCreateMetricWithLabels(h, labels), nil
}
// WithLabelValues works as GetMetricWithLabelValues, but panics if an error
// occurs. The method allows neat syntax like:
// httpReqs.WithLabelValues("404", "POST").Inc()
func (m *MetricVec) WithLabelValues(lvs ...string) Metric {
metric, err := m.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return metric
}
// With works as GetMetricWith, but panics if an error occurs. The method allows
// neat syntax like:
// httpReqs.With(Labels{"status":"404", "method":"POST"}).Inc()
func (m *MetricVec) With(labels Labels) Metric {
metric, err := m.GetMetricWith(labels)
if err != nil {
panic(err)
}
return metric
}
// DeleteLabelValues removes the metric where the variable labels are the same
// as those passed in as labels (same order as the VariableLabels in Desc). It
// returns true if a metric was deleted.
//
// It is not an error if the number of label values is not the same as the
// number of VariableLabels in Desc. However, such inconsistent label count can
// never match an actual Metric, so the method will always return false in that
// case.
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider Delete(Labels) as an
// alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
// See also the CounterVec example.
func (m *MetricVec) DeleteLabelValues(lvs ...string) bool {
m.mtx.Lock()
defer m.mtx.Unlock()
h, err := m.hashLabelValues(lvs)
if err != nil {
return false
}
return m.deleteByHashWithLabelValues(h, lvs)
}
// Delete deletes the metric where the variable labels are the same as those
// passed in as labels. It returns true if a metric was deleted.
//
// It is not an error if the number and names of the Labels are inconsistent
// with those of the VariableLabels in the Desc of the MetricVec. However, such
// inconsistent Labels can never match an actual Metric, so the method will
// always return false in that case.
//
// This method is used for the same purpose as DeleteLabelValues(...string). See
// there for pros and cons of the two methods.
func (m *MetricVec) Delete(labels Labels) bool {
m.mtx.Lock()
defer m.mtx.Unlock()
h, err := m.hashLabels(labels)
if err != nil {
return false
}
return m.deleteByHashWithLabels(h, labels)
}
// deleteByHashWithLabelValues removes the metric from the hash bucket h. If
// there are multiple matches in the bucket, use lvs to select a metric and
// remove only that metric.
func (m *MetricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool {
metrics, ok := m.children[h]
if !ok {
return false
}
i := m.findMetricWithLabelValues(metrics, lvs)
if i >= len(metrics) {
return false
}
if len(metrics) > 1 {
m.children[h] = append(metrics[:i], metrics[i+1:]...)
} else {
delete(m.children, h)
}
return true
}
// deleteByHashWithLabels removes the metric from the hash bucket h. If there
// are multiple matches in the bucket, use lvs to select a metric and remove
// only that metric.
func (m *MetricVec) deleteByHashWithLabels(h uint64, labels Labels) bool {
metrics, ok := m.children[h]
if !ok {
return false
}
i := m.findMetricWithLabels(metrics, labels)
if i >= len(metrics) {
return false
}
if len(metrics) > 1 {
m.children[h] = append(metrics[:i], metrics[i+1:]...)
} else {
delete(m.children, h)
}
return true
}
// Reset deletes all metrics in this vector.
func (m *MetricVec) Reset() {
m.mtx.Lock()
defer m.mtx.Unlock()
for h := range m.children {
delete(m.children, h)
}
}
func (m *MetricVec) hashLabelValues(vals []string) (uint64, error) {
if len(vals) != len(m.desc.variableLabels) {
return 0, errInconsistentCardinality
}
h := hashNew()
for _, val := range vals {
h = m.hashAdd(h, val)
h = m.hashAddByte(h, model.SeparatorByte)
}
return h, nil
}
func (m *MetricVec) hashLabels(labels Labels) (uint64, error) {
if len(labels) != len(m.desc.variableLabels) {
return 0, errInconsistentCardinality
}
h := hashNew()
for _, label := range m.desc.variableLabels {
val, ok := labels[label]
if !ok {
return 0, fmt.Errorf("label name %q missing in label map", label)
}
h = m.hashAdd(h, val)
h = m.hashAddByte(h, model.SeparatorByte)
}
return h, nil
}
// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
// or creates it and returns the new one.
//
// This function holds the mutex.
func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string) Metric {
m.mtx.RLock()
metric, ok := m.getMetricWithLabelValues(hash, lvs)
m.mtx.RUnlock()
if ok {
return metric
}
m.mtx.Lock()
defer m.mtx.Unlock()
metric, ok = m.getMetricWithLabelValues(hash, lvs)
if !ok {
// Copy to avoid allocation in case wo don't go down this code path.
copiedLVs := make([]string, len(lvs))
copy(copiedLVs, lvs)
metric = m.newMetric(copiedLVs...)
m.children[hash] = append(m.children[hash], metricWithLabelValues{values: copiedLVs, metric: metric})
}
return metric
}
// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
// or creates it and returns the new one.
//
// This function holds the mutex.
func (m *MetricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metric {
m.mtx.RLock()
metric, ok := m.getMetricWithLabels(hash, labels)
m.mtx.RUnlock()
if ok {
return metric
}
m.mtx.Lock()
defer m.mtx.Unlock()
metric, ok = m.getMetricWithLabels(hash, labels)
if !ok {
lvs := m.extractLabelValues(labels)
metric = m.newMetric(lvs...)
m.children[hash] = append(m.children[hash], metricWithLabelValues{values: lvs, metric: metric})
}
return metric
}
// getMetricWithLabelValues gets a metric while handling possible collisions in
// the hash space. Must be called while holding read mutex.
func (m *MetricVec) getMetricWithLabelValues(h uint64, lvs []string) (Metric, bool) {
metrics, ok := m.children[h]
if ok {
if i := m.findMetricWithLabelValues(metrics, lvs); i < len(metrics) {
return metrics[i].metric, true
}
}
return nil, false
}
// getMetricWithLabels gets a metric while handling possible collisions in
// the hash space. Must be called while holding read mutex.
func (m *MetricVec) getMetricWithLabels(h uint64, labels Labels) (Metric, bool) {
metrics, ok := m.children[h]
if ok {
if i := m.findMetricWithLabels(metrics, labels); i < len(metrics) {
return metrics[i].metric, true
}
}
return nil, false
}
// findMetricWithLabelValues returns the index of the matching metric or
// len(metrics) if not found.
func (m *MetricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, lvs []string) int {
for i, metric := range metrics {
if m.matchLabelValues(metric.values, lvs) {
return i
}
}
return len(metrics)
}
// findMetricWithLabels returns the index of the matching metric or len(metrics)
// if not found.
func (m *MetricVec) findMetricWithLabels(metrics []metricWithLabelValues, labels Labels) int {
for i, metric := range metrics {
if m.matchLabels(metric.values, labels) {
return i
}
}
return len(metrics)
}
func (m *MetricVec) matchLabelValues(values []string, lvs []string) bool {
if len(values) != len(lvs) {
return false
}
for i, v := range values {
if v != lvs[i] {
return false
}
}
return true
}
func (m *MetricVec) matchLabels(values []string, labels Labels) bool {
if len(labels) != len(values) {
return false
}
for i, k := range m.desc.variableLabels {
if values[i] != labels[k] {
return false
}
}
return true
}
func (m *MetricVec) extractLabelValues(labels Labels) []string {
labelValues := make([]string, len(labels))
for i, k := range m.desc.variableLabels {
labelValues[i] = labels[k]
}
return labelValues
}