127 lines
3.4 KiB
Go
127 lines
3.4 KiB
Go
/*
|
|
Copyright 2014 The Kubernetes 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 recognizer
|
|
|
|
import (
|
|
"bufio"
|
|
"bytes"
|
|
"fmt"
|
|
"io"
|
|
|
|
"k8s.io/apimachinery/pkg/runtime"
|
|
"k8s.io/apimachinery/pkg/runtime/schema"
|
|
)
|
|
|
|
type RecognizingDecoder interface {
|
|
runtime.Decoder
|
|
// RecognizesData should return true if the input provided in the provided reader
|
|
// belongs to this decoder, or an error if the data could not be read or is ambiguous.
|
|
// Unknown is true if the data could not be determined to match the decoder type.
|
|
// Decoders should assume that they can read as much of peek as they need (as the caller
|
|
// provides) and may return unknown if the data provided is not sufficient to make a
|
|
// a determination. When peek returns EOF that may mean the end of the input or the
|
|
// end of buffered input - recognizers should return the best guess at that time.
|
|
RecognizesData(peek io.Reader) (ok, unknown bool, err error)
|
|
}
|
|
|
|
// NewDecoder creates a decoder that will attempt multiple decoders in an order defined
|
|
// by:
|
|
//
|
|
// 1. The decoder implements RecognizingDecoder and identifies the data
|
|
// 2. All other decoders, and any decoder that returned true for unknown.
|
|
//
|
|
// The order passed to the constructor is preserved within those priorities.
|
|
func NewDecoder(decoders ...runtime.Decoder) runtime.Decoder {
|
|
return &decoder{
|
|
decoders: decoders,
|
|
}
|
|
}
|
|
|
|
type decoder struct {
|
|
decoders []runtime.Decoder
|
|
}
|
|
|
|
var _ RecognizingDecoder = &decoder{}
|
|
|
|
func (d *decoder) RecognizesData(peek io.Reader) (bool, bool, error) {
|
|
var (
|
|
lastErr error
|
|
anyUnknown bool
|
|
)
|
|
data, _ := bufio.NewReaderSize(peek, 1024).Peek(1024)
|
|
for _, r := range d.decoders {
|
|
switch t := r.(type) {
|
|
case RecognizingDecoder:
|
|
ok, unknown, err := t.RecognizesData(bytes.NewBuffer(data))
|
|
if err != nil {
|
|
lastErr = err
|
|
continue
|
|
}
|
|
anyUnknown = anyUnknown || unknown
|
|
if !ok {
|
|
continue
|
|
}
|
|
return true, false, nil
|
|
}
|
|
}
|
|
return false, anyUnknown, lastErr
|
|
}
|
|
|
|
func (d *decoder) Decode(data []byte, gvk *schema.GroupVersionKind, into runtime.Object) (runtime.Object, *schema.GroupVersionKind, error) {
|
|
var (
|
|
lastErr error
|
|
skipped []runtime.Decoder
|
|
)
|
|
|
|
// try recognizers, record any decoders we need to give a chance later
|
|
for _, r := range d.decoders {
|
|
switch t := r.(type) {
|
|
case RecognizingDecoder:
|
|
buf := bytes.NewBuffer(data)
|
|
ok, unknown, err := t.RecognizesData(buf)
|
|
if err != nil {
|
|
lastErr = err
|
|
continue
|
|
}
|
|
if unknown {
|
|
skipped = append(skipped, t)
|
|
continue
|
|
}
|
|
if !ok {
|
|
continue
|
|
}
|
|
return r.Decode(data, gvk, into)
|
|
default:
|
|
skipped = append(skipped, t)
|
|
}
|
|
}
|
|
|
|
// try recognizers that returned unknown or didn't recognize their data
|
|
for _, r := range skipped {
|
|
out, actual, err := r.Decode(data, gvk, into)
|
|
if err != nil {
|
|
lastErr = err
|
|
continue
|
|
}
|
|
return out, actual, nil
|
|
}
|
|
|
|
if lastErr == nil {
|
|
lastErr = fmt.Errorf("no serialization format matched the provided data")
|
|
}
|
|
return nil, nil, lastErr
|
|
}
|