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Add firebase support

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This commit is contained in:
Philipp Heckel 2021-10-29 13:58:14 -04:00
parent 4677e724ee
commit b145e693a5
7 changed files with 293 additions and 161 deletions
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27
cmd/app.go
View file

@ -8,8 +8,10 @@ import (
"github.com/urfave/cli/v2/altsrc"
"heckel.io/ntfy/config"
"heckel.io/ntfy/server"
"heckel.io/ntfy/util"
"log"
"os"
"time"
)
// New creates a new CLI application
@ -18,7 +20,9 @@ func New() *cli.App {
&cli.StringFlag{Name: "config", Aliases: []string{"c"}, EnvVars: []string{"NTFY_CONFIG_FILE"}, Value: "/etc/ntfy/config.yml", DefaultText: "/etc/ntfy/config.yml", Usage: "config file"},
altsrc.NewStringFlag(&cli.StringFlag{Name: "listen-http", Aliases: []string{"l"}, EnvVars: []string{"NTFY_LISTEN_HTTP"}, Value: config.DefaultListenHTTP, Usage: "ip:port used to as listen address"}),
altsrc.NewStringFlag(&cli.StringFlag{Name: "firebase-key-file", Aliases: []string{"F"}, EnvVars: []string{"NTFY_FIREBASE_KEY_FILE"}, Usage: "Firebase credentials file; if set additionally publish to FCM topic"}),
altsrc.NewDurationFlag(&cli.DurationFlag{Name: "message-buffer-duration", Aliases: []string{"b"}, EnvVars: []string{"NTFY_MESSAGE_BUFFER_DURATION"}, Value: config.DefaultMessageBufferDuration, Usage: "buffer messages in memory for this time to allow `since` requests"}),
altsrc.NewDurationFlag(&cli.DurationFlag{Name: "keepalive-interval", Aliases: []string{"k"}, EnvVars: []string{"NTFY_KEEPALIVE_INTERVAL"}, Value: config.DefaultKeepaliveInterval, Usage: "default interval of keepalive messages"}),
altsrc.NewDurationFlag(&cli.DurationFlag{Name: "manager-interval", Aliases: []string{"m"}, EnvVars: []string{"NTFY_MANAGER_INTERVAL"}, Value: config.DefaultManagerInterval, Usage: "default interval of for message pruning and stats printing"}),
}
return &cli.App{
Name: "ntfy",
@ -41,17 +45,27 @@ func execRun(c *cli.Context) error {
// Read all the options
listenHTTP := c.String("listen-http")
firebaseKeyFile := c.String("firebase-key-file")
messageBufferDuration := c.Duration("message-buffer-duration")
keepaliveInterval := c.Duration("keepalive-interval")
managerInterval := c.Duration("manager-interval")
// Check values
if firebaseKeyFile != "" && !fileExists(firebaseKeyFile) {
if firebaseKeyFile != "" && !util.FileExists(firebaseKeyFile) {
return errors.New("if set, FCM key file must exist")
} else if keepaliveInterval < 5*time.Second {
return errors.New("keepalive interval cannot be lower than five seconds")
} else if managerInterval < 5*time.Second {
return errors.New("manager interval cannot be lower than five seconds")
} else if messageBufferDuration < managerInterval {
return errors.New("message buffer duration cannot be lower than manager interval")
}
// Run main bot, can be killed by signal
// Run server
conf := config.New(listenHTTP)
conf.FirebaseKeyFile = firebaseKeyFile
conf.MessageBufferDuration = messageBufferDuration
conf.KeepaliveInterval = keepaliveInterval
conf.ManagerInterval = managerInterval
s, err := server.New(conf)
if err != nil {
log.Fatalln(err)
@ -68,9 +82,9 @@ func execRun(c *cli.Context) error {
func initConfigFileInputSource(configFlag string, flags []cli.Flag) cli.BeforeFunc {
return func(context *cli.Context) error {
configFile := context.String(configFlag)
if context.IsSet(configFlag) && !fileExists(configFile) {
if context.IsSet(configFlag) && !util.FileExists(configFile) {
return fmt.Errorf("config file %s does not exist", configFile)
} else if !context.IsSet(configFlag) && !fileExists(configFile) {
} else if !context.IsSet(configFlag) && !util.FileExists(configFile) {
return nil
}
inputSource, err := altsrc.NewYamlSourceFromFile(configFile)
@ -80,8 +94,3 @@ func initConfigFileInputSource(configFlag string, flags []cli.Flag) cli.BeforeFu
return altsrc.ApplyInputSourceValues(context, inputSource, flags)
}
}
func fileExists(filename string) bool {
stat, _ := os.Stat(filename)
return stat != nil
}

15
config/config.go
View file

@ -9,8 +9,9 @@ import (
// Defines default config settings
const (
DefaultListenHTTP = ":80"
DefaultMessageBufferDuration = 12 * time.Hour
DefaultKeepaliveInterval = 30 * time.Second
defaultManagerInterval = time.Minute
DefaultManagerInterval = time.Minute
)
// Defines the max number of requests, here:
@ -23,21 +24,23 @@ var (
// Config is the main config struct for the application. Use New to instantiate a default config struct.
type Config struct {
ListenHTTP string
Limit rate.Limit
LimitBurst int
FirebaseKeyFile string
MessageBufferDuration time.Duration
KeepaliveInterval time.Duration
ManagerInterval time.Duration
Limit rate.Limit
LimitBurst int
}
// New instantiates a default new config
func New(listenHTTP string) *Config {
return &Config{
ListenHTTP: listenHTTP,
FirebaseKeyFile: "",
MessageBufferDuration: DefaultMessageBufferDuration,
KeepaliveInterval: DefaultKeepaliveInterval,
ManagerInterval: DefaultManagerInterval,
Limit: defaultLimit,
LimitBurst: defaultLimitBurst,
FirebaseKeyFile: "",
KeepaliveInterval: DefaultKeepaliveInterval,
ManagerInterval: defaultManagerInterval,
}
}

84
server/index.html
View file

@ -38,14 +38,31 @@
</p>
<p id="error"></p>
<h2>Publishing messages</h2>
<p>
Publishing messages can be done via PUT or POST using. Topics are created on the fly by subscribing or publishing to them.
Because there is no sign-up, <b>the topic is essentially a password</b>, so pick something that's not easily guessable.
</p>
<p class="smallMarginBottom">
Here's an example showing how to publish a message using <tt>curl</tt>:
</p>
<code>
curl -d "long process is done" ntfy.sh/mytopic
</code>
<p class="smallMarginBottom">
Here's an example in JS with <tt>fetch()</tt> (see <a href="https://github.com/binwiederhier/ntfy/tree/main/examples">full example</a>):
</p>
<code>
fetch('https://ntfy.sh/mytopic', {<br/>
&nbsp;&nbsp;method: 'POST', // PUT works too<br/>
&nbsp;&nbsp;body: 'Hello from the other side.'<br/>
})
</code>
<h2>Subscribe to a topic</h2>
<p>
Topics are created on the fly by subscribing to them. You can create and subscribe to a topic either in this web UI, or in
your own app by subscribing to an <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventSource">EventSource</a>,
a JSON feed, or raw feed.
</p>
<p>
Because there is no sign-up, <b>the topic is essentially a password</b>, so pick something that's not easily guessable.
You can create and subscribe to a topic either in this web UI, or in your own app by subscribing to an
<a href="https://developer.mozilla.org/en-US/docs/Web/API/EventSource">EventSource</a>, a JSON feed, or raw feed.
</p>
<h3>Subscribe via web</h3>
@ -66,7 +83,7 @@
<h3>Subscribe via your app, or via the CLI</h3>
<p class="smallMarginBottom">
Using <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventSource">EventSource</a>, you can consume
Using <a href="https://developer.mozilla.org/en-US/docs/Web/API/EventSource">EventSource</a> in JS, you can consume
notifications like this (see <a href="https://github.com/binwiederhier/ntfy/tree/main/examples">full example</a>):
</p>
<code>
@ -76,30 +93,29 @@
};
</code>
<p class="smallMarginBottom">
Or you can use <tt>curl</tt> or any other HTTP library. Here's an example for the <tt>/json</tt> endpoint,
which prints one JSON message per line (keepalive and open messages have an "event" field):
</p>
<code>
$ curl -s ntfy.sh/mytopic/json<br/>
{"time":1635359841,"event":"open"}<br/>
{"time":1635359844,"message":"This is a notification"}<br/>
{"time":1635359851,"event":"keepalive"}
</code>
<p class="smallMarginBottom">
Using the <tt>/sse</tt> endpoint (SSE, server-sent events stream):
You can also use the same <tt>/sse</tt> endpoint via <tt>curl</tt> or any other HTTP library:
</p>
<code>
$ curl -s ntfy.sh/mytopic/sse<br/>
event: open<br/>
data: {"time":1635359796,"event":"open"}<br/><br/>
data: {"id":"weSj9RtNkj","time":1635528898,"event":"open","topic":"mytopic"}<br/><br/>
data: {"time":1635359803,"message":"This is a notification"}<br/><br/>
data: {"id":"p0M5y6gcCY","time":1635528909,"event":"message","topic":"mytopic","message":"Hi!"}<br/><br/>
event: keepalive<br/>
data: {"time":1635359806,"event":"keepalive"}
data: {"id":"VNxNIg5fpt","time":1635528928,"event":"keepalive","topic":"test"}
</code>
<p class="smallMarginBottom">
Using the <tt>/raw</tt> endpoint (empty lines are keepalive messages):
To consume JSON instead, use the <tt>/json</tt> endpoint, which prints one message per line:
</p>
<code>
$ curl -s ntfy.sh/mytopic/json<br/>
{"id":"SLiKI64DOt","time":1635528757,"event":"open","topic":"mytopic"}<br/>
{"id":"hwQ2YpKdmg","time":1635528741,"event":"message","topic":"mytopic","message":"Hi!"}<br/>
{"id":"DGUDShMCsc","time":1635528787,"event":"keepalive","topic":"mytopic"}
</code>
<p class="smallMarginBottom">
Or use the <tt>/raw</tt> endpoint if you need something super simple (empty lines are keepalive messages):
</p>
<code>
$ curl -s ntfy.sh/mytopic/raw<br/>
@ -107,27 +123,25 @@
This is a notification
</code>
<h2>Publishing messages</h2>
<h3>Message buffering and polling</h3>
<p class="smallMarginBottom">
Publishing messages can be done via PUT or POST using. Here's an example using <tt>curl</tt>:
Messages are buffered in memory for a few hours to account for network interruptions of subscribers.
You can read back what you missed by using the <tt>since=...</tt> query parameter. It takes either a
duration (e.g. <tt>10m</tt> or <tt>30s</tt>) or a Unix timestamp (e.g. <tt>1635528757</tt>):
</p>
<code>
curl -d "long process is done" ntfy.sh/mytopic
$ curl -s "ntfy.sh/mytopic/json?since=10m"<br/>
# Same output as above, but includes messages from up to 10 minutes ago
</code>
<p class="smallMarginBottom">
Here's an example in JS with <tt>fetch()</tt> (see <a href="https://github.com/binwiederhier/ntfy/tree/main/examples">full example</a>):
You can also just poll for messages if you don't like the long-standing connection using the <tt>poll=1</tt>
query parameter. The connection will end after all available messages have been read. This parameter has to be
combined with <tt>since=</tt>.
</p>
<code>
fetch('https://ntfy.sh/mytopic', {<br/>
&nbsp;&nbsp;method: 'POST', // PUT works too<br/>
&nbsp;&nbsp;body: 'Hello from the other side.'<br/>
})
$ curl -s "ntfy.sh/mytopic/json?poll=1&since=10m"<br/>
# Returns messages from up to 10 minutes ago and ends the connection
</code>
<p>
Messages published to a non-existing topic or a topic without subscribers will not be delivered later.
There is (currently) no buffering of any kind. If you're not listening, the message won't be delivered.
</p>
<h2>FAQ</h2>
<p>
<b>Isn't this like ...?</b><br/>

29
server/message.go
View file

@ -1,6 +1,9 @@
package server
import "time"
import (
"heckel.io/ntfy/util"
"time"
)
// List of possible events
const (
@ -9,10 +12,16 @@ const (
messageEvent = "message"
)
const (
messageIDLength = 10
)
// message represents a message published to a topic
type message struct {
ID string `json:"id"` // Random message ID
Time int64 `json:"time"` // Unix time in seconds
Event string `json:"event,omitempty"` // One of the above
Event string `json:"event"` // One of the above
Topic string `json:"topic"`
Message string `json:"message,omitempty"`
}
@ -20,25 +29,27 @@ type message struct {
type messageEncoder func(msg *message) (string, error)
// newMessage creates a new message with the current timestamp
func newMessage(event string, msg string) *message {
func newMessage(event, topic, msg string) *message {
return &message{
ID: util.RandomString(messageIDLength),
Time: time.Now().Unix(),
Event: event,
Topic: topic,
Message: msg,
}
}
// newOpenMessage is a convenience method to create an open message
func newOpenMessage() *message {
return newMessage(openEvent, "")
func newOpenMessage(topic string) *message {
return newMessage(openEvent, topic, "")
}
// newKeepaliveMessage is a convenience method to create a keepalive message
func newKeepaliveMessage() *message {
return newMessage(keepaliveEvent, "")
func newKeepaliveMessage(topic string) *message {
return newMessage(keepaliveEvent, topic, "")
}
// newDefaultMessage is a convenience method to create a notification message
func newDefaultMessage(msg string) *message {
return newMessage(messageEvent, msg)
func newDefaultMessage(topic, msg string) *message {
return newMessage(messageEvent, topic, msg)
}

199
server/server.go
View file

@ -17,17 +17,23 @@ import (
"net"
"net/http"
"regexp"
"strconv"
"strings"
"sync"
"time"
)
// TODO add "max connections open" limit
// TODO add "max messages in a topic" limit
// TODO add "max topics" limit
// Server is the main server
type Server struct {
config *config.Config
topics map[string]*topic
visitors map[string]*visitor
firebase *messaging.Client
firebase subscriber
messages int64
mu sync.Mutex
}
@ -57,6 +63,7 @@ var (
jsonRegex = regexp.MustCompile(`^/[^/]+/json$`)
sseRegex = regexp.MustCompile(`^/[^/]+/sse$`)
rawRegex = regexp.MustCompile(`^/[^/]+/raw$`)
staticRegex = regexp.MustCompile(`^/static/.+`)
//go:embed "index.html"
@ -65,30 +72,57 @@ var (
//go:embed static
webStaticFs embed.FS
errHTTPBadRequest = &errHTTP{http.StatusBadRequest, http.StatusText(http.StatusBadRequest)}
errHTTPNotFound = &errHTTP{http.StatusNotFound, http.StatusText(http.StatusNotFound)}
errHTTPTooManyRequests = &errHTTP{http.StatusTooManyRequests, http.StatusText(http.StatusTooManyRequests)}
)
func New(conf *config.Config) (*Server, error) {
var fcm *messaging.Client
var firebaseSubscriber subscriber
if conf.FirebaseKeyFile != "" {
fb, err := firebase.NewApp(context.Background(), nil, option.WithCredentialsFile(conf.FirebaseKeyFile))
if err != nil {
return nil, err
}
fcm, err = fb.Messaging(context.Background())
var err error
firebaseSubscriber, err = createFirebaseSubscriber(conf)
if err != nil {
return nil, err
}
}
return &Server{
config: conf,
firebase: fcm,
firebase: firebaseSubscriber,
topics: make(map[string]*topic),
visitors: make(map[string]*visitor),
}, nil
}
func createFirebaseSubscriber(conf *config.Config) (subscriber, error) {
fb, err := firebase.NewApp(context.Background(), nil, option.WithCredentialsFile(conf.FirebaseKeyFile))
if err != nil {
return nil, err
}
msg, err := fb.Messaging(context.Background())
if err != nil {
return nil, err
}
return func(m *message) error {
_, err := msg.Send(context.Background(), &messaging.Message{
Data: map[string]string{
"id": m.ID,
"time": fmt.Sprintf("%d", m.Time),
"event": m.Event,
"topic": m.Topic,
"message": m.Message,
},
Notification: &messaging.Notification{
Title: m.Topic, // FIXME convert to ntfy.sh/$topic instead
Body: m.Message,
ImageURL: "",
},
Topic: m.Topic,
})
return err
}, nil
}
func (s *Server) Run() error {
go func() {
ticker := time.NewTicker(s.config.ManagerInterval)
@ -106,28 +140,6 @@ func (s *Server) listenAndServe() error {
return http.ListenAndServe(s.config.ListenHTTP, nil)
}
func (s *Server) updateStatsAndExpire() {
s.mu.Lock()
defer s.mu.Unlock()
// Expire visitors from rate visitors map
for ip, v := range s.visitors {
if time.Since(v.seen) > visitorExpungeAfter {
delete(s.visitors, ip)
}
}
// Print stats
var subscribers, messages int
for _, t := range s.topics {
subs, msgs := t.Stats()
subscribers += subs
messages += msgs
}
log.Printf("Stats: %d topic(s), %d subscriber(s), %d message(s) sent, %d visitor(s)",
len(s.topics), subscribers, messages, len(s.visitors))
}
func (s *Server) handle(w http.ResponseWriter, r *http.Request) {
if err := s.handleInternal(w, r); err != nil {
if e, ok := err.(*errHTTP); ok {
@ -147,14 +159,14 @@ func (s *Server) handleInternal(w http.ResponseWriter, r *http.Request) error {
return s.handleHome(w, r)
} else if r.Method == http.MethodGet && staticRegex.MatchString(r.URL.Path) {
return s.handleStatic(w, r)
} else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && topicRegex.MatchString(r.URL.Path) {
return s.handlePublish(w, r)
} else if r.Method == http.MethodGet && jsonRegex.MatchString(r.URL.Path) {
return s.handleSubscribeJSON(w, r)
} else if r.Method == http.MethodGet && sseRegex.MatchString(r.URL.Path) {
return s.handleSubscribeSSE(w, r)
} else if r.Method == http.MethodGet && rawRegex.MatchString(r.URL.Path) {
return s.handleSubscribeRaw(w, r)
} else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && topicRegex.MatchString(r.URL.Path) {
return s.handlePublishHTTP(w, r)
} else if r.Method == http.MethodOptions {
return s.handleOptions(w, r)
}
@ -166,42 +178,28 @@ func (s *Server) handleHome(w http.ResponseWriter, r *http.Request) error {
return err
}
func (s *Server) handlePublishHTTP(w http.ResponseWriter, r *http.Request) error {
t, err := s.topic(r.URL.Path[1:])
if err != nil {
return err
}
func (s *Server) handleStatic(w http.ResponseWriter, r *http.Request) error {
http.FileServer(http.FS(webStaticFs)).ServeHTTP(w, r)
return nil
}
func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request) error {
t := s.createTopic(r.URL.Path[1:])
reader := io.LimitReader(r.Body, messageLimit)
b, err := io.ReadAll(reader)
if err != nil {
return err
}
if err := t.Publish(newDefaultMessage(string(b))); err != nil {
return err
}
if err := s.maybePublishFirebase(t.id, string(b)); err != nil {
if err := t.Publish(newDefaultMessage(t.id, string(b))); err != nil {
return err
}
w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
s.mu.Lock()
s.messages++
s.mu.Unlock()
return nil
}
func (s *Server) maybePublishFirebase(topic, message string) error {
_, err := s.firebase.Send(context.Background(), &messaging.Message{
Data: map[string]string{
"topic": topic,
"message": message,
},
Notification: &messaging.Notification{
Title: "ntfy.sh/" + topic,
Body: message,
ImageURL: "",
},
Topic: topic,
})
return err
}
func (s *Server) handleSubscribeJSON(w http.ResponseWriter, r *http.Request) error {
encoder := func(msg *message) (string, error) {
var buf bytes.Buffer
@ -239,6 +237,11 @@ func (s *Server) handleSubscribeRaw(w http.ResponseWriter, r *http.Request) erro
func (s *Server) handleSubscribe(w http.ResponseWriter, r *http.Request, format string, contentType string, encoder messageEncoder) error {
t := s.createTopic(strings.TrimSuffix(r.URL.Path[1:], "/"+format)) // Hack
since, err := parseSince(r)
if err != nil {
return err
}
poll := r.URL.Query().Has("poll")
sub := func(msg *message) error {
m, err := encoder(msg)
if err != nil {
@ -252,11 +255,17 @@ func (s *Server) handleSubscribe(w http.ResponseWriter, r *http.Request, format
}
return nil
}
subscriberID := t.Subscribe(sub)
defer s.unsubscribe(t, subscriberID)
w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
w.Header().Set("Content-Type", contentType)
if err := sub(newOpenMessage()); err != nil { // Send out open message
if poll {
return sendOldMessages(t, since, sub)
}
subscriberID := t.Subscribe(sub)
defer t.Unsubscribe(subscriberID)
if err := sub(newOpenMessage(t.id)); err != nil { // Send out open message
return err
}
if err := sendOldMessages(t, since, sub); err != nil {
return err
}
for {
@ -266,49 +275,85 @@ func (s *Server) handleSubscribe(w http.ResponseWriter, r *http.Request, format
case <-r.Context().Done():
return nil
case <-time.After(s.config.KeepaliveInterval):
if err := sub(newKeepaliveMessage()); err != nil { // Send keepalive message
if err := sub(newKeepaliveMessage(t.id)); err != nil { // Send keepalive message
return err
}
}
}
}
func sendOldMessages(t *topic, since time.Time, sub subscriber) error {
if since.IsZero() {
return nil
}
for _, m := range t.Messages(since) {
if err := sub(m); err != nil {
return err
}
}
return nil
}
func parseSince(r *http.Request) (time.Time, error) {
if !r.URL.Query().Has("since") {
return time.Time{}, nil
}
if since, err := strconv.ParseInt(r.URL.Query().Get("since"), 10, 64); err == nil {
return time.Unix(since, 0), nil
}
if d, err := time.ParseDuration(r.URL.Query().Get("since")); err == nil {
return time.Now().Add(-1 * d), nil
}
return time.Time{}, errHTTPBadRequest
}
func (s *Server) handleOptions(w http.ResponseWriter, r *http.Request) error {
w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
w.Header().Set("Access-Control-Allow-Methods", "GET, PUT, POST")
return nil
}
func (s *Server) handleStatic(w http.ResponseWriter, r *http.Request) error {
http.FileServer(http.FS(webStaticFs)).ServeHTTP(w, r)
return nil
}
func (s *Server) createTopic(id string) *topic {
s.mu.Lock()
defer s.mu.Unlock()
if _, ok := s.topics[id]; !ok {
s.topics[id] = newTopic(id)
if s.firebase != nil {
s.topics[id].Subscribe(s.firebase)
}
}
return s.topics[id]
}
func (s *Server) topic(topicID string) (*topic, error) {
func (s *Server) updateStatsAndExpire() {
s.mu.Lock()
defer s.mu.Unlock()
c, ok := s.topics[topicID]
if !ok {
return nil, errHTTPNotFound
}
return c, nil
}
func (s *Server) unsubscribe(t *topic, subscriberID int) {
s.mu.Lock()
defer s.mu.Unlock()
if subscribers := t.Unsubscribe(subscriberID); subscribers == 0 {
// Expire visitors from rate visitors map
for ip, v := range s.visitors {
if time.Since(v.seen) > visitorExpungeAfter {
delete(s.visitors, ip)
}
}
// Prune old messages, remove topics without subscribers
for _, t := range s.topics {
t.Prune(s.config.MessageBufferDuration)
subs, msgs := t.Stats()
if msgs == 0 && (subs == 0 || (s.firebase != nil && subs == 1)) {
delete(s.topics, t.id)
}
}
// Print stats
var subscribers, messages int
for _, t := range s.topics {
subs, msgs := t.Stats()
subscribers += subs
messages += msgs
}
log.Printf("Stats: %d message(s) published, %d topic(s) active, %d subscriber(s), %d message(s) buffered, %d visitor(s)",
s.messages, len(s.topics), subscribers, messages, len(s.visitors))
}
// visitor creates or retrieves a rate.Limiter for the given visitor.

39
server/topic.go
View file

@ -2,7 +2,6 @@ package server
import (
"context"
"errors"
"log"
"math/rand"
"sync"
@ -14,7 +13,7 @@ import (
type topic struct {
id string
subscribers map[int]subscriber
messages int
messages []*message
last time.Time
ctx context.Context
cancel context.CancelFunc
@ -45,21 +44,17 @@ func (t *topic) Subscribe(s subscriber) int {
return subscriberID
}
func (t *topic) Unsubscribe(id int) int {
func (t *topic) Unsubscribe(id int) {
t.mu.Lock()
defer t.mu.Unlock()
delete(t.subscribers, id)
return len(t.subscribers)
}
func (t *topic) Publish(m *message) error {
t.mu.Lock()
defer t.mu.Unlock()
if len(t.subscribers) == 0 {
return errors.New("no subscribers")
}
t.last = time.Now()
t.messages++
t.messages = append(t.messages, m)
for _, s := range t.subscribers {
if err := s(m); err != nil {
log.Printf("error publishing message to subscriber")
@ -68,10 +63,36 @@ func (t *topic) Publish(m *message) error {
return nil
}
func (t *topic) Messages(since time.Time) []*message {
t.mu.Lock()
defer t.mu.Unlock()
messages := make([]*message, 0) // copy!
for _, m := range t.messages {
msgTime := time.Unix(m.Time, 0)
if msgTime == since || msgTime.After(since) {
messages = append(messages, m)
}
}
return messages
}
func (t *topic) Prune(keep time.Duration) {
t.mu.Lock()
defer t.mu.Unlock()
for i, m := range t.messages {
msgTime := time.Unix(m.Time, 0)
if time.Since(msgTime) < keep {
t.messages = t.messages[i:]
return
}
}
t.messages = make([]*message, 0)
}
func (t *topic) Stats() (subscribers int, messages int) {
t.mu.Lock()
defer t.mu.Unlock()
return len(t.subscribers), t.messages
return len(t.subscribers), len(t.messages)
}
func (t *topic) Close() {

29
util/util.go Normal file
View file

@ -0,0 +1,29 @@
package util
import (
"math/rand"
"os"
"time"
)
const (
randomStringCharset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
)
var (
random = rand.New(rand.NewSource(time.Now().UnixNano()))
)
func FileExists(filename string) bool {
stat, _ := os.Stat(filename)
return stat != nil
}
// RandomString returns a random string with a given length
func RandomString(length int) string {
b := make([]byte, length)
for i := range b {
b[i] = randomStringCharset[random.Intn(len(randomStringCharset))]
}
return string(b)
}