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-rw-r--r--vendor/github.com/gopackage/ddp/ddp_client.go654
1 files changed, 654 insertions, 0 deletions
diff --git a/vendor/github.com/gopackage/ddp/ddp_client.go b/vendor/github.com/gopackage/ddp/ddp_client.go
new file mode 100644
index 00000000..8d6323b7
--- /dev/null
+++ b/vendor/github.com/gopackage/ddp/ddp_client.go
@@ -0,0 +1,654 @@
+package ddp
+
+import (
+ "encoding/json"
+ "fmt"
+ "io"
+ "log"
+ "sync"
+ "time"
+
+ "golang.org/x/net/websocket"
+ "errors"
+)
+
+const (
+ DISCONNECTED = iota
+ DIALING
+ CONNECTING
+ CONNECTED
+)
+
+type ConnectionListener interface {
+ Connected()
+}
+
+type ConnectionNotifier interface {
+ AddConnectionListener(listener ConnectionListener)
+}
+
+type StatusListener interface {
+ Status(status int)
+}
+
+type StatusNotifier interface {
+ AddStatusListener(listener StatusListener)
+}
+
+// Client represents a DDP client connection. The DDP client establish a DDP
+// session and acts as a message pump for other tools.
+type Client struct {
+ // HeartbeatInterval is the time between heartbeats to send
+ HeartbeatInterval time.Duration
+ // HeartbeatTimeout is the time for a heartbeat ping to timeout
+ HeartbeatTimeout time.Duration
+ // ReconnectInterval is the time between reconnections on bad connections
+ ReconnectInterval time.Duration
+
+ // writeStats controls statistics gathering for current websocket writes.
+ writeSocketStats *WriterStats
+ // writeStats controls statistics gathering for overall client writes.
+ writeStats *WriterStats
+ // writeLog controls logging for client writes.
+ writeLog *WriterLogger
+ // readStats controls statistics gathering for current websocket reads.
+ readSocketStats *ReaderStats
+ // readStats controls statistics gathering for overall client reads.
+ readStats *ReaderStats
+ // readLog control logging for clietn reads.
+ readLog *ReaderLogger
+ // reconnects in the number of reconnections the client has made
+ reconnects int64
+ // pingsIn is the number of pings received from the server
+ pingsIn int64
+ // pingsOut is te number of pings sent by the client
+ pingsOut int64
+
+ // session contains the DDP session token (can be used for reconnects and debugging).
+ session string
+ // version contains the negotiated DDP protocol version in use.
+ version string
+ // serverID the cluster node ID for the server we connected to
+ serverID string
+ // ws is the underlying websocket being used.
+ ws *websocket.Conn
+ // encoder is a JSON encoder to send outgoing packets to the websocket.
+ encoder *json.Encoder
+ // url the URL the websocket is connected to
+ url string
+ // origin is the origin for the websocket connection
+ origin string
+ // inbox is an incoming message channel
+ inbox chan map[string]interface{}
+ // errors is an incoming errors channel
+ errors chan error
+ // pingTimer is a timer for sending regular pings to the server
+ pingTimer *time.Timer
+ // pings tracks inflight pings based on each ping ID.
+ pings map[string][]*pingTracker
+ // calls tracks method invocations that are still in flight
+ calls map[string]*Call
+ // subs tracks active subscriptions. Map contains name->args
+ subs map[string]*Call
+ // collections contains all the collections currently subscribed
+ collections map[string]Collection
+ // connectionStatus is the current connection status of the client
+ connectionStatus int
+ // reconnectTimer is the timer tracking reconnections
+ reconnectTimer *time.Timer
+ // reconnectLock protects access to reconnection
+ reconnectLock *sync.Mutex
+
+ // statusListeners will be informed when the connection status of the client changes
+ statusListeners []StatusListener
+ // connectionListeners will be informed when a connection to the server is established
+ connectionListeners []ConnectionListener
+
+ // idManager tracks IDs for ddp messages
+ idManager
+}
+
+// NewClient creates a default client (using an internal websocket) to the
+// provided URL using the origin for the connection. The client will
+// automatically connect, upgrade to a websocket, and establish a DDP
+// connection session before returning the client. The client will
+// automatically and internally handle heartbeats and reconnects.
+//
+// TBD create an option to use an external websocket (aka htt.Transport)
+// TBD create an option to substitute heartbeat and reconnect behavior (aka http.Tranport)
+// TBD create an option to hijack the connection (aka http.Hijacker)
+// TBD create profiling features (aka net/http/pprof)
+func NewClient(url, origin string) *Client {
+ c := &Client{
+ HeartbeatInterval: time.Minute, // Meteor impl default + 10 (we ping last)
+ HeartbeatTimeout: 15 * time.Second, // Meteor impl default
+ ReconnectInterval: 5 * time.Second,
+ collections: map[string]Collection{},
+ url: url,
+ origin: origin,
+ inbox: make(chan map[string]interface{}, 100),
+ errors: make(chan error, 100),
+ pings: map[string][]*pingTracker{},
+ calls: map[string]*Call{},
+ subs: map[string]*Call{},
+ connectionStatus: DISCONNECTED,
+ reconnectLock: &sync.Mutex{},
+
+ // Stats
+ writeSocketStats: NewWriterStats(nil),
+ writeStats: NewWriterStats(nil),
+ readSocketStats: NewReaderStats(nil),
+ readStats: NewReaderStats(nil),
+
+ // Loggers
+ writeLog: NewWriterTextLogger(nil),
+ readLog: NewReaderTextLogger(nil),
+
+ idManager: *newidManager(),
+ }
+ c.encoder = json.NewEncoder(c.writeStats)
+ c.SetSocketLogActive(false)
+
+ // We spin off an inbox processing goroutine
+ go c.inboxManager()
+
+ return c
+}
+
+// Session returns the negotiated session token for the connection.
+func (c *Client) Session() string {
+ return c.session
+}
+
+// Version returns the negotiated protocol version in use by the client.
+func (c *Client) Version() string {
+ return c.version
+}
+
+// AddStatusListener in order to receive status change updates.
+func (c *Client) AddStatusListener(listener StatusListener) {
+ c.statusListeners = append(c.statusListeners, listener)
+}
+
+// AddConnectionListener in order to receive connection updates.
+func (c *Client) AddConnectionListener(listener ConnectionListener) {
+ c.connectionListeners = append(c.connectionListeners, listener)
+}
+
+// status updates all status listeners with the new client status.
+func (c *Client) status(status int) {
+ if c.connectionStatus == status {
+ return
+ }
+ c.connectionStatus = status
+ for _, listener := range c.statusListeners {
+ listener.Status(status)
+ }
+}
+
+// Connect attempts to connect the client to the server.
+func (c *Client) Connect() error {
+ c.status(DIALING)
+ ws, err := websocket.Dial(c.url, "", c.origin)
+ if err != nil {
+ c.Close()
+ log.Println("Dial error", err)
+ c.reconnectLater()
+ return err
+ }
+ // Start DDP connection
+ c.start(ws, NewConnect())
+ return nil
+}
+
+// Reconnect attempts to reconnect the client to the server on the existing
+// DDP session.
+//
+// TODO needs a reconnect backoff so we don't trash a down server
+// TODO reconnect should not allow more reconnects while a reconnection is already in progress.
+func (c *Client) Reconnect() {
+ func() {
+ c.reconnectLock.Lock()
+ defer c.reconnectLock.Unlock()
+ if c.reconnectTimer != nil {
+ c.reconnectTimer.Stop()
+ c.reconnectTimer = nil
+ }
+ }()
+
+ c.Close()
+
+ c.reconnects++
+
+ // Reconnect
+ c.status(DIALING)
+ ws, err := websocket.Dial(c.url, "", c.origin)
+ if err != nil {
+ c.Close()
+ log.Println("Dial error", err)
+ c.reconnectLater()
+ return
+ }
+
+ c.start(ws, NewReconnect(c.session))
+
+ // --------------------------------------------------------------------
+ // We resume inflight or ongoing subscriptions - we don't have to wait
+ // for connection confirmation (messages can be pipelined).
+ // --------------------------------------------------------------------
+
+ // Send calls that haven't been confirmed - may not have been sent
+ // and effects should be idempotent
+ for _, call := range c.calls {
+ c.Send(NewMethod(call.ID, call.ServiceMethod, call.Args.([]interface{})))
+ }
+
+ // Resend subscriptions and patch up collections
+ for _, sub := range c.subs {
+ c.Send(NewSub(sub.ID, sub.ServiceMethod, sub.Args.([]interface{})))
+ }
+}
+
+// Subscribe subscribes to data updates.
+func (c *Client) Subscribe(subName string, done chan *Call, args ...interface{}) *Call {
+
+ if args == nil {
+ args = []interface{}{}
+ }
+ call := new(Call)
+ call.ID = c.newID()
+ call.ServiceMethod = subName
+ call.Args = args
+ call.Owner = c
+
+ if done == nil {
+ done = make(chan *Call, 10) // buffered.
+ } else {
+ // If caller passes done != nil, it must arrange that
+ // done has enough buffer for the number of simultaneous
+ // RPCs that will be using that channel. If the channel
+ // is totally unbuffered, it's best not to run at all.
+ if cap(done) == 0 {
+ log.Panic("ddp.rpc: done channel is unbuffered")
+ }
+ }
+ call.Done = done
+ c.subs[call.ID] = call
+
+ // Save this subscription to the client so we can reconnect
+ subArgs := make([]interface{}, len(args))
+ copy(subArgs, args)
+
+ c.Send(NewSub(call.ID, subName, args))
+
+ return call
+}
+
+// Sub sends a synchronous subscription request to the server.
+func (c *Client) Sub(subName string, args ...interface{}) error {
+ call := <-c.Subscribe(subName, make(chan *Call, 1), args...).Done
+ return call.Error
+}
+
+// Go invokes the function asynchronously. It returns the Call structure representing
+// the invocation. The done channel will signal when the call is complete by returning
+// the same Call object. If done is nil, Go will allocate a new channel.
+// If non-nil, done must be buffered or Go will deliberately crash.
+//
+// Go and Call are modeled after the standard `net/rpc` package versions.
+func (c *Client) Go(serviceMethod string, done chan *Call, args ...interface{}) *Call {
+
+ if args == nil {
+ args = []interface{}{}
+ }
+ call := new(Call)
+ call.ID = c.newID()
+ call.ServiceMethod = serviceMethod
+ call.Args = args
+ call.Owner = c
+ if done == nil {
+ done = make(chan *Call, 10) // buffered.
+ } else {
+ // If caller passes done != nil, it must arrange that
+ // done has enough buffer for the number of simultaneous
+ // RPCs that will be using that channel. If the channel
+ // is totally unbuffered, it's best not to run at all.
+ if cap(done) == 0 {
+ log.Panic("ddp.rpc: done channel is unbuffered")
+ }
+ }
+ call.Done = done
+ c.calls[call.ID] = call
+
+ c.Send(NewMethod(call.ID, serviceMethod, args))
+
+ return call
+}
+
+// Call invokes the named function, waits for it to complete, and returns its error status.
+func (c *Client) Call(serviceMethod string, args ...interface{}) (interface{}, error) {
+ call := <-c.Go(serviceMethod, make(chan *Call, 1), args...).Done
+ return call.Reply, call.Error
+}
+
+// Ping sends a heartbeat signal to the server. The Ping doesn't look for
+// a response but may trigger the connection to reconnect if the ping timesout.
+// This is primarily useful for reviving an unresponsive Client connection.
+func (c *Client) Ping() {
+ c.PingPong(c.newID(), c.HeartbeatTimeout, func(err error) {
+ if err != nil {
+ // Is there anything else we should or can do?
+ c.reconnectLater()
+ }
+ })
+}
+
+// PingPong sends a heartbeat signal to the server and calls the provided
+// function when a pong is received. An optional id can be sent to help
+// track the responses - or an empty string can be used. It is the
+// responsibility of the caller to respond to any errors that may occur.
+func (c *Client) PingPong(id string, timeout time.Duration, handler func(error)) {
+ err := c.Send(NewPing(id))
+ if err != nil {
+ handler(err)
+ return
+ }
+ c.pingsOut++
+ pings, ok := c.pings[id]
+ if !ok {
+ pings = make([]*pingTracker, 0, 5)
+ }
+ tracker := &pingTracker{handler: handler, timeout: timeout, timer: time.AfterFunc(timeout, func() {
+ handler(fmt.Errorf("ping timeout"))
+ })}
+ c.pings[id] = append(pings, tracker)
+}
+
+// Send transmits messages to the server. The msg parameter must be json
+// encoder compatible.
+func (c *Client) Send(msg interface{}) error {
+ return c.encoder.Encode(msg)
+}
+
+// Close implements the io.Closer interface.
+func (c *Client) Close() {
+ // Shutdown out all outstanding pings
+ if c.pingTimer != nil {
+ c.pingTimer.Stop()
+ c.pingTimer = nil
+ }
+
+ // Close websocket
+ if c.ws != nil {
+ c.ws.Close()
+ c.ws = nil
+ }
+ for _, collection := range c.collections {
+ collection.reset()
+ }
+ c.status(DISCONNECTED)
+}
+
+// ResetStats resets the statistics for the client.
+func (c *Client) ResetStats() {
+ c.readSocketStats.Reset()
+ c.readStats.Reset()
+ c.writeSocketStats.Reset()
+ c.writeStats.Reset()
+ c.reconnects = 0
+ c.pingsIn = 0
+ c.pingsOut = 0
+}
+
+// Stats returns the read and write statistics of the client.
+func (c *Client) Stats() *ClientStats {
+ return &ClientStats{
+ Reads: c.readSocketStats.Snapshot(),
+ TotalReads: c.readStats.Snapshot(),
+ Writes: c.writeSocketStats.Snapshot(),
+ TotalWrites: c.writeStats.Snapshot(),
+ Reconnects: c.reconnects,
+ PingsSent: c.pingsOut,
+ PingsRecv: c.pingsIn,
+ }
+}
+
+// SocketLogActive returns the current logging status for the socket.
+func (c *Client) SocketLogActive() bool {
+ return c.writeLog.Active
+}
+
+// SetSocketLogActive to true to enable logging of raw socket data.
+func (c *Client) SetSocketLogActive(active bool) {
+ c.writeLog.Active = active
+ c.readLog.Active = active
+}
+
+// CollectionByName retrieves a collection by it's name.
+func (c *Client) CollectionByName(name string) Collection {
+ collection, ok := c.collections[name]
+ if !ok {
+ collection = NewCollection(name)
+ c.collections[name] = collection
+ }
+ return collection
+}
+
+// CollectionStats returns a snapshot of statistics for the currently known collections.
+func (c *Client) CollectionStats() []CollectionStats {
+ stats := make([]CollectionStats, 0, len(c.collections))
+ for name, collection := range c.collections {
+ stats = append(stats, CollectionStats{Name: name, Count: len(collection.FindAll())})
+ }
+ return stats
+}
+
+// start starts a new client connection on the provided websocket
+func (c *Client) start(ws *websocket.Conn, connect *Connect) {
+
+ c.status(CONNECTING)
+
+ c.ws = ws
+ c.writeLog.SetWriter(ws)
+ c.writeSocketStats = NewWriterStats(c.writeLog)
+ c.writeStats.SetWriter(c.writeSocketStats)
+ c.readLog.SetReader(ws)
+ c.readSocketStats = NewReaderStats(c.readLog)
+ c.readStats.SetReader(c.readSocketStats)
+
+ // We spin off an inbox stuffing goroutine
+ go c.inboxWorker(c.readStats)
+
+ c.Send(connect)
+}
+
+// inboxManager pulls messages from the inbox and routes them to appropriate
+// handlers.
+func (c *Client) inboxManager() {
+ for {
+ select {
+ case msg := <-c.inbox:
+ // Message!
+ //log.Println("Got message", msg)
+ mtype, ok := msg["msg"]
+ if ok {
+ switch mtype.(string) {
+ // Connection management
+ case "connected":
+ c.status(CONNECTED)
+ for _, collection := range c.collections {
+ collection.init()
+ }
+ c.version = "1" // Currently the only version we support
+ c.session = msg["session"].(string)
+ // Start automatic heartbeats
+ c.pingTimer = time.AfterFunc(c.HeartbeatInterval, func() {
+ c.Ping()
+ c.pingTimer.Reset(c.HeartbeatInterval)
+ })
+ // Notify connection listeners
+ for _, listener := range c.connectionListeners {
+ go listener.Connected()
+ }
+ case "failed":
+ log.Fatalf("IM Failed to connect, we support version 1 but server supports %s", msg["version"])
+
+ // Heartbeats
+ case "ping":
+ // We received a ping - need to respond with a pong
+ id, ok := msg["id"]
+ if ok {
+ c.Send(NewPong(id.(string)))
+ } else {
+ c.Send(NewPong(""))
+ }
+ c.pingsIn++
+ case "pong":
+ // We received a pong - we can clear the ping tracker and call its handler
+ id, ok := msg["id"]
+ var key string
+ if ok {
+ key = id.(string)
+ }
+ pings, ok := c.pings[key]
+ if ok && len(pings) > 0 {
+ ping := pings[0]
+ pings = pings[1:]
+ if len(key) == 0 || len(pings) > 0 {
+ c.pings[key] = pings
+ }
+ ping.timer.Stop()
+ ping.handler(nil)
+ }
+
+ // Live Data
+ case "nosub":
+ log.Println("Subscription returned a nosub error", msg)
+ // Clear related subscriptions
+ sub, ok := msg["id"]
+ if ok {
+ id := sub.(string)
+ runningSub := c.subs[id]
+
+ if runningSub != nil {
+ runningSub.Error = errors.New("Subscription returned a nosub error")
+ runningSub.done()
+ delete(c.subs, id)
+ }
+ }
+ case "ready":
+ // Run 'done' callbacks on all ready subscriptions
+ subs, ok := msg["subs"]
+ if ok {
+ for _, sub := range subs.([]interface{}) {
+ call, ok := c.subs[sub.(string)]
+ if ok {
+ call.done()
+ }
+ }
+ }
+ case "added":
+ c.collectionBy(msg).added(msg)
+ case "changed":
+ c.collectionBy(msg).changed(msg)
+ case "removed":
+ c.collectionBy(msg).removed(msg)
+ case "addedBefore":
+ c.collectionBy(msg).addedBefore(msg)
+ case "movedBefore":
+ c.collectionBy(msg).movedBefore(msg)
+
+ // RPC
+ case "result":
+ id, ok := msg["id"]
+ if ok {
+ call := c.calls[id.(string)]
+ delete(c.calls, id.(string))
+ e, ok := msg["error"]
+ if ok {
+ txt, _ := json.Marshal(e)
+ call.Error = fmt.Errorf(string(txt))
+ call.Reply = e
+ } else {
+ call.Reply = msg["result"]
+ }
+ call.done()
+ }
+ case "updated":
+ // We currently don't do anything with updated status
+
+ default:
+ // Ignore?
+ log.Println("Server sent unexpected message", msg)
+ }
+ } else {
+ // Current Meteor server sends an undocumented DDP message
+ // (looks like clustering "hint"). We will register and
+ // ignore rather than log an error.
+ serverID, ok := msg["server_id"]
+ if ok {
+ switch ID := serverID.(type) {
+ case string:
+ c.serverID = ID
+ default:
+ log.Println("Server cluster node", serverID)
+ }
+ } else {
+ log.Println("Server sent message with no `msg` field", msg)
+ }
+ }
+ case err := <-c.errors:
+ log.Println("Websocket error", err)
+ }
+ }
+}
+
+func (c *Client) collectionBy(msg map[string]interface{}) Collection {
+ n, ok := msg["collection"]
+ if !ok {
+ return NewMockCollection()
+ }
+ switch name := n.(type) {
+ case string:
+ return c.CollectionByName(name)
+ default:
+ return NewMockCollection()
+ }
+}
+
+// inboxWorker pulls messages from a websocket, decodes JSON packets, and
+// stuffs them into a message channel.
+func (c *Client) inboxWorker(ws io.Reader) {
+ dec := json.NewDecoder(ws)
+ for {
+ var event interface{}
+
+ if err := dec.Decode(&event); err == io.EOF {
+ break
+ } else if err != nil {
+ c.errors <- err
+ }
+ if c.pingTimer != nil {
+ c.pingTimer.Reset(c.HeartbeatInterval)
+ }
+ if event == nil {
+ log.Println("Inbox worker found nil event. May be due to broken websocket. Reconnecting.")
+ break
+ } else {
+ c.inbox <- event.(map[string]interface{})
+ }
+ }
+
+ c.reconnectLater()
+}
+
+// reconnectLater schedules a reconnect for later. We need to make sure that we don't
+// block, and that we don't reconnect more frequently than once every c.ReconnectInterval
+func (c *Client) reconnectLater() {
+ c.Close()
+ c.reconnectLock.Lock()
+ defer c.reconnectLock.Unlock()
+ if c.reconnectTimer == nil {
+ c.reconnectTimer = time.AfterFunc(c.ReconnectInterval, c.Reconnect)
+ }
+}