You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
546 lines
15 KiB
546 lines
15 KiB
package client
|
|
|
|
import (
|
|
"context"
|
|
"encoding/json"
|
|
"fmt"
|
|
"net"
|
|
"net/http"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/gorilla/websocket"
|
|
metrics "github.com/rcrowley/go-metrics"
|
|
|
|
tmrand "github.com/tendermint/tendermint/libs/rand"
|
|
"github.com/tendermint/tendermint/libs/service"
|
|
tmsync "github.com/tendermint/tendermint/libs/sync"
|
|
types "github.com/tendermint/tendermint/rpc/jsonrpc/types"
|
|
)
|
|
|
|
const (
|
|
defaultMaxReconnectAttempts = 25
|
|
defaultWriteWait = 0
|
|
defaultReadWait = 0
|
|
defaultPingPeriod = 0
|
|
)
|
|
|
|
// WSClient is a JSON-RPC client, which uses WebSocket for communication with
|
|
// the remote server.
|
|
//
|
|
// WSClient is safe for concurrent use by multiple goroutines.
|
|
type WSClient struct { // nolint: maligned
|
|
conn *websocket.Conn
|
|
|
|
Address string // IP:PORT or /path/to/socket
|
|
Endpoint string // /websocket/url/endpoint
|
|
Dialer func(string, string) (net.Conn, error)
|
|
|
|
// Single user facing channel to read RPCResponses from, closed only when the
|
|
// client is being stopped.
|
|
ResponsesCh chan types.RPCResponse
|
|
|
|
// Callback, which will be called each time after successful reconnect.
|
|
onReconnect func()
|
|
|
|
// internal channels
|
|
send chan types.RPCRequest // user requests
|
|
backlog chan types.RPCRequest // stores a single user request received during a conn failure
|
|
reconnectAfter chan error // reconnect requests
|
|
readRoutineQuit chan struct{} // a way for readRoutine to close writeRoutine
|
|
|
|
// Maximum reconnect attempts (0 or greater; default: 25).
|
|
maxReconnectAttempts int
|
|
|
|
// Support both ws and wss protocols
|
|
protocol string
|
|
|
|
wg sync.WaitGroup
|
|
|
|
mtx tmsync.RWMutex
|
|
sentLastPingAt time.Time
|
|
reconnecting bool
|
|
nextReqID int
|
|
// sentIDs map[types.JSONRPCIntID]bool // IDs of the requests currently in flight
|
|
|
|
// Time allowed to write a message to the server. 0 means block until operation succeeds.
|
|
writeWait time.Duration
|
|
|
|
// Time allowed to read the next message from the server. 0 means block until operation succeeds.
|
|
readWait time.Duration
|
|
|
|
// Send pings to server with this period. Must be less than readWait. If 0, no pings will be sent.
|
|
pingPeriod time.Duration
|
|
|
|
service.BaseService
|
|
|
|
// Time between sending a ping and receiving a pong. See
|
|
// https://godoc.org/github.com/rcrowley/go-metrics#Timer.
|
|
PingPongLatencyTimer metrics.Timer
|
|
}
|
|
|
|
// NewWS returns a new client. See the commentary on the func(*WSClient)
|
|
// functions for a detailed description of how to configure ping period and
|
|
// pong wait time. The endpoint argument must begin with a `/`.
|
|
// An error is returned on invalid remote. The function panics when remote is nil.
|
|
func NewWS(remoteAddr, endpoint string, options ...func(*WSClient)) (*WSClient, error) {
|
|
parsedURL, err := newParsedURL(remoteAddr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// default to ws protocol, unless wss is explicitly specified
|
|
if parsedURL.Scheme != protoWSS {
|
|
parsedURL.Scheme = protoWS
|
|
}
|
|
|
|
dialFn, err := makeHTTPDialer(remoteAddr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
c := &WSClient{
|
|
Address: parsedURL.GetTrimmedHostWithPath(),
|
|
Dialer: dialFn,
|
|
Endpoint: endpoint,
|
|
PingPongLatencyTimer: metrics.NewTimer(),
|
|
|
|
maxReconnectAttempts: defaultMaxReconnectAttempts,
|
|
readWait: defaultReadWait,
|
|
writeWait: defaultWriteWait,
|
|
pingPeriod: defaultPingPeriod,
|
|
protocol: parsedURL.Scheme,
|
|
|
|
// sentIDs: make(map[types.JSONRPCIntID]bool),
|
|
}
|
|
c.BaseService = *service.NewBaseService(nil, "WSClient", c)
|
|
for _, option := range options {
|
|
option(c)
|
|
}
|
|
return c, nil
|
|
}
|
|
|
|
// MaxReconnectAttempts sets the maximum number of reconnect attempts before returning an error.
|
|
// It should only be used in the constructor and is not Goroutine-safe.
|
|
func MaxReconnectAttempts(max int) func(*WSClient) {
|
|
return func(c *WSClient) {
|
|
c.maxReconnectAttempts = max
|
|
}
|
|
}
|
|
|
|
// ReadWait sets the amount of time to wait before a websocket read times out.
|
|
// It should only be used in the constructor and is not Goroutine-safe.
|
|
func ReadWait(readWait time.Duration) func(*WSClient) {
|
|
return func(c *WSClient) {
|
|
c.readWait = readWait
|
|
}
|
|
}
|
|
|
|
// WriteWait sets the amount of time to wait before a websocket write times out.
|
|
// It should only be used in the constructor and is not Goroutine-safe.
|
|
func WriteWait(writeWait time.Duration) func(*WSClient) {
|
|
return func(c *WSClient) {
|
|
c.writeWait = writeWait
|
|
}
|
|
}
|
|
|
|
// PingPeriod sets the duration for sending websocket pings.
|
|
// It should only be used in the constructor - not Goroutine-safe.
|
|
func PingPeriod(pingPeriod time.Duration) func(*WSClient) {
|
|
return func(c *WSClient) {
|
|
c.pingPeriod = pingPeriod
|
|
}
|
|
}
|
|
|
|
// OnReconnect sets the callback, which will be called every time after
|
|
// successful reconnect.
|
|
func OnReconnect(cb func()) func(*WSClient) {
|
|
return func(c *WSClient) {
|
|
c.onReconnect = cb
|
|
}
|
|
}
|
|
|
|
// String returns WS client full address.
|
|
func (c *WSClient) String() string {
|
|
return fmt.Sprintf("WSClient{%s (%s)}", c.Address, c.Endpoint)
|
|
}
|
|
|
|
// OnStart implements service.Service by dialing a server and creating read and
|
|
// write routines.
|
|
func (c *WSClient) OnStart() error {
|
|
err := c.dial()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
c.ResponsesCh = make(chan types.RPCResponse)
|
|
|
|
c.send = make(chan types.RPCRequest)
|
|
// 1 additional error may come from the read/write
|
|
// goroutine depending on which failed first.
|
|
c.reconnectAfter = make(chan error, 1)
|
|
// capacity for 1 request. a user won't be able to send more because the send
|
|
// channel is unbuffered.
|
|
c.backlog = make(chan types.RPCRequest, 1)
|
|
|
|
c.startReadWriteRoutines()
|
|
go c.reconnectRoutine()
|
|
|
|
return nil
|
|
}
|
|
|
|
// Stop overrides service.Service#Stop. There is no other way to wait until Quit
|
|
// channel is closed.
|
|
func (c *WSClient) Stop() error {
|
|
if err := c.BaseService.Stop(); err != nil {
|
|
return err
|
|
}
|
|
// only close user-facing channels when we can't write to them
|
|
c.wg.Wait()
|
|
close(c.ResponsesCh)
|
|
|
|
return nil
|
|
}
|
|
|
|
// IsReconnecting returns true if the client is reconnecting right now.
|
|
func (c *WSClient) IsReconnecting() bool {
|
|
c.mtx.RLock()
|
|
defer c.mtx.RUnlock()
|
|
return c.reconnecting
|
|
}
|
|
|
|
// IsActive returns true if the client is running and not reconnecting.
|
|
func (c *WSClient) IsActive() bool {
|
|
return c.IsRunning() && !c.IsReconnecting()
|
|
}
|
|
|
|
// Send the given RPC request to the server. Results will be available on
|
|
// ResponsesCh, errors, if any, on ErrorsCh. Will block until send succeeds or
|
|
// ctx.Done is closed.
|
|
func (c *WSClient) Send(ctx context.Context, request types.RPCRequest) error {
|
|
select {
|
|
case c.send <- request:
|
|
c.Logger.Info("sent a request", "req", request)
|
|
// c.mtx.Lock()
|
|
// c.sentIDs[request.ID.(types.JSONRPCIntID)] = true
|
|
// c.mtx.Unlock()
|
|
return nil
|
|
case <-ctx.Done():
|
|
return ctx.Err()
|
|
}
|
|
}
|
|
|
|
// Call enqueues a call request onto the Send queue. Requests are JSON encoded.
|
|
func (c *WSClient) Call(ctx context.Context, method string, params map[string]interface{}) error {
|
|
request, err := types.MapToRequest(c.nextRequestID(), method, params)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return c.Send(ctx, request)
|
|
}
|
|
|
|
// CallWithArrayParams enqueues a call request onto the Send queue. Params are
|
|
// in a form of array (e.g. []interface{}{"abcd"}). Requests are JSON encoded.
|
|
func (c *WSClient) CallWithArrayParams(ctx context.Context, method string, params []interface{}) error {
|
|
request, err := types.ArrayToRequest(c.nextRequestID(), method, params)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return c.Send(ctx, request)
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// Private methods
|
|
|
|
func (c *WSClient) nextRequestID() types.JSONRPCIntID {
|
|
c.mtx.Lock()
|
|
id := c.nextReqID
|
|
c.nextReqID++
|
|
c.mtx.Unlock()
|
|
return types.JSONRPCIntID(id)
|
|
}
|
|
|
|
func (c *WSClient) dial() error {
|
|
dialer := &websocket.Dialer{
|
|
NetDial: c.Dialer,
|
|
Proxy: http.ProxyFromEnvironment,
|
|
}
|
|
rHeader := http.Header{}
|
|
conn, _, err := dialer.Dial(c.protocol+"://"+c.Address+c.Endpoint, rHeader) // nolint:bodyclose
|
|
if err != nil {
|
|
return err
|
|
}
|
|
c.conn = conn
|
|
return nil
|
|
}
|
|
|
|
// reconnect tries to redial up to maxReconnectAttempts with exponential
|
|
// backoff.
|
|
func (c *WSClient) reconnect() error {
|
|
attempt := 0
|
|
|
|
c.mtx.Lock()
|
|
c.reconnecting = true
|
|
c.mtx.Unlock()
|
|
defer func() {
|
|
c.mtx.Lock()
|
|
c.reconnecting = false
|
|
c.mtx.Unlock()
|
|
}()
|
|
|
|
for {
|
|
jitter := time.Duration(tmrand.Float64() * float64(time.Second)) // 1s == (1e9 ns)
|
|
backoffDuration := jitter + ((1 << uint(attempt)) * time.Second)
|
|
|
|
c.Logger.Info("reconnecting", "attempt", attempt+1, "backoff_duration", backoffDuration)
|
|
time.Sleep(backoffDuration)
|
|
|
|
err := c.dial()
|
|
if err != nil {
|
|
c.Logger.Error("failed to redial", "err", err)
|
|
} else {
|
|
c.Logger.Info("reconnected")
|
|
if c.onReconnect != nil {
|
|
go c.onReconnect()
|
|
}
|
|
return nil
|
|
}
|
|
|
|
attempt++
|
|
|
|
if attempt > c.maxReconnectAttempts {
|
|
return fmt.Errorf("reached maximum reconnect attempts: %w", err)
|
|
}
|
|
}
|
|
}
|
|
|
|
func (c *WSClient) startReadWriteRoutines() {
|
|
c.wg.Add(2)
|
|
c.readRoutineQuit = make(chan struct{})
|
|
go c.readRoutine()
|
|
go c.writeRoutine()
|
|
}
|
|
|
|
func (c *WSClient) processBacklog() error {
|
|
select {
|
|
case request := <-c.backlog:
|
|
if c.writeWait > 0 {
|
|
if err := c.conn.SetWriteDeadline(time.Now().Add(c.writeWait)); err != nil {
|
|
c.Logger.Error("failed to set write deadline", "err", err)
|
|
}
|
|
}
|
|
if err := c.conn.WriteJSON(request); err != nil {
|
|
c.Logger.Error("failed to resend request", "err", err)
|
|
c.reconnectAfter <- err
|
|
// requeue request
|
|
c.backlog <- request
|
|
return err
|
|
}
|
|
c.Logger.Info("resend a request", "req", request)
|
|
default:
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (c *WSClient) reconnectRoutine() {
|
|
for {
|
|
select {
|
|
case originalError := <-c.reconnectAfter:
|
|
// wait until writeRoutine and readRoutine finish
|
|
c.wg.Wait()
|
|
if err := c.reconnect(); err != nil {
|
|
c.Logger.Error("failed to reconnect", "err", err, "original_err", originalError)
|
|
if err = c.Stop(); err != nil {
|
|
c.Logger.Error("failed to stop conn", "error", err)
|
|
}
|
|
|
|
return
|
|
}
|
|
// drain reconnectAfter
|
|
LOOP:
|
|
for {
|
|
select {
|
|
case <-c.reconnectAfter:
|
|
default:
|
|
break LOOP
|
|
}
|
|
}
|
|
err := c.processBacklog()
|
|
if err == nil {
|
|
c.startReadWriteRoutines()
|
|
}
|
|
|
|
case <-c.Quit():
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
// The client ensures that there is at most one writer to a connection by
|
|
// executing all writes from this goroutine.
|
|
func (c *WSClient) writeRoutine() {
|
|
var ticker *time.Ticker
|
|
if c.pingPeriod > 0 {
|
|
// ticker with a predefined period
|
|
ticker = time.NewTicker(c.pingPeriod)
|
|
} else {
|
|
// ticker that never fires
|
|
ticker = &time.Ticker{C: make(<-chan time.Time)}
|
|
}
|
|
|
|
defer func() {
|
|
ticker.Stop()
|
|
c.conn.Close()
|
|
// err != nil {
|
|
// ignore error; it will trigger in tests
|
|
// likely because it's closing an already closed connection
|
|
// }
|
|
c.wg.Done()
|
|
}()
|
|
|
|
for {
|
|
select {
|
|
case request := <-c.send:
|
|
if c.writeWait > 0 {
|
|
if err := c.conn.SetWriteDeadline(time.Now().Add(c.writeWait)); err != nil {
|
|
c.Logger.Error("failed to set write deadline", "err", err)
|
|
}
|
|
}
|
|
if err := c.conn.WriteJSON(request); err != nil {
|
|
c.Logger.Error("failed to send request", "err", err)
|
|
c.reconnectAfter <- err
|
|
// add request to the backlog, so we don't lose it
|
|
c.backlog <- request
|
|
return
|
|
}
|
|
case <-ticker.C:
|
|
if c.writeWait > 0 {
|
|
if err := c.conn.SetWriteDeadline(time.Now().Add(c.writeWait)); err != nil {
|
|
c.Logger.Error("failed to set write deadline", "err", err)
|
|
}
|
|
}
|
|
if err := c.conn.WriteMessage(websocket.PingMessage, []byte{}); err != nil {
|
|
c.Logger.Error("failed to write ping", "err", err)
|
|
c.reconnectAfter <- err
|
|
return
|
|
}
|
|
c.mtx.Lock()
|
|
c.sentLastPingAt = time.Now()
|
|
c.mtx.Unlock()
|
|
c.Logger.Debug("sent ping")
|
|
case <-c.readRoutineQuit:
|
|
return
|
|
case <-c.Quit():
|
|
if err := c.conn.WriteMessage(
|
|
websocket.CloseMessage,
|
|
websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""),
|
|
); err != nil {
|
|
c.Logger.Error("failed to write message", "err", err)
|
|
}
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
// The client ensures that there is at most one reader to a connection by
|
|
// executing all reads from this goroutine.
|
|
func (c *WSClient) readRoutine() {
|
|
defer func() {
|
|
c.conn.Close()
|
|
// err != nil {
|
|
// ignore error; it will trigger in tests
|
|
// likely because it's closing an already closed connection
|
|
// }
|
|
c.wg.Done()
|
|
}()
|
|
|
|
c.conn.SetPongHandler(func(string) error {
|
|
// gather latency stats
|
|
c.mtx.RLock()
|
|
t := c.sentLastPingAt
|
|
c.mtx.RUnlock()
|
|
c.PingPongLatencyTimer.UpdateSince(t)
|
|
|
|
c.Logger.Debug("got pong")
|
|
return nil
|
|
})
|
|
|
|
for {
|
|
// reset deadline for every message type (control or data)
|
|
if c.readWait > 0 {
|
|
if err := c.conn.SetReadDeadline(time.Now().Add(c.readWait)); err != nil {
|
|
c.Logger.Error("failed to set read deadline", "err", err)
|
|
}
|
|
}
|
|
_, data, err := c.conn.ReadMessage()
|
|
if err != nil {
|
|
if !websocket.IsUnexpectedCloseError(err, websocket.CloseNormalClosure) {
|
|
return
|
|
}
|
|
|
|
c.Logger.Error("failed to read response", "err", err)
|
|
close(c.readRoutineQuit)
|
|
c.reconnectAfter <- err
|
|
return
|
|
}
|
|
|
|
var response types.RPCResponse
|
|
err = json.Unmarshal(data, &response)
|
|
if err != nil {
|
|
c.Logger.Error("failed to parse response", "err", err, "data", string(data))
|
|
continue
|
|
}
|
|
|
|
if err = validateResponseID(response.ID); err != nil {
|
|
c.Logger.Error("error in response ID", "id", response.ID, "err", err)
|
|
continue
|
|
}
|
|
|
|
// TODO: events resulting from /subscribe do not work with ->
|
|
// because they are implemented as responses with the subscribe request's
|
|
// ID. According to the spec, they should be notifications (requests
|
|
// without IDs).
|
|
// https://github.com/tendermint/tendermint/issues/2949
|
|
// c.mtx.Lock()
|
|
// if _, ok := c.sentIDs[response.ID.(types.JSONRPCIntID)]; !ok {
|
|
// c.Logger.Error("unsolicited response ID", "id", response.ID, "expected", c.sentIDs)
|
|
// c.mtx.Unlock()
|
|
// continue
|
|
// }
|
|
// delete(c.sentIDs, response.ID.(types.JSONRPCIntID))
|
|
// c.mtx.Unlock()
|
|
// Combine a non-blocking read on BaseService.Quit with a non-blocking write on ResponsesCh to avoid blocking
|
|
// c.wg.Wait() in c.Stop(). Note we rely on Quit being closed so that it sends unlimited Quit signals to stop
|
|
// both readRoutine and writeRoutine
|
|
|
|
c.Logger.Info("got response", "id", response.ID, "result", fmt.Sprintf("%X", response.Result))
|
|
|
|
select {
|
|
case <-c.Quit():
|
|
case c.ResponsesCh <- response:
|
|
}
|
|
}
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// Predefined methods
|
|
|
|
// Subscribe to a query. Note the server must have a "subscribe" route
|
|
// defined.
|
|
func (c *WSClient) Subscribe(ctx context.Context, query string) error {
|
|
params := map[string]interface{}{"query": query}
|
|
return c.Call(ctx, "subscribe", params)
|
|
}
|
|
|
|
// Unsubscribe from a query. Note the server must have a "unsubscribe" route
|
|
// defined.
|
|
func (c *WSClient) Unsubscribe(ctx context.Context, query string) error {
|
|
params := map[string]interface{}{"query": query}
|
|
return c.Call(ctx, "unsubscribe", params)
|
|
}
|
|
|
|
// UnsubscribeAll from all. Note the server must have a "unsubscribe_all" route
|
|
// defined.
|
|
func (c *WSClient) UnsubscribeAll(ctx context.Context) error {
|
|
params := map[string]interface{}{}
|
|
return c.Call(ctx, "unsubscribe_all", params)
|
|
}
|