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package rpcclient
import (
"encoding/json"
"fmt"
"net"
"net/http"
"time"
"github.com/gorilla/websocket"
. "github.com/tendermint/go-common"
"github.com/tendermint/go-rpc/types"
)
const (
wsResultsChannelCapacity = 10
wsErrorsChannelCapacity = 1
wsWriteTimeoutSeconds = 10
)
type WSClient struct {
BaseService
Address string // IP:PORT or /path/to/socket
Endpoint string // /websocket/url/endpoint
Dialer func(string, string) (net.Conn, error)
*websocket.Conn
ResultsCh chan json.RawMessage // closes upon WSClient.Stop()
ErrorsCh chan error // closes upon WSClient.Stop()
}
// create a new connection
func NewWSClient(remoteAddr, endpoint string) *WSClient {
addr, dialer := makeHTTPDialer(remoteAddr)
wsClient := &WSClient{
Address: addr,
Dialer: dialer,
Endpoint: endpoint,
Conn: nil,
ResultsCh: make(chan json.RawMessage, wsResultsChannelCapacity),
ErrorsCh: make(chan error, wsErrorsChannelCapacity),
}
wsClient.BaseService = *NewBaseService(log, "WSClient", wsClient)
return wsClient
}
func (wsc *WSClient) String() string {
return wsc.Address + ", " + wsc.Endpoint
}
func (wsc *WSClient) OnStart() error {
wsc.BaseService.OnStart()
err := wsc.dial()
if err != nil {
return err
}
go wsc.receiveEventsRoutine()
return nil
}
func (wsc *WSClient) dial() error {
// Dial
dialer := &websocket.Dialer{
NetDial: wsc.Dialer,
Proxy: http.ProxyFromEnvironment,
}
rHeader := http.Header{}
con, _, err := dialer.Dial("ws://"+wsc.Address+wsc.Endpoint, rHeader)
if err != nil {
return err
}
// Set the ping/pong handlers
con.SetPingHandler(func(m string) error {
// NOTE: https://github.com/gorilla/websocket/issues/97
go con.WriteControl(websocket.PongMessage, []byte(m), time.Now().Add(time.Second*wsWriteTimeoutSeconds))
return nil
})
con.SetPongHandler(func(m string) error {
// NOTE: https://github.com/gorilla/websocket/issues/97
return nil
})
wsc.Conn = con
return nil
}
func (wsc *WSClient) OnStop() {
wsc.BaseService.OnStop()
// ResultsCh/ErrorsCh is closed in receiveEventsRoutine.
}
func (wsc *WSClient) receiveEventsRoutine() {
for {
_, data, err := wsc.ReadMessage()
if err != nil {
log.Info("WSClient failed to read message", "error", err, "data", string(data))
wsc.Stop()
break
} else {
var response rpctypes.RPCResponse
err := json.Unmarshal(data, &response)
if err != nil {
log.Info("WSClient failed to parse message", "error", err, "data", string(data))
wsc.ErrorsCh <- err
continue
}
if response.Error != "" {
wsc.ErrorsCh <- fmt.Errorf(response.Error)
continue
}
wsc.ResultsCh <- *response.Result
}
}
// Cleanup
close(wsc.ResultsCh)
close(wsc.ErrorsCh)
}
// subscribe to an event
func (wsc *WSClient) Subscribe(eventid string) error {
err := wsc.WriteJSON(rpctypes.RPCRequest{
JSONRPC: "2.0",
ID: "",
Method: "subscribe",
Params: []interface{}{eventid},
})
return err
}
// unsubscribe from an event
func (wsc *WSClient) Unsubscribe(eventid string) error {
err := wsc.WriteJSON(rpctypes.RPCRequest{
JSONRPC: "2.0",
ID: "",
Method: "unsubscribe",
Params: []interface{}{eventid},
})
return err
}