vendor/github.com/btcsuite/btcd/rpcclient/examples/btcdwebsockets/main.go

   1 // Copyright (c) 2014-2017 The btcsuite developers
   2 // Use of this source code is governed by an ISC
   3 // license that can be found in the LICENSE file.
   4
   5 package main
   6
   7 import (
   8         "io/ioutil"
   9         "log"
  10         "path/filepath"
  11         "time"
  12
  13         "github.com/btcsuite/btcd/rpcclient"
  14         "github.com/btcsuite/btcd/wire"
  15         "github.com/btcsuite/btcutil"
  16 )
  17
  18 func main() {
  19         // Only override the handlers for notifications you care about.
  20         // Also note most of these handlers will only be called if you register
  21         // for notifications.  See the documentation of the rpcclient
  22         // NotificationHandlers type for more details about each handler.
  23         ntfnHandlers := rpcclient.NotificationHandlers{
  24                 OnFilteredBlockConnected: func(height int32, header *wire.BlockHeader, txns []*btcutil.Tx) {
  25                         log.Printf("Block connected: %v (%d) %v",
  26                                 header.BlockHash(), height, header.Timestamp)
  27                 },
  28                 OnFilteredBlockDisconnected: func(height int32, header *wire.BlockHeader) {
  29                         log.Printf("Block disconnected: %v (%d) %v",
  30                                 header.BlockHash(), height, header.Timestamp)
  31                 },
  32         }
  33
  34         // Connect to local btcd RPC server using websockets.
  35         btcdHomeDir := btcutil.AppDataDir("btcd", false)
  36         certs, err := ioutil.ReadFile(filepath.Join(btcdHomeDir, "rpc.cert"))
  37         if err != nil {
  38                 log.Fatal(err)
  39         }
  40         connCfg := &rpcclient.ConnConfig{
  41                 Host:         "localhost:8334",
  42                 Endpoint:     "ws",
  43                 User:         "yourrpcuser",
  44                 Pass:         "yourrpcpass",
  45                 Certificates: certs,
  46         }
  47         client, err := rpcclient.New(connCfg, &ntfnHandlers)
  48         if err != nil {
  49                 log.Fatal(err)
  50         }
  51
  52         // Register for block connect and disconnect notifications.
  53         if err := client.NotifyBlocks(); err != nil {
  54                 log.Fatal(err)
  55         }
  56         log.Println("NotifyBlocks: Registration Complete")
  57
  58         // Get the current block count.
  59         blockCount, err := client.GetBlockCount()
  60         if err != nil {
  61                 log.Fatal(err)
  62         }
  63         log.Printf("Block count: %d", blockCount)
  64
  65         // For this example gracefully shutdown the client after 10 seconds.
  66         // Ordinarily when to shutdown the client is highly application
  67         // specific.
  68         log.Println("Client shutdown in 10 seconds...")
  69         time.AfterFunc(time.Second*10, func() {
  70                 log.Println("Client shutting down...")
  71                 client.Shutdown()
  72                 log.Println("Client shutdown complete.")
  73         })
  74
  75         // Wait until the client either shuts down gracefully (or the user
  76         // terminates the process with Ctrl+C).
  77         client.WaitForShutdown()
  78 }