blockbook/bitcoinrpc.go

146 lines
3.6 KiB
Go

package main
import (
"encoding/hex"
"log"
"net/http"
"time"
lru "github.com/hashicorp/golang-lru"
)
// BitcoinRPC is an interface to JSON-RPC bitcoind service.
type BitcoinRPC struct {
client JSONRPC
Parser BlockParser
txCache *lru.Cache
}
// NewBitcoinRPC returns new BitcoinRPC instance.
func NewBitcoinRPC(url string, user string, password string, timeout time.Duration) *BitcoinRPC {
return &BitcoinRPC{
client: JSONRPC{
Client: http.Client{Timeout: timeout},
URL: url,
User: user,
Password: password,
},
}
}
// EnableCache turns on LRU caching for transaction lookups.
func (b *BitcoinRPC) EnableCache(size int) error {
c, err := lru.New(size)
if err != nil {
return err
}
b.txCache = c
return nil
}
// ClearCache purges the cache used for transaction results.
func (b *BitcoinRPC) ClearCache() {
if b.txCache != nil {
b.txCache.Purge()
}
}
// GetBlock returns information about the block with the given hash.
func (b *BitcoinRPC) GetBlock(hash string) (block *Block, err error) {
if b.Parser != nil {
return b.GetBlockAndParse(hash)
} else {
return b.GetParsedBlock(hash)
}
}
// GetBlockAndParse returns information about the block with the given hash.
//
// It downloads raw block and parses it in-process.
func (b *BitcoinRPC) GetBlockAndParse(hash string) (block *Block, err error) {
log.Printf("rpc: getblock (verbose=false) %v", hash)
var header BlockHeader
err = b.client.Call("getblockheader", &header, hash)
if err != nil {
return
}
var raw string
err = b.client.Call("getblock", &raw, hash, false) // verbose=false
if err != nil {
return
}
data, err := hex.DecodeString(raw)
if err != nil {
return
}
block, err = b.Parser.ParseBlock(data)
if err == nil {
block.Hash = header.Hash
block.Height = header.Height
block.Next = header.Next
}
return
}
// GetParsedBlock returns information about the block with the given hash.
//
// It downloads parsed block with transaction IDs and then looks them up,
// one by one.
func (b *BitcoinRPC) GetParsedBlock(hash string) (block *Block, err error) {
log.Printf("rpc: getblock (verbose=true) %v", hash)
block = &Block{}
err = b.client.Call("getblock", block, hash, true) // verbose=true
if err != nil {
return
}
for _, txid := range block.Txids {
tx, err := b.GetTransaction(txid)
if err != nil {
return nil, err
}
block.Txs = append(block.Txs, tx)
}
return
}
// GetBestBlockHash returns hash of the tip of the best-block-chain.
func (b *BitcoinRPC) GetBestBlockHash() (hash string, err error) {
log.Printf("rpc: getbestblockhash")
err = b.client.Call("getbestblockhash", &hash)
return
}
// GetBlockHash returns hash of block in best-block-chain at given height.
func (b *BitcoinRPC) GetBlockHash(height uint32) (hash string, err error) {
log.Printf("rpc: getblockhash %v", height)
err = b.client.Call("getblockhash", &hash, height)
return
}
// GetTransaction returns the number of blocks in the longest chain. If the
// transaction cache is turned on, returned Tx.Confirmations is stale.
func (b *BitcoinRPC) GetTransaction(txid string) (tx *Tx, err error) {
if b.txCache != nil {
if cachedTx, ok := b.txCache.Get(txid); ok {
tx = cachedTx.(*Tx)
return
}
}
log.Printf("rpc: getrawtransaction %v", txid)
tx = &Tx{}
err = b.client.Call("getrawtransaction", tx, txid, true) // verbose = true
if b.txCache != nil {
b.txCache.Add(txid, tx)
}
return
}
// GetAddresses returns all unique addresses from given transaction output.
func (b *BitcoinRPC) GetAddresses(txid string, vout uint32) ([]string, error) {
tx, err := b.GetTransaction(txid)
if err != nil {
return nil, err
}
return tx.Vout[vout].ScriptPubKey.Addresses, nil
}