rpcserver: Allow tx result creation without block.

This commit modifies the createTxRawResult code path along with callers
to work with block headers as opposed to btcutil.Blocks.  This in turn
allows the code in handleGetRawTransaction and
handleSearchRawTransactions to perform a much cheaper block header load
as opposed to a full block load.

While here, also very slightly optimize the createVinList function to
avoid creating a util.Tx wrapper and to take advantage of the
btcutil.Amount type added after the function was originally written

rpcserver.go

@@ -615,10 +615,9 @@ func handleDebugLevel(s *rpcServer, cmd interface{}, closeChan <-chan struct{})
 // createVinList returns a slice of JSON objects for the inputs of the passed
 // transaction.
 func createVinList(mtx *wire.MsgTx) []btcjson.Vin {
-	tx := btcutil.NewTx(mtx)
 	vinList := make([]btcjson.Vin, len(mtx.TxIn))
 	for i, v := range mtx.TxIn {
-		if blockchain.IsCoinBase(tx) {
+		if blockchain.IsCoinBaseTx(mtx) {
 			vinList[i].Coinbase = hex.EncodeToString(v.SignatureScript)
 		} else {
 			vinList[i].Txid = v.PreviousOutPoint.Hash.String()
@@ -644,7 +643,7 @@ func createVoutList(mtx *wire.MsgTx, chainParams *chaincfg.Params) []btcjson.Vou
 	voutList := make([]btcjson.Vout, len(mtx.TxOut))
 	for i, v := range mtx.TxOut {
 		voutList[i].N = uint32(i)
-		voutList[i].Value = float64(v.Value) / btcutil.SatoshiPerBitcoin
+		voutList[i].Value = btcutil.Amount(v.Value).ToBTC()
 
 		// The disassembled string will contain [error] inline if the
 		// script doesn't fully parse, so ignore the error here.
@@ -675,9 +674,9 @@ func createVoutList(mtx *wire.MsgTx, chainParams *chaincfg.Params) []btcjson.Vou
 
 // createTxRawResult converts the passed transaction and associated parameters
 // to a raw transaction JSON object.
-func createTxRawResult(chainParams *chaincfg.Params, txHash string,
+func createTxRawResult(chainParams *chaincfg.Params, mtx *wire.MsgTx,
-	mtx *wire.MsgTx, blk *btcutil.Block, maxIdx int64,
+	txHash string, blkHeader *wire.BlockHeader, blkHash string,
-	blkHash *wire.ShaHash) (*btcjson.TxRawResult, error) {
+	blkHeight int64, chainHeight int64) (*btcjson.TxRawResult, error) {
 
 	mtxHex, err := messageToHex(mtx)
 	if err != nil {
@@ -693,15 +692,12 @@ func createTxRawResult(chainParams *chaincfg.Params, txHash string,
 		LockTime: mtx.LockTime,
 	}
 
-	if blk != nil {
+	if blkHeader != nil {
-		blockHeader := &blk.MsgBlock().Header
-		idx := blk.Height()
-
 		// This is not a typo, they are identical in bitcoind as well.
-		txReply.Time = blockHeader.Timestamp.Unix()
+		txReply.Time = blkHeader.Timestamp.Unix()
-		txReply.Blocktime = blockHeader.Timestamp.Unix()
+		txReply.Blocktime = blkHeader.Timestamp.Unix()
-		txReply.BlockHash = blkHash.String()
+		txReply.BlockHash = blkHash
-		txReply.Confirmations = uint64(1 + maxIdx - idx)
+		txReply.Confirmations = uint64(1 + chainHeight - blkHeight)
 	}
 
 	return txReply, nil
@@ -1035,11 +1031,9 @@ func handleGetBlock(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (i
 		txns := blk.Transactions()
 		rawTxns := make([]btcjson.TxRawResult, len(txns))
 		for i, tx := range txns {
-			txHash := tx.Sha().String()
-			mtx := tx.MsgTx()
-
 			rawTxn, err := createTxRawResult(s.server.chainParams,
-				txHash, mtx, blk, maxIdx, sha)
+				tx.MsgTx(), tx.Sha().String(), blockHeader,
+				sha.String(), idx, maxIdx)
 			if err != nil {
 				return nil, err
 			}
@@ -2258,6 +2252,7 @@ func handleGetRawTransaction(s *rpcServer, cmd interface{}, closeChan <-chan str
 	// try the block database.
 	var mtx *wire.MsgTx
 	var blkHash *wire.ShaHash
+	var blkHeight int64
 	tx, err := s.server.txMemPool.FetchTransaction(txHash)
 	if err != nil {
 		txList, err := s.server.db.FetchTxBySha(txHash)
@@ -2268,10 +2263,10 @@ func handleGetRawTransaction(s *rpcServer, cmd interface{}, closeChan <-chan str
 			}
 		}
 
-		lastTx := len(txList) - 1
+		lastTx := txList[len(txList)-1]
-		mtx = txList[lastTx].Tx
+		mtx = lastTx.Tx
-
+		blkHash = lastTx.BlkSha
-		blkHash = txList[lastTx].BlkSha
+		blkHeight = lastTx.Height
 	} else {
 		mtx = tx.MsgTx()
 	}
@@ -2290,10 +2285,11 @@ func handleGetRawTransaction(s *rpcServer, cmd interface{}, closeChan <-chan str
 		return mtxHex, nil
 	}
 
-	var blk *btcutil.Block
+	var blkHeader *wire.BlockHeader
-	var maxIdx int64
+	var blkHashStr string
+	var chainHeight int64
 	if blkHash != nil {
-		blk, err = s.server.db.FetchBlockBySha(blkHash)
+		blkHeader, err = s.server.db.FetchBlockHeaderBySha(blkHash)
 		if err != nil {
 			rpcsLog.Errorf("Error fetching sha: %v", err)
 			return nil, &btcjson.RPCError{
@@ -2302,15 +2298,17 @@ func handleGetRawTransaction(s *rpcServer, cmd interface{}, closeChan <-chan str
 			}
 		}
 
-		_, maxIdx, err = s.server.db.NewestSha()
+		_, chainHeight, err = s.server.db.NewestSha()
 		if err != nil {
 			context := "Failed to get newest hash"
 			return nil, internalRPCError(err.Error(), context)
 		}
+
+		blkHashStr = blkHash.String()
 	}
 
-	rawTxn, err := createTxRawResult(s.server.chainParams, c.Txid, mtx, blk,
+	rawTxn, err := createTxRawResult(s.server.chainParams, mtx,
-		maxIdx, blkHash)
+		txHash.String(), blkHeader, blkHashStr, blkHeight, chainHeight)
 	if err != nil {
 		return nil, err
 	}
@@ -2946,9 +2944,11 @@ func handleSearchRawTransactions(s *rpcServer, cmd interface{}, closeChan <-chan
 		// within a block. So we conditionally fetch a txs
 		// embedded block here. This will be reflected in the
 		// final JSON output (mempool won't have confirmations).
-		var blk *btcutil.Block
+		var blkHeader *wire.BlockHeader
+		var blkHashStr string
+		var blkHeight int64
 		if txReply.BlkSha != nil {
-			blk, err = s.server.db.FetchBlockBySha(txReply.BlkSha)
+			blkHeader, err = s.server.db.FetchBlockHeaderBySha(txReply.BlkSha)
 			if err != nil {
 				rpcsLog.Errorf("Error fetching sha: %v", err)
 				return nil, &btcjson.RPCError{
@@ -2956,15 +2956,12 @@ func handleSearchRawTransactions(s *rpcServer, cmd interface{}, closeChan <-chan
 					Message: "Block not found",
 				}
 			}
+			blkHashStr = txReply.BlkSha.String()
+			blkHeight = txReply.Height
 		}
 
-		var blkHash *wire.ShaHash
+		rawTxn, err := createTxRawResult(s.server.chainParams, mtx,
-		if blk != nil {
+			txHash, blkHeader, blkHashStr, blkHeight, maxIdx)
-			blkHash = blk.Sha()
-		}
-
-		rawTxn, err := createTxRawResult(s.server.chainParams,
-			txHash, mtx, blk, maxIdx, blkHash)
 		if err != nil {
 			return nil, err
 		}

rpcwebsocket.go

@@ -487,8 +487,8 @@ func (m *wsNotificationManager) notifyForNewTx(clients map[chan struct{}]*wsClie
 			}
 
 			net := m.server.server.chainParams
-			rawTx, err := createTxRawResult(net, txShaStr, mtx, nil,
+			rawTx, err := createTxRawResult(net, mtx, txShaStr, nil,
-				0, nil)
+				"", 0, 0)
 			if err != nil {
 				return
 			}