From 0dd81ad003c805dde3470ed6424b0ba3f4dd5805 Mon Sep 17 00:00:00 2001
From: David Hill <dhill@conformal.com>
Date: Thu, 5 Jun 2014 13:45:43 -0400
Subject: [PATCH] Use NewReader instead of NewBuffer.

NewReader is slightly faster than NewBuffer, but more importantly,
ensures the data is read-only.
---
 ldb/block.go   |  4 ++--
 ldb/leveldb.go |  8 ++++----
 ldb/tx.go      | 30 +++++++++++++++---------------
 3 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/ldb/block.go b/ldb/block.go
index 5d4ff22f..25e4c1af 100644
--- a/ldb/block.go
+++ b/ldb/block.go
@@ -61,7 +61,7 @@ func (db *LevelDb) FetchBlockHeaderBySha(sha *btcwire.ShaHash) (bh *btcwire.Bloc
 	// Only deserialize the header portion and ensure the transaction count
 	// is zero since this is a standalone header.
 	var blockHeader btcwire.BlockHeader
-	err = blockHeader.Deserialize(bytes.NewBuffer(buf))
+	err = blockHeader.Deserialize(bytes.NewReader(buf))
 	if err != nil {
 		return nil, err
 	}
@@ -125,7 +125,7 @@ func (db *LevelDb) getBlk(sha *btcwire.ShaHash) (rblkHeight int64, rbuf []byte,
 func (db *LevelDb) setBlk(sha *btcwire.ShaHash, blkHeight int64, buf []byte) {
 	// serialize
 	var lw [8]byte
-	binary.LittleEndian.PutUint64(lw[:], uint64(blkHeight))
+	binary.LittleEndian.PutUint64(lw[0:8], uint64(blkHeight))
 
 	shaKey := shaBlkToKey(sha)
 	blkKey := int64ToKey(blkHeight)
diff --git a/ldb/leveldb.go b/ldb/leveldb.go
index 1e797a5a..2d7a6e4a 100644
--- a/ldb/leveldb.go
+++ b/ldb/leveldb.go
@@ -649,10 +649,10 @@ func (db *LevelDb) processBatches() error {
 		for txSha, txU := range db.txUpdateMap {
 			key := shaTxToKey(&txSha)
 			if txU.delete {
-				log.Tracef("deleting tx %v", txSha)
+				//log.Tracef("deleting tx %v", txSha)
 				db.lbatch.Delete(key)
 			} else {
-				log.Tracef("inserting tx %v", txSha)
+				//log.Tracef("inserting tx %v", txSha)
 				txdat := db.formatTx(txU)
 				db.lbatch.Put(key, txdat)
 			}
@@ -660,10 +660,10 @@ func (db *LevelDb) processBatches() error {
 		for txSha, txSu := range db.txSpentUpdateMap {
 			key := shaSpentTxToKey(&txSha)
 			if txSu.delete {
-				log.Tracef("deleting tx %v", txSha)
+				//log.Tracef("deleting tx %v", txSha)
 				db.lbatch.Delete(key)
 			} else {
-				log.Tracef("inserting tx %v", txSha)
+				//log.Tracef("inserting tx %v", txSha)
 				txdat := db.formatTxFullySpent(txSu.txl)
 				db.lbatch.Put(key, txdat)
 			}
diff --git a/ldb/tx.go b/ldb/tx.go
index c010998f..ef7ec77b 100644
--- a/ldb/tx.go
+++ b/ldb/tx.go
@@ -67,9 +67,9 @@ func (db *LevelDb) formatTx(txu *txUpdateObj) []byte {
 	spentbuf := txu.spentData
 
 	txW := make([]byte, 16+len(spentbuf))
-	binary.LittleEndian.PutUint64(txW[:], blkHeight)
-	binary.LittleEndian.PutUint32(txW[8:], txOff)
-	binary.LittleEndian.PutUint32(txW[12:], txLen)
+	binary.LittleEndian.PutUint64(txW[0:8], blkHeight)
+	binary.LittleEndian.PutUint32(txW[8:12], txOff)
+	binary.LittleEndian.PutUint32(txW[12:16], txLen)
 	copy(txW[16:], spentbuf)
 
 	return txW[:]
@@ -82,9 +82,9 @@ func (db *LevelDb) getTxData(txsha *btcwire.ShaHash) (int64, int, int, []byte, e
 		return 0, 0, 0, nil, err
 	}
 
-	blkHeight := binary.LittleEndian.Uint64(buf)
-	txOff := binary.LittleEndian.Uint32(buf[8:])
-	txLen := binary.LittleEndian.Uint32(buf[12:])
+	blkHeight := binary.LittleEndian.Uint64(buf[0:8])
+	txOff := binary.LittleEndian.Uint32(buf[8:12])
+	txLen := binary.LittleEndian.Uint32(buf[12:16])
 
 	spentBuf := make([]byte, len(buf)-16)
 	copy(spentBuf, buf[16:])
@@ -109,10 +109,10 @@ func (db *LevelDb) getTxFullySpent(txsha *btcwire.ShaHash) ([]*spentTx, error) {
 	for i := range spentTxList {
 		offset := i * 20
 
-		blkHeight := binary.LittleEndian.Uint64(buf[offset:])
-		txOff := binary.LittleEndian.Uint32(buf[offset+8:])
-		txLen := binary.LittleEndian.Uint32(buf[offset+12:])
-		numTxO := binary.LittleEndian.Uint32(buf[offset+16:])
+		blkHeight := binary.LittleEndian.Uint64(buf[offset:offset+8])
+		txOff := binary.LittleEndian.Uint32(buf[offset+8:offset+12])
+		txLen := binary.LittleEndian.Uint32(buf[offset+12:offset+16])
+		numTxO := binary.LittleEndian.Uint32(buf[offset+16:offset+20])
 
 		sTx := spentTx{
 			blkHeight: int64(blkHeight),
@@ -137,10 +137,10 @@ func (db *LevelDb) formatTxFullySpent(sTxList []*spentTx) []byte {
 		numTxO := uint32(sTx.numTxO)
 		offset := i * 20
 
-		binary.LittleEndian.PutUint64(txW[offset:], blkHeight)
-		binary.LittleEndian.PutUint32(txW[offset+8:], txOff)
-		binary.LittleEndian.PutUint32(txW[offset+12:], txLen)
-		binary.LittleEndian.PutUint32(txW[offset+16:], numTxO)
+		binary.LittleEndian.PutUint64(txW[offset:offset+8], blkHeight)
+		binary.LittleEndian.PutUint32(txW[offset+8:offset+12], txOff)
+		binary.LittleEndian.PutUint32(txW[offset+12:offset+16], txLen)
+		binary.LittleEndian.PutUint32(txW[offset+16:offset+20], numTxO)
 	}
 
 	return txW
@@ -272,7 +272,7 @@ func (db *LevelDb) fetchTxDataByLoc(blkHeight int64, txOff int, txLen int, txspe
 		err = btcdb.TxShaMissing
 		return
 	}
-	rbuf := bytes.NewBuffer(blkbuf[txOff : txOff+txLen])
+	rbuf := bytes.NewReader(blkbuf[txOff : txOff+txLen])
 
 	var tx btcwire.MsgTx
 	err = tx.Deserialize(rbuf)