From 19880b177e1ebb08ea7f98d22af3143234f44c6b Mon Sep 17 00:00:00 2001
From: Dave Collins <davec@conformal.com>
Date: Sat, 26 Oct 2013 18:02:09 -0500
Subject: [PATCH] Optimize InsertBlock with cached tx hashes.

This commit optimizes InsertBlock slightly by using the cached transaction
hashes instead of recomputing them.  Also, while here, use the
ShaHash.IsEqual function to do comparisons for consistency.

This is ongoing work towards conformal/btcd#25.

ok @drahn.
---
 ldb/leveldb.go | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/ldb/leveldb.go b/ldb/leveldb.go
index a3d98d22..f6352615 100644
--- a/ldb/leveldb.go
+++ b/ldb/leveldb.go
@@ -289,11 +289,11 @@ func (db *LevelDb) DropAfterBlockBySha(sha *btcwire.ShaHash) (rerr error) {
 			}
 		}
 		// rather than iterate the list of tx backward, do it twice.
-		for _, tx := range blk.MsgBlock().Transactions {
-			txSha, _ := tx.TxSha()
+		txShas, _ := blk.TxShas()
+		for _, txSha := range txShas {
 			var txUo txUpdateObj
 			txUo.delete = true
-			db.txUpdateMap[txSha] = &txUo
+			db.txUpdateMap[*txSha] = &txUo
 		}
 		db.lBatch().Delete(shaBlkToKey(blksha))
 		db.lBatch().Delete(int64ToKey(height))
@@ -347,8 +347,7 @@ func (db *LevelDb) InsertBlock(block *btcutil.Block) (height int64, rerr error)
 	// miners, the sha of the transaction exists in a previous block,
 	// detect this condition and 'accept' the block.
 	for txidx, tx := range mblock.Transactions {
-		var txsha btcwire.ShaHash
-		txsha, err = tx.TxSha()
+		txsha, err := block.TxSha(txidx)
 		if err != nil {
 			log.Warnf("failed to compute tx name block %v idx %v err %v", blocksha, txidx, err)
 			return 0, err
@@ -362,7 +361,7 @@ func (db *LevelDb) InsertBlock(block *btcutil.Block) (height int64, rerr error)
 			if err != nil {
 				panic("invalid sha string in source")
 			}
-			if txsha == *dupsha {
+			if txsha.IsEqual(dupsha) {
 				//log.Tracef("skipping sha %v %v", dupsha, newheight)
 				continue
 			}
@@ -372,7 +371,7 @@ func (db *LevelDb) InsertBlock(block *btcutil.Block) (height int64, rerr error)
 			if err != nil {
 				panic("invalid sha string in source")
 			}
-			if txsha == *dupsha {
+			if txsha.IsEqual(dupsha) {
 				//log.Tracef("skipping sha %v %v", dupsha, newheight)
 				continue
 			}
@@ -385,15 +384,15 @@ func (db *LevelDb) InsertBlock(block *btcutil.Block) (height int64, rerr error)
 			}
 		}
 
-		err = db.insertTx(&txsha, newheight, txloc[txidx].TxStart, txloc[txidx].TxLen, spentbuf)
+		err = db.insertTx(txsha, newheight, txloc[txidx].TxStart, txloc[txidx].TxLen, spentbuf)
 		if err != nil {
-			log.Warnf("block %v idx %v failed to insert tx %v %v err %v", blocksha, newheight, &txsha, txidx, err)
+			log.Warnf("block %v idx %v failed to insert tx %v %v err %v", blocksha, newheight, txsha, txidx, err)
 
 			return
 		}
 		err = db.doSpend(tx)
 		if err != nil {
-			log.Warnf("block %v idx %v failed to spend tx %v %v err %v", blocksha, newheight, &txsha, txidx, err)
+			log.Warnf("block %v idx %v failed to spend tx %v %v err %v", blocksha, newheight, txsha, txidx, err)
 
 			return
 		}