Update for recent btcdb API changes.

Since the underlying database driver can now return an error when looking
up if blocks and transactions exist, the HaveBlock function now includes
an error return to allow any underlying errors to be exposed.

chain.go

@@ -175,8 +175,12 @@ func (b *BlockChain) DisableVerify(disable bool) {
 // be like part of the main chain, on a side chain, or in the orphan pool.
 //
 // This function is NOT safe for concurrent access.
-func (b *BlockChain) HaveBlock(hash *btcwire.ShaHash) bool {
+func (b *BlockChain) HaveBlock(hash *btcwire.ShaHash) (bool, error) {
-	return b.IsKnownOrphan(hash) || b.blockExists(hash)
+	exists, err := b.blockExists(hash)
+	if err != nil {
+		return false, err
+	}
+	return b.IsKnownOrphan(hash) || exists, nil
 }
 
 // IsKnownOrphan returns whether the passed hash is currently a known orphan.

chain_test.go

@@ -97,7 +97,11 @@ func TestHaveBlock(t *testing.T) {
 			continue
 		}
 
-		result := chain.HaveBlock(hash)
+		result, err := chain.HaveBlock(hash)
+		if err != nil {
+			t.Errorf("HaveBlock #%d unexpected error: %v", i, err)
+			return
+		}
 		if result != test.want {
 			t.Errorf("HaveBlock #%d got %v want %v", i, result,
 				test.want)

checkpoints.go

@@ -103,7 +103,12 @@ func (b *BlockChain) findPreviousCheckpoint() (*btcutil.Block, error) {
 		// that we already have.
 		checkpointIndex := -1
 		for i := numCheckpoints - 1; i >= 0; i-- {
-			if b.db.ExistsSha(checkpoints[i].Hash) {
+			exists, err := b.db.ExistsSha(checkpoints[i].Hash)
+			if err != nil {
+				return nil, err
+			}
+
+			if exists {
 				checkpointIndex = i
 				break
 			}
@@ -222,7 +227,11 @@ func (b *BlockChain) IsCheckpointCandidate(block *btcutil.Block) (bool, error) {
 	}
 
 	// A checkpoint must be in the main chain.
-	if !b.db.ExistsSha(blockHash) {
+	exists, err := b.db.ExistsSha(blockHash)
+	if err != nil {
+		return false, err
+	}
+	if !exists {
 		return false, nil
 	}
 

process.go

@@ -38,10 +38,10 @@ const (
 
 // blockExists determines whether a block with the given hash exists either in
 // the main chain or any side chains.
-func (b *BlockChain) blockExists(hash *btcwire.ShaHash) bool {
+func (b *BlockChain) blockExists(hash *btcwire.ShaHash) (bool, error) {
 	// Check memory chain first (could be main chain or side chain blocks).
 	if _, ok := b.index[*hash]; ok {
-		return true
+		return true, nil
 	}
 
 	// Check in database (rest of main chain not in memory).
@@ -125,7 +125,11 @@ func (b *BlockChain) ProcessBlock(block *btcutil.Block, flags BehaviorFlags) (bo
 	log.Tracef("Processing block %v", blockHash)
 
 	// The block must not already exist in the main chain or side chains.
-	if b.blockExists(blockHash) {
+	exists, err := b.blockExists(blockHash)
+	if err != nil {
+		return false, err
+	}
+	if exists {
 		str := fmt.Sprintf("already have block %v", blockHash)
 		return false, ruleError(ErrDuplicateBlock, str)
 	}
@@ -185,7 +189,12 @@ func (b *BlockChain) ProcessBlock(block *btcutil.Block, flags BehaviorFlags) (bo
 
 	// Handle orphan blocks.
 	prevHash := &blockHeader.PrevBlock
-	if !prevHash.IsEqual(zeroHash) && !b.blockExists(prevHash) {
+	if !prevHash.IsEqual(zeroHash) {
+		prevHashExists, err := b.blockExists(prevHash)
+		if err != nil {
+			return false, err
+		}
+		if !prevHashExists {
 			if !dryRun {
 				log.Infof("Adding orphan block %v with parent %v",
 					blockHash, prevHash)
@@ -194,6 +203,7 @@ func (b *BlockChain) ProcessBlock(block *btcutil.Block, flags BehaviorFlags) (bo
 
 			return true, nil
 		}
+	}
 
 	// The block has passed all context independent checks and appears sane
 	// enough to potentially accept it into the block chain.