Merge pull request #1272 from Roasbeef/remove-bucket-autocreation

channeldb: modify updateChanBucket to no longer auto-create buckets

channeldb/channel.go

@@ -504,44 +504,47 @@ func (c *OpenChannel) RefreshShortChanID() error {
 // updateChanBucket is a helper function that returns a writable bucket that a
 // channel's data resides in given: the public key for the node, the outpoint,
 // and the chainhash that the channel resides on.
+//
+// NOTE: This function assumes that all the relevant descendent buckets already
+// exist.
 func updateChanBucket(tx *bolt.Tx, nodeKey *btcec.PublicKey,
 	outPoint *wire.OutPoint, chainHash chainhash.Hash) (*bolt.Bucket, error) {
 
 	// First fetch the top level bucket which stores all data related to
 	// current, active channels.
-	openChanBucket, err := tx.CreateBucketIfNotExists(openChannelBucket)
+	openChanBucket := tx.Bucket(openChannelBucket)
-	if err != nil {
+	if openChanBucket == nil {
-		return nil, err
+		return nil, ErrNoChanDBExists
 	}
 
 	// Within this top level bucket, fetch the bucket dedicated to storing
 	// open channel data specific to the remote node.
 	nodePub := nodeKey.SerializeCompressed()
-	nodeChanBucket, err := openChanBucket.CreateBucketIfNotExists(nodePub)
+	nodeChanBucket := openChanBucket.Bucket(nodePub)
-	if err != nil {
+	if nodeChanBucket == nil {
-		return nil, err
+		return nil, ErrNoActiveChannels
 	}
 
 	// We'll then recurse down an additional layer in order to fetch the
 	// bucket for this particular chain.
 	chainBucket, err := nodeChanBucket.CreateBucketIfNotExists(chainHash[:])
 	if err != nil {
-		return nil, err
+		return nil, ErrNodeNotFound
 	}
 
 	// With the bucket for the node fetched, we can now go down another
 	// level, creating the bucket (if it doesn't exist), for this channel
 	// itself.
 	var chanPointBuf bytes.Buffer
-	chanPointBuf.Grow(outPointSize)
 	if err := writeOutpoint(&chanPointBuf, outPoint); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("unable to write outpoint: %v", err)
 	}
 	chanBucket, err := chainBucket.CreateBucketIfNotExists(
 		chanPointBuf.Bytes(),
 	)
-	if err != nil {
+	if chanBucket == nil {
-		return nil, err
+		return nil, fmt.Errorf("unable to find bucket for "+
+			"chan_point=%v", outPoint)
 	}
 
 	return chanBucket, nil
@@ -578,7 +581,6 @@ func readChanBucket(tx *bolt.Tx, nodeKey *btcec.PublicKey,
 	// With the bucket for the node fetched, we can now go down another
 	// level, for this channel itself.
 	var chanPointBuf bytes.Buffer
-	chanPointBuf.Grow(outPointSize)
 	if err := writeOutpoint(&chanPointBuf, outPoint); err != nil {
 		return nil, err
 	}
@@ -595,8 +597,38 @@ func readChanBucket(tx *bolt.Tx, nodeKey *btcec.PublicKey,
 // to sync the contents of an OpenChannel while re-using an existing database
 // transaction.
 func (c *OpenChannel) fullSync(tx *bolt.Tx) error {
-	chanBucket, err := updateChanBucket(tx, c.IdentityPub,
+	// First fetch the top level bucket which stores all data related to
-		&c.FundingOutpoint, c.ChainHash)
+	// current, active channels.
+	openChanBucket, err := tx.CreateBucketIfNotExists(openChannelBucket)
+	if err != nil {
+		return err
+	}
+
+	// Within this top level bucket, fetch the bucket dedicated to storing
+	// open channel data specific to the remote node.
+	nodePub := c.IdentityPub.SerializeCompressed()
+	nodeChanBucket, err := openChanBucket.CreateBucketIfNotExists(nodePub)
+	if err != nil {
+		return err
+	}
+
+	// We'll then recurse down an additional layer in order to fetch the
+	// bucket for this particular chain.
+	chainBucket, err := nodeChanBucket.CreateBucketIfNotExists(c.ChainHash[:])
+	if err != nil {
+		return err
+	}
+
+	// With the bucket for the node fetched, we can now go down another
+	// level, creating the bucket (if it doesn't exist), for this channel
+	// itself.
+	var chanPointBuf bytes.Buffer
+	if err := writeOutpoint(&chanPointBuf, &c.FundingOutpoint); err != nil {
+		return err
+	}
+	chanBucket, err := chainBucket.CreateBucketIfNotExists(
+		chanPointBuf.Bytes(),
+	)
 	if err != nil {
 		return err
 	}
@@ -611,8 +643,9 @@ func (c *OpenChannel) MarkAsOpen(openLoc lnwire.ShortChannelID) error {
 	defer c.Unlock()
 
 	if err := c.Db.Update(func(tx *bolt.Tx) error {
-		chanBucket, err := updateChanBucket(tx, c.IdentityPub,
+		chanBucket, err := updateChanBucket(
-			&c.FundingOutpoint, c.ChainHash)
+			tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
+		)
 		if err != nil {
 			return err
 		}
@@ -658,8 +691,9 @@ func (c *OpenChannel) MarkCommitmentBroadcasted() error {
 
 func (c *OpenChannel) putChanStatus(status ChannelStatus) error {
 	if err := c.Db.Update(func(tx *bolt.Tx) error {
-		chanBucket, err := updateChanBucket(tx, c.IdentityPub,
+		chanBucket, err := updateChanBucket(
-			&c.FundingOutpoint, c.ChainHash)
+			tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
+		)
 		if err != nil {
 			return err
 		}
@@ -795,8 +829,9 @@ func (c *OpenChannel) UpdateCommitment(newCommitment *ChannelCommitment) error {
 	defer c.Unlock()
 
 	err := c.Db.Update(func(tx *bolt.Tx) error {
-		chanBucket, err := updateChanBucket(tx, c.IdentityPub,
+		chanBucket, err := updateChanBucket(
-			&c.FundingOutpoint, c.ChainHash)
+			tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
+		)
 		if err != nil {
 			return err
 		}
@@ -1215,8 +1250,9 @@ func (c *OpenChannel) AppendRemoteCommitChain(diff *CommitDiff) error {
 	return c.Db.Update(func(tx *bolt.Tx) error {
 		// First, we'll grab the writable bucket where this channel's
 		// data resides.
-		chanBucket, err := updateChanBucket(tx, c.IdentityPub,
+		chanBucket, err := updateChanBucket(
-			&c.FundingOutpoint, c.ChainHash)
+			tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
+		)
 		if err != nil {
 			return err
 		}
@@ -1305,8 +1341,9 @@ func (c *OpenChannel) InsertNextRevocation(revKey *btcec.PublicKey) error {
 	c.RemoteNextRevocation = revKey
 
 	err := c.Db.Update(func(tx *bolt.Tx) error {
-		chanBucket, err := updateChanBucket(tx, c.IdentityPub,
+		chanBucket, err := updateChanBucket(
-			&c.FundingOutpoint, c.ChainHash)
+			tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
+		)
 		if err != nil {
 			return err
 		}
@@ -1334,8 +1371,9 @@ func (c *OpenChannel) AdvanceCommitChainTail(fwdPkg *FwdPkg) error {
 	var newRemoteCommit *ChannelCommitment
 
 	err := c.Db.Update(func(tx *bolt.Tx) error {
-		chanBucket, err := updateChanBucket(tx, c.IdentityPub,
+		chanBucket, err := updateChanBucket(
-			&c.FundingOutpoint, c.ChainHash)
+			tx, c.IdentityPub, &c.FundingOutpoint, c.ChainHash,
+		)
 		if err != nil {
 			return err
 		}
@@ -1724,7 +1762,6 @@ func (c *OpenChannel) CloseChannel(summary *ChannelCloseSummary) error {
 		}
 
 		var chanPointBuf bytes.Buffer
-		chanPointBuf.Grow(outPointSize)
 		err := writeOutpoint(&chanPointBuf, &c.FundingOutpoint)
 		if err != nil {
 			return err