Remove RWTransaction.Bucket().

Add an reference to the RWTransaction onto Transaction so that calls to
Transaction.Bucket() and Transaction.Buckets() return writable buckets
when attached to a writabe transaction.

rwtransaction.go

@@ -18,34 +18,13 @@ type RWTransaction struct {
 // init initializes the transaction.
 func (t *RWTransaction) init(db *DB) {
 	t.Transaction.init(db)
+	t.Transaction.rwtransaction = t
 	t.pages = make(map[pgid]*page)
 
 	// Increment the transaction id.
 	t.meta.txnid += txnid(1)
 }
 
-// Bucket retrieves a writable bucket by name.
-// Returns nil if the bucket does not exist.
-func (t *RWTransaction) Bucket(name string) *Bucket {
-	b := t.Transaction.Bucket(name)
-	if b == nil {
-		return nil
-	}
-
-	b.rwtransaction = t
-	return b
-}
-
-// Buckets retrieves a list of all buckets.
-// All returned buckets are writable.
-func (t *RWTransaction) Buckets() []*Bucket {
-	buckets := t.Transaction.Buckets()
-	for _, b := range buckets {
-		b.rwtransaction = t
-	}
-	return buckets
-}
-
 // CreateBucket creates a new bucket.
 // Returns an error if the bucket already exists, if the bucket name is blank, or if the bucket name is too long.
 func (t *RWTransaction) CreateBucket(name string) error {

transaction.go

@@ -9,6 +9,7 @@ package bolt
 // A long running read transaction can cause the database to quickly grow.
 type Transaction struct {
 	db            *DB
+	rwtransaction *RWTransaction
 	meta          *meta
 	buckets       *buckets
 	pages         map[pgid]*page
@@ -38,6 +39,9 @@ func (t *Transaction) id() txnid {
 
 // Close closes the transaction and releases any pages it is using.
 func (t *Transaction) Close() {
+	if t.rwtransaction != nil {
+		t.rwtransaction.Rollback()
+	}
 	t.db.removeTransaction(t)
 }
 
@@ -46,7 +50,7 @@ func (t *Transaction) DB() *DB {
 	return t.db
 }
 
-// Bucket retrieves a read-only bucket by name.
+// Bucket retrieves a bucket by name.
 // Returns nil if the bucket does not exist.
 func (t *Transaction) Bucket(name string) *Bucket {
 	b := t.buckets.get(name)
@@ -58,15 +62,20 @@ func (t *Transaction) Bucket(name string) *Bucket {
 		bucket:        b,
 		name:          name,
 		transaction:   t,
+		rwtransaction: t.rwtransaction,
 	}
 }
 
 // Buckets retrieves a list of all buckets.
-// All returned buckets are read-only.
 func (t *Transaction) Buckets() []*Bucket {
 	buckets := make([]*Bucket, 0, len(t.buckets.items))
 	for name, b := range t.buckets.items {
-		bucket := &Bucket{bucket: b, transaction: t, name: name}
+		bucket := &Bucket{
+			bucket:        b,
+			name:          name,
+			transaction:   t,
+			rwtransaction: t.rwtransaction,
+		}
 		buckets = append(buckets, bucket)
 	}
 	return buckets