Add RWTransaction.Delete().

db_test.go

@@ -191,6 +191,20 @@ func TestDBPutRandom(t *testing.T) {
 	}
 }
 
+// Ensure that a bucket can delete an existing key.
+func TestDBDelete(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.CreateBucket("widgets")
+		db.Put("widgets", []byte("foo"), []byte("bar"))
+		err := db.Delete("widgets", []byte("foo"))
+		assert.NoError(t, err)
+		value, err := db.Get("widgets", []byte("foo"))
+		if assert.NoError(t, err) {
+			assert.Nil(t, value)
+		}
+	})
+}
+
 // withDB executes a function with a database reference.
 func withDB(fn func(*DB, string)) {
 	f, _ := ioutil.TempFile("", "bolt-")

node.go

@@ -61,6 +61,20 @@ func (n *node) put(oldKey, newKey, value []byte, pgid pgid) {
 	inode.pgid = pgid
 }
 
+// del removes a key from the node.
+func (n *node) del(key []byte) {
+	// Find index of key.
+	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].key, key) != -1 })
+
+	// Exit if the key isn't found.
+	if !bytes.Equal(n.inodes[index].key, key) {
+		return
+	}
+
+	// Delete inode from the node.
+	n.inodes = append(n.inodes[:index], n.inodes[index+1:]...)
+}
+
 // read initializes the node from a page.
 func (n *node) read(p *page) {
 	n.pgid = p.id

rwtransaction.go

@@ -70,19 +70,29 @@ func (t *RWTransaction) Put(name string, key []byte, value []byte) error {
 		return &Error{"data too large", nil}
 	}
 
-	// Insert a new node.
+	// Move cursor to correct position.
 	c := b.cursor()
 	c.Get(key)
+
+	// Insert the key/value.
 	t.node(c.stack).put(key, key, value, 0)
 
 	return nil
 }
 
 func (t *RWTransaction) Delete(name string, key []byte) error {
-	// TODO: Traverse to the correct node.
-	// TODO: If missing, exit.
-	// TODO: Remove node from page.
-	// TODO: If page is empty then add it to the freelist.
+	b := t.Bucket(name)
+	if b == nil {
+		return &Error{"bucket not found", nil}
+	}
+
+	// Move cursor to correct position.
+	c := b.cursor()
+	c.Get(key)
+
+	// Delete the node if we have a matching key.
+	t.node(c.stack).del(key)
+
 	return nil
 }