Merge pull request #7 from benbjohnson/delete

RWTransaction.Delete()

cursor.go

@@ -41,7 +41,6 @@ func (c *Cursor) Get(key []byte) []byte {
 	}
 
 	// If our target node isn't the same key as what's passed in then return nil.
-	// c.page().hexdump(512)
 	if !bytes.Equal(key, c.node().key()) {
 		return nil
 	}

db_test.go

@@ -1,14 +1,11 @@
 package bolt
 
 import (
-	"bytes"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
 	"syscall"
 	"testing"
-	"testing/quick"
 	"time"
 	"unsafe"
 
@@ -156,39 +153,18 @@ func TestDBPut(t *testing.T) {
 	})
 }
 
-// Ensure that a bucket can write random keys and values across multiple txns.
-func TestDBPutRandom(t *testing.T) {
-	f := func(items testKeyValuePairs) bool {
-		withOpenDB(func(db *DB, path string) {
-			db.CreateBucket("widgets")
-			for _, item := range items {
-				if len(item.Key) == 0 {
-					continue
-				}
-				if err := db.Put("widgets", item.Key, item.Value); err != nil {
-					panic("put error: " + err.Error())
-				}
-			}
-			for _, item := range items {
-				if len(item.Key) == 0 {
-					continue
-				}
-				value, err := db.Get("widgets", item.Key)
-				if err != nil {
-					panic("get error: " + err.Error())
-				}
-				if !bytes.Equal(value, []byte(item.Value)) {
-					// db.CopyFile("/tmp/bolt.random.db")
-					t.Fatalf("value mismatch:\n%x\n%x", item.Value, value)
-				}
-			}
-			fmt.Fprint(os.Stderr, ".")
-		})
-		return true
-	}
-	if err := quick.Check(f, qc()); err != nil {
-		t.Error(err)
-	}
+// 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.

meta.go

@@ -1,6 +1,6 @@
 package bolt
 
-const magic uint32 = 0xDEADC0DE
+const magic uint32 = 0xED0CDAED
 
 type meta struct {
 	magic    uint32

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
@@ -134,14 +148,16 @@ func (n *node) split(pageSize int) []*node {
 	threshold := pageSize / 2
 
 	// Group into smaller pages and target a given fill size.
-	size := 0
-	current := &node{isLeaf: n.isLeaf}
-	nodes := make([]*node, 0)
+	size := pageHeaderSize
+	inodes := n.inodes
+	current := n
+	current.inodes = nil
+	var nodes []*node
 
-	for i, inode := range n.inodes {
+	for i, inode := range inodes {
 		elemSize := n.pageElementSize() + len(inode.key) + len(inode.value)
 
-		if len(current.inodes) >= minKeysPerPage && i < len(n.inodes)-minKeysPerPage && size+elemSize > threshold {
+		if len(current.inodes) >= minKeysPerPage && i < len(inodes)-minKeysPerPage && size+elemSize > threshold {
 			size = pageHeaderSize
 			nodes = append(nodes, current)
 			current = &node{isLeaf: n.isLeaf}

node_test.go

@@ -91,7 +91,7 @@ func TestNodeSplit(t *testing.T) {
 	n.put([]byte("00000004"), []byte("00000004"), []byte("0123456701234567"), 0)
 	n.put([]byte("00000005"), []byte("00000005"), []byte("0123456701234567"), 0)
 
-	// Split between 3 & 4.
+	// Split between 2 & 3.
 	nodes := n.split(100)
 
 	assert.Equal(t, len(nodes), 2)

quick_test.go

@@ -1,9 +1,13 @@
 package bolt
 
 import (
+	"bytes"
 	"flag"
+	"fmt"
 	"math/rand"
+	"os"
 	"reflect"
+	"testing"
 	"testing/quick"
 	"time"
 )
@@ -18,45 +22,78 @@ import (
 //   -quick.maxvsize  The maximum size of a value.
 //
 
-var seed, testMaxItemCount, testMaxKeySize, testMaxValueSize int
+var qseed, qmaxitems, qmaxksize, qmaxvsize int
 
 func init() {
-	flag.IntVar(&seed, "quick.seed", int(time.Now().UnixNano())%100000, "")
-	flag.IntVar(&testMaxItemCount, "quick.maxitems", 1024, "")
-	flag.IntVar(&testMaxKeySize, "quick.maxksize", 1024, "")
-	flag.IntVar(&testMaxValueSize, "quick.maxvsize", 1024, "")
-	warn("seed:", seed)
+	flag.IntVar(&qseed, "quick.seed", int(time.Now().UnixNano())%100000, "")
+	flag.IntVar(&qmaxitems, "quick.maxitems", 1000, "")
+	flag.IntVar(&qmaxksize, "quick.maxksize", 1024, "")
+	flag.IntVar(&qmaxvsize, "quick.maxvsize", 1024, "")
+	flag.Parse()
+	warn("seed:", qseed)
 }
 
-// qc creates a testing/quick configuration.
-func qc() *quick.Config {
-	return &quick.Config{Rand: rand.New(rand.NewSource(int64(seed)))}
+// Ensure that a bucket can write random keys and values across multiple txns.
+func TestQuickPut(t *testing.T) {
+	index := 0
+	f := func(items testdata) bool {
+		withOpenDB(func(db *DB, path string) {
+			m := make(map[string][]byte)
+
+			db.CreateBucket("widgets")
+
+			for _, item := range items {
+				if err := db.Put("widgets", item.Key, item.Value); err != nil {
+					panic("put error: " + err.Error())
+				}
+				m[string(item.Key)] = item.Value
+
+				// Verify all key/values so far.
+				i := 0
+				for k, v := range m {
+					value, err := db.Get("widgets", []byte(k))
+					if err != nil {
+						panic("get error: " + err.Error())
+					}
+					if !bytes.Equal(value, v) {
+						db.CopyFile("/tmp/bolt.random.db")
+						t.Fatalf("value mismatch [run %d] (%d of %d):\nkey: %x\ngot: %x\nexp: %x", index, i, len(m), []byte(k), v, value)
+					}
+					i++
+				}
+			}
+
+			fmt.Fprint(os.Stderr, ".")
+		})
+		index++
+		return true
+	}
+	if err := quick.Check(f, &quick.Config{Rand: rand.New(rand.NewSource(int64(qseed)))}); err != nil {
+		t.Error(err)
+	}
+	fmt.Fprint(os.Stderr, "\n")
 }
 
-type testKeyValuePairs []testKeyValuePair
+type testdata []testdataitem
 
-func (t testKeyValuePairs) Generate(rand *rand.Rand, size int) reflect.Value {
-	n := rand.Intn(testMaxItemCount-1) + 1
-	items := make(testKeyValuePairs, n)
+func (t testdata) Generate(rand *rand.Rand, size int) reflect.Value {
+	n := rand.Intn(qmaxitems-1) + 1
+	items := make(testdata, n)
 	for i := 0; i < n; i++ {
-		items[i].Generate(rand, size)
+		item := &items[i]
+		item.Key = randByteSlice(rand, 1, qmaxksize)
+		item.Value = randByteSlice(rand, 0, qmaxvsize)
 	}
 	return reflect.ValueOf(items)
 }
 
-type testKeyValuePair struct {
+type testdataitem struct {
 	Key   []byte
 	Value []byte
 }
 
-func (t testKeyValuePair) Generate(rand *rand.Rand, size int) reflect.Value {
-	t.Key = randByteSlice(rand, 1, testMaxKeySize)
-	t.Value = randByteSlice(rand, 0, testMaxValueSize)
-	return reflect.ValueOf(t)
-}
-
 func randByteSlice(rand *rand.Rand, minSize, maxSize int) []byte {
-	n := rand.Intn(maxSize - minSize) + minSize
+	n := rand.Intn(maxSize-minSize) + minSize
 	b := make([]byte, n)
 	for i := 0; i < n; i++ {
 		b[i] = byte(rand.Intn(255))

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
 }
 
@@ -237,7 +247,10 @@ func (t *RWTransaction) write() error {
 	for _, p := range pages {
 		size := (int(p.overflow) + 1) * t.db.pageSize
 		buf := (*[maxAllocSize]byte)(unsafe.Pointer(p))[:size]
-		t.db.file.WriteAt(buf, int64(p.id)*int64(t.db.pageSize))
+		offset := int64(p.id) * int64(t.db.pageSize)
+		if _, err := t.db.file.WriteAt(buf, offset); err != nil {
+			return err
+		}
 	}
 
 	return nil

sys.go

@@ -25,16 +25,6 @@ func (s *sys) get(key string) *bucket {
 	return s.buckets[key]
 }
 
-// getByRoot retrieves a bucket by root page id.
-func (s *sys) getByRoot(pgid pgid) *bucket {
-	for _, b := range s.buckets {
-		if b.root == pgid {
-			return b
-		}
-	}
-	panic("root not found")
-}
-
 // put sets a new value for a bucket.
 func (s *sys) put(key string, b *bucket) {
 	s.buckets[key] = b

transaction_test.go

@@ -0,0 +1,30 @@
+package bolt
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// Ensure that a Transaction can retrieve a bucket.
+func TestTransactionBucketMissing(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.CreateBucket("widgets")
+		b, err := db.Bucket("widgets")
+		assert.NoError(t, err)
+		if assert.NotNil(t, b) {
+			assert.Equal(t, "widgets", b.Name())
+		}
+	})
+}
+
+// Ensure that a Transaction retrieving a non-existent key returns nil.
+func TestTransactionGetMising(t *testing.T) {
+	withOpenDB(func(db *DB, path string) {
+		db.CreateBucket("widgets")
+		db.Put("widgets", []byte("foo"), []byte("bar"))
+		value, err := db.Get("widgets", []byte("no_such_key"))
+		assert.NoError(t, err)
+		assert.Nil(t, value)
+	})
+}