Refactor: add and use db.NamespacedKV

internal/db/blockmap.go

@@ -199,7 +199,7 @@ func (f *BlockFinder) Fix(folder, file string, index int32, oldHash, newHash []b
 //	   file name (variable size)
 func toBlockKey(hash []byte, folder, file string) []byte {
 	o := make([]byte, 1+64+32+len(file))
-	o[0] = keyTypeBlock
+	o[0] = KeyTypeBlock
 	copy(o[1:], []byte(folder))
 	copy(o[1+64:], []byte(hash))
 	copy(o[1+64+32:], []byte(file))
@@ -210,7 +210,7 @@ func fromBlockKey(data []byte) (string, string) {
 	if len(data) < 1+64+32+1 {
 		panic("Incorrect key length")
 	}
-	if data[0] != keyTypeBlock {
+	if data[0] != KeyTypeBlock {
 		panic("Incorrect key type")
 	}
 

internal/db/leveldb.go

@@ -50,9 +50,11 @@ func clock(v int64) int64 {
 }
 
 const (
-	keyTypeDevice = iota
-	keyTypeGlobal
-	keyTypeBlock
+	KeyTypeDevice = iota
+	KeyTypeGlobal
+	KeyTypeBlock
+	KeyTypeDeviceStatistic
+	KeyTypeFolderStatistic
 )
 
 type fileVersion struct {
@@ -112,7 +114,7 @@ const batchFlushSize = 64
 //	   name (variable size)
 func deviceKey(folder, device, file []byte) []byte {
 	k := make([]byte, 1+64+32+len(file))
-	k[0] = keyTypeDevice
+	k[0] = KeyTypeDevice
 	if len(folder) > 64 {
 		panic("folder name too long")
 	}
@@ -145,7 +147,7 @@ func deviceKeyDevice(key []byte) []byte {
 //	   name (variable size)
 func globalKey(folder, file []byte) []byte {
 	k := make([]byte, 1+64+len(file))
-	k[0] = keyTypeGlobal
+	k[0] = KeyTypeGlobal
 	if len(folder) > 64 {
 		panic("folder name too long")
 	}
@@ -915,7 +917,7 @@ func ldbListFolders(db *leveldb.DB) []string {
 		snap.Release()
 	}()
 
-	dbi := snap.NewIterator(util.BytesPrefix([]byte{keyTypeGlobal}), nil)
+	dbi := snap.NewIterator(util.BytesPrefix([]byte{KeyTypeGlobal}), nil)
 	defer dbi.Release()
 
 	folderExists := make(map[string]bool)
@@ -953,7 +955,7 @@ func ldbDropFolder(db *leveldb.DB, folder []byte) {
 	}()
 
 	// Remove all items related to the given folder from the device->file bucket
-	dbi := snap.NewIterator(util.BytesPrefix([]byte{keyTypeDevice}), nil)
+	dbi := snap.NewIterator(util.BytesPrefix([]byte{KeyTypeDevice}), nil)
 	for dbi.Next() {
 		itemFolder := deviceKeyFolder(dbi.Key())
 		if bytes.Compare(folder, itemFolder) == 0 {
@@ -963,7 +965,7 @@ func ldbDropFolder(db *leveldb.DB, folder []byte) {
 	dbi.Release()
 
 	// Remove all items related to the given folder from the global bucket
-	dbi = snap.NewIterator(util.BytesPrefix([]byte{keyTypeGlobal}), nil)
+	dbi = snap.NewIterator(util.BytesPrefix([]byte{KeyTypeGlobal}), nil)
 	for dbi.Next() {
 		itemFolder := globalKeyFolder(dbi.Key())
 		if bytes.Compare(folder, itemFolder) == 0 {

internal/db/namespaced.go

@@ -0,0 +1,106 @@
+// Copyright (C) 2014 The Syncthing Authors.
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+// more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program. If not, see <http://www.gnu.org/licenses/>.
+
+package db
+
+import (
+	"encoding/binary"
+	"time"
+
+	"github.com/syndtr/goleveldb/leveldb"
+)
+
+// NamespacedKV is a simple key-value store using a specific namespace within
+// a leveldb.
+type NamespacedKV struct {
+	db     *leveldb.DB
+	prefix []byte
+}
+
+// NewNamespacedKV returns a new NamespacedKV that lives in the namespace
+// specified by the prefix.
+func NewNamespacedKV(db *leveldb.DB, prefix string) *NamespacedKV {
+	return &NamespacedKV{
+		db:     db,
+		prefix: []byte(prefix),
+	}
+}
+
+// PutInt64 stores a new int64. Any existing value (even if of another type)
+// is overwritten.
+func (n *NamespacedKV) PutInt64(key string, val int64) {
+	keyBs := append(n.prefix, []byte(key)...)
+	var valBs [8]byte
+	binary.BigEndian.PutUint64(valBs[:], uint64(val))
+	n.db.Put(keyBs, valBs[:], nil)
+}
+
+// Int64 returns the stored value interpreted as an int64 and a boolean that
+// is false if no value was stored at the key.
+func (n *NamespacedKV) Int64(key string) (int64, bool) {
+	keyBs := append(n.prefix, []byte(key)...)
+	valBs, err := n.db.Get(keyBs, nil)
+	if err != nil {
+		return 0, false
+	}
+	val := binary.BigEndian.Uint64(valBs)
+	return int64(val), true
+}
+
+// PutTime stores a new time.Time. Any existing value (even if of another
+// type) is overwritten.
+func (n *NamespacedKV) PutTime(key string, val time.Time) {
+	keyBs := append(n.prefix, []byte(key)...)
+	valBs, _ := val.MarshalBinary() // never returns an error
+	n.db.Put(keyBs, valBs, nil)
+}
+
+// Time returns the stored value interpreted as a time.Time and a boolean
+// that is false if no value was stored at the key.
+func (n NamespacedKV) Time(key string) (time.Time, bool) {
+	var t time.Time
+	keyBs := append(n.prefix, []byte(key)...)
+	valBs, err := n.db.Get(keyBs, nil)
+	if err != nil {
+		return t, false
+	}
+	err = t.UnmarshalBinary(valBs)
+	return t, err == nil
+}
+
+// PutString stores a new string. Any existing value (even if of another type)
+// is overwritten.
+func (n *NamespacedKV) PutString(key, val string) {
+	keyBs := append(n.prefix, []byte(key)...)
+	n.db.Put(keyBs, []byte(val), nil)
+}
+
+// String returns the stored value interpreted as a string and a boolean that
+// is false if no value was stored at the key.
+func (n NamespacedKV) String(key string) (string, bool) {
+	keyBs := append(n.prefix, []byte(key)...)
+	valBs, err := n.db.Get(keyBs, nil)
+	if err != nil {
+		return "", false
+	}
+	return string(valBs), true
+}
+
+// Delete deletes the specified key. It is allowed to delete a nonexistent
+// key.
+func (n NamespacedKV) Delete(key string) {
+	keyBs := append(n.prefix, []byte(key)...)
+	n.db.Delete(keyBs, nil)
+}

internal/db/namespaced_test.go

@@ -0,0 +1,101 @@
+// Copyright (C) 2014 The Syncthing Authors.
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+// more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program. If not, see <http://www.gnu.org/licenses/>.
+
+package db
+
+import (
+	"testing"
+	"time"
+
+	"github.com/syndtr/goleveldb/leveldb"
+	"github.com/syndtr/goleveldb/leveldb/storage"
+)
+
+func TestNamespacedInt(t *testing.T) {
+	ldb, err := leveldb.Open(storage.NewMemStorage(), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	n1 := NewNamespacedKV(ldb, "foo")
+	n2 := NewNamespacedKV(ldb, "bar")
+
+	// Key is missing to start with
+
+	if v, ok := n1.Int64("test"); v != 0 || ok {
+		t.Errorf("Incorrect return v %v != 0 || ok %v != false", v, ok)
+	}
+
+	n1.PutInt64("test", 42)
+
+	// It should now exist in n1
+
+	if v, ok := n1.Int64("test"); v != 42 || !ok {
+		t.Errorf("Incorrect return v %v != 42 || ok %v != true", v, ok)
+	}
+
+	// ... but not in n2, which is in a different namespace
+
+	if v, ok := n2.Int64("test"); v != 0 || ok {
+		t.Errorf("Incorrect return v %v != 0 || ok %v != false", v, ok)
+	}
+
+	n1.Delete("test")
+
+	// It should no longer exist
+
+	if v, ok := n1.Int64("test"); v != 0 || ok {
+		t.Errorf("Incorrect return v %v != 0 || ok %v != false", v, ok)
+	}
+}
+
+func TestNamespacedTime(t *testing.T) {
+	ldb, err := leveldb.Open(storage.NewMemStorage(), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	n1 := NewNamespacedKV(ldb, "foo")
+
+	if v, ok := n1.Time("test"); v != (time.Time{}) || ok {
+		t.Errorf("Incorrect return v %v != %v || ok %v != false", v, time.Time{}, ok)
+	}
+
+	now := time.Now()
+	n1.PutTime("test", now)
+
+	if v, ok := n1.Time("test"); v != now || !ok {
+		t.Errorf("Incorrect return v %v != %v || ok %v != true", v, now, ok)
+	}
+}
+
+func TestNamespacedString(t *testing.T) {
+	ldb, err := leveldb.Open(storage.NewMemStorage(), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	n1 := NewNamespacedKV(ldb, "foo")
+
+	if v, ok := n1.String("test"); v != "" || ok {
+		t.Errorf("Incorrect return v %q != \"\" || ok %v != false", v, ok)
+	}
+
+	n1.PutString("test", "yo")
+
+	if v, ok := n1.String("test"); v != "yo" || !ok {
+		t.Errorf("Incorrect return v %q != \"yo\" || ok %v != true", v, ok)
+	}
+}