From 38e5d7262c25cf69c5a5ff9f570dc627d0968787 Mon Sep 17 00:00:00 2001
From: siddontang <siddontang@gmail.com>
Date: Mon, 10 Nov 2014 11:07:21 +0800
Subject: [PATCH] leveldb batch support data

optimize later
---
 store/leveldb/batch.go | 35 +++++++++++++++++++++++++++++++++--
 store/leveldb/db.go    |  7 +------
 2 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/store/leveldb/batch.go b/store/leveldb/batch.go
index 777e11c..542a322 100644
--- a/store/leveldb/batch.go
+++ b/store/leveldb/batch.go
@@ -7,22 +7,45 @@ package leveldb
 import "C"
 
 import (
+	"github.com/siddontang/goleveldb/leveldb"
 	"unsafe"
 )
 
+/*
+	It's not easy to let leveldb support Data() function like rocksdb,
+	so here, we will use goleveldb batch instead
+
+	later optimize
+*/
+
 type WriteBatch struct {
 	db     *DB
 	wbatch *C.leveldb_writebatch_t
+
+	gbatch *leveldb.Batch
+}
+
+func newWriteBatch(db *DB) *WriteBatch {
+	w := new(WriteBatch)
+	w.db = db
+	w.wbatch = C.leveldb_writebatch_create()
+	w.gbatch = new(leveldb.Batch)
+
+	return w
 }
 
 func (w *WriteBatch) Close() error {
 	C.leveldb_writebatch_destroy(w.wbatch)
 	w.wbatch = nil
 
+	w.gbatch = nil
+
 	return nil
 }
 
 func (w *WriteBatch) Put(key, value []byte) {
+	w.gbatch.Put(key, value)
+
 	var k, v *C.char
 	if len(key) != 0 {
 		k = (*C.char)(unsafe.Pointer(&key[0]))
@@ -38,20 +61,29 @@ func (w *WriteBatch) Put(key, value []byte) {
 }
 
 func (w *WriteBatch) Delete(key []byte) {
+	w.gbatch.Delete(key)
+
 	C.leveldb_writebatch_delete(w.wbatch,
 		(*C.char)(unsafe.Pointer(&key[0])), C.size_t(len(key)))
 }
 
 func (w *WriteBatch) Commit() error {
+	w.gbatch.Reset()
+
 	return w.commit(w.db.writeOpts)
 }
 
 func (w *WriteBatch) SyncCommit() error {
+	w.gbatch.Reset()
+
 	return w.commit(w.db.syncOpts)
 }
 
 func (w *WriteBatch) Rollback() error {
 	C.leveldb_writebatch_clear(w.wbatch)
+
+	w.gbatch.Reset()
+
 	return nil
 }
 
@@ -65,6 +97,5 @@ func (w *WriteBatch) commit(wb *WriteOptions) error {
 }
 
 func (w *WriteBatch) Data() []byte {
-	//todo later
-	return nil
+	return w.gbatch.Dump()
 }
diff --git a/store/leveldb/db.go b/store/leveldb/db.go
index e5ab88c..a2d9c26 100644
--- a/store/leveldb/db.go
+++ b/store/leveldb/db.go
@@ -182,12 +182,7 @@ func (db *DB) SyncDelete(key []byte) error {
 }
 
 func (db *DB) NewWriteBatch() driver.IWriteBatch {
-	wb := &WriteBatch{
-		db:     db,
-		wbatch: C.leveldb_writebatch_create(),
-	}
-
-	return wb
+	return newWriteBatch(db)
 }
 
 func (db *DB) NewIterator() driver.IIterator {