From 5b9d311f5dc06d447fd6019eb6845a77c1d09d88 Mon Sep 17 00:00:00 2001
From: siddontang <siddontang@gmail.com>
Date: Mon, 5 May 2014 17:00:11 +0800
Subject: [PATCH] add helper function, batch add explicit Close

---
 leveldb/batch.go        | 11 ++++----
 leveldb/db.go           | 57 +++++++++++++++++++++++++++++++++++++++++
 leveldb/leveldb_test.go |  3 ++-
 leveldb/snapshot.go     | 57 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 122 insertions(+), 6 deletions(-)

diff --git a/leveldb/batch.go b/leveldb/batch.go
index 945531c..f65226a 100644
--- a/leveldb/batch.go
+++ b/leveldb/batch.go
@@ -18,17 +18,18 @@ func (wb *WriteBatch) Delete(key []byte) {
 }
 
 func (wb *WriteBatch) Commit() error {
-	err := wb.db.db.Write(wb.db.writeOpts, wb.wb)
-	wb.close()
-	return err
+	return wb.db.db.Write(wb.db.writeOpts, wb.wb)
 }
 
 func (wb *WriteBatch) Rollback() {
 	wb.wb.Clear()
-	wb.close()
 }
 
-func (wb *WriteBatch) close() {
+func (wb *WriteBatch) Close() {
+	if wb.wb == nil {
+		return
+	}
+
 	wb.wb.Close()
 	wb.wb = nil
 }
diff --git a/leveldb/db.go b/leveldb/db.go
index 6da4160..5acd187 100644
--- a/leveldb/db.go
+++ b/leveldb/db.go
@@ -3,6 +3,8 @@ package leveldb
 import (
 	"encoding/json"
 	"github.com/jmhodges/levigo"
+	"github.com/siddontang/golib/hack"
+	"strconv"
 )
 
 const defaultFilterBits int = 10
@@ -155,3 +157,58 @@ func (db *DB) ReverseIterator(rbegin []byte, rend []byte, limit int) *Iterator {
 func (db *DB) NewSnapshot() *Snapshot {
 	return newSnapshot(db)
 }
+
+func (db *DB) GetInt(key []byte) (int64, error) {
+	v, err := db.Get(key)
+	if err != nil {
+		return 0, err
+	} else if v == nil {
+		return 0, nil
+	}
+
+	return strconv.ParseInt(hack.String(v), 10, 64)
+}
+
+func (db *DB) GetUInt(key []byte) (uint64, error) {
+	v, err := db.Get(key)
+	if err != nil {
+		return 0, err
+	} else if v == nil {
+		return 0, nil
+	}
+
+	return strconv.ParseUint(hack.String(v), 10, 64)
+}
+
+func (db *DB) GetFloat(key []byte) (float64, error) {
+	v, err := db.Get(key)
+	if err != nil {
+		return 0, err
+	} else if v == nil {
+		return 0, nil
+	}
+
+	return strconv.ParseFloat(hack.String(v), 64)
+}
+
+func (db *DB) GetString(key []byte) (string, error) {
+	v, err := db.Get(key)
+	if err != nil {
+		return "", err
+	} else if v == nil {
+		return "", nil
+	}
+
+	return hack.String(v), nil
+}
+
+func (db *DB) GetSlice(key []byte) ([]byte, error) {
+	v, err := db.Get(key)
+	if err != nil {
+		return nil, err
+	} else if v == nil {
+		return []byte{}, nil
+	}
+
+	return v, nil
+}
diff --git a/leveldb/leveldb_test.go b/leveldb/leveldb_test.go
index a31e5b4..06b94f8 100644
--- a/leveldb/leveldb_test.go
+++ b/leveldb/leveldb_test.go
@@ -73,6 +73,8 @@ func TestBatch(t *testing.T) {
 	db.Put(key2, value)
 
 	wb := db.NewWriteBatch()
+	defer wb.Close()
+
 	wb.Delete(key2)
 	wb.Put(key1, []byte("hello world2"))
 
@@ -92,7 +94,6 @@ func TestBatch(t *testing.T) {
 		t.Fatal(string(v))
 	}
 
-	wb = db.NewWriteBatch()
 	wb.Delete(key1)
 
 	wb.Rollback()
diff --git a/leveldb/snapshot.go b/leveldb/snapshot.go
index 0663b5c..1801bcc 100644
--- a/leveldb/snapshot.go
+++ b/leveldb/snapshot.go
@@ -2,6 +2,8 @@ package leveldb
 
 import (
 	"github.com/jmhodges/levigo"
+	"github.com/siddontang/golib/hack"
+	"strconv"
 )
 
 type Snapshot struct {
@@ -45,3 +47,58 @@ func (s *Snapshot) Iterator(begin []byte, end []byte, limit int) *Iterator {
 func (s *Snapshot) ReverseIterator(rbegin []byte, rend []byte, limit int) *Iterator {
 	return newIterator(s.db, s.iteratorOpts, rbegin, rend, limit, backward)
 }
+
+func (s *Snapshot) GetInt(key []byte) (int64, error) {
+	v, err := s.Get(key)
+	if err != nil {
+		return 0, err
+	} else if v == nil {
+		return 0, nil
+	}
+
+	return strconv.ParseInt(hack.String(v), 10, 64)
+}
+
+func (s *Snapshot) GetUInt(key []byte) (uint64, error) {
+	v, err := s.Get(key)
+	if err != nil {
+		return 0, err
+	} else if v == nil {
+		return 0, nil
+	}
+
+	return strconv.ParseUint(hack.String(v), 10, 64)
+}
+
+func (s *Snapshot) GetFloat(key []byte) (float64, error) {
+	v, err := s.Get(key)
+	if err != nil {
+		return 0, err
+	} else if v == nil {
+		return 0, nil
+	}
+
+	return strconv.ParseFloat(hack.String(v), 64)
+}
+
+func (s *Snapshot) GetString(key []byte) (string, error) {
+	v, err := s.Get(key)
+	if err != nil {
+		return "", err
+	} else if v == nil {
+		return "", nil
+	}
+
+	return hack.String(v), nil
+}
+
+func (s *Snapshot) GetSlice(key []byte) ([]byte, error) {
+	v, err := s.Get(key)
+	if err != nil {
+		return nil, err
+	} else if v == nil {
+		return []byte{}, nil
+	}
+
+	return v, nil
+}