Migrate to LevelDB

Signed-off-by: Yuan Si <do4suki@gmail.com>

database/leveldb.go

@@ -0,0 +1,69 @@
+package database
+
+import (
+	"errors"
+	"honoka-chan/config"
+
+	"github.com/syndtr/goleveldb/leveldb"
+	"github.com/syndtr/goleveldb/leveldb/util"
+)
+
+type LevelDbImpl struct {
+	ldb *leveldb.DB
+}
+
+var (
+	LevelDb LevelDbImpl
+	err     error
+)
+
+func init() {
+	LevelDb.InitDb()
+}
+
+func (ldb *LevelDbImpl) InitDb() {
+	ldb.ldb, err = leveldb.OpenFile(config.Conf.LevelDb.DataPath, nil)
+	if err != nil {
+		panic(err.Error())
+	}
+}
+
+func (ldb *LevelDbImpl) Get(key []byte) (res []byte, err error) {
+	if len(key) == 0 {
+		return nil, errors.New("key is null")
+	}
+	res, err = ldb.ldb.Get(key, nil)
+	if err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+func (ldb *LevelDbImpl) Put(key, value []byte) (err error) {
+	if len(key) == 0 {
+		return errors.New("key is null")
+	}
+	err = ldb.ldb.Put(key, value, nil)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (ldb *LevelDbImpl) List() (res map[string]string) {
+	res = make(map[string]string)
+	iter := ldb.ldb.NewIterator(nil, nil)
+	for iter.Next() {
+		res[string(iter.Key())] = string(iter.Value())
+	}
+	return res
+}
+
+func (ldb *LevelDbImpl) ListPrefix(prefix []byte) (res map[string]string) {
+	res = make(map[string]string)
+	iter := ldb.ldb.NewIterator(util.BytesPrefix(prefix), nil)
+	for iter.Next() {
+		res[string(iter.Key())] = string(iter.Value())
+	}
+	return res
+}