diff options
Diffstat (limited to 'vendor/github.com/dexon-foundation/dexon-consensus/core/db/level-db.go')
-rw-r--r-- | vendor/github.com/dexon-foundation/dexon-consensus/core/db/level-db.go | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus/core/db/level-db.go b/vendor/github.com/dexon-foundation/dexon-consensus/core/db/level-db.go new file mode 100644 index 000000000..6983d3a5e --- /dev/null +++ b/vendor/github.com/dexon-foundation/dexon-consensus/core/db/level-db.go @@ -0,0 +1,127 @@ +// Copyright 2018 The dexon-consensus Authors +// This file is part of the dexon-consensus library. +// +// The dexon-consensus library is free software: you can redistribute it +// and/or modify it under the terms of the GNU Lesser General Public License as +// published by the Free Software Foundation, either version 3 of the License, +// or (at your option) any later version. +// +// The dexon-consensus library 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 Lesser +// General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the dexon-consensus library. If not, see +// <http://www.gnu.org/licenses/>. + +package db + +import ( + "encoding/json" + + "github.com/syndtr/goleveldb/leveldb" + + "github.com/dexon-foundation/dexon-consensus/common" + "github.com/dexon-foundation/dexon-consensus/core/types" +) + +// LevelDBBackedDB is a leveldb backed DB implementation. +type LevelDBBackedDB struct { + db *leveldb.DB +} + +// NewLevelDBBackedDB initialize a leveldb-backed database. +func NewLevelDBBackedDB( + path string) (lvl *LevelDBBackedDB, err error) { + + dbInst, err := leveldb.OpenFile(path, nil) + if err != nil { + return + } + lvl = &LevelDBBackedDB{db: dbInst} + return +} + +// Close implement Closer interface, which would release allocated resource. +func (lvl *LevelDBBackedDB) Close() error { + return lvl.db.Close() +} + +// HasBlock implements the Reader.Has method. +func (lvl *LevelDBBackedDB) HasBlock(hash common.Hash) bool { + exists, err := lvl.db.Has([]byte(hash[:]), nil) + if err != nil { + // TODO(missionliao): Modify the interface to return error. + panic(err) + } + return exists +} + +// GetBlock implements the Reader.GetBlock method. +func (lvl *LevelDBBackedDB) GetBlock( + hash common.Hash) (block types.Block, err error) { + + queried, err := lvl.db.Get([]byte(hash[:]), nil) + if err != nil { + if err == leveldb.ErrNotFound { + err = ErrBlockDoesNotExist + } + return + } + err = json.Unmarshal(queried, &block) + if err != nil { + return + } + return +} + +// UpdateBlock implements the Writer.UpdateBlock method. +func (lvl *LevelDBBackedDB) UpdateBlock(block types.Block) (err error) { + // NOTE: we didn't handle changes of block hash (and it + // should not happen). + marshaled, err := json.Marshal(&block) + if err != nil { + return + } + + if !lvl.HasBlock(block.Hash) { + err = ErrBlockDoesNotExist + return + } + err = lvl.db.Put( + []byte(block.Hash[:]), + marshaled, + nil) + if err != nil { + return + } + return +} + +// PutBlock implements the Writer.PutBlock method. +func (lvl *LevelDBBackedDB) PutBlock(block types.Block) (err error) { + marshaled, err := json.Marshal(&block) + if err != nil { + return + } + if lvl.HasBlock(block.Hash) { + err = ErrBlockExists + return + } + err = lvl.db.Put( + []byte(block.Hash[:]), + marshaled, + nil) + if err != nil { + return + } + return +} + +// GetAllBlocks implements Reader.GetAllBlocks method, which allows callers +// to retrieve all blocks in DB. +func (lvl *LevelDBBackedDB) GetAllBlocks() (BlockIterator, error) { + // TODO (mission): Implement this part via goleveldb's iterator. + return nil, ErrNotImplemented +} |