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Diffstat (limited to 'core/blockdb/level-db.go')
-rw-r--r-- | core/blockdb/level-db.go | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/core/blockdb/level-db.go b/core/blockdb/level-db.go new file mode 100644 index 0000000..79099c0 --- /dev/null +++ b/core/blockdb/level-db.go @@ -0,0 +1,127 @@ +// Copyright 2018 The dexon-consensus-core Authors +// This file is part of the dexon-consensus-core library. +// +// The dexon-consensus-core 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-core 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-core library. If not, see +// <http://www.gnu.org/licenses/>. + +package blockdb + +import ( + "encoding/json" + + "github.com/syndtr/goleveldb/leveldb" + + "github.com/dexon-foundation/dexon-consensus-core/common" + "github.com/dexon-foundation/dexon-consensus-core/core/types" +) + +// LevelDBBackedBlockDB is a leveldb backed BlockDB implementation. +type LevelDBBackedBlockDB struct { + db *leveldb.DB +} + +// NewLevelDBBackedBlockDB initialize a leveldb-backed block database. +func NewLevelDBBackedBlockDB( + path string) (lvl *LevelDBBackedBlockDB, err error) { + + db, err := leveldb.OpenFile(path, nil) + if err != nil { + return + } + lvl = &LevelDBBackedBlockDB{db: db} + return +} + +// Close implement Closer interface, which would release allocated resource. +func (lvl *LevelDBBackedBlockDB) Close() error { + return lvl.db.Close() +} + +// Has implements the Reader.Has method. +func (lvl *LevelDBBackedBlockDB) Has(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 +} + +// Get implements the Reader.Get method. +func (lvl *LevelDBBackedBlockDB) Get( + 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 +} + +// Update implements the Writer.Update method. +func (lvl *LevelDBBackedBlockDB) Update(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.Has(block.Hash) { + err = ErrBlockDoesNotExist + return + } + err = lvl.db.Put( + []byte(block.Hash[:]), + marshaled, + nil) + if err != nil { + return + } + return +} + +// Put implements the Writer.Put method. +func (lvl *LevelDBBackedBlockDB) Put(block types.Block) (err error) { + marshaled, err := json.Marshal(&block) + if err != nil { + return + } + if lvl.Has(block.Hash) { + err = ErrBlockExists + return + } + err = lvl.db.Put( + []byte(block.Hash[:]), + marshaled, + nil) + if err != nil { + return + } + return +} + +// GetAll implements Reader.GetAll method, which allows callers +// to retrieve all blocks in DB. +func (lvl *LevelDBBackedBlockDB) GetAll() (BlockIterator, error) { + // TODO (mission): Implement this part via goleveldb's iterator. + return nil, ErrNotImplemented +} |