diff options
Diffstat (limited to 'vendor/github.com/byzantine-lab/dexon-consensus/core/blockdb/memory.go')
-rw-r--r-- | vendor/github.com/byzantine-lab/dexon-consensus/core/blockdb/memory.go | 183 |
1 files changed, 0 insertions, 183 deletions
diff --git a/vendor/github.com/byzantine-lab/dexon-consensus/core/blockdb/memory.go b/vendor/github.com/byzantine-lab/dexon-consensus/core/blockdb/memory.go deleted file mode 100644 index b45af229b..000000000 --- a/vendor/github.com/byzantine-lab/dexon-consensus/core/blockdb/memory.go +++ /dev/null @@ -1,183 +0,0 @@ -// 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 blockdb - -import ( - "encoding/json" - "io/ioutil" - "os" - "sync" - - "github.com/dexon-foundation/dexon-consensus/common" - "github.com/dexon-foundation/dexon-consensus/core/types" -) - -type seqIterator struct { - idx int - db *MemBackedBlockDB -} - -func (seq *seqIterator) Next() (types.Block, error) { - curIdx := seq.idx - seq.idx++ - return seq.db.getByIndex(curIdx) -} - -// MemBackedBlockDB is a memory backed BlockDB implementation. -type MemBackedBlockDB struct { - blocksMutex sync.RWMutex - blockHashSequence common.Hashes - blocksByHash map[common.Hash]*types.Block - persistantFilePath string -} - -// NewMemBackedBlockDB initialize a memory-backed block database. -func NewMemBackedBlockDB(persistantFilePath ...string) (db *MemBackedBlockDB, err error) { - db = &MemBackedBlockDB{ - blockHashSequence: common.Hashes{}, - blocksByHash: make(map[common.Hash]*types.Block), - } - if len(persistantFilePath) == 0 || len(persistantFilePath[0]) == 0 { - return - } - db.persistantFilePath = persistantFilePath[0] - buf, err := ioutil.ReadFile(db.persistantFilePath) - if err != nil { - if !os.IsNotExist(err) { - // Something unexpected happened. - return - } - // It's expected behavior that file doesn't exists, we should not - // report error on it. - err = nil - return - } - - // Init this instance by file content, it's a temporary way - // to export those private field for JSON encoding. - toLoad := struct { - Sequence common.Hashes - ByHash map[common.Hash]*types.Block - }{} - err = json.Unmarshal(buf, &toLoad) - if err != nil { - return - } - db.blockHashSequence = toLoad.Sequence - db.blocksByHash = toLoad.ByHash - return -} - -// Has returns wheter or not the DB has a block identified with the hash. -func (m *MemBackedBlockDB) Has(hash common.Hash) bool { - m.blocksMutex.RLock() - defer m.blocksMutex.RUnlock() - - _, ok := m.blocksByHash[hash] - return ok -} - -// Get returns a block given a hash. -func (m *MemBackedBlockDB) Get(hash common.Hash) (types.Block, error) { - m.blocksMutex.RLock() - defer m.blocksMutex.RUnlock() - - return m.internalGet(hash) -} - -func (m *MemBackedBlockDB) internalGet(hash common.Hash) (types.Block, error) { - b, ok := m.blocksByHash[hash] - if !ok { - return types.Block{}, ErrBlockDoesNotExist - } - return *b, nil -} - -// Put inserts a new block into the database. -func (m *MemBackedBlockDB) Put(block types.Block) error { - if m.Has(block.Hash) { - return ErrBlockExists - } - - m.blocksMutex.Lock() - defer m.blocksMutex.Unlock() - - m.blockHashSequence = append(m.blockHashSequence, block.Hash) - m.blocksByHash[block.Hash] = &block - return nil -} - -// Update updates a block in the database. -func (m *MemBackedBlockDB) Update(block types.Block) error { - if !m.Has(block.Hash) { - return ErrBlockDoesNotExist - } - - m.blocksMutex.Lock() - defer m.blocksMutex.Unlock() - - m.blocksByHash[block.Hash] = &block - return nil -} - -// Close implement Closer interface, which would release allocated resource. -func (m *MemBackedBlockDB) Close() (err error) { - // Save internal state to a pretty-print json file. It's a temporary way - // to dump private file via JSON encoding. - if len(m.persistantFilePath) == 0 { - return - } - - m.blocksMutex.RLock() - defer m.blocksMutex.RUnlock() - - toDump := struct { - Sequence common.Hashes - ByHash map[common.Hash]*types.Block - }{ - Sequence: m.blockHashSequence, - ByHash: m.blocksByHash, - } - - // Dump to JSON with 2-space indent. - buf, err := json.Marshal(&toDump) - if err != nil { - return - } - - err = ioutil.WriteFile(m.persistantFilePath, buf, 0644) - return -} - -func (m *MemBackedBlockDB) getByIndex(idx int) (types.Block, error) { - m.blocksMutex.RLock() - defer m.blocksMutex.RUnlock() - - if idx >= len(m.blockHashSequence) { - return types.Block{}, ErrIterationFinished - } - - hash := m.blockHashSequence[idx] - return m.internalGet(hash) -} - -// GetAll implement Reader.GetAll method, which allows caller -// to retrieve all blocks in DB. -func (m *MemBackedBlockDB) GetAll() (BlockIterator, error) { - return &seqIterator{db: m}, nil -} |