76 lines
1.9 KiB
Go
76 lines
1.9 KiB
Go
package db
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import (
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"github.com/syndtr/goleveldb/leveldb"
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"github.com/syndtr/goleveldb/leveldb/iterator"
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"github.com/syndtr/goleveldb/leveldb/storage"
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"github.com/syndtr/goleveldb/leveldb/util"
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)
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// Storage is an interface for common db operations.
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type Storage interface {
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Put([]byte, []byte) error
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Delete([]byte) error
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Get([]byte) ([]byte, error)
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NewIterator(*util.Range) iterator.Iterator
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}
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// CommitStorage allows to write all tx/batched values atomically.
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type CommitStorage interface {
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Storage
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Commit() error
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}
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// TransactionalStorage adds transaction features on top of regular storage.
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type TransactionalStorage interface {
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Storage
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NewTx() CommitStorage
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}
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// NewMemoryLevelDBStorage returns LevelDBStorage instance with in memory leveldb backend.
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func NewMemoryLevelDBStorage() (LevelDBStorage, error) {
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mdb, err := leveldb.Open(storage.NewMemStorage(), nil)
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if err != nil {
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return LevelDBStorage{}, err
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}
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return NewLevelDBStorage(mdb), nil
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}
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// NewLevelDBStorage creates new LevelDBStorage instance.
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func NewLevelDBStorage(db *leveldb.DB) LevelDBStorage {
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return LevelDBStorage{db: db}
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}
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// LevelDBStorage wrapper around leveldb.DB.
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type LevelDBStorage struct {
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db *leveldb.DB
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}
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// Put upserts given key/value pair.
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func (db LevelDBStorage) Put(key, buf []byte) error {
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return db.db.Put(key, buf, nil)
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}
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// Delete removes given key from database..
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func (db LevelDBStorage) Delete(key []byte) error {
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return db.db.Delete(key, nil)
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}
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// Get returns value for a given key.
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func (db LevelDBStorage) Get(key []byte) ([]byte, error) {
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return db.db.Get(key, nil)
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}
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// NewIterator returns new leveldb iterator.Iterator instance for a given range.
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func (db LevelDBStorage) NewIterator(slice *util.Range) iterator.Iterator {
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return db.db.NewIterator(slice, nil)
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}
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// NewTx is a wrapper around leveldb.Batch that allows to write atomically.
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func (db LevelDBStorage) NewTx() CommitStorage {
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return LevelDBTx{
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batch: &leveldb.Batch{},
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db: db,
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}
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}
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