rocksdb/include/leveldb/write_batch.h

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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
//
// WriteBatch holds a collection of updates to apply atomically to a DB.
//
// The updates are applied in the order in which they are added
// to the WriteBatch. For example, the value of "key" will be "v3"
// after the following batch is written:
//
// batch.Put("key", "v1");
// batch.Delete("key");
// batch.Put("key", "v2");
// batch.Put("key", "v3");
#ifndef STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
#define STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
#include <string>
namespace leveldb {
class Slice;
class WriteBatch {
public:
WriteBatch();
~WriteBatch();
// Store the mapping "key->value" in the database.
void Put(const Slice& key, const Slice& value);
// If the database contains a mapping for "key", erase it. Else do nothing.
void Delete(const Slice& key);
// Clear all updates buffered in this batch.
void Clear();
private:
friend class WriteBatchInternal;
std::string rep_; // See comment in write_batch.cc for the format of rep_
// Intentionally copyable
};
}
#endif // STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_