1
0
Fork 0
arangodb/arangod/Aql/ShortStringStorage.h

76 lines
2.1 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_AQL_SHORT_STRING_STORAGE_H
#define ARANGOD_AQL_SHORT_STRING_STORAGE_H 1
#include "Basics/Common.h"
namespace arangodb {
namespace aql {
struct ResourceMonitor;
class ShortStringStorage {
public:
ShortStringStorage(ShortStringStorage const&) = delete;
ShortStringStorage& operator=(ShortStringStorage const&) = delete;
ShortStringStorage(ResourceMonitor*, size_t);
~ShortStringStorage();
/// @brief register a short string
char* registerString(char const* p, size_t length);
/// @brief register a short string, unescaping it
char* unescape(char const* p, size_t length, size_t* outLength);
private:
/// @brief allocate a new block of memory
void allocateBlock();
public:
/// @brief maximum length of strings in short string storage
static constexpr size_t maxStringLength = 127;
private:
ResourceMonitor* _resourceMonitor;
/// @brief already allocated string blocks
std::vector<char*> _blocks;
/// @brief size of each block
size_t const _blockSize;
/// @brief offset into current block
char* _current;
/// @brief end of current block
char* _end;
};
} // namespace aql
} // namespace arangodb
#endif