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/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program 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
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/base/data_range.h"
#include "mongo/base/status_with.h"
#include "mongo/base/string_data.h"
#include "mongo/platform/atomic_word.h"
#include <type_traits>
namespace mongo {
enum class MessageCompressor : uint8_t {
kNoop = 0,
kSnappy = 1,
kZlib = 2,
kZstd = 3,
kExtended = 255,
};
StringData getMessageCompressorName(MessageCompressor id);
using MessageCompressorId = std::underlying_type<MessageCompressor>::type;
class MessageCompressorBase {
MONGO_DISALLOW_COPYING(MessageCompressorBase);
public:
virtual ~MessageCompressorBase() = default;
/*
* Returns the name for subclass compressors (e.g. "snappy", "zlib", "zstd" or "noop")
*/
const std::string& getName() const {
return _name;
}
/*
* Returns the numeric ID for subclass compressors (e.g. 1 or 0)
*/
MessageCompressorId getId() const {
return _id;
}
/*
* This returns the maximum output size of a call to compressData. It is used
* by the MessageCompressorManager to determine how big a buffer to allocate.
*/
virtual std::size_t getMaxCompressedSize(size_t inputSize) = 0;
/*
* This method compresses the data in the input ConstDataRange into the output DataRange.
* It returns the number of bytes actually compressed into the output range, or an error
* status.
*/
virtual StatusWith<std::size_t> compressData(ConstDataRange input, DataRange output) = 0;
/*
* This method decompresses the data in the input ConstDataRange into the output DataRange.
* It returns the number of bytes actually decompressed into the output range, or an error
* status.
*/
virtual StatusWith<std::size_t> decompressData(ConstDataRange input, DataRange output) = 0;
/*
* This returns the number of bytes passed in the input for compressData
*/
int64_t getCompressorBytesIn() const {
return _compressBytesIn.loadRelaxed();
}
/*
* This returns the number of bytes written to output for compressData
*/
int64_t getCompressorBytesOut() const {
return _compressBytesOut.loadRelaxed();
}
/*
* This returns the number of bytes passed in the input for decompressData
*/
int64_t getDecompressorBytesIn() const {
return _decompressBytesIn.loadRelaxed();
}
/*
* This returns the number of bytes written to output for decompressData
*/
int64_t getDecompressorBytesOut() const {
return _decompressBytesOut.loadRelaxed();
}
protected:
/*
* This is called by sub-classes to intialize their ID/name fields.
*/
MessageCompressorBase(MessageCompressor id)
: _id{static_cast<MessageCompressorId>(id)},
_name{getMessageCompressorName(id).toString()} {}
/*
* Called by sub-classes to bump their bytesIn/bytesOut counters for compression
*/
void counterHitCompress(int64_t bytesIn, int64_t bytesOut) {
_compressBytesIn.addAndFetch(bytesIn);
_compressBytesOut.addAndFetch(bytesOut);
}
/*
* Called by sub-classes to bump their bytesIn/bytesOut counters for decompression
*/
void counterHitDecompress(int64_t bytesIn, int64_t bytesOut) {
_decompressBytesIn.addAndFetch(bytesIn);
_decompressBytesOut.addAndFetch(bytesOut);
}
private:
const MessageCompressorId _id;
const std::string _name;
AtomicWord<long long> _compressBytesIn;
AtomicWord<long long> _compressBytesOut;
AtomicWord<long long> _decompressBytesIn;
AtomicWord<long long> _decompressBytesOut;
};
} // namespace mongo
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