mirror of
https://github.com/google/leveldb.git
synced 2024-12-21 03:47:46 +08:00
144 lines
3.8 KiB
C++
144 lines
3.8 KiB
C++
// Copyright (c) 2018 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.
|
|
|
|
#ifndef STORAGE_LEVELDB_PORT_PORT_STDCXX_H_
|
|
#define STORAGE_LEVELDB_PORT_PORT_STDCXX_H_
|
|
|
|
// port/port_config.h availability is automatically detected via __has_include
|
|
// in newer compilers. If LEVELDB_HAS_PORT_CONFIG_H is defined, it overrides the
|
|
// configuration detection.
|
|
#if defined(LEVELDB_HAS_PORT_CONFIG_H)
|
|
|
|
#if LEVELDB_HAS_PORT_CONFIG_H
|
|
#include "port/port_config.h"
|
|
#endif // LEVELDB_HAS_PORT_CONFIG_H
|
|
|
|
#elif defined(__has_include)
|
|
|
|
#if __has_include("port/port_config.h")
|
|
#include "port/port_config.h"
|
|
#endif // __has_include("port/port_config.h")
|
|
|
|
#endif // defined(LEVELDB_HAS_PORT_CONFIG_H)
|
|
|
|
#if HAVE_CRC32C
|
|
#include <crc32c/crc32c.h>
|
|
#endif // HAVE_CRC32C
|
|
#if HAVE_SNAPPY
|
|
#include <snappy.h>
|
|
#endif // HAVE_SNAPPY
|
|
|
|
#include <cassert>
|
|
#include <cstddef>
|
|
#include <cstdint>
|
|
#include <condition_variable> // NOLINT
|
|
#include <mutex> // NOLINT
|
|
#include <string>
|
|
|
|
#include "port/thread_annotations.h"
|
|
|
|
namespace leveldb {
|
|
namespace port {
|
|
|
|
static const bool kLittleEndian = !LEVELDB_IS_BIG_ENDIAN;
|
|
|
|
class CondVar;
|
|
|
|
// Thinly wraps std::mutex.
|
|
class LOCKABLE Mutex {
|
|
public:
|
|
Mutex() = default;
|
|
~Mutex() = default;
|
|
|
|
Mutex(const Mutex&) = delete;
|
|
Mutex& operator=(const Mutex&) = delete;
|
|
|
|
void Lock() EXCLUSIVE_LOCK_FUNCTION() { mu_.lock(); }
|
|
void Unlock() UNLOCK_FUNCTION() { mu_.unlock(); }
|
|
void AssertHeld() ASSERT_EXCLUSIVE_LOCK() { }
|
|
|
|
private:
|
|
friend class CondVar;
|
|
std::mutex mu_;
|
|
};
|
|
|
|
// Thinly wraps std::condition_variable.
|
|
class CondVar {
|
|
public:
|
|
explicit CondVar(Mutex* mu) : mu_(mu) { assert(mu != nullptr); }
|
|
~CondVar() = default;
|
|
|
|
CondVar(const CondVar&) = delete;
|
|
CondVar& operator=(const CondVar&) = delete;
|
|
|
|
void Wait() {
|
|
std::unique_lock<std::mutex> lock(mu_->mu_, std::adopt_lock);
|
|
cv_.wait(lock);
|
|
lock.release();
|
|
}
|
|
void Signal() { cv_.notify_one(); }
|
|
void SignalAll() { cv_.notify_all(); }
|
|
private:
|
|
std::condition_variable cv_;
|
|
Mutex* const mu_;
|
|
};
|
|
|
|
inline bool Snappy_Compress(const char* input, size_t length,
|
|
std::string* output) {
|
|
#if HAVE_SNAPPY
|
|
output->resize(snappy::MaxCompressedLength(length));
|
|
size_t outlen;
|
|
snappy::RawCompress(input, length, &(*output)[0], &outlen);
|
|
output->resize(outlen);
|
|
return true;
|
|
#else
|
|
// Silence compiler warnings about unused arguments.
|
|
(void)input; (void)length; (void)output;
|
|
#endif // HAVE_SNAPPY
|
|
|
|
return false;
|
|
}
|
|
|
|
inline bool Snappy_GetUncompressedLength(const char* input, size_t length,
|
|
size_t* result) {
|
|
#if HAVE_SNAPPY
|
|
return snappy::GetUncompressedLength(input, length, result);
|
|
#else
|
|
// Silence compiler warnings about unused arguments.
|
|
(void)input; (void)length; (void)result;
|
|
return false;
|
|
#endif // HAVE_SNAPPY
|
|
}
|
|
|
|
inline bool Snappy_Uncompress(const char* input, size_t length, char* output) {
|
|
#if HAVE_SNAPPY
|
|
return snappy::RawUncompress(input, length, output);
|
|
#else
|
|
// Silence compiler warnings about unused arguments.
|
|
(void)input; (void)length; (void)output;
|
|
return false;
|
|
#endif // HAVE_SNAPPY
|
|
}
|
|
|
|
inline bool GetHeapProfile(void (*func)(void*, const char*, int), void* arg) {
|
|
// Silence compiler warnings about unused arguments.
|
|
(void)func; (void)arg;
|
|
return false;
|
|
}
|
|
|
|
inline uint32_t AcceleratedCRC32C(uint32_t crc, const char* buf, size_t size) {
|
|
#if HAVE_CRC32C
|
|
return ::crc32c::Extend(crc, reinterpret_cast<const uint8_t*>(buf), size);
|
|
#else
|
|
// Silence compiler warnings about unused arguments.
|
|
(void)crc; (void)buf; (void)size;
|
|
return 0;
|
|
#endif // HAVE_CRC32C
|
|
}
|
|
|
|
} // namespace port
|
|
} // namespace leveldb
|
|
|
|
#endif // STORAGE_LEVELDB_PORT_PORT_STDCXX_H_
|