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Diffstat (limited to 'src/leveldb/port/port_stdcxx.h')
-rw-r--r-- | src/leveldb/port/port_stdcxx.h | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/src/leveldb/port/port_stdcxx.h b/src/leveldb/port/port_stdcxx.h new file mode 100644 index 0000000000..e9cb0e53af --- /dev/null +++ b/src/leveldb/port/port_stdcxx.h @@ -0,0 +1,153 @@ +// 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 <condition_variable> // NOLINT +#include <cstddef> +#include <cstdint> +#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_ |