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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.
//
// See port_example.h for documentation for the following types/functions.
#ifndef STORAGE_LEVELDB_PORT_PORT_CHROMIUM_H_
#define STORAGE_LEVELDB_PORT_PORT_CHROMIUM_H_
#include <cstddef>
#include <cstdint>
#include <string>
#include "base/check.h"
#include "base/synchronization/condition_variable.h"
#include "base/synchronization/lock.h"
#include "base/thread_annotations.h"
#include "base/threading/thread_restrictions.h"
namespace leveldb {
namespace port {
class LOCKABLE Mutex {
public:
Mutex() = default;
~Mutex() = default;
Mutex(const Mutex&) = delete;
Mutex& operator=(const Mutex&) = delete;
void Lock() EXCLUSIVE_LOCK_FUNCTION() { lock_.Acquire(); }
void Unlock() UNLOCK_FUNCTION() { lock_.Release(); }
void AssertHeld() ASSERT_EXCLUSIVE_LOCK() { lock_.AssertAcquired(); }
private:
friend class CondVar;
base::Lock lock_;
};
// Thinly wraps base::ConditionVariable.
class CondVar {
public:
explicit CondVar(Mutex* mu) : cv_(&mu->lock_) { DCHECK(mu); }
~CondVar() = default;
CondVar(const CondVar&) = delete;
CondVar& operator=(const CondVar&) = delete;
void Wait() {
// This is an allowed use of base-sync-primitives.
// LevelDB has a different I/O model than Chromium - it uses condition
// variables to coordinate batch writes for efficiency, among other things.
// Since use of base::ConditionVariable is an implementation detail of
// Chromium's port, this is a better option than annotating all upstream
// call sites with a ScopedAllow, which would leave us vulnerable to
// upstream changes adding a Wait(). See https://crbug.com/1330845.
base::ScopedAllowBaseSyncPrimitives allow_base_sync_primitives;
cv_.Wait();
}
void Signal() { cv_.Signal(); }
void SignalAll() { cv_.Broadcast(); }
private:
base::ConditionVariable cv_;
};
bool Snappy_Compress(const char* input, size_t input_length,
std::string* output);
bool Snappy_GetUncompressedLength(const char* input, size_t length,
size_t* result);
bool Snappy_Uncompress(const char* input_data, size_t input_length,
char* output);
inline bool Zstd_Compress(int level,
const char* input,
size_t length,
std::string* output) {
return false;
}
inline bool Zstd_GetUncompressedLength(const char* input, size_t length,
size_t* result) {
return false;
}
inline bool Zstd_Uncompress(const char* input, size_t length, char* output) {
return false;
}
inline bool GetHeapProfile(void (*func)(void*, const char*, int), void* arg) {
return false;
}
uint32_t AcceleratedCRC32C(uint32_t crc, const char* buf, size_t size);
} // namespace port
} // namespace leveldb
#endif // STORAGE_LEVELDB_PORT_PORT_CHROMIUM_H_
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