162 lines
4.6 KiB
C++
162 lines
4.6 KiB
C++
// LevelDB Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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//
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// See port_example.h for documentation for the following types/functions.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the distribution.
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// * Neither the name of the University of California, Berkeley nor the
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// names of its contributors may be used to endorse or promote products
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// derived from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
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// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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// DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
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// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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#ifndef STORAGE_LEVELDB_PORT_PORT_WIN_H_
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#define STORAGE_LEVELDB_PORT_PORT_WIN_H_
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#ifdef _MSC_VER
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#define snprintf _snprintf
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#define close _close
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#define fread_unlocked _fread_nolock
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#endif
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#ifdef SNAPPY
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#include <snappy/snappy.h>
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#endif
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#include <string>
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#include <stdint.h>
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namespace leveldb {
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namespace port {
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// Windows is little endian (for now :p)
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static const bool kLittleEndian = true;
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class CondVar;
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class Mutex {
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public:
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Mutex();
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~Mutex();
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void Lock();
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void Unlock();
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void AssertHeld();
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private:
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friend class CondVar;
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// critical sections are more efficient than mutexes
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// but they are not recursive and can only be used to synchronize threads within the same process
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// additionnaly they cannot be used with SignalObjectAndWait that we use for CondVar
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// we use opaque void * to avoid including windows.h in port_win.h
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void * mutex_;
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// No copying
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Mutex(const Mutex&);
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void operator=(const Mutex&);
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};
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// the Win32 API offers a dependable condition variable mechanism, but only starting with
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// Windows 2008 and Vista
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// no matter what we will implement our own condition variable with a semaphore
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// implementation as described in a paper written by Douglas C. Schmidt and Irfan Pyarali
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class CondVar {
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public:
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explicit CondVar(Mutex* mu);
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~CondVar();
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void Wait();
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void Signal();
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void SignalAll();
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private:
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Mutex* mu_;
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Mutex wait_mtx_;
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long waiting_;
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void * sema_;
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void * event_;
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bool broadcasted_;
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};
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// Storage for a lock-free pointer
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class AtomicPointer {
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private:
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void * rep_;
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public:
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AtomicPointer() : rep_(NULL) { }
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explicit AtomicPointer(void* v);
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void* Acquire_Load() const;
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void Release_Store(void* v);
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void* NoBarrier_Load() const;
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void NoBarrier_Store(void* v);
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};
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typedef volatile long OnceType;
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#define LEVELDB_ONCE_INIT (0)
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extern void InitOnce(OnceType* once, void (*initializer)());
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inline bool Snappy_Compress(const char* input, size_t length,
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::std::string* output) {
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#ifdef SNAPPY
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output->resize(snappy::MaxCompressedLength(length));
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size_t outlen;
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snappy::RawCompress(input, length, &(*output)[0], &outlen);
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output->resize(outlen);
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return true;
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#endif
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return false;
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}
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inline bool Snappy_GetUncompressedLength(const char* input, size_t length,
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size_t* result) {
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#ifdef SNAPPY
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return snappy::GetUncompressedLength(input, length, result);
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#else
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return false;
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#endif
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}
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inline bool Snappy_Uncompress(const char* input, size_t length,
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char* output) {
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#ifdef SNAPPY
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return snappy::RawUncompress(input, length, output);
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#else
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return false;
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#endif
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}
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inline bool GetHeapProfile(void (*func)(void*, const char*, int), void* arg) {
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return false;
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}
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}
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}
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#endif // STORAGE_LEVELDB_PORT_PORT_WIN_H_
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