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Diffstat (limited to 'src/leveldb/port/port_win.h')
-rw-r--r-- | src/leveldb/port/port_win.h | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/src/leveldb/port/port_win.h b/src/leveldb/port/port_win.h new file mode 100644 index 0000000000..45bf2f0ea7 --- /dev/null +++ b/src/leveldb/port/port_win.h @@ -0,0 +1,174 @@ +// LevelDB 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. + +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// * Neither the name of the University of California, Berkeley nor the +// names of its contributors may be used to endorse or promote products +// derived from this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY +// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +// DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY +// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +// + +#ifndef STORAGE_LEVELDB_PORT_PORT_WIN_H_ +#define STORAGE_LEVELDB_PORT_PORT_WIN_H_ + +#ifdef _MSC_VER +#define snprintf _snprintf +#define close _close +#define fread_unlocked _fread_nolock +#endif + +#include <string> +#include <stdint.h> +#ifdef SNAPPY +#include <snappy.h> +#endif + +namespace leveldb { +namespace port { + +// Windows is little endian (for now :p) +static const bool kLittleEndian = true; + +class CondVar; + +class Mutex { + public: + Mutex(); + ~Mutex(); + + void Lock(); + void Unlock(); + void AssertHeld(); + + private: + friend class CondVar; + // critical sections are more efficient than mutexes + // but they are not recursive and can only be used to synchronize threads within the same process + // we use opaque void * to avoid including windows.h in port_win.h + void * cs_; + + // No copying + Mutex(const Mutex&); + void operator=(const Mutex&); +}; + +// the Win32 API offers a dependable condition variable mechanism, but only starting with +// Windows 2008 and Vista +// no matter what we will implement our own condition variable with a semaphore +// implementation as described in a paper written by Andrew D. Birrell in 2003 +class CondVar { + public: + explicit CondVar(Mutex* mu); + ~CondVar(); + void Wait(); + void Signal(); + void SignalAll(); + private: + Mutex* mu_; + + Mutex wait_mtx_; + long waiting_; + + void * sem1_; + void * sem2_; + + +}; + +class OnceType { +public: +// OnceType() : init_(false) {} + OnceType(const OnceType &once) : init_(once.init_) {} + OnceType(bool f) : init_(f) {} + void InitOnce(void (*initializer)()) { + mutex_.Lock(); + if (!init_) { + init_ = true; + initializer(); + } + mutex_.Unlock(); + } + +private: + bool init_; + Mutex mutex_; +}; + +#define LEVELDB_ONCE_INIT false +extern void InitOnce(port::OnceType*, void (*initializer)()); + +// Storage for a lock-free pointer +class AtomicPointer { + private: + void * rep_; + public: + AtomicPointer() : rep_(NULL) { } + explicit AtomicPointer(void* v); + void* Acquire_Load() const; + + void Release_Store(void* v); + + void* NoBarrier_Load() const; + + void NoBarrier_Store(void* v); +}; + +inline bool Snappy_Compress(const char* input, size_t length, + ::std::string* output) { +#ifdef SNAPPY + output->resize(snappy::MaxCompressedLength(length)); + size_t outlen; + snappy::RawCompress(input, length, &(*output)[0], &outlen); + output->resize(outlen); + return true; +#endif + + return false; +} + +inline bool Snappy_GetUncompressedLength(const char* input, size_t length, + size_t* result) { +#ifdef SNAPPY + return snappy::GetUncompressedLength(input, length, result); +#else + return false; +#endif +} + +inline bool Snappy_Uncompress(const char* input, size_t length, + char* output) { +#ifdef SNAPPY + return snappy::RawUncompress(input, length, output); +#else + return false; +#endif +} + +inline bool GetHeapProfile(void (*func)(void*, const char*, int), void* arg) { + return false; +} + +} +} + +#endif // STORAGE_LEVELDB_PORT_PORT_WIN_H_ |