port/port_posix.h

   1 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file. See the AUTHORS file for names of contributors.
   4 //
   5 // See port_example.h for documentation for the following types/functions.
   6
   7 #ifndef STORAGE_LEVELDB_PORT_PORT_POSIX_H_
   8 #define STORAGE_LEVELDB_PORT_PORT_POSIX_H_
   9
  10 #undef PLATFORM_IS_LITTLE_ENDIAN
  11 #if defined(OS_MACOSX)
  12   #include <machine/endian.h>
  13   #if defined(__DARWIN_LITTLE_ENDIAN) && defined(__DARWIN_BYTE_ORDER)
  14     #define PLATFORM_IS_LITTLE_ENDIAN \
  15         (__DARWIN_BYTE_ORDER == __DARWIN_LITTLE_ENDIAN)
  16   #endif
  17 #elif defined(OS_SOLARIS)
  18   #include <sys/isa_defs.h>
  19   #ifdef _LITTLE_ENDIAN
  20     #define PLATFORM_IS_LITTLE_ENDIAN true
  21   #else
  22     #define PLATFORM_IS_LITTLE_ENDIAN false
  23   #endif
  24 #elif defined(OS_FREEBSD) || defined(OS_OPENBSD) ||\
  25       defined(OS_NETBSD) || defined(OS_DRAGONFLYBSD)
  26   #include <sys/types.h>
  27   #include <sys/endian.h>
  28   #define PLATFORM_IS_LITTLE_ENDIAN (_BYTE_ORDER == _LITTLE_ENDIAN)
  29 #elif defined(OS_HPUX)
  30   #define PLATFORM_IS_LITTLE_ENDIAN false
  31 #elif defined(OS_ANDROID)
  32   // Due to a bug in the NDK x86 <sys/endian.h> definition,
  33   // _BYTE_ORDER must be used instead of __BYTE_ORDER on Android.
  34   // See http://code.google.com/p/android/issues/detail?id=39824
  35   #include <endian.h>
  36   #define PLATFORM_IS_LITTLE_ENDIAN  (_BYTE_ORDER == _LITTLE_ENDIAN)
  37 #else
  38   #include <endian.h>
  39 #endif
  40
  41 #include <pthread.h>
  42 #ifdef SNAPPY
  43 #include <snappy.h>
  44 #endif
  45 #include <stdint.h>
  46 #include <string>
  47 #include "port/atomic_pointer.h"
  48
  49 #ifndef PLATFORM_IS_LITTLE_ENDIAN
  50 #define PLATFORM_IS_LITTLE_ENDIAN (__BYTE_ORDER == __LITTLE_ENDIAN)
  51 #endif
  52
  53 #if defined(OS_MACOSX) || defined(OS_SOLARIS) || defined(OS_FREEBSD) ||\
  54     defined(OS_NETBSD) || defined(OS_OPENBSD) || defined(OS_DRAGONFLYBSD) ||\
  55     defined(OS_ANDROID) || defined(OS_HPUX) || defined(CYGWIN)
  56 // Use fread/fwrite/fflush on platforms without _unlocked variants
  57 #define fread_unlocked fread
  58 #define fwrite_unlocked fwrite
  59 #define fflush_unlocked fflush
  60 #endif
  61
  62 #if defined(OS_FREEBSD) ||\
  63     defined(OS_OPENBSD) || defined(OS_DRAGONFLYBSD)
  64 // Use fsync() on platforms without fdatasync()
  65 #define fdatasync fsync
  66 #endif
  67
  68 #if defined(OS_MACOSX)
  69 #define fdatasync(fd) fcntl(fd, F_FULLFSYNC, 0)
  70 #endif
  71
  72 #if defined(OS_ANDROID) && __ANDROID_API__ < 9
  73 // fdatasync() was only introduced in API level 9 on Android. Use fsync()
  74 // when targetting older platforms.
  75 #define fdatasync fsync
  76 #endif
  77
  78 namespace leveldb {
  79 namespace port {
  80
  81 static const bool kLittleEndian = PLATFORM_IS_LITTLE_ENDIAN;
  82 #undef PLATFORM_IS_LITTLE_ENDIAN
  83
  84 class CondVar;
  85
  86 class Mutex {
  87  public:
  88   Mutex();
  89   ~Mutex();
  90
  91   void Lock();
  92   void Unlock();
  93   void AssertHeld() { }
  94
  95  private:
  96   friend class CondVar;
  97   pthread_mutex_t mu_;
  98
  99   // No copying
 100   Mutex(const Mutex&);
 101   void operator=(const Mutex&);
 102 };
 103
 104 class CondVar {
 105  public:
 106   explicit CondVar(Mutex* mu);
 107   ~CondVar();
 108   void Wait();
 109   void Signal();
 110   void SignalAll();
 111  private:
 112   pthread_cond_t cv_;
 113   Mutex* mu_;
 114 };
 115
 116 typedef pthread_once_t OnceType;
 117 #define LEVELDB_ONCE_INIT PTHREAD_ONCE_INIT
 118 extern void InitOnce(OnceType* once, void (*initializer)());
 119
 120 inline bool Snappy_Compress(const char* input, size_t length,
 121                             ::std::string* output) {
 122 #ifdef SNAPPY
 123   output->resize(snappy::MaxCompressedLength(length));
 124   size_t outlen;
 125   snappy::RawCompress(input, length, &(*output)[0], &outlen);
 126   output->resize(outlen);
 127   return true;
 128 #endif
 129
 130   return false;
 131 }
 132
 133 inline bool Snappy_GetUncompressedLength(const char* input, size_t length,
 134                                          size_t* result) {
 135 #ifdef SNAPPY
 136   return snappy::GetUncompressedLength(input, length, result);
 137 #else
 138   return false;
 139 #endif
 140 }
 141
 142 inline bool Snappy_Uncompress(const char* input, size_t length,
 143                               char* output) {
 144 #ifdef SNAPPY
 145   return snappy::RawUncompress(input, length, output);
 146 #else
 147   return false;
 148 #endif
 149 }
 150
 151 inline bool GetHeapProfile(void (*func)(void*, const char*, int), void* arg) {
 152   return false;
 153 }
 154
 155 uint32_t AcceleratedCRC32C(uint32_t crc, const char* buf, size_t size);
 156
 157 } // namespace port
 158 } // namespace leveldb
 159
 160 #endif  // STORAGE_LEVELDB_PORT_PORT_POSIX_H_