source/libs/zziplib/zziplib-src/zzip/__mmap.h

   1 #ifndef __ZZIP_INTERNAL_MMAP_H
   2 #define __ZZIP_INTERNAL_MMAP_H
   3 #include <zzip/types.h>
   4
   5 /*
   6  * DO NOT USE THIS CODE.
   7  *
   8  * It is an internal header file for zziplib that carries some inline
   9  * functions (or just static members) and a few defines, simply to be
  10  * able to reuse these across - and have everything in a specific place.
  11  *
  12  * Copyright (c) 2002,2003 Guido Draheim
  13  *          All rights reserved,
  14  *          use under the restrictions of the
  15  *          Lesser GNU General Public License
  16  *          or alternatively the restrictions
  17  *          of the Mozilla Public License 1.1
  18  */
  19
  20 #ifdef _USE_MMAP
  21 #if    defined ZZIP_HAVE_SYS_MMAN_H
  22 #include <sys/mman.h>
  23 #define USE_POSIX_MMAP 1
  24 #elif defined ZZIP_HAVE_WINBASE_H || defined WIN32
  25 #include <windows.h>
  26 #define USE_WIN32_MMAP 1
  27 #else
  28 #undef _USE_MMAP
  29 #endif
  30 #endif
  31
  32 /* -------------- specify MMAP function imports --------------------------- */
  33
  34 #if     defined  USE_POSIX_MMAP
  35 #define USE_MMAP 1
  36
  37 #define _zzip_mmap(user, fd, offs, len) \
  38               mmap (0, len, PROT_READ, MAP_SHARED, fd, offs)
  39 #define _zzip_munmap(user, ptr, len) \
  40               munmap (ptr, len)
  41 #define _zzip_getpagesize(user) getpagesize()
  42
  43 #ifndef MAP_FAILED /* hpux10.20 does not have it */
  44 #define MAP_FAILED ((void*)(-1))
  45 #endif
  46
  47 #elif   defined USE_WIN32_MMAP
  48 #define USE_MMAP 1
  49 #ifndef MAP_FAILED
  50 #define MAP_FAILED 0
  51 #endif
  52 /* we (ab)use the "*user" variable to store the FileMapping handle */
  53                  /* and make sure (sizeof(*user) == sizeof(HANDLE)) */
  54
  55 static size_t win32_getpagesize (void)
  56 {
  57     SYSTEM_INFO si; GetSystemInfo (&si);
  58     return si.dwAllocationGranularity;
  59 }
  60 #ifdef _WIN64
  61 static void*  win32_mmap (__int64* user, int fd, zzip_off_t offs, size_t len)
  62 #else
  63 static void*  win32_mmap (long* user, int fd, zzip_off_t offs, size_t len)
  64 #endif
  65 {
  66     if (! user || *user != 1) /* || offs % getpagesize() */
  67         return 0;
  68   {
  69     HANDLE hFile = (HANDLE)_get_osfhandle(fd);
  70     if (hFile)
  71 #ifdef _WIN64
  72         *user = (__int64) CreateFileMapping (hFile, 0, PAGE_READONLY, 0, 0, NULL);
  73 #else
  74         *user = (long) CreateFileMapping (hFile, 0, PAGE_READONLY, 0, 0, NULL);
  75 #endif
  76     if (*user)
  77     {
  78         char* p = 0;
  79         p = MapViewOfFile(*(HANDLE*)user, FILE_MAP_READ, 0, offs, len);
  80         if (p) return p;
  81         CloseHandle (*(HANDLE*)user); *user = 1;
  82     }
  83     return MAP_FAILED;
  84   }
  85 }
  86 #ifdef _WIN64
  87 static void win32_munmap (__int64* user, char* fd_map, size_t len)
  88 #else
  89 static void win32_munmap (long* user, char* fd_map, size_t len)
  90 #endif
  91 {
  92     UnmapViewOfFile (fd_map);
  93     CloseHandle (*(HANDLE*)user); *user = 1;
  94 }
  95 #ifdef _WIN64
  96 #define _zzip_mmap(user, fd, offs, len) \
  97         win32_mmap ((__int64*) &(user), fd, offs, len)
  98 #define _zzip_munmap(user, ptr, len) \
  99         win32_munmap ((__int64*) &(user), ptr, len)
 100 #else
 101 #define _zzip_mmap(user, fd, offs, len) \
 102         win32_mmap ((long*) &(user), fd, offs, len)
 103 #define _zzip_munmap(user, ptr, len) \
 104         win32_munmap ((long*) &(user), ptr, len)
 105 #endif
 106 #define _zzip_getpagesize(user) win32_getpagesize()
 107 #else   /* disable */
 108 #define USE_MMAP 0
 109 /* USE_MAP is intentional: we expect the compiler to do some "code removal"
 110  * on any source code enclosed in if (USE_MMAP) {...}   i.e. the unreachable
 111  * branch of an if (0) {....} is not emitted to the final object binary. */
 112
 113 #ifndef MAP_FAILED
 114 #define MAP_FAILED  0
 115 #endif
 116
 117 #define _zzip_mmap(user, fd, offs, len) (MAP_FAILED)
 118 #define _zzip_munmap(user, ptr, len) {}
 119 #define _zzip_getpagesize(user) 1
 120
 121 #endif /* USE_MMAP defines */
 122
 123
 124 #endif