src/unix/map.c

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7 #include <git2/common.h>
   8
   9 #if !defined(GIT_WIN32) && !defined(NO_MMAP)
  10
  11 #include "map.h"
  12 #include <sys/mman.h>
  13 #include <unistd.h>
  14 #include <errno.h>
  15
  16 long git__page_size(void)
  17 {
  18         return sysconf(_SC_PAGE_SIZE);
  19 }
  20
  21 int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offset)
  22 {
  23         int mprot = 0;
  24         int mflag = 0;
  25
  26         GIT_MMAP_VALIDATE(out, len, prot, flags);
  27
  28         out->data = NULL;
  29         out->len = 0;
  30
  31         if (prot & GIT_PROT_WRITE)
  32                 mprot = PROT_WRITE;
  33         else if (prot & GIT_PROT_READ)
  34                 mprot = PROT_READ;
  35
  36         if ((flags & GIT_MAP_TYPE) == GIT_MAP_SHARED)
  37                 mflag = MAP_SHARED;
  38         else if ((flags & GIT_MAP_TYPE) == GIT_MAP_PRIVATE)
  39                 mflag = MAP_PRIVATE;
  40         else
  41                 mflag = MAP_SHARED;
  42
  43         out->data = mmap(NULL, len, mprot, mflag, fd, offset);
  44
  45         if (!out->data || out->data == MAP_FAILED) {
  46                 giterr_set(GITERR_OS, "Failed to mmap. Could not write data");
  47                 return -1;
  48         }
  49
  50         out->len = len;
  51
  52         return 0;
  53 }
  54
  55 int p_munmap(git_map *map)
  56 {
  57         assert(map != NULL);
  58         munmap(map->data, map->len);
  59
  60         return 0;
  61 }
  62
  63 #endif
  64