src/unix/map.c

   1 /*
   2  * Copyright (C) 2009-2011 the libgit2 contributors
   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 #ifndef GIT_WIN32
  10
  11 #include "map.h"
  12 #include <sys/mman.h>
  13 #include <errno.h>
  14
  15 int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offset)
  16 {
  17         int mprot = 0;
  18         int mflag = 0;
  19
  20         assert((out != NULL) && (len > 0));
  21
  22         if ((out == NULL) || (len == 0)) {
  23                 errno = EINVAL;
  24                 return git__throw(GIT_ERROR, "Failed to mmap. No map or zero length");
  25         }
  26
  27         out->data = NULL;
  28         out->len = 0;
  29
  30         if (prot & GIT_PROT_WRITE)
  31                 mprot = PROT_WRITE;
  32         else if (prot & GIT_PROT_READ)
  33                 mprot = PROT_READ;
  34         else {
  35                 errno = EINVAL;
  36                 return git__throw(GIT_ERROR, "Failed to mmap. Invalid protection parameters");
  37         }
  38
  39         if ((flags & GIT_MAP_TYPE) == GIT_MAP_SHARED)
  40                 mflag = MAP_SHARED;
  41         else if ((flags & GIT_MAP_TYPE) == GIT_MAP_PRIVATE)
  42                 mflag = MAP_PRIVATE;
  43
  44         if (flags & GIT_MAP_FIXED) {
  45                 errno = EINVAL;
  46                 return git__throw(GIT_ERROR, "Failed to mmap. FIXED not set");
  47         }
  48
  49         out->data = mmap(NULL, len, mprot, mflag, fd, offset);
  50         if (!out->data || out->data == MAP_FAILED)
  51                 return git__throw(GIT_EOSERR, "Failed to mmap. Could not write data");
  52         out->len = len;
  53
  54         return GIT_SUCCESS;
  55 }
  56
  57 int p_munmap(git_map *map)
  58 {
  59         assert(map != NULL);
  60
  61         if (!map)
  62                 return git__throw(GIT_ERROR, "Failed to munmap. Map does not exist");
  63
  64         munmap(map->data, map->len);
  65
  66         return GIT_SUCCESS;
  67 }
  68
  69 #endif
  70