/*

 * Copyright (C) the libgit2 contributors. All rights reserved.

 *

 * This file is part of libgit2, distributed under the GNU GPL v2 with

 * a Linking Exception. For full terms see the included COPYING file.

 */

#include "git2_util.h"

#if !defined(GIT_WIN32) && !defined(NO_MMAP)

#include "map.h"

#include <sys/mman.h>

#include <unistd.h>

#include <errno.h>

int git__page_size(size_t *page_size)

{

  long sc_page_size = sysconf(_SC_PAGE_SIZE);

  if (sc_page_size < 0) {

    git_error_set(GIT_ERROR_OS, "can't determine system page size");

    return -1;

  }

  *page_size = (size_t) sc_page_size;

  return 0;

}

int git__mmap_alignment(size_t *alignment)

{

  return git__page_size(alignment);

}

int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, off64_t offset)

{

  int mprot = PROT_READ;

  int mflag = 0;

  GIT_MMAP_VALIDATE(out, len, prot, flags);

  out->data = NULL;

  out->len = 0;

  if (prot & GIT_PROT_WRITE)

    mprot |= PROT_WRITE;

  if ((flags & GIT_MAP_TYPE) == GIT_MAP_SHARED)

    mflag = MAP_SHARED;

  else if ((flags & GIT_MAP_TYPE) == GIT_MAP_PRIVATE)

    mflag = MAP_PRIVATE;

  else

    mflag = MAP_SHARED;

  out->data = mmap(NULL, len, mprot, mflag, fd, offset);

  if (!out->data || out->data == MAP_FAILED) {

    git_error_set(GIT_ERROR_OS, "failed to mmap. Could not write data");

    return -1;

  }

  out->len = len;

  return 0;

}

int p_munmap(git_map *map)

{

  GIT_ASSERT_ARG(map);

  munmap(map->data, map->len);

  map->data = NULL;

  map->len = 0;

  return 0;

}

#endif