thodg/libgit2/src/util/unix/map.c

• Show log

  Commit

• Hash : c3b7ace9
  Author :
  Date : 2021-11-14T16:43:53
  

  refactor: make util an object library Instead of simply including the utility files directly, make them a cmake object library for easy reusability between other projects within libgit2. Now the top-level `src` is responsible for platform selection, while the next-level `libgit2` and `util` configurations are responsible for identifying what objects they include.

Download

• src/util/unix/map.c

• /*
   * 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
  
  

Download