thodg/libgit2/src/unix/map.c

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• Hash : f7310540
  Author :
  Date : 2014-05-13T02:41:48
  

  indexer: use mmap for writing Some OSs cannot keep their ideas about file content straight when mixing standard IO with file mapping. As we use mmap for reading from the packfile, let's make writing to the pack file use mmap.

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• src/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/common.h>
  
  #if !defined(GIT_WIN32) && !defined(NO_MMAP)
  
  #include "map.h"
  #include <sys/mman.h>
  #include <unistd.h>
  #include <errno.h>
  
  long git__page_size(void)
  {
  	return sysconf(_SC_PAGE_SIZE);
  }
  
  int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offset)
  {
  	int mprot = 0;
  	int mflag = 0;
  
  	GIT_MMAP_VALIDATE(out, len, prot, flags);
  
  	out->data = NULL;
  	out->len = 0;
  
  	if (prot & GIT_PROT_WRITE)
  		mprot = PROT_WRITE;
  	else if (prot & GIT_PROT_READ)
  		mprot = PROT_READ;
  
  	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) {
  		giterr_set(GITERR_OS, "Failed to mmap. Could not write data");
  		return -1;
  	}
  
  	out->len = len;
  
  	return 0;
  }
  
  int p_munmap(git_map *map)
  {
  	assert(map != NULL);
  	munmap(map->data, map->len);
  
  	return 0;
  }
  
  #endif
  
  

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