thodg/libgit2/src/sysdir.c

• Show log

  Commit

• Hash : 1fafead5
  Author :
  Date : 2016-07-29T12:59:42
  

  sysdir: use the standard `init` pattern Don't try to determine when sysdirs are uninitialized. Instead, simply initialize them all at `git_libgit2_init` time and never try to reinitialize, except when consumers explicitly call `git_sysdir_set`. Looking at the buffer length is especially problematic, since there may no appropriate path for that value. (For example, the Windows-specific programdata directory has no value on non-Windows machines.) Previously we would continually trying to re-lookup these values, which could get racy if two different threads are each calling `git_sysdir_get` and trying to lookup / clear the value simultaneously.

Download

• src/sysdir.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 "common.h"
  #include "sysdir.h"
  #include "global.h"
  #include "buffer.h"
  #include "path.h"
  #include <ctype.h>
  #if GIT_WIN32
  #include "win32/findfile.h"
  #endif
  
  static int git_sysdir_guess_programdata_dirs(git_buf *out)
  {
  #ifdef GIT_WIN32
  	return git_win32__find_programdata_dirs(out);
  #else
  	git_buf_clear(out);
  	return 0;
  #endif
  }
  
  static int git_sysdir_guess_system_dirs(git_buf *out)
  {
  #ifdef GIT_WIN32
  	return git_win32__find_system_dirs(out, L"etc\\");
  #else
  	return git_buf_sets(out, "/etc");
  #endif
  }
  
  static int git_sysdir_guess_global_dirs(git_buf *out)
  {
  #ifdef GIT_WIN32
  	return git_win32__find_global_dirs(out);
  #else
  	int error = git__getenv(out, "HOME");
  
  	if (error == GIT_ENOTFOUND) {
  		giterr_clear();
  		error = 0;
  	}
  
  	return error;
  #endif
  }
  
  static int git_sysdir_guess_xdg_dirs(git_buf *out)
  {
  #ifdef GIT_WIN32
  	return git_win32__find_xdg_dirs(out);
  #else
  	git_buf env = GIT_BUF_INIT;
  	int error;
  
  	if ((error = git__getenv(&env, "XDG_CONFIG_HOME")) == 0)
  		error = git_buf_joinpath(out, env.ptr, "git");
  
  	if (error == GIT_ENOTFOUND && (error = git__getenv(&env, "HOME")) == 0)
  		error = git_buf_joinpath(out, env.ptr, ".config/git");
  
  	if (error == GIT_ENOTFOUND) {
  		giterr_clear();
  		error = 0;
  	}
  
  	git_buf_free(&env);
  	return error;
  #endif
  }
  
  static int git_sysdir_guess_template_dirs(git_buf *out)
  {
  #ifdef GIT_WIN32
  	return git_win32__find_system_dirs(out, L"share\\git-core\\templates");
  #else
  	return git_buf_sets(out, "/usr/share/git-core/templates");
  #endif
  }
  
  struct git_sysdir__dir {
  	git_buf buf;
  	int (*guess)(git_buf *out);
  };
  
  static struct git_sysdir__dir git_sysdir__dirs[] = {
  	{ GIT_BUF_INIT, git_sysdir_guess_system_dirs },
  	{ GIT_BUF_INIT, git_sysdir_guess_global_dirs },
  	{ GIT_BUF_INIT, git_sysdir_guess_xdg_dirs },
  	{ GIT_BUF_INIT, git_sysdir_guess_programdata_dirs },
  	{ GIT_BUF_INIT, git_sysdir_guess_template_dirs },
  };
  
  static void git_sysdir_global_shutdown(void)
  {
  	size_t i;
  
  	for (i = 0; i < ARRAY_SIZE(git_sysdir__dirs); ++i)
  		git_buf_free(&git_sysdir__dirs[i].buf);
  }
  
  int git_sysdir_global_init(void)
  {
  	size_t i;
  	int error = 0;
  
  	for (i = 0; !error && i < ARRAY_SIZE(git_sysdir__dirs); i++)
  		error = git_sysdir__dirs[i].guess(&git_sysdir__dirs[i].buf);
  
  	git__on_shutdown(git_sysdir_global_shutdown);
  
  	return error;
  }
  
  static int git_sysdir_check_selector(git_sysdir_t which)
  {
  	if (which < ARRAY_SIZE(git_sysdir__dirs))
  		return 0;
  
  	giterr_set(GITERR_INVALID, "config directory selector out of range");
  	return -1;
  }
  
  
  int git_sysdir_get(const git_buf **out, git_sysdir_t which)
  {
  	assert(out);
  
  	*out = NULL;
  
  	GITERR_CHECK_ERROR(git_sysdir_check_selector(which));
  
  	*out = &git_sysdir__dirs[which].buf;
  	return 0;
  }
  
  int git_sysdir_get_str(
  	char *out,
  	size_t outlen,
  	git_sysdir_t which)
  {
  	const git_buf *path = NULL;
  
  	GITERR_CHECK_ERROR(git_sysdir_check_selector(which));
  	GITERR_CHECK_ERROR(git_sysdir_get(&path, which));
  
  	if (!out || path->size >= outlen) {
  		giterr_set(GITERR_NOMEMORY, "Buffer is too short for the path");
  		return GIT_EBUFS;
  	}
  
  	git_buf_copy_cstr(out, outlen, path);
  	return 0;
  }
  
  #define PATH_MAGIC "$PATH"
  
  int git_sysdir_set(git_sysdir_t which, const char *search_path)
  {
  	const char *expand_path = NULL;
  	git_buf merge = GIT_BUF_INIT;
  
  	GITERR_CHECK_ERROR(git_sysdir_check_selector(which));
  
  	if (search_path != NULL)
  		expand_path = strstr(search_path, PATH_MAGIC);
  
  	/* reset the default if this path has been cleared */
  	if (!search_path || expand_path)
  		git_sysdir__dirs[which].guess(&git_sysdir__dirs[which].buf);
  
  	/* if $PATH is not referenced, then just set the path */
  	if (!expand_path) {
  		if (search_path)
  			git_buf_sets(&git_sysdir__dirs[which].buf, search_path);
  
  		goto done;
  	}
  
  	/* otherwise set to join(before $PATH, old value, after $PATH) */
  	if (expand_path > search_path)
  		git_buf_set(&merge, search_path, expand_path - search_path);
  
  	if (git_buf_len(&git_sysdir__dirs[which].buf))
  		git_buf_join(&merge, GIT_PATH_LIST_SEPARATOR,
  			merge.ptr, git_sysdir__dirs[which].buf.ptr);
  
  	expand_path += strlen(PATH_MAGIC);
  	if (*expand_path)
  		git_buf_join(&merge, GIT_PATH_LIST_SEPARATOR, merge.ptr, expand_path);
  
  	git_buf_swap(&git_sysdir__dirs[which].buf, &merge);
  	git_buf_free(&merge);
  
  done:
  	if (git_buf_oom(&git_sysdir__dirs[which].buf))
  		return -1;
  
  	return 0;
  }
  
  static int git_sysdir_find_in_dirlist(
  	git_buf *path,
  	const char *name,
  	git_sysdir_t which,
  	const char *label)
  {
  	size_t len;
  	const char *scan, *next = NULL;
  	const git_buf *syspath;
  
  	GITERR_CHECK_ERROR(git_sysdir_get(&syspath, which));
  	if (!syspath || !git_buf_len(syspath))
  		goto done;
  
  	for (scan = git_buf_cstr(syspath); scan; scan = next) {
  		/* find unescaped separator or end of string */
  		for (next = scan; *next; ++next) {
  			if (*next == GIT_PATH_LIST_SEPARATOR &&
  				(next <= scan || next[-1] != '\\'))
  				break;
  		}
  
  		len = (size_t)(next - scan);
  		next = (*next ? next + 1 : NULL);
  		if (!len)
  			continue;
  
  		GITERR_CHECK_ERROR(git_buf_set(path, scan, len));
  		if (name)
  			GITERR_CHECK_ERROR(git_buf_joinpath(path, path->ptr, name));
  
  		if (git_path_exists(path->ptr))
  			return 0;
  	}
  
  done:
  	git_buf_free(path);
  	giterr_set(GITERR_OS, "The %s file '%s' doesn't exist", label, name);
  	return GIT_ENOTFOUND;
  }
  
  int git_sysdir_find_system_file(git_buf *path, const char *filename)
  {
  	return git_sysdir_find_in_dirlist(
  		path, filename, GIT_SYSDIR_SYSTEM, "system");
  }
  
  int git_sysdir_find_global_file(git_buf *path, const char *filename)
  {
  	return git_sysdir_find_in_dirlist(
  		path, filename, GIT_SYSDIR_GLOBAL, "global");
  }
  
  int git_sysdir_find_xdg_file(git_buf *path, const char *filename)
  {
  	return git_sysdir_find_in_dirlist(
  		path, filename, GIT_SYSDIR_XDG, "global/xdg");
  }
  
  int git_sysdir_find_programdata_file(git_buf *path, const char *filename)
  {
  	return git_sysdir_find_in_dirlist(
  		path, filename, GIT_SYSDIR_PROGRAMDATA, "ProgramData");
  }
  
  int git_sysdir_find_template_dir(git_buf *path)
  {
  	return git_sysdir_find_in_dirlist(
  		path, NULL, GIT_SYSDIR_TEMPLATE, "template");
  }
  
  

Download