thodg/libgit2/src/attr_file.c

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• Hash : 40ed4990
  Author :
  Date : 2014-02-11T14:45:37
  

  Add diff threading tests and attr file cache locks This adds a basic test of doing simultaneous diffs on multiple threads and adds basic locking for the attr file cache because that was the immediate problem that arose from these tests.

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• src/attr_file.c

• #include "common.h"
  #include "repository.h"
  #include "filebuf.h"
  #include "attr.h"
  #include "git2/blob.h"
  #include "git2/tree.h"
  #include <ctype.h>
  
  static int sort_by_hash_and_name(const void *a_raw, const void *b_raw);
  static void git_attr_rule__clear(git_attr_rule *rule);
  static bool parse_optimized_patterns(
  	git_attr_fnmatch *spec,
  	git_pool *pool,
  	const char *pattern);
  
  int git_attr_file__new(
  	git_attr_file **attrs_ptr,
  	git_attr_file_source from,
  	const char *path,
  	git_pool *pool)
  {
  	git_attr_file *attrs = NULL;
  
  	attrs = git__calloc(1, sizeof(git_attr_file));
  	GITERR_CHECK_ALLOC(attrs);
  	GIT_REFCOUNT_INC(attrs);
  
  	if (pool)
  		attrs->pool = pool;
  	else {
  		attrs->pool = git__calloc(1, sizeof(git_pool));
  		if (!attrs->pool || git_pool_init(attrs->pool, 1, 0) < 0)
  			goto fail;
  		attrs->pool_is_allocated = true;
  	}
  
  	if (path) {
  		size_t len = strlen(path);
  
  		attrs->key = git_pool_malloc(attrs->pool, (uint32_t)len + 3);
  		GITERR_CHECK_ALLOC(attrs->key);
  
  		attrs->key[0] = '0' + (char)from;
  		attrs->key[1] = '#';
  		memcpy(&attrs->key[2], path, len);
  		attrs->key[len + 2] = '\0';
  	}
  
  	if (git_vector_init(&attrs->rules, 4, NULL) < 0)
  		goto fail;
  
  	*attrs_ptr = attrs;
  	return 0;
  
  fail:
  	git_attr_file__free(attrs);
  	attrs_ptr = NULL;
  	return -1;
  }
  
  int git_attr_file__parse_buffer(
  	git_repository *repo, void *parsedata, const char *buffer, git_attr_file *attrs)
  {
  	int error = 0;
  	const char *scan = NULL, *context = NULL;
  	git_attr_rule *rule = NULL;
  
  	GIT_UNUSED(parsedata);
  
  	assert(buffer && attrs);
  
  	scan = buffer;
  
  	/* if subdir file path, convert context for file paths */
  	if (attrs->key &&
  		git_path_root(attrs->key + 2) < 0 &&
  		git__suffixcmp(attrs->key, "/" GIT_ATTR_FILE) == 0)
  		context = attrs->key + 2;
  
  	while (!error && *scan) {
  		/* allocate rule if needed */
  		if (!rule) {
  			if (!(rule = git__calloc(1, sizeof(git_attr_rule)))) {
  				error = -1;
  				break;
  			}
  			rule->match.flags = GIT_ATTR_FNMATCH_ALLOWNEG |
  				GIT_ATTR_FNMATCH_ALLOWMACRO;
  		}
  
  		/* parse the next "pattern attr attr attr" line */
  		if (!(error = git_attr_fnmatch__parse(
  				&rule->match, attrs->pool, context, &scan)) &&
  			!(error = git_attr_assignment__parse(
  				repo, attrs->pool, &rule->assigns, &scan)))
  		{
  			if (rule->match.flags & GIT_ATTR_FNMATCH_MACRO)
  				/* should generate error/warning if this is coming from any
  				 * file other than .gitattributes at repo root.
  				 */
  				error = git_attr_cache__insert_macro(repo, rule);
  			else
  				error = git_vector_insert(&attrs->rules, rule);
  		}
  
  		/* if the rule wasn't a pattern, on to the next */
  		if (error < 0) {
  			git_attr_rule__clear(rule); /* reset rule contents */
  			if (error == GIT_ENOTFOUND)
  				error = 0;
  		} else {
  			rule = NULL; /* vector now "owns" the rule */
  		}
  	}
  
  	git_attr_rule__free(rule);
  
  	return error;
  }
  
  int git_attr_file__new_and_load(
  	git_attr_file **attrs_ptr,
  	const char *path)
  {
  	int error;
  	git_buf content = GIT_BUF_INIT;
  
  	if ((error = git_attr_file__new(attrs_ptr, 0, path, NULL)) < 0)
  		return error;
  
  	if (!(error = git_futils_readbuffer(&content, path)))
  		error = git_attr_file__parse_buffer(
  			NULL, NULL, git_buf_cstr(&content), *attrs_ptr);
  
  	git_buf_free(&content);
  
  	if (error) {
  		git_attr_file__free(*attrs_ptr);
  		*attrs_ptr = NULL;
  	}
  
  	return error;
  }
  
  void git_attr_file__clear_rules(git_attr_file *file)
  {
  	unsigned int i;
  	git_attr_rule *rule;
  
  	git_vector_foreach(&file->rules, i, rule)
  		git_attr_rule__free(rule);
  
  	git_vector_free(&file->rules);
  }
  
  static void attr_file_free(git_attr_file *file)
  {
  	git_attr_file__clear_rules(file);
  
  	if (file->pool_is_allocated) {
  		git_pool_clear(file->pool);
  		git__free(file->pool);
  	}
  	file->pool = NULL;
  
  	git__free(file);
  }
  
  void git_attr_file__free(git_attr_file *file)
  {
  	if (!file)
  		return;
  	GIT_REFCOUNT_DEC(file, attr_file_free);
  }
  
  uint32_t git_attr_file__name_hash(const char *name)
  {
  	uint32_t h = 5381;
  	int c;
  	assert(name);
  	while ((c = (int)*name++) != 0)
  		h = ((h << 5) + h) + c;
  	return h;
  }
  
  
  int git_attr_file__lookup_one(
  	git_attr_file *file,
  	const git_attr_path *path,
  	const char *attr,
  	const char **value)
  {
  	size_t i;
  	git_attr_name name;
  	git_attr_rule *rule;
  
  	*value = NULL;
  
  	name.name = attr;
  	name.name_hash = git_attr_file__name_hash(attr);
  
  	git_attr_file__foreach_matching_rule(file, path, i, rule) {
  		size_t pos;
  
  		if (!git_vector_bsearch(&pos, &rule->assigns, &name)) {
  			*value = ((git_attr_assignment *)
  					  git_vector_get(&rule->assigns, pos))->value;
  			break;
  		}
  	}
  
  	return 0;
  }
  
  
  bool git_attr_fnmatch__match(
  	git_attr_fnmatch *match,
  	const git_attr_path *path)
  {
  	int fnm;
  	int icase_flags = (match->flags & GIT_ATTR_FNMATCH_ICASE) ? FNM_CASEFOLD : 0;
  
  	if (match->flags & GIT_ATTR_FNMATCH_DIRECTORY && !path->is_dir)
  		return false;
  
  	if (match->flags & GIT_ATTR_FNMATCH_FULLPATH)
  		fnm = p_fnmatch(match->pattern, path->path, FNM_PATHNAME | icase_flags);
  	else if (path->is_dir)
  		fnm = p_fnmatch(match->pattern, path->basename, FNM_LEADING_DIR | icase_flags);
  	else
  		fnm = p_fnmatch(match->pattern, path->basename, icase_flags);
  
  	return (fnm == FNM_NOMATCH) ? false : true;
  }
  
  bool git_attr_rule__match(
  	git_attr_rule *rule,
  	const git_attr_path *path)
  {
  	bool matched = git_attr_fnmatch__match(&rule->match, path);
  
  	if (rule->match.flags & GIT_ATTR_FNMATCH_NEGATIVE)
  		matched = !matched;
  
  	return matched;
  }
  
  
  git_attr_assignment *git_attr_rule__lookup_assignment(
  	git_attr_rule *rule, const char *name)
  {
  	size_t pos;
  	git_attr_name key;
  	key.name = name;
  	key.name_hash = git_attr_file__name_hash(name);
  
  	if (git_vector_bsearch(&pos, &rule->assigns, &key))
  		return NULL;
  
  	return git_vector_get(&rule->assigns, pos);
  }
  
  int git_attr_path__init(
  	git_attr_path *info, const char *path, const char *base)
  {
  	ssize_t root;
  
  	/* build full path as best we can */
  	git_buf_init(&info->full, 0);
  
  	if (git_path_join_unrooted(&info->full, path, base, &root) < 0)
  		return -1;
  
  	info->path = info->full.ptr + root;
  
  	/* remove trailing slashes */
  	while (info->full.size > 0) {
  		if (info->full.ptr[info->full.size - 1] != '/')
  			break;
  		info->full.size--;
  	}
  	info->full.ptr[info->full.size] = '\0';
  
  	/* skip leading slashes in path */
  	while (*info->path == '/')
  		info->path++;
  
  	/* find trailing basename component */
  	info->basename = strrchr(info->path, '/');
  	if (info->basename)
  		info->basename++;
  	if (!info->basename || !*info->basename)
  		info->basename = info->path;
  
  	info->is_dir = (int)git_path_isdir(info->full.ptr);
  
  	return 0;
  }
  
  void git_attr_path__free(git_attr_path *info)
  {
  	git_buf_free(&info->full);
  	info->path = NULL;
  	info->basename = NULL;
  }
  
  /*
   * From gitattributes(5):
   *
   * Patterns have the following format:
   *
   * - A blank line matches no files, so it can serve as a separator for
   *   readability.
   *
   * - A line starting with # serves as a comment.
   *
   * - An optional prefix ! which negates the pattern; any matching file
   *   excluded by a previous pattern will become included again. If a negated
   *   pattern matches, this will override lower precedence patterns sources.
   *
   * - If the pattern ends with a slash, it is removed for the purpose of the
   *   following description, but it would only find a match with a directory. In
   *   other words, foo/ will match a directory foo and paths underneath it, but
   *   will not match a regular file or a symbolic link foo (this is consistent
   *   with the way how pathspec works in general in git).
   *
   * - If the pattern does not contain a slash /, git treats it as a shell glob
   *   pattern and checks for a match against the pathname without leading
   *   directories.
   *
   * - Otherwise, git treats the pattern as a shell glob suitable for consumption
   *   by fnmatch(3) with the FNM_PATHNAME flag: wildcards in the pattern will
   *   not match a / in the pathname. For example, "Documentation/\*.html" matches
   *   "Documentation/git.html" but not "Documentation/ppc/ppc.html". A leading
   *   slash matches the beginning of the pathname; for example, "/\*.c" matches
   *   "cat-file.c" but not "mozilla-sha1/sha1.c".
   */
  
  /*
   * This will return 0 if the spec was filled out,
   * GIT_ENOTFOUND if the fnmatch does not require matching, or
   * another error code there was an actual problem.
   */
  int git_attr_fnmatch__parse(
  	git_attr_fnmatch *spec,
  	git_pool *pool,
  	const char *source,
  	const char **base)
  {
  	const char *pattern, *scan;
  	int slash_count, allow_space;
  
  	assert(spec && base && *base);
  
  	if (parse_optimized_patterns(spec, pool, *base))
  		return 0;
  
  	spec->flags = (spec->flags & GIT_ATTR_FNMATCH__INCOMING);
  	allow_space = ((spec->flags & GIT_ATTR_FNMATCH_ALLOWSPACE) != 0);
  
  	pattern = *base;
  
  	while (git__isspace(*pattern)) pattern++;
  	if (!*pattern || *pattern == '#') {
  		*base = git__next_line(pattern);
  		return GIT_ENOTFOUND;
  	}
  
  	if (*pattern == '[' && (spec->flags & GIT_ATTR_FNMATCH_ALLOWMACRO) != 0) {
  		if (strncmp(pattern, "[attr]", 6) == 0) {
  			spec->flags = spec->flags | GIT_ATTR_FNMATCH_MACRO;
  			pattern += 6;
  		}
  		/* else a character range like [a-e]* which is accepted */
  	}
  
  	if (*pattern == '!' && (spec->flags & GIT_ATTR_FNMATCH_ALLOWNEG) != 0) {
  		spec->flags = spec->flags | GIT_ATTR_FNMATCH_NEGATIVE;
  		pattern++;
  	}
  
  	slash_count = 0;
  	for (scan = pattern; *scan != '\0'; ++scan) {
  		/* scan until (non-escaped) white space */
  		if (git__isspace(*scan) && *(scan - 1) != '\\') {
  			if (!allow_space || (*scan != ' ' && *scan != '\t'))
  				break;
  		}
  
  		if (*scan == '/') {
  			spec->flags = spec->flags | GIT_ATTR_FNMATCH_FULLPATH;
  			slash_count++;
  			if (pattern == scan)
  				pattern++;
  		}
  		/* remember if we see an unescaped wildcard in pattern */
  		else if (git__iswildcard(*scan) &&
  			(scan == pattern || (*(scan - 1) != '\\')))
  			spec->flags = spec->flags | GIT_ATTR_FNMATCH_HASWILD;
  	}
  
  	*base = scan;
  
  	if ((spec->length = scan - pattern) == 0)
  		return GIT_ENOTFOUND;
  
  	if (pattern[spec->length - 1] == '/') {
  		spec->length--;
  		spec->flags = spec->flags | GIT_ATTR_FNMATCH_DIRECTORY;
  		if (--slash_count <= 0)
  			spec->flags = spec->flags & ~GIT_ATTR_FNMATCH_FULLPATH;
  	}
  
  	if ((spec->flags & GIT_ATTR_FNMATCH_FULLPATH) != 0 &&
  		source != NULL && git_path_root(pattern) < 0)
  	{
          /* use context path minus the trailing filename */
          char *slash = strrchr(source, '/');
          size_t sourcelen = slash ? slash - source + 1 : 0;
  
  		/* given an unrooted fullpath match from a file inside a repo,
  		 * prefix the pattern with the relative directory of the source file
  		 */
  		spec->pattern = git_pool_malloc(
  			pool, (uint32_t)(sourcelen + spec->length + 1));
  		if (spec->pattern) {
  			memcpy(spec->pattern, source, sourcelen);
  			memcpy(spec->pattern + sourcelen, pattern, spec->length);
  			spec->length += sourcelen;
  			spec->pattern[spec->length] = '\0';
  		}
  	} else {
  		spec->pattern = git_pool_strndup(pool, pattern, spec->length);
  	}
  
  	if (!spec->pattern) {
  		*base = git__next_line(pattern);
  		return -1;
  	} else {
  		/* strip '\' that might have be used for internal whitespace */
  		spec->length = git__unescape(spec->pattern);
  	}
  
  	return 0;
  }
  
  static bool parse_optimized_patterns(
  	git_attr_fnmatch *spec,
  	git_pool *pool,
  	const char *pattern)
  {
  	if (!pattern[1] && (pattern[0] == '*' || pattern[0] == '.')) {
  		spec->flags = GIT_ATTR_FNMATCH_MATCH_ALL;
  		spec->pattern = git_pool_strndup(pool, pattern, 1);
  		spec->length = 1;
  
  		return true;
  	}
  
  	return false;
  }
  
  static int sort_by_hash_and_name(const void *a_raw, const void *b_raw)
  {
  	const git_attr_name *a = a_raw;
  	const git_attr_name *b = b_raw;
  
  	if (b->name_hash < a->name_hash)
  		return 1;
  	else if (b->name_hash > a->name_hash)
  		return -1;
  	else
  		return strcmp(b->name, a->name);
  }
  
  static void git_attr_assignment__free(git_attr_assignment *assign)
  {
  	/* name and value are stored in a git_pool associated with the
  	 * git_attr_file, so they do not need to be freed here
  	 */
  	assign->name = NULL;
  	assign->value = NULL;
  	git__free(assign);
  }
  
  static int merge_assignments(void **old_raw, void *new_raw)
  {
  	git_attr_assignment **old = (git_attr_assignment **)old_raw;
  	git_attr_assignment *new = (git_attr_assignment *)new_raw;
  
  	GIT_REFCOUNT_DEC(*old, git_attr_assignment__free);
  	*old = new;
  	return GIT_EEXISTS;
  }
  
  int git_attr_assignment__parse(
  	git_repository *repo,
  	git_pool *pool,
  	git_vector *assigns,
  	const char **base)
  {
  	int error;
  	const char *scan = *base;
  	git_attr_assignment *assign = NULL;
  
  	assert(assigns && !assigns->length);
  
  	git_vector_set_cmp(assigns, sort_by_hash_and_name);
  
  	while (*scan && *scan != '\n') {
  		const char *name_start, *value_start;
  
  		/* skip leading blanks */
  		while (git__isspace(*scan) && *scan != '\n') scan++;
  
  		/* allocate assign if needed */
  		if (!assign) {
  			assign = git__calloc(1, sizeof(git_attr_assignment));
  			GITERR_CHECK_ALLOC(assign);
  			GIT_REFCOUNT_INC(assign);
  		}
  
  		assign->name_hash = 5381;
  		assign->value = git_attr__true;
  
  		/* look for magic name prefixes */
  		if (*scan == '-') {
  			assign->value = git_attr__false;
  			scan++;
  		} else if (*scan == '!') {
  			assign->value = git_attr__unset; /* explicit unspecified state */
  			scan++;
  		} else if (*scan == '#') /* comment rest of line */
  			break;
  
  		/* find the name */
  		name_start = scan;
  		while (*scan && !git__isspace(*scan) && *scan != '=') {
  			assign->name_hash =
  				((assign->name_hash << 5) + assign->name_hash) + *scan;
  			scan++;
  		}
  		if (scan == name_start) {
  			/* must have found lone prefix (" - ") or leading = ("=foo")
  			 * or end of buffer -- advance until whitespace and continue
  			 */
  			while (*scan && !git__isspace(*scan)) scan++;
  			continue;
  		}
  
  		/* allocate permanent storage for name */
  		assign->name = git_pool_strndup(pool, name_start, scan - name_start);
  		GITERR_CHECK_ALLOC(assign->name);
  
  		/* if there is an equals sign, find the value */
  		if (*scan == '=') {
  			for (value_start = ++scan; *scan && !git__isspace(*scan); ++scan);
  
  			/* if we found a value, allocate permanent storage for it */
  			if (scan > value_start) {
  				assign->value = git_pool_strndup(pool, value_start, scan - value_start);
  				GITERR_CHECK_ALLOC(assign->value);
  			}
  		}
  
  		/* expand macros (if given a repo with a macro cache) */
  		if (repo != NULL && assign->value == git_attr__true) {
  			git_attr_rule *macro =
  				git_attr_cache__lookup_macro(repo, assign->name);
  
  			if (macro != NULL) {
  				unsigned int i;
  				git_attr_assignment *massign;
  
  				git_vector_foreach(&macro->assigns, i, massign) {
  					GIT_REFCOUNT_INC(massign);
  
  					error = git_vector_insert_sorted(
  						assigns, massign, &merge_assignments);
  					if (error < 0 && error != GIT_EEXISTS)
  						return error;
  				}
  			}
  		}
  
  		/* insert allocated assign into vector */
  		error = git_vector_insert_sorted(assigns, assign, &merge_assignments);
  		if (error < 0 && error != GIT_EEXISTS)
  			return error;
  
  		/* clear assign since it is now "owned" by the vector */
  		assign = NULL;
  	}
  
  	if (assign != NULL)
  		git_attr_assignment__free(assign);
  
  	*base = git__next_line(scan);
  
  	return (assigns->length == 0) ? GIT_ENOTFOUND : 0;
  }
  
  static void git_attr_rule__clear(git_attr_rule *rule)
  {
  	unsigned int i;
  	git_attr_assignment *assign;
  
  	if (!rule)
  		return;
  
  	if (!(rule->match.flags & GIT_ATTR_FNMATCH_IGNORE)) {
  		git_vector_foreach(&rule->assigns, i, assign)
  			GIT_REFCOUNT_DEC(assign, git_attr_assignment__free);
  		git_vector_free(&rule->assigns);
  	}
  
  	/* match.pattern is stored in a git_pool, so no need to free */
  	rule->match.pattern = NULL;
  	rule->match.length = 0;
  }
  
  void git_attr_rule__free(git_attr_rule *rule)
  {
  	git_attr_rule__clear(rule);
  	git__free(rule);
  }
  
  

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