From 9fc42d609197ef331f1c5b2ce5ef6fc9f2ee634f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 30 Mar 2007 20:39:30 -0700 Subject: [PATCH] Optimize directory listing with pathspec limiter. The way things are set up, you can now pass a "pathspec" to the "read_directory()" function. If you pass NULL, it acts exactly like it used to do (read everything). If you pass a non-NULL pointer, it will simplify it into a "these are the prefixes without any special characters", and stop any readdir() early if the path in question doesn't match any of the prefixes. NOTE! This does *not* obviate the need for the caller to do the *exact* pathspec match later. It's a first-level filter on "read_directory()", but it does not do the full pathspec thing. Maybe it should. But in the meantime, builtin-add.c really does need to do first read_directory(dir, .., pathspec); if (pathspec) prune_directory(dir, pathspec, baselen); ie the "prune_directory()" part will do the *exact* pathspec pruning, while the "read_directory()" will use the pathspec just to do some quick high-level pruning of the directories it will recurse into. Signed-off-by: Linus Torvalds Signed-off-by: Junio C Hamano --- builtin-add.c | 2 +- builtin-ls-files.c | 2 +- dir.c | 96 +++++++++++++++++++++++++++++++++++++++++++--- dir.h | 2 +- wt-status.c | 2 +- 5 files changed, 95 insertions(+), 9 deletions(-) diff --git a/builtin-add.c b/builtin-add.c index 9fcf514db..871e23f0f 100644 --- a/builtin-add.c +++ b/builtin-add.c @@ -87,7 +87,7 @@ static void fill_directory(struct dir_struct *dir, const char **pathspec) } /* Read the directory and prune it */ - read_directory(dir, path, base, baselen); + read_directory(dir, path, base, baselen, pathspec); if (pathspec) prune_directory(dir, pathspec, baselen); } diff --git a/builtin-ls-files.c b/builtin-ls-files.c index 4e1d5af63..74a6acacc 100644 --- a/builtin-ls-files.c +++ b/builtin-ls-files.c @@ -216,7 +216,7 @@ static void show_files(struct dir_struct *dir, const char *prefix) if (baselen) path = base = prefix; - read_directory(dir, path, base, baselen); + read_directory(dir, path, base, baselen, pathspec); if (show_others) show_other_files(dir); if (show_killed) diff --git a/dir.c b/dir.c index b48e19dc0..7426fde33 100644 --- a/dir.c +++ b/dir.c @@ -8,6 +8,11 @@ #include "cache.h" #include "dir.h" +struct path_simplify { + int len; + const char *path; +}; + int common_prefix(const char **pathspec) { const char *path, *slash, *next; @@ -292,6 +297,31 @@ static int dir_exists(const char *dirname, int len) return !strncmp(active_cache[pos]->name, dirname, len); } +/* + * This is an inexact early pruning of any recursive directory + * reading - if the path cannot possibly be in the pathspec, + * return true, and we'll skip it early. + */ +static int simplify_away(const char *path, int pathlen, const struct path_simplify *simplify) +{ + if (simplify) { + for (;;) { + const char *match = simplify->path; + int len = simplify->len; + + if (!match) + break; + if (len > pathlen) + len = pathlen; + if (!memcmp(path, match, len)) + return 0; + simplify++; + } + return 1; + } + return 0; +} + /* * Read a directory tree. We currently ignore anything but * directories, regular files and symlinks. That's because git @@ -301,7 +331,7 @@ static int dir_exists(const char *dirname, int len) * Also, we ignore the name ".git" (even if it is not a directory). * That likely will not change. */ -static int read_directory_recursive(struct dir_struct *dir, const char *path, const char *base, int baselen, int check_only) +static int read_directory_recursive(struct dir_struct *dir, const char *path, const char *base, int baselen, int check_only, const struct path_simplify *simplify) { DIR *fdir = opendir(path); int contents = 0; @@ -324,6 +354,8 @@ static int read_directory_recursive(struct dir_struct *dir, const char *path, co continue; len = strlen(de->d_name); memcpy(fullname + baselen, de->d_name, len+1); + if (simplify_away(fullname, baselen + len, simplify)) + continue; if (excluded(dir, fullname) != dir->show_ignored) { if (!dir->show_ignored || DTYPE(de) != DT_DIR) { continue; @@ -350,13 +382,13 @@ static int read_directory_recursive(struct dir_struct *dir, const char *path, co if (dir->hide_empty_directories && !read_directory_recursive(dir, fullname, fullname, - baselen + len, 1)) + baselen + len, 1, simplify)) continue; break; } contents += read_directory_recursive(dir, - fullname, fullname, baselen + len, 0); + fullname, fullname, baselen + len, 0, simplify); continue; case DT_REG: case DT_LNK: @@ -386,8 +418,61 @@ static int cmp_name(const void *p1, const void *p2) e2->name, e2->len); } -int read_directory(struct dir_struct *dir, const char *path, const char *base, int baselen) +/* + * Return the length of the "simple" part of a path match limiter. + */ +static int simple_length(const char *match) { + const char special[256] = { + [0] = 1, ['?'] = 1, + ['\\'] = 1, ['*'] = 1, + ['['] = 1 + }; + int len = -1; + + for (;;) { + unsigned char c = *match++; + len++; + if (special[c]) + return len; + } +} + +static struct path_simplify *create_simplify(const char **pathspec) +{ + int nr, alloc = 0; + struct path_simplify *simplify = NULL; + + if (!pathspec) + return NULL; + + for (nr = 0 ; ; nr++) { + const char *match; + if (nr >= alloc) { + alloc = alloc_nr(alloc); + simplify = xrealloc(simplify, alloc * sizeof(*simplify)); + } + match = *pathspec++; + if (!match) + break; + simplify[nr].path = match; + simplify[nr].len = simple_length(match); + } + simplify[nr].path = NULL; + simplify[nr].len = 0; + return simplify; +} + +static void free_simplify(struct path_simplify *simplify) +{ + if (simplify) + free(simplify); +} + +int read_directory(struct dir_struct *dir, const char *path, const char *base, int baselen, const char **pathspec) +{ + struct path_simplify *simplify = create_simplify(pathspec); + /* * Make sure to do the per-directory exclude for all the * directories leading up to our base. @@ -414,7 +499,8 @@ int read_directory(struct dir_struct *dir, const char *path, const char *base, i } } - read_directory_recursive(dir, path, base, baselen, 0); + read_directory_recursive(dir, path, base, baselen, 0, simplify); + free_simplify(simplify); qsort(dir->entries, dir->nr, sizeof(struct dir_entry *), cmp_name); return dir->nr; } diff --git a/dir.h b/dir.h index 7233d65bb..33c31f25f 100644 --- a/dir.h +++ b/dir.h @@ -48,7 +48,7 @@ extern int common_prefix(const char **pathspec); #define MATCHED_EXACTLY 3 extern int match_pathspec(const char **pathspec, const char *name, int namelen, int prefix, char *seen); -extern int read_directory(struct dir_struct *, const char *path, const char *base, int baselen); +extern int read_directory(struct dir_struct *, const char *path, const char *base, int baselen, const char **pathspec); extern int push_exclude_per_directory(struct dir_struct *, const char *, int); extern void pop_exclude_per_directory(struct dir_struct *, int); diff --git a/wt-status.c b/wt-status.c index a25632bc8..a0559905a 100644 --- a/wt-status.c +++ b/wt-status.c @@ -260,7 +260,7 @@ static void wt_status_print_untracked(struct wt_status *s) if (file_exists(x)) add_excludes_from_file(&dir, x); - read_directory(&dir, ".", "", 0); + read_directory(&dir, ".", "", 0, NULL); for(i = 0; i < dir.nr; i++) { /* check for matching entry, which is unmerged; lifted from * builtin-ls-files:show_other_files */ -- 2.26.2