Merge branch 'pw/fast-import-dataref-parsing' into maint
[gitweb.git] / symlinks.c
index 1d6b35b858020300f502e2a9341b82d4fa8a61fd..290036744bcfd390f91e75db49bf620bb12c12ea 100644 (file)
@@ -32,19 +32,13 @@ static int longest_path_match(const char *name_a, int len_a,
        return match_len;
 }
 
-static struct cache_def {
-       char path[PATH_MAX + 1];
-       int len;
-       int flags;
-       int track_flags;
-       int prefix_len_stat_func;
-} cache;
+static struct cache_def default_cache;
 
-static inline void reset_lstat_cache(void)
+static inline void reset_lstat_cache(struct cache_def *cache)
 {
-       cache.path[0] = '\0';
-       cache.len = 0;
-       cache.flags = 0;
+       cache->path[0] = '\0';
+       cache->len = 0;
+       cache->flags = 0;
        /*
         * The track_flags and prefix_len_stat_func members is only
         * set by the safeguard rule inside lstat_cache()
@@ -70,23 +64,25 @@ static inline void reset_lstat_cache(void)
  * of the prefix, where the cache should use the stat() function
  * instead of the lstat() function to test each path component.
  */
-static int lstat_cache(const char *name, int len,
-                      int track_flags, int prefix_len_stat_func)
+static int lstat_cache_matchlen(struct cache_def *cache,
+                               const char *name, int len,
+                               int *ret_flags, int track_flags,
+                               int prefix_len_stat_func)
 {
        int match_len, last_slash, last_slash_dir, previous_slash;
-       int match_flags, ret_flags, save_flags, max_len, ret;
+       int save_flags, max_len, ret;
        struct stat st;
 
-       if (cache.track_flags != track_flags ||
-           cache.prefix_len_stat_func != prefix_len_stat_func) {
+       if (cache->track_flags != track_flags ||
+           cache->prefix_len_stat_func != prefix_len_stat_func) {
                /*
                 * As a safeguard rule we clear the cache if the
                 * values of track_flags and/or prefix_len_stat_func
                 * does not match with the last supplied values.
                 */
-               reset_lstat_cache();
-               cache.track_flags = track_flags;
-               cache.prefix_len_stat_func = prefix_len_stat_func;
+               reset_lstat_cache(cache);
+               cache->track_flags = track_flags;
+               cache->prefix_len_stat_func = prefix_len_stat_func;
                match_len = last_slash = 0;
        } else {
                /*
@@ -94,11 +90,15 @@ static int lstat_cache(const char *name, int len,
                 * the 2 "excluding" path types.
                 */
                match_len = last_slash =
-                       longest_path_match(name, len, cache.path, cache.len,
+                       longest_path_match(name, len, cache->path, cache->len,
                                           &previous_slash);
-               match_flags = cache.flags & track_flags & (FL_NOENT|FL_SYMLINK);
-               if (match_flags && match_len == cache.len)
-                       return match_flags;
+               *ret_flags = cache->flags & track_flags & (FL_NOENT|FL_SYMLINK);
+
+               if (!(track_flags & FL_FULLPATH) && match_len == len)
+                       match_len = last_slash = previous_slash;
+
+               if (*ret_flags && match_len == cache->len)
+                       return match_len;
                /*
                 * If we now have match_len > 0, we would know that
                 * the matched part will always be a directory.
@@ -107,44 +107,44 @@ static int lstat_cache(const char *name, int len,
                 * a substring of the cache on a path component basis,
                 * we can return immediately.
                 */
-               match_flags = track_flags & FL_DIR;
-               if (match_flags && len == match_len)
-                       return match_flags;
+               *ret_flags = track_flags & FL_DIR;
+               if (*ret_flags && len == match_len)
+                       return match_len;
        }
 
        /*
         * Okay, no match from the cache so far, so now we have to
         * check the rest of the path components.
         */
-       ret_flags = FL_DIR;
+       *ret_flags = FL_DIR;
        last_slash_dir = last_slash;
        max_len = len < PATH_MAX ? len : PATH_MAX;
        while (match_len < max_len) {
                do {
-                       cache.path[match_len] = name[match_len];
+                       cache->path[match_len] = name[match_len];
                        match_len++;
                } while (match_len < max_len && name[match_len] != '/');
                if (match_len >= max_len && !(track_flags & FL_FULLPATH))
                        break;
                last_slash = match_len;
-               cache.path[last_slash] = '\0';
+               cache->path[last_slash] = '\0';
 
                if (last_slash <= prefix_len_stat_func)
-                       ret = stat(cache.path, &st);
+                       ret = stat(cache->path, &st);
                else
-                       ret = lstat(cache.path, &st);
+                       ret = lstat(cache->path, &st);
 
                if (ret) {
-                       ret_flags = FL_LSTATERR;
+                       *ret_flags = FL_LSTATERR;
                        if (errno == ENOENT)
-                               ret_flags |= FL_NOENT;
+                               *ret_flags |= FL_NOENT;
                } else if (S_ISDIR(st.st_mode)) {
                        last_slash_dir = last_slash;
                        continue;
                } else if (S_ISLNK(st.st_mode)) {
-                       ret_flags = FL_SYMLINK;
+                       *ret_flags = FL_SYMLINK;
                } else {
-                       ret_flags = FL_ERR;
+                       *ret_flags = FL_ERR;
                }
                break;
        }
@@ -154,11 +154,11 @@ static int lstat_cache(const char *name, int len,
         * path types, FL_NOENT, FL_SYMLINK and FL_DIR, can be cached
         * for the moment!
         */
-       save_flags = ret_flags & track_flags & (FL_NOENT|FL_SYMLINK);
+       save_flags = *ret_flags & track_flags & (FL_NOENT|FL_SYMLINK);
        if (save_flags && last_slash > 0 && last_slash <= PATH_MAX) {
-               cache.path[last_slash] = '\0';
-               cache.len = last_slash;
-               cache.flags = save_flags;
+               cache->path[last_slash] = '\0';
+               cache->len = last_slash;
+               cache->flags = save_flags;
        } else if ((track_flags & FL_DIR) &&
                   last_slash_dir > 0 && last_slash_dir <= PATH_MAX) {
                /*
@@ -172,64 +172,76 @@ static int lstat_cache(const char *name, int len,
                 * can still cache the path components before the last
                 * one (the found symlink or non-existing component).
                 */
-               cache.path[last_slash_dir] = '\0';
-               cache.len = last_slash_dir;
-               cache.flags = FL_DIR;
+               cache->path[last_slash_dir] = '\0';
+               cache->len = last_slash_dir;
+               cache->flags = FL_DIR;
        } else {
-               reset_lstat_cache();
+               reset_lstat_cache(cache);
        }
-       return ret_flags;
+       return match_len;
 }
 
-/*
- * Invalidate the given 'name' from the cache, if 'name' matches
- * completely with the cache.
- */
-void invalidate_lstat_cache(const char *name, int len)
+static int lstat_cache(struct cache_def *cache, const char *name, int len,
+                      int track_flags, int prefix_len_stat_func)
 {
-       int match_len, previous_slash;
-
-       match_len = longest_path_match(name, len, cache.path, cache.len,
-                                      &previous_slash);
-       if (len == match_len) {
-               if ((cache.track_flags & FL_DIR) && previous_slash > 0) {
-                       cache.path[previous_slash] = '\0';
-                       cache.len = previous_slash;
-                       cache.flags = FL_DIR;
-               } else
-                       reset_lstat_cache();
-       }
+       int flags;
+       (void)lstat_cache_matchlen(cache, name, len, &flags, track_flags,
+                       prefix_len_stat_func);
+       return flags;
 }
 
+#define USE_ONLY_LSTAT  0
+
 /*
- * Completely clear the contents of the cache
+ * Return non-zero if path 'name' has a leading symlink component
  */
-void clear_lstat_cache(void)
+int threaded_has_symlink_leading_path(struct cache_def *cache, const char *name, int len)
 {
-       reset_lstat_cache();
+       return lstat_cache(cache, name, len, FL_SYMLINK|FL_DIR, USE_ONLY_LSTAT) & FL_SYMLINK;
 }
 
-#define USE_ONLY_LSTAT  0
-
 /*
  * Return non-zero if path 'name' has a leading symlink component
  */
 int has_symlink_leading_path(const char *name, int len)
 {
-       return lstat_cache(name, len,
-                          FL_SYMLINK|FL_DIR, USE_ONLY_LSTAT) &
-               FL_SYMLINK;
+       return threaded_has_symlink_leading_path(&default_cache, name, len);
+}
+
+/*
+ * Return zero if path 'name' has a leading symlink component or
+ * if some leading path component does not exists.
+ *
+ * Return -1 if leading path exists and is a directory.
+ *
+ * Return path length if leading path exists and is neither a
+ * directory nor a symlink.
+ */
+int check_leading_path(const char *name, int len)
+{
+    return threaded_check_leading_path(&default_cache, name, len);
 }
 
 /*
- * Return non-zero if path 'name' has a leading symlink component or
+ * Return zero if path 'name' has a leading symlink component or
  * if some leading path component does not exists.
+ *
+ * Return -1 if leading path exists and is a directory.
+ *
+ * Return path length if leading path exists and is neither a
+ * directory nor a symlink.
  */
-int has_symlink_or_noent_leading_path(const char *name, int len)
+int threaded_check_leading_path(struct cache_def *cache, const char *name, int len)
 {
-       return lstat_cache(name, len,
-                          FL_SYMLINK|FL_NOENT|FL_DIR, USE_ONLY_LSTAT) &
-               (FL_SYMLINK|FL_NOENT);
+       int flags;
+       int match_len = lstat_cache_matchlen(cache, name, len, &flags,
+                          FL_SYMLINK|FL_NOENT|FL_DIR, USE_ONLY_LSTAT);
+       if (flags & FL_NOENT)
+               return 0;
+       else if (flags & FL_DIR)
+               return -1;
+       else
+               return match_len;
 }
 
 /*
@@ -241,7 +253,19 @@ int has_symlink_or_noent_leading_path(const char *name, int len)
  */
 int has_dirs_only_path(const char *name, int len, int prefix_len)
 {
-       return lstat_cache(name, len,
+       return threaded_has_dirs_only_path(&default_cache, name, len, prefix_len);
+}
+
+/*
+ * Return non-zero if all path components of 'name' exists as a
+ * directory.  If prefix_len > 0, we will test with the stat()
+ * function instead of the lstat() function for a prefix length of
+ * 'prefix_len', thus we then allow for symlinks in the prefix part as
+ * long as those points to real existing directories.
+ */
+int threaded_has_dirs_only_path(struct cache_def *cache, const char *name, int len, int prefix_len)
+{
+       return lstat_cache(cache, name, len,
                           FL_DIR|FL_FULLPATH, prefix_len) &
                FL_DIR;
 }
@@ -263,7 +287,6 @@ static void do_remove_scheduled_dirs(int new_len)
                         removal.path[removal.len] != '/');
        }
        removal.len = new_len;
-       return;
 }
 
 void schedule_dir_for_removal(const char *name, int len)
@@ -296,11 +319,9 @@ void schedule_dir_for_removal(const char *name, int len)
                       last_slash - match_len);
                removal.len = last_slash;
        }
-       return;
 }
 
 void remove_scheduled_dirs(void)
 {
        do_remove_scheduled_dirs(0);
-       return;
 }