#include "cache.h"
-static struct cache_def {
- char path[PATH_MAX + 1];
- int len;
- int flags;
- int track_flags;
- int prefix_len_stat_func;
-} cache;
-
/*
* Returns the length (on a path component basis) of the longest
- * common prefix match of 'name' and the cached path string.
+ * common prefix match of 'name_a' and 'name_b'.
*/
-static inline int longest_match_lstat_cache(int len, const char *name,
- int *previous_slash)
+static int longest_path_match(const char *name_a, int len_a,
+ const char *name_b, int len_b,
+ int *previous_slash)
{
int max_len, match_len = 0, match_len_prev = 0, i = 0;
- max_len = len < cache.len ? len : cache.len;
- while (i < max_len && name[i] == cache.path[i]) {
- if (name[i] == '/') {
+ max_len = len_a < len_b ? len_a : len_b;
+ while (i < max_len && name_a[i] == name_b[i]) {
+ if (name_a[i] == '/') {
match_len_prev = match_len;
match_len = i;
}
i++;
}
- /* Is the cached path string a substring of 'name'? */
- if (i == cache.len && cache.len < len && name[cache.len] == '/') {
- match_len_prev = match_len;
- match_len = cache.len;
- /* Is 'name' a substring of the cached path string? */
- } else if ((i == len && len < cache.len && cache.path[len] == '/') ||
- (i == len && len == cache.len)) {
+ /*
+ * Is 'name_b' a substring of 'name_a', the other way around,
+ * or is 'name_a' and 'name_b' the exact same string?
+ */
+ if (i >= max_len && ((len_a > len_b && name_a[len_b] == '/') ||
+ (len_a < len_b && name_b[len_a] == '/') ||
+ (len_a == len_b))) {
match_len_prev = match_len;
- match_len = len;
+ match_len = i;
}
*previous_slash = match_len_prev;
return match_len;
}
-static inline void reset_lstat_cache(int track_flags, int prefix_len_stat_func)
+static struct cache_def {
+ char path[PATH_MAX + 1];
+ int len;
+ int flags;
+ int track_flags;
+ int prefix_len_stat_func;
+} cache;
+
+static inline void reset_lstat_cache(void)
{
cache.path[0] = '\0';
cache.len = 0;
cache.flags = 0;
- cache.track_flags = track_flags;
- cache.prefix_len_stat_func = prefix_len_stat_func;
+ /*
+ * The track_flags and prefix_len_stat_func members is only
+ * set by the safeguard rule inside lstat_cache()
+ */
}
#define FL_DIR (1 << 0)
* 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(int len, const char *name,
+static int lstat_cache(const char *name, int len,
int track_flags, int prefix_len_stat_func)
{
int match_len, last_slash, last_slash_dir, previous_slash;
if (cache.track_flags != track_flags ||
cache.prefix_len_stat_func != prefix_len_stat_func) {
/*
- * As a safeguard we clear the cache if the values of
- * track_flags and/or prefix_len_stat_func does not
- * match with the last supplied values.
+ * 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(track_flags, prefix_len_stat_func);
+ reset_lstat_cache();
+ cache.track_flags = track_flags;
+ cache.prefix_len_stat_func = prefix_len_stat_func;
match_len = last_slash = 0;
} else {
/*
* the 2 "excluding" path types.
*/
match_len = last_slash =
- longest_match_lstat_cache(len, name, &previous_slash);
+ 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;
cache.path[last_slash] = '\0';
cache.len = last_slash;
cache.flags = save_flags;
- } else if (track_flags & FL_DIR &&
+ } else if ((track_flags & FL_DIR) &&
last_slash_dir > 0 && last_slash_dir <= PATH_MAX) {
/*
* We have a separate test for the directory case,
cache.len = last_slash_dir;
cache.flags = FL_DIR;
} else {
- reset_lstat_cache(track_flags, prefix_len_stat_func);
+ reset_lstat_cache();
}
return ret_flags;
}
* Invalidate the given 'name' from the cache, if 'name' matches
* completely with the cache.
*/
-void invalidate_lstat_cache(int len, const char *name)
+void invalidate_lstat_cache(const char *name, int len)
{
int match_len, previous_slash;
- match_len = longest_match_lstat_cache(len, name, &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(cache.track_flags,
- cache.prefix_len_stat_func);
+ reset_lstat_cache();
}
}
*/
void clear_lstat_cache(void)
{
- reset_lstat_cache(0, 0);
+ reset_lstat_cache();
}
#define USE_ONLY_LSTAT 0
/*
* Return non-zero if path 'name' has a leading symlink component
*/
-int has_symlink_leading_path(int len, const char *name)
+int has_symlink_leading_path(const char *name, int len)
{
- return lstat_cache(len, name,
+ return lstat_cache(name, len,
FL_SYMLINK|FL_DIR, USE_ONLY_LSTAT) &
FL_SYMLINK;
}
* Return non-zero if path 'name' has a leading symlink component or
* if some leading path component does not exists.
*/
-int has_symlink_or_noent_leading_path(int len, const char *name)
+int has_symlink_or_noent_leading_path(const char *name, int len)
{
- return lstat_cache(len, name,
+ return lstat_cache(name, len,
FL_SYMLINK|FL_NOENT|FL_DIR, USE_ONLY_LSTAT) &
(FL_SYMLINK|FL_NOENT);
}
* 'prefix_len', thus we then allow for symlinks in the prefix part as
* long as those points to real existing directories.
*/
-int has_dirs_only_path(int len, const char *name, int prefix_len)
+int has_dirs_only_path(const char *name, int len, int prefix_len)
{
- return lstat_cache(len, name,
+ return lstat_cache(name, len,
FL_DIR|FL_FULLPATH, prefix_len) &
FL_DIR;
}
+
+static struct removal_def {
+ char path[PATH_MAX];
+ int len;
+} removal;
+
+static void do_remove_scheduled_dirs(int new_len)
+{
+ while (removal.len > new_len) {
+ removal.path[removal.len] = '\0';
+ if (rmdir(removal.path))
+ break;
+ do {
+ removal.len--;
+ } while (removal.len > new_len &&
+ removal.path[removal.len] != '/');
+ }
+ removal.len = new_len;
+ return;
+}
+
+void schedule_dir_for_removal(const char *name, int len)
+{
+ int match_len, last_slash, i, previous_slash;
+
+ match_len = last_slash = i =
+ longest_path_match(name, len, removal.path, removal.len,
+ &previous_slash);
+ /* Find last slash inside 'name' */
+ while (i < len) {
+ if (name[i] == '/')
+ last_slash = i;
+ i++;
+ }
+
+ /*
+ * If we are about to go down the directory tree, we check if
+ * we must first go upwards the tree, such that we then can
+ * remove possible empty directories as we go upwards.
+ */
+ if (match_len < last_slash && match_len < removal.len)
+ do_remove_scheduled_dirs(match_len);
+ /*
+ * If we go deeper down the directory tree, we only need to
+ * save the new path components as we go down.
+ */
+ if (match_len < last_slash) {
+ memcpy(&removal.path[match_len], &name[match_len],
+ last_slash - match_len);
+ removal.len = last_slash;
+ }
+ return;
+}
+
+void remove_scheduled_dirs(void)
+{
+ do_remove_scheduled_dirs(0);
+ return;
+}