Create an option for the dir_iterator API to iterate over subdirectories
only after having iterated through their contents. This feature was
predicted, although not implemented by 0fe5043 ("dir_iterator: new API
for iterating over a directory tree", 2016-06-18).
Add the "flags" parameter to dir_iterator_create, allowing for the
aforementioned "depth-first" iteration mode to be enabled. Currently,
the only acceptable flag is DIR_ITERATOR_DEPTH_FIRST.
This is useful for recursively removing a directory and calling rmdir()
on a directory only after all of its contents have been wiped.
Amend a call to dir_iterator_begin() to pass the flags parameter
introduced.
Signed-off-by: Daniel Ferreira <bnmvco@xxxxxxxxx>
---
dir-iterator.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++----
dir-iterator.h | 17 ++++++++++++-----
refs/files-backend.c | 2 +-
3 files changed, 62 insertions(+), 10 deletions(-)
diff --git a/dir-iterator.c b/dir-iterator.c
index 3ac984b..05d53d2 100644
--- a/dir-iterator.c
+++ b/dir-iterator.c
@@ -47,6 +47,9 @@ struct dir_iterator_int {
* that will be included in this iteration.
*/
struct dir_iterator_level *levels;
+
+ /* Holds the flags passed to dir_iterator_begin(). */
+ unsigned flags;
};
static inline void push_dir_level(struct dir_iterator_int *iter, struct dir_iterator_level *level)
@@ -113,12 +116,14 @@ int dir_iterator_advance(struct dir_iterator *dir_iterator)
iter->base.path.buf, strerror(errno));
/* Popping the level is handled below */
}
- } else if (S_ISDIR(iter->base.st.st_mode)) {
+ } else if (S_ISDIR(iter->base.st.st_mode) &&
+ !(iter->flags & DIR_ITERATOR_POST_ORDER_TRAVERSAL)) {
if (level->dir_state == DIR_STATE_ITER) {
/*
* The directory was just iterated
* over; now prepare to iterate into
- * it.
+ * it (unless an option is set for us
+ * to do otherwise).
*/
push_dir_level(iter, level);
continue;
@@ -152,7 +157,7 @@ int dir_iterator_advance(struct dir_iterator *dir_iterator)
de = readdir(level->dir);
if (!de) {
- /* This level is exhausted; pop up a level. */
+ /* This level is exhausted */
if (errno) {
warning("error reading directory %s: %s",
iter->base.path.buf, strerror(errno));
@@ -160,6 +165,32 @@ int dir_iterator_advance(struct dir_iterator *dir_iterator)
warning("error closing directory %s: %s",
iter->base.path.buf, strerror(errno));
+ if (iter->flags & DIR_ITERATOR_POST_ORDER_TRAVERSAL) {
+ /* If we are handling dirpaths after their contents,
+ * we have to iterate over the directory now that we'll
+ * have finished iterating into it. */
+ level->dir = NULL;
+
+ if (pop_dir_level(iter) == 0)
+ return dir_iterator_abort(dir_iterator);
+
+ level = &iter->levels[iter->levels_nr - 1];
+ /* Since we are iterating through the dirpath
+ * after we have gone through it, we still need
+ * to get rid of the trailing slash we appended.
+ *
+ * This may generate issues if we ever want to
+ * iterate through the root directory AND have
+ * post-order traversal enabled.
+ */
+ strbuf_strip_suffix(&iter->base.path, "/");
+
+ if (set_iterator_data(iter, level))
+ continue;
+
+ return ITER_OK;
+ }
+
level->dir = NULL;
if (pop_dir_level(iter) == 0)
return dir_iterator_abort(dir_iterator);
@@ -174,6 +205,18 @@ int dir_iterator_advance(struct dir_iterator *dir_iterator)
if (set_iterator_data(iter, level))
continue;
+ /*
+ * If we want to iterate dirs after files, we shall
+ * begin looking into them *before* we return the dir
+ * itself.
+ */
+ if (S_ISDIR(iter->base.st.st_mode) &&
+ (iter->flags & DIR_ITERATOR_POST_ORDER_TRAVERSAL)) {
+ push_dir_level(iter, level);
+
+ break;
+ }
+
return ITER_OK;
}
}
@@ -200,7 +243,7 @@ int dir_iterator_abort(struct dir_iterator *dir_iterator)
return ITER_DONE;
}
-struct dir_iterator *dir_iterator_begin(const char *path)
+struct dir_iterator *dir_iterator_begin(const char *path, unsigned flags)
{
struct dir_iterator_int *iter = xcalloc(1, sizeof(*iter));
struct dir_iterator *dir_iterator = &iter->base;
@@ -208,6 +251,8 @@ struct dir_iterator *dir_iterator_begin(const char *path)
if (!path || !*path)
die("BUG: empty path passed to dir_iterator_begin()");
+ iter->flags = flags;
+
strbuf_init(&iter->base.path, PATH_MAX);
strbuf_addstr(&iter->base.path, path);
diff --git a/dir-iterator.h b/dir-iterator.h
index 27739e6..649ccf6 100644
--- a/dir-iterator.h
+++ b/dir-iterator.h
@@ -11,8 +11,7 @@
* Every time dir_iterator_advance() is called, update the members of
* the dir_iterator structure to reflect the next path in the
* iteration. The order that paths are iterated over within a
- * directory is undefined, but directory paths are always iterated
- * over before the subdirectory contents.
+ * directory is undefined.
*
* A typical iteration looks like this:
*
@@ -38,6 +37,13 @@
* dir_iterator_advance() again.
*/
+/* Possible flags for dir_iterator_begin().
+ *
+ * DIR_ITERATOR_POST_ORDER_TRAVERSAL: ensures subdirectories and
+ * their contents are iterated through before the containing directory.
+ */
+#define DIR_ITERATOR_POST_ORDER_TRAVERSAL (1 << 0)
+
struct dir_iterator {
/* The current path: */
struct strbuf path;
@@ -57,15 +63,16 @@ struct dir_iterator {
};
/*
- * Start a directory iteration over path. Return a dir_iterator that
- * holds the internal state of the iteration.
+ * Start a directory iteration over path, with options specified in
+ * 'flags'. Return a dir_iterator that holds the internal state of
+ * the iteration.
*
* The iteration includes all paths under path, not including path
* itself and not including "." or ".." entries.
*
* path is the starting directory. An internal copy will be made.
*/
-struct dir_iterator *dir_iterator_begin(const char *path);
+struct dir_iterator *dir_iterator_begin(const char *path, unsigned flags);
/*
* Advance the iterator to the first or next item and return ITER_OK.
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 50188e9..b4bba74 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -3346,7 +3346,7 @@ static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_st
files_downcast(ref_store, 0, "reflog_iterator_begin");
base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);
- iter->dir_iterator = dir_iterator_begin(git_path("logs"));
+ iter->dir_iterator = dir_iterator_begin(git_path("logs"), 0);
return ref_iterator;
}
--
2.7.4 (Apple Git-66)