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 <bnm...@gmail.com> --- 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)