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authorTavian Barnes <tavianator@tavianator.com>2015-09-06 18:35:02 -0400
committerTavian Barnes <tavianator@tavianator.com>2015-09-06 18:35:02 -0400
commit3c04b862ff35e2c040adbdb4d17310bff1f8cb35 (patch)
tree520b81f0bada27fbead47b494d3651e770eedb19
parent2199c8b55dcd34334ef71f12707e17704f1b3d10 (diff)
downloadbfs-3c04b862ff35e2c040adbdb4d17310bff1f8cb35.tar.xz
Factor some code out of bftw().
-rw-r--r--bftw.c249
1 files changed, 172 insertions, 77 deletions
diff --git a/bftw.c b/bftw.c
index ade7dfb..894fe30 100644
--- a/bftw.c
+++ b/bftw.c
@@ -496,34 +496,159 @@ static int ftwbuf_stat(struct BFTW *ftwbuf, struct stat *sb, int fd, const char
return 0;
}
-int bftw(const char *path, bftw_fn *fn, int nopenfd, int flags, void *ptr) {
- int ret = -1, err = 0;
+/**
+ * Holds the current state of the bftw() traversal.
+ */
+typedef struct {
+ /** bftw() callback. */
+ bftw_fn *fn;
+ /** bftw() flags. */
+ int flags;
+ /** bftw() callback data. */
+ void *ptr;
- dircache cache;
- dircache_init(&cache, nopenfd);
+ /** The appropriate errno value, if any. */
+ int error;
- dircache_entry *current = NULL;
+ /** The cache of open directories. */
+ dircache cache;
+ /** The current dircache entry. */
+ dircache_entry *current;
+ /** The queue of directories left to explore. */
dirqueue queue;
- dirqueue_init(&queue);
-
- dynstr dynpath;
- dynstr_init(&dynpath);
+ /** The current path being explored. */
+ dynstr path;
+ /** Extra data about the current file. */
struct BFTW ftwbuf;
- ftwbuf_init(&ftwbuf, 0, 0);
+ /** stat() buffer for the current file. */
+ struct stat statbuf;
+} bftw_state;
- struct stat sb;
- if (ftwbuf_stat(&ftwbuf, &sb, AT_FDCWD, path) != 0) {
- if (!(flags & BFTW_RECOVER)) {
- goto fail;
+/**
+ * Initialize the bftw() state.
+ */
+static void bftw_state_init(bftw_state *state, bftw_fn *fn, int nopenfd, int flags, void *ptr) {
+ state->fn = fn;
+ state->flags = flags;
+ state->ptr = ptr;
+
+ state->error = 0;
+
+ dircache_init(&state->cache, nopenfd);
+ state->current = NULL;
+
+ dirqueue_init(&state->queue);
+
+ dynstr_init(&state->path);
+}
+
+/**
+ * Set the current path.
+ */
+static int bftw_set_path(bftw_state *state, const struct dirent *de, const char *name) {
+ size_t base = 0;
+ size_t level = 0;
+ int fd = AT_FDCWD;
+
+ dircache_entry *current = state->current;
+ if (current) {
+ base = current->nameoff + current->namelen;
+ level = current->depth + 1;
+ fd = dirfd(current->dir);
+ }
+
+ if (dynstr_concat(&state->path, base, name) != 0) {
+ return -1;
+ }
+
+ ftwbuf_init(&state->ftwbuf, base, level);
+
+ if (de) {
+ ftwbuf_use_dirent(&state->ftwbuf, de);
+ }
+
+ if ((state->flags & BFTW_STAT) || state->ftwbuf.typeflag == BFTW_UNKNOWN) {
+ if (ftwbuf_stat(&state->ftwbuf, &state->statbuf, fd, name) != 0) {
+ state->error = errno;
+ ftwbuf_set_error(&state->ftwbuf, state->error);
}
+ }
+
+ return 0;
+}
+
+/** internal action: Abort the traversal. */
+#define BFTW_FAIL (-1)
- err = errno;
- ftwbuf_set_error(&ftwbuf, err);
+/**
+ * Invoke the callback on the given path.
+ */
+static int bftw_handle_path(bftw_state *state) {
+ // Never give the callback BFTW_ERROR unless BFTW_RECOVER is specified
+ if (state->ftwbuf.typeflag == BFTW_ERROR && !(state->flags & BFTW_RECOVER)) {
+ return BFTW_FAIL;
}
- switch (fn(path, &ftwbuf, ptr)) {
+ int action = state->fn(state->path.str, &state->ftwbuf, state->ptr);
+ switch (action) {
+ case BFTW_CONTINUE:
+ case BFTW_SKIP_SIBLINGS:
+ case BFTW_SKIP_SUBTREE:
+ case BFTW_STOP:
+ return action;
+
+ default:
+ state->error = EINVAL;
+ return BFTW_FAIL;
+ }
+}
+
+/**
+ * Push a new entry onto the queue.
+ */
+static int bftw_push(bftw_state *state, const char *name) {
+ dircache_entry *entry = dircache_add(&state->cache, state->current, name);
+ if (!entry) {
+ return -1;
+ }
+
+ return dirqueue_push(&state->queue, entry);
+}
+
+/**
+ * Pop an entry off the queue.
+ */
+static void bftw_pop(bftw_state *state) {
+ dircache_entry_free(&state->cache, state->current);
+ state->current = dirqueue_pop(&state->queue);
+}
+
+/**
+ * Dispose of the bftw() state.
+ */
+static void bftw_state_free(bftw_state *state) {
+ while (state->current) {
+ bftw_pop(state);
+ }
+
+ dynstr_free(&state->path);
+}
+
+int bftw(const char *path, bftw_fn *fn, int nopenfd, int flags, void *ptr) {
+ int ret = -1;
+
+ bftw_state state;
+ bftw_state_init(&state, fn, nopenfd, flags, ptr);
+
+ // Handle 'path' itself first
+
+ if (bftw_set_path(&state, NULL, path) != 0) {
+ goto fail;
+ }
+
+ switch (bftw_handle_path(&state)) {
case BFTW_CONTINUE:
case BFTW_SKIP_SIBLINGS:
break;
@@ -532,38 +657,34 @@ int bftw(const char *path, bftw_fn *fn, int nopenfd, int flags, void *ptr) {
case BFTW_STOP:
goto done;
- default:
- err = EINVAL;
+ case BFTW_FAIL:
goto fail;
}
- if (err != 0 || ftwbuf.typeflag != BFTW_DIR) {
+ if (state.ftwbuf.typeflag != BFTW_DIR) {
goto done;
}
- current = dircache_add(&cache, NULL, path);
- if (!current) {
+ // Now start the breadth-first search
+
+ state.current = dircache_add(&state.cache, NULL, path);
+ if (!state.current) {
goto fail;
}
do {
- if (dircache_entry_path(current, &dynpath) != 0) {
+ if (dircache_entry_path(state.current, &state.path) != 0) {
goto fail;
}
- size_t pathlen = dynpath.length;
- DIR *dir = dircache_entry_open(&cache, current, dynpath.str);
+ DIR *dir = dircache_entry_open(&state.cache, state.current, state.path.str);
if (!dir) {
- if (!(flags & BFTW_RECOVER)) {
- goto fail;
- }
-
- err = errno;
+ state.error = errno;
- ftwbuf_init(&ftwbuf, current->nameoff, current->depth);
- ftwbuf_set_error(&ftwbuf, err);
+ ftwbuf_init(&state.ftwbuf, state.current->nameoff, state.current->depth);
+ ftwbuf_set_error(&state.ftwbuf, state.error);
- switch (fn(dynpath.str, &ftwbuf, ptr)) {
+ switch (bftw_handle_path(&state)) {
case BFTW_CONTINUE:
case BFTW_SKIP_SIBLINGS:
case BFTW_SKIP_SUBTREE:
@@ -572,8 +693,7 @@ int bftw(const char *path, bftw_fn *fn, int nopenfd, int flags, void *ptr) {
case BFTW_STOP:
goto done;
- default:
- err = EINVAL;
+ case BFTW_FAIL:
goto fail;
}
}
@@ -584,75 +704,50 @@ int bftw(const char *path, bftw_fn *fn, int nopenfd, int flags, void *ptr) {
continue;
}
- if (dynstr_concat(&dynpath, pathlen, de->d_name) != 0) {
+ if (bftw_set_path(&state, de, de->d_name) != 0) {
goto fail;
}
- ftwbuf_init(&ftwbuf, pathlen, current->depth + 1);
- ftwbuf_use_dirent(&ftwbuf, de);
-
- if ((flags & BFTW_STAT) || ftwbuf.typeflag == BFTW_UNKNOWN) {
- if (ftwbuf_stat(&ftwbuf, &sb, dirfd(dir), de->d_name) != 0) {
- if (!(flags & BFTW_RECOVER)) {
- goto fail;
- }
-
- err = errno;
- ftwbuf_set_error(&ftwbuf, err);
- }
- }
-
- switch (fn(dynpath.str, &ftwbuf, ptr)) {
+ switch (bftw_handle_path(&state)) {
case BFTW_CONTINUE:
- if (ftwbuf.typeflag == BFTW_DIR) {
- dircache_entry *next = dircache_add(&cache, current, de->d_name);
- if (!next) {
- goto fail;
- }
-
- if (dirqueue_push(&queue, next) != 0) {
- goto fail;
- }
- }
break;
case BFTW_SKIP_SIBLINGS:
goto next;
case BFTW_SKIP_SUBTREE:
- break;
+ continue;
case BFTW_STOP:
goto done;
- default:
- err = EINVAL;
+ case BFTW_FAIL:
goto fail;
}
+
+ if (state.ftwbuf.typeflag == BFTW_DIR) {
+ if (bftw_push(&state, de->d_name) != 0) {
+ goto fail;
+ }
+ }
}
next:
- dircache_entry_free(&cache, current);
- current = dirqueue_pop(&queue);
- } while (current);
+ bftw_pop(&state);
+ } while (state.current);
done:
- if (err == 0) {
+ if (state.error == 0) {
ret = 0;
}
fail:
- if (err == 0) {
- err = errno;
- }
-
- while (current) {
- dircache_entry_free(&cache, current);
- current = dirqueue_pop(&queue);
+ if (state.error == 0) {
+ state.error = errno;
}
- dynstr_free(&dynpath);
+ bftw_state_free(&state);
- errno = err;
+ errno = state.error;
return ret;
}