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-rw-r--r--bftw.c229
1 files changed, 150 insertions, 79 deletions
diff --git a/bftw.c b/bftw.c
index 5b95495..33931f1 100644
--- a/bftw.c
+++ b/bftw.c
@@ -73,6 +73,8 @@ struct bftw_file {
/** An open descriptor to this file, or -1. */
int fd;
+ /** This file's type, if known. */
+ enum bftw_typeflag typeflag;
/** The device number, for cycle detection. */
dev_t dev;
/** The inode number, for cycle detection. */
@@ -324,6 +326,7 @@ static struct bftw_file *bftw_file_new(struct bftw_cache *cache, struct bftw_fil
file->refcount = 1;
file->fd = -1;
+ file->typeflag = BFTW_UNKNOWN;
file->dev = -1;
file->ino = -1;
@@ -944,6 +947,32 @@ static void bftw_stat_init(struct bftw_stat *cache) {
}
/**
+ * Open a file if necessary.
+ *
+ * @param file
+ * The file to open.
+ * @param path
+ * The path to that file or one of its descendants.
+ * @return
+ * The opened file descriptor, or -1 on error.
+ */
+static int bftw_ensure_open(struct bftw_cache *cache, struct bftw_file *file, const char *path) {
+ int ret = file->fd;
+
+ if (ret < 0) {
+ char *copy = strndup(path, file->nameoff + file->namelen);
+ if (!copy) {
+ return -1;
+ }
+
+ ret = bftw_file_open(cache, file, copy);
+ free(copy);
+ }
+
+ return ret;
+}
+
+/**
* Initialize the buffers with data about the current path.
*/
static void bftw_init_ftwbuf(struct bftw_state *state, enum bftw_visit visit) {
@@ -956,6 +985,7 @@ static void bftw_init_ftwbuf(struct bftw_state *state, enum bftw_visit visit) {
ftwbuf->root = file ? file->root : ftwbuf->path;
ftwbuf->depth = 0;
ftwbuf->visit = visit;
+ ftwbuf->typeflag = BFTW_UNKNOWN;
ftwbuf->error = reader->error;
ftwbuf->at_fd = AT_FDCWD;
ftwbuf->at_path = ftwbuf->path;
@@ -963,18 +993,26 @@ static void bftw_init_ftwbuf(struct bftw_state *state, enum bftw_visit visit) {
bftw_stat_init(&ftwbuf->lstat_cache);
bftw_stat_init(&ftwbuf->stat_cache);
- if (file) {
+ struct bftw_file *parent = NULL;
+ if (de) {
+ parent = file;
+ ftwbuf->depth = file->depth + 1;
+ ftwbuf->typeflag = bftw_dirent_typeflag(de);
+ ftwbuf->nameoff = bftw_child_nameoff(file);
+ } else if (file) {
+ parent = file->parent;
ftwbuf->depth = file->depth;
+ ftwbuf->typeflag = file->typeflag;
+ ftwbuf->nameoff = file->nameoff;
+ }
- if (de) {
- ++ftwbuf->depth;
- ftwbuf->nameoff = bftw_child_nameoff(file);
-
- ftwbuf->at_fd = file->fd;
+ if (parent) {
+ // Try to ensure the immediate parent is open, to avoid ENAMETOOLONG
+ if (bftw_ensure_open(&state->cache, parent, state->path) >= 0) {
+ ftwbuf->at_fd = parent->fd;
ftwbuf->at_path += ftwbuf->nameoff;
} else {
- ftwbuf->nameoff = file->nameoff;
- bftw_file_base(file, &ftwbuf->at_fd, &ftwbuf->at_path);
+ ftwbuf->error = errno;
}
}
@@ -986,12 +1024,6 @@ static void bftw_init_ftwbuf(struct bftw_state *state, enum bftw_visit visit) {
if (ftwbuf->error != 0) {
ftwbuf->typeflag = BFTW_ERROR;
return;
- } else if (de) {
- ftwbuf->typeflag = bftw_dirent_typeflag(de);
- } else if (ftwbuf->depth > 0) {
- ftwbuf->typeflag = BFTW_DIR;
- } else {
- ftwbuf->typeflag = BFTW_UNKNOWN;
}
int follow_flags = BFTW_LOGICAL;
@@ -1029,6 +1061,18 @@ static void bftw_init_ftwbuf(struct bftw_state *state, enum bftw_visit visit) {
}
}
+/** Fill file identity information from an ftwbuf. */
+static void bftw_fill_id(struct bftw_file *file, const struct BFTW *ftwbuf) {
+ const struct bfs_stat *statbuf = ftwbuf->stat_cache.buf;
+ if (!statbuf || (ftwbuf->stat_flags & BFS_STAT_NOFOLLOW)) {
+ statbuf = ftwbuf->lstat_cache.buf;
+ }
+ if (statbuf) {
+ file->dev = statbuf->dev;
+ file->ino = statbuf->ino;
+ }
+}
+
/**
* Visit a path, invoking the callback.
*/
@@ -1053,30 +1097,44 @@ static enum bftw_action bftw_visit(struct bftw_state *state, const char *name, e
break;
case BFTW_PRUNE:
case BFTW_STOP:
- return ret;
+ goto done;
default:
state->error = EINVAL;
return BFTW_STOP;
}
if (visit != BFTW_PRE || ftwbuf->typeflag != BFTW_DIR) {
- return BFTW_PRUNE;
+ ret = BFTW_PRUNE;
+ goto done;
}
- if ((state->flags & BFTW_XDEV) && state->file) {
- const struct bfs_stat *statbuf = bftw_stat(ftwbuf, ftwbuf->stat_flags);
- if (statbuf && statbuf->dev != state->file->dev) {
- return BFTW_PRUNE;
+ if (state->flags & BFTW_XDEV) {
+ const struct bftw_file *parent = state->file;
+ if (parent && !name) {
+ parent = parent->parent;
+ }
+
+ if (parent) {
+ const struct bfs_stat *statbuf = bftw_stat(ftwbuf, ftwbuf->stat_flags);
+ if (statbuf && statbuf->dev != parent->dev) {
+ ret = BFTW_PRUNE;
+ goto done;
+ }
}
}
- return BFTW_CONTINUE;
+done:
+ if (state->file && !name) {
+ bftw_fill_id(state->file, ftwbuf);
+ }
+
+ return ret;
}
/**
* Push a new file onto the queue.
*/
-static int bftw_push(struct bftw_state *state, const char *name) {
+static int bftw_push(struct bftw_state *state, const char *name, bool fill_id) {
struct bftw_file *parent = state->file;
struct bftw_file *file = bftw_file_new(&state->cache, parent, name);
if (!file) {
@@ -1084,14 +1142,13 @@ static int bftw_push(struct bftw_state *state, const char *name) {
return -1;
}
- const struct BFTW *ftwbuf = &state->ftwbuf;
- const struct bfs_stat *statbuf = ftwbuf->stat_cache.buf;
- if (!statbuf || (ftwbuf->stat_flags & BFS_STAT_NOFOLLOW)) {
- statbuf = ftwbuf->lstat_cache.buf;
+ struct dirent *de = state->reader.de;
+ if (de) {
+ file->typeflag = bftw_dirent_typeflag(de);
}
- if (statbuf) {
- file->dev = statbuf->dev;
- file->ino = statbuf->ino;
+
+ if (fill_id) {
+ bftw_fill_id(file, &state->ftwbuf);
}
if (state->strategy == BFTW_DFS) {
@@ -1161,12 +1218,14 @@ static enum bftw_action bftw_release_reader(struct bftw_state *state, bool do_vi
/**
* Finalize and free a file we're done with.
*/
-static enum bftw_action bftw_release_file(struct bftw_state *state, bool do_visit) {
+static enum bftw_action bftw_release_file(struct bftw_state *state, bool visit_file, bool visit_parents) {
enum bftw_action ret = BFTW_CONTINUE;
if (!(state->flags & BFTW_DEPTH)) {
- do_visit = false;
+ visit_file = false;
+ visit_parents = false;
}
+ bool do_visit = visit_file;
while (state->file) {
if (bftw_file_decref(&state->cache, state->file) > 0) {
@@ -1177,9 +1236,10 @@ static enum bftw_action bftw_release_file(struct bftw_state *state, bool do_visi
if (do_visit) {
if (bftw_visit(state, NULL, BFTW_POST) == BFTW_STOP) {
ret = BFTW_STOP;
- do_visit = false;
+ visit_parents = false;
}
}
+ do_visit = visit_parents;
struct bftw_file *parent = state->file->parent;
bftw_file_free(&state->cache, state->file);
@@ -1195,7 +1255,7 @@ static enum bftw_action bftw_release_file(struct bftw_state *state, bool do_visi
static void bftw_drain_queue(struct bftw_state *state, struct bftw_queue *queue) {
while (queue->head) {
state->file = bftw_queue_pop(queue);
- bftw_release_file(state, false);
+ bftw_release_file(state, false, false);
}
}
@@ -1210,7 +1270,7 @@ static int bftw_state_destroy(struct bftw_state *state) {
bftw_release_reader(state, false);
- bftw_release_file(state, false);
+ bftw_release_file(state, false, false);
bftw_drain_queue(state, &state->prequeue);
bftw_drain_queue(state, &state->queue);
@@ -1221,9 +1281,9 @@ static int bftw_state_destroy(struct bftw_state *state) {
}
/**
- * bftw() implementation for breadth- and depth-first search.
+ * Breadth-first bftw() implementation.
*/
-static int bftw_impl(const struct bftw_args *args) {
+static int bftw_bfs(const struct bftw_args *args) {
struct bftw_state state;
if (bftw_state_init(&state, args) != 0) {
return -1;
@@ -1241,13 +1301,14 @@ static int bftw_impl(const struct bftw_args *args) {
goto done;
}
- if (bftw_push(&state, path) != 0) {
+ if (bftw_push(&state, path, true) != 0) {
goto done;
}
}
while (bftw_pop(&state) > 0) {
struct bftw_reader *reader = bftw_open(&state);
+
while (bftw_reader_read(reader) > 0) {
const char *name = reader->de->d_name;
@@ -1260,7 +1321,7 @@ static int bftw_impl(const struct bftw_args *args) {
goto done;
}
- if (bftw_push(&state, name) != 0) {
+ if (bftw_push(&state, name, true) != 0) {
goto done;
}
}
@@ -1268,7 +1329,7 @@ static int bftw_impl(const struct bftw_args *args) {
if (bftw_release_reader(&state, true) == BFTW_STOP) {
goto done;
}
- if (bftw_release_file(&state, true) == BFTW_STOP) {
+ if (bftw_release_file(&state, true, true) == BFTW_STOP) {
goto done;
}
}
@@ -1278,51 +1339,53 @@ done:
}
/**
- * Depth-first search state.
+ * Depth-first bftw() implementation.
*/
-struct bftw_dfs_state {
- /** The wrapped callback. */
- bftw_callback *delegate;
- /** The wrapped callback arguments. */
- void *ptr;
- /** Whether to quit the search. */
- bool quit;
-};
+static int bftw_dfs(const struct bftw_args *args) {
+ struct bftw_state state;
+ if (bftw_state_init(&state, args) != 0) {
+ return -1;
+ }
-/** Depth-first callback function. */
-static enum bftw_action bftw_dfs_callback(const struct BFTW *ftwbuf, void *ptr) {
- struct bftw_dfs_state *state = ptr;
- enum bftw_action ret = state->delegate(ftwbuf, state->ptr);
- if (ret == BFTW_STOP || (ret == BFTW_PRUNE && ftwbuf->depth == 0)) {
- state->quit = true;
+ for (size_t i = 0; i < args->npaths; ++i) {
+ if (bftw_push(&state, args->paths[i], false) != 0) {
+ goto done;
+ }
}
- return ret;
-}
-/**
- * Depth-first bftw() wrapper.
- */
-static int bftw_dfs(const struct bftw_args *args) {
- // bftw_impl() will process all the roots first, but we don't want that
- // for depth-first searches
+ while (bftw_pop(&state) > 0) {
+ bool visit_post = true;
- struct bftw_dfs_state state = {
- .delegate = args->callback,
- .ptr = args->ptr,
- .quit = false,
- };
+ switch (bftw_visit(&state, NULL, BFTW_PRE)) {
+ case BFTW_CONTINUE:
+ break;
+ case BFTW_PRUNE:
+ visit_post = false;
+ goto next;
+ case BFTW_STOP:
+ goto done;
+ }
- struct bftw_args dfs_args = *args;
- dfs_args.npaths = 1;
- dfs_args.callback = bftw_dfs_callback;
- dfs_args.ptr = &state;
+ struct bftw_reader *reader = bftw_open(&state);
- int ret = 0;
- for (size_t i = 0; i < args->npaths && ret == 0 && !state.quit; ++i) {
- ret = bftw_impl(&dfs_args);
- ++dfs_args.paths;
+ while (bftw_reader_read(reader) > 0) {
+ if (bftw_push(&state, reader->de->d_name, false) != 0) {
+ goto done;
+ }
+ }
+
+ if (bftw_release_reader(&state, true) == BFTW_STOP) {
+ goto done;
+ }
+
+ next:
+ if (bftw_release_file(&state, visit_post, true) == BFTW_STOP) {
+ goto done;
+ }
}
- return ret;
+
+done:
+ return bftw_state_destroy(&state);
}
/**
@@ -1425,7 +1488,15 @@ static int bftw_ids(const struct bftw_args *args) {
while (ret == 0 && !state.quit && !state.bottom) {
state.bottom = true;
- ret = bftw_impl(&ids_args);
+
+ // bftw_bfs() is more efficient than bftw_dfs() since it visits
+ // directory entries as it reads them. With args->strategy ==
+ // BFTW_DFS, it gives a hybrid ordering that visits immediate
+ // children first, then deeper descendants depth-first. This
+ // doesn't matter for iterative deepening since we only visit
+ // one level at a time.
+ ret = bftw_bfs(&ids_args);
+
++state.depth;
}
@@ -1434,7 +1505,7 @@ static int bftw_ids(const struct bftw_args *args) {
while (ret == 0 && !state.quit && state.depth > 0) {
--state.depth;
- ret = bftw_impl(&ids_args);
+ ret = bftw_bfs(&ids_args);
}
}
@@ -1451,7 +1522,7 @@ static int bftw_ids(const struct bftw_args *args) {
int bftw(const struct bftw_args *args) {
switch (args->strategy) {
case BFTW_BFS:
- return bftw_impl(args);
+ return bftw_bfs(args);
case BFTW_DFS:
return bftw_dfs(args);
case BFTW_IDS: