demux_playlist: add option to control recursive directory loading

Directories were always loaded recursively, which can be slow
(e.g. one of the subdirectories is a mounting point to a slow device)
and can unexpectedly expand into a massive playlist.

Due to the problems described in 503dada42f,
this defaults to recursive loading.

ref. https://github.com/mpv-player/mpv/issues/9652

DOCS/interface-changes.rst

@@ -84,6 +84,7 @@ Interface changes
       passthrough the mpv window
     - icc and gpu-shader cache are now saved by default (use --no-icc-shader-cache and
       --no-gpu-shader-cache to disable)
+    - add `--directory-mode=recursive|lazy|ignore`
  --- mpv 0.35.0 ---
     - add the `--vo=gpu-next` video output driver, as well as the options
       `--allow-delayed-peak-detect`, `--builtin-scalers`,

DOCS/man/options.rst

@@ -3945,6 +3945,13 @@ Demuxer
     libarchive opens all volumes anyway when playing the main file, even though
     mpv iterated no archive entries yet.
 
+``--directory-mode=<recursive|lazy|ignore>``
+    When opening a directory, open subdirectories recursively, lazily or not at
+    all (default: recursive).
+
+    Values other then ``recursive`` can lead to problems with resuming playlists
+    (`RESUMING PLAYBACK`_) and possibly other things.
+
 Input
 -----
 

demux/demux_playlist.c

@@ -24,6 +24,7 @@
 
 #include "common/common.h"
 #include "options/options.h"
+#include "options/m_config.h"
 #include "common/msg.h"
 #include "common/playlist.h"
 #include "misc/thread_tools.h"
@@ -35,6 +36,31 @@
 
 #define PROBE_SIZE (8 * 1024)
 
+enum dir_mode {
+    DIR_RECURSIVE,
+    DIR_LAZY,
+    DIR_IGNORE,
+};
+
+#define OPT_BASE_STRUCT struct demux_playlist_opts
+struct demux_playlist_opts {
+    int dir_mode;
+};
+
+struct m_sub_options demux_playlist_conf = {
+    .opts = (const struct m_option[]) {
+        {"directory-mode", OPT_CHOICE(dir_mode,
+            {"recursive", DIR_RECURSIVE},
+            {"lazy", DIR_LAZY},
+            {"ignore", DIR_IGNORE})},
+        {0}
+    },
+    .size = sizeof(struct demux_playlist_opts),
+    .defaults = &(const struct demux_playlist_opts){
+        .dir_mode = DIR_RECURSIVE,
+    },
+};
+
 static bool check_mimetype(struct stream *s, const char *const *list)
 {
     if (s->mime_type) {
@@ -59,6 +85,7 @@ struct pl_parser {
     enum demux_check check_level;
     struct stream *real_stream;
     char *format;
+    struct demux_playlist_opts *opts;
 };
 
 
@@ -323,6 +350,7 @@ static bool scan_dir(struct pl_parser *p, char *path,
         return false;
     }
 
+    int dir_mode = p->opts->dir_mode;
     struct dirent *ep;
     while ((ep = readdir(dp))) {
         if (ep->d_name[0] == '.')
@@ -334,16 +362,18 @@ static bool scan_dir(struct pl_parser *p, char *path,
         char *file = mp_path_join(p, path, ep->d_name);
 
         struct stat st;
-        if (stat(file, &st) == 0 && S_ISDIR(st.st_mode)) {
+        if (dir_mode != DIR_LAZY && stat(file, &st) == 0 && S_ISDIR(st.st_mode)) {
-            for (int n = 0; n < num_dir_stack; n++) {
+            if (dir_mode != DIR_IGNORE) {
-                if (same_st(&dir_stack[n], &st)) {
+                for (int n = 0; n < num_dir_stack; n++) {
-                    MP_VERBOSE(p, "Skip recursive entry: %s\n", file);
+                    if (same_st(&dir_stack[n], &st)) {
-                    goto skip;
+                        MP_VERBOSE(p, "Skip recursive entry: %s\n", file);
+                        goto skip;
+                    }
                 }
-            }
 
-            dir_stack[num_dir_stack] = st;
+                dir_stack[num_dir_stack] = st;
-            scan_dir(p, file, dir_stack, num_dir_stack + 1, files, num_files);
+                scan_dir(p, file, dir_stack, num_dir_stack + 1, files, num_files);
+            }
         } else {
             MP_TARRAY_APPEND(p, *files, *num_files, file);
         }
@@ -458,6 +488,7 @@ static int open_file(struct demuxer *demuxer, enum demux_check check)
     p->error = false;
     p->s = demuxer->stream;
     p->utf16 = stream_skip_bom(p->s);
+    p->opts = mp_get_config_group(demuxer, demuxer->global, &demux_playlist_conf);
     bool ok = fmt->parse(p) >= 0 && !p->error;
     if (p->add_base)
         playlist_add_base_path(p->pl, mp_dirname(demuxer->filename));
@@ -471,7 +502,7 @@ static int open_file(struct demuxer *demuxer, enum demux_check check)
     return ok ? 0 : -1;
 }
 
-const struct demuxer_desc demuxer_desc_playlist = {
+const demuxer_desc_t demuxer_desc_playlist = {
     .name = "playlist",
     .desc = "Playlist file",
     .open = open_file,

options/options.c

@@ -63,6 +63,7 @@ extern const struct m_sub_options zimg_conf;
 extern const struct m_sub_options drm_conf;
 extern const struct m_sub_options demux_rawaudio_conf;
 extern const struct m_sub_options demux_rawvideo_conf;
+extern const struct m_sub_options demux_playlist_conf;
 extern const struct m_sub_options demux_lavf_conf;
 extern const struct m_sub_options demux_mkv_conf;
 extern const struct m_sub_options demux_cue_conf;
@@ -591,6 +592,7 @@ static const m_option_t mp_opts[] = {
     {"", OPT_SUBSTRUCT(demux_lavf, demux_lavf_conf)},
     {"demuxer-rawaudio", OPT_SUBSTRUCT(demux_rawaudio, demux_rawaudio_conf)},
     {"demuxer-rawvideo", OPT_SUBSTRUCT(demux_rawvideo, demux_rawvideo_conf)},
+    {"", OPT_SUBSTRUCT(demux_playlist, demux_playlist_conf)},
     {"demuxer-mkv", OPT_SUBSTRUCT(demux_mkv, demux_mkv_conf)},
     {"demuxer-cue", OPT_SUBSTRUCT(demux_cue, demux_cue_conf)},
 

options/options.h

@@ -326,6 +326,7 @@ typedef struct MPOpts {
 
     struct demux_rawaudio_opts *demux_rawaudio;
     struct demux_rawvideo_opts *demux_rawvideo;
+    struct demux_playlist_opts *demux_playlist;
     struct demux_lavf_opts *demux_lavf;
     struct demux_mkv_opts *demux_mkv;
     struct demux_cue_opts *demux_cue;