stream_rar: treat rar files as playlists

Refactors an older hack, which for some reason used a more complicated
way. This generates the playlist representing the contents of the rar
file in demux_playlist.c. The pseudo-demuxer could easily be separate
from the the playlist parsers (and in fact there's almost no shared
code), but I don't think this obscure feature deserves a separate file.

Sample files created with:

    rar a -v20000k -m0 files.rar file1.mkv file1.mkv

demux/demux_playlist.c

@@ -23,6 +23,7 @@
 #include "common/playlist.h"
 #include "options/path.h"
 #include "stream/stream.h"
+#include "stream/rar.h"
 #include "demux.h"
 
 #define PROBE_SIZE (8 * 1024)
@@ -188,6 +189,29 @@ static int parse_pls(struct pl_parser *p)
     return 0;
 }
 
+static int parse_rar(struct pl_parser *p)
+{
+    if (RarProbe(p->s))
+        return -1;
+    if (p->probing)
+        return 0;
+
+    int count;
+    rar_file_t **files;
+    if (RarParse(p->s, &count, &files))
+        return -1;
+
+    char *prefix = mp_url_escape(p, p->real_stream->url, "~|");
+    for (int n = 0; n < count; n++) {
+        // stream_rar.c does the real work
+        playlist_add_file(p->pl,
+                talloc_asprintf(p, "rar://%s|%s", prefix, files[n]->name));
+        RarFileDelete(files[n]);
+    }
+    talloc_free(files);
+    return 0;
+}
+
 static int parse_txt(struct pl_parser *p)
 {
     if (!p->force)
@@ -220,6 +244,7 @@ static const struct pl_format formats[] = {
     {"mov", parse_mov_rtsptext},
     {"pls", parse_pls,
      MIME_TYPES("audio/x-scpls")},
+    {"rar", parse_rar},
     {"txt", parse_txt},
 };
 

stream/stream.c

@@ -74,8 +74,7 @@ extern const stream_info_t stream_info_dvdnav;
 extern const stream_info_t stream_info_bdmv_dir;
 extern const stream_info_t stream_info_bluray;
 extern const stream_info_t stream_info_bdnav;
-extern const stream_info_t stream_info_rar_filter;
-extern const stream_info_t stream_info_rar_entry;
+extern const stream_info_t stream_info_rar;
 extern const stream_info_t stream_info_edl;
 
 static const stream_info_t *const stream_list[] = {
@@ -115,8 +114,7 @@ static const stream_info_t *const stream_list[] = {
     &stream_info_null,
     &stream_info_mf,
     &stream_info_edl,
-    &stream_info_rar_filter,
-    &stream_info_rar_entry,
+    &stream_info_rar,
     &stream_info_file,
     NULL
 };

stream/stream_rar.c

@@ -43,11 +43,10 @@ This works as follows:
 
 - stream_open() with file01.rar
     - is opened as normal file (stream_file.c or others) first
-    - stream_info_rar_filter stream filter applies
-    - leads to rar_filter_open()
+    - the rar code in demux_playlist.c detects it
     - if multi-part, opens file02.rar, file03.rar, etc. as actual streams
       (recursive opening is prevented with the STREAM_NO_FILTERS flag)
-    - read accesses return a m3u playlist with entries like:
+    - it returns a playlist like this to the player:
         rar://bla01.rar|subfile.mkv
       (one such entry for each file contained in the rar)
 - stream_open() with the playlist entry, e.g. rar://bla01.rar|subfile.mkv
@@ -143,76 +142,10 @@ static int rar_entry_open(stream_t *stream)
     return STREAM_OK;
 }
 
-static int rar_filter_fill_buffer(stream_t *s, char *buffer, int max_len)
-{
-    struct stream *m = s->priv;
-    return stream_read_partial(m, buffer, max_len);
-}
-
-static int rar_filter_seek(stream_t *s, int64_t newpos)
-{
-    struct stream *m = s->priv;
-    return stream_seek(m, newpos);
-}
-
-static void rar_filter_close(stream_t *s)
-{
-    struct stream *m = s->priv;
-    free_stream(m);
-}
-
-static int rar_filter_control(stream_t *s, int cmd, void *arg)
-{
-    struct stream *m = s->priv;
-    return stream_control(m, cmd, arg);
-}
-
-static int rar_filter_open(stream_t *stream)
-{
-    struct stream *rar = stream->source;
-    if (!rar)
-        return STREAM_UNSUPPORTED;
-
-    int count;
-    rar_file_t **files;
-    if (!rar || RarProbe(rar) || RarParse(rar, &count, &files))
-        return STREAM_UNSUPPORTED;
-
-    void *tmp = talloc_new(NULL);
-
-    // Create a playlist containing all entries of the .rar file. The URLs
-    // link to rar_entry_open().
-    char *prefix = mp_url_escape(tmp, stream->url, "~|");
-    char *pl = talloc_strdup(tmp, "#EXTM3U\n");
-    for (int n = 0; n < count; n++) {
-        pl = talloc_asprintf_append_buffer(pl, "rar://%s|%s\n",
-                                           prefix, files[n]->name);
-        RarFileDelete(files[n]);
-    }
-    talloc_free(files);
-
-    struct stream *m = open_memory_stream(pl, strlen(pl));
-
-    stream->priv = m;
-    stream->fill_buffer = rar_filter_fill_buffer;
-    stream->seek = rar_filter_seek;
-    stream->seekable = true;
-    stream->close = rar_filter_close;
-    stream->control = rar_filter_control;
-    stream->safe_origin = true;
-
-    talloc_free(tmp);
-    return STREAM_OK;
-}
-
-const stream_info_t stream_info_rar_entry = {
-    .name = "rar_entry",
+const stream_info_t stream_info_rar = {
+    .name = "rar",
     .open = rar_entry_open,
     .protocols = (const char*const[]){ "rar", NULL },
-};
-
-const stream_info_t stream_info_rar_filter = {
-    .name = "rar_filter",
-    .open = rar_filter_open,
-    .stream_filter = true,
+    .is_safe = true,
+    .is_network = true, // safe over network
 };