New command searchplaylist

NEWS

@@ -10,7 +10,7 @@ ver 0.24 (not yet released)
   - show PCRE support in "config" response
   - apply Unicode normalization to case-insensitive filter expressions
   - stickers on playlists and some tag types
-  - new commands "stickernames" and "playlistlength"
+  - new commands "stickernames", "playlistlength" and "searchplaylist"
   - new "search"/"find" filter "added-since"
   - allow range in listplaylist and listplaylistinfo
   - "sticker find" supports sort and window parameter and new sticker compare operators "eq", "lt" and "gt"

doc/protocol.rst

@@ -994,6 +994,14 @@ remote playlists (absolute URI with a supported scheme).
     plugins are supported. A range may be specified to list
     only a part of the playlist. [#since_0_24]_
 
+.. _command_searchplaylist:
+
+:command:`searchplaylist {NAME} {FILTER} [{START:END}]`
+    Search the playlist for songs matching
+    ``FILTER`` (see :ref:`Filters <filter_syntax>`).  Playlist
+    plugins are supported. A range may be specified to list
+    only a part of the playlist.
+
 .. _command_listplaylists:
 
 :command:`listplaylists`

src/command/AllCommands.cxx

@@ -176,6 +176,7 @@ static constexpr struct command commands[] = {
 	{ "searchaddpl", PERMISSION_CONTROL, 2, -1, handle_searchaddpl },
 	{ "searchcount", PERMISSION_READ, 1, -1, handle_searchcount },
 #endif
+	{ "searchplaylist", PERMISSION_READ, 2, 3, handle_searchplaylist },
 	{ "seek", PERMISSION_PLAYER, 2, 2, handle_seek },
 	{ "seekcur", PERMISSION_PLAYER, 1, 1, handle_seekcur },
 	{ "seekid", PERMISSION_PLAYER, 2, 2, handle_seekid },

src/command/PlaylistCommands.cxx

@@ -15,6 +15,7 @@
 #include "PlaylistError.hxx"
 #include "db/PlaylistVector.hxx"
 #include "SongLoader.hxx"
+#include "song/Filter.hxx"
 #include "song/DetachedSong.hxx"
 #include "BulkEdit.hxx"
 #include "playlist/Length.hxx"
@@ -26,6 +27,7 @@
 #include "Mapper.hxx"
 #include "fs/AllocatedPath.hxx"
 #include "time/ChronoUtil.hxx"
+#include "util/Exception.hxx"
 #include "util/UriExtract.hxx"
 #include "LocateUri.hxx"
 
@@ -129,7 +131,7 @@ handle_listplaylist(Client &client, Request args, Response &r)
 	RangeArg range = args.ParseOptional(1, RangeArg::All());
 
 	playlist_file_print(r, client.GetPartition(), SongLoader(client),
-			    name, range.start, range.end, false);
+			    name, range.start, range.end, false, nullptr);
 	return CommandResult::OK;
 }
 
@@ -146,7 +148,39 @@ handle_listplaylistinfo(Client &client, Request args, Response &r)
 	RangeArg range = args.ParseOptional(1, RangeArg::All());
 
 	playlist_file_print(r, client.GetPartition(), SongLoader(client),
-			    name, range.start, range.end, true);
+			    name, range.start, range.end, true, nullptr);
+	return CommandResult::OK;
+}
+
+CommandResult
+handle_searchplaylist(Client &client, Request args, Response &r)
+{
+	const auto name = LocateUri(UriPluginKind::PLAYLIST, args.front(),
+				    &client
+#ifdef ENABLE_DATABASE
+					   , nullptr
+#endif
+					   );
+	args.shift();
+
+	RangeArg window = RangeArg::All();
+	if (args.size() == 2) {
+		window = args.ParseRange(args.size() - 1);
+		args.pop_back();
+	}
+
+	SongFilter filter;
+	try {
+		filter.Parse(args, true);
+	} catch (...) {
+		r.Error(ACK_ERROR_ARG,
+			GetFullMessage(std::current_exception()).c_str());
+		return CommandResult::ERROR;
+	}
+	filter.Optimize();
+
+	playlist_file_print(r, client.GetPartition(), SongLoader(client),
+				   name, window.start, window.end, true, &filter);
 	return CommandResult::OK;
 }
 

src/command/PlaylistCommands.hxx

@@ -26,6 +26,9 @@ handle_listplaylist(Client &client, Request request, Response &response);
 CommandResult
 handle_listplaylistinfo(Client &client, Request request, Response &response);
 
+CommandResult
+handle_searchplaylist(Client &client, Request request, Response &response);
+
 CommandResult
 handle_playlistlength(Client &client, Request request, Response &response);
 

src/playlist/Print.cxx

@@ -8,7 +8,9 @@
 #include "PlaylistSong.hxx"
 #include "SongEnumerator.hxx"
 #include "SongPrint.hxx"
+#include "song/Filter.hxx"
 #include "song/DetachedSong.hxx"
+#include "song/LightSong.hxx"
 #include "input/Error.hxx"
 #include "fs/Traits.hxx"
 #include "thread/Mutex.hxx"
@@ -50,13 +52,55 @@ playlist_provider_print(Response &r,
 	}
 }
 
+static void
+playlist_provider_search_print(Response &r,
+			       const SongLoader &loader,
+			       const char *uri,
+			       SongEnumerator &e,
+			       unsigned start_index,
+			       unsigned end_index,
+			       SongFilter *filter) noexcept
+{
+	const auto base_uri = uri != nullptr
+		? PathTraitsUTF8::GetParent(uri)
+		: ".";
+
+	std::unique_ptr<DetachedSong> song;
+
+	unsigned skip = start_index;
+	unsigned n = end_index - start_index;
+
+	while ((song = e.NextSong()) != nullptr) {
+		const bool detail = playlist_check_translate_song(*song, base_uri,
+								  loader);
+		if (!filter->Match(static_cast<LightSong>(*song)))
+			continue;
+
+		if (skip > 0) {
+			--skip;
+			continue;
+		}
+
+		if (detail)
+			song_print_info(r, *song);
+		else
+			/* fallback if no detail was requested or no
+			   detail was available */
+			song_print_uri(r, *song);
+
+		if (--n == 0)
+			break;
+	}
+}
+
 void
 playlist_file_print(Response &r, Partition &partition,
 		    const SongLoader &loader,
 		    const LocatedUri &uri,
 		    unsigned start_index,
 		    unsigned end_index,
-		    bool detail)
+		    bool detail,
+		    SongFilter *filter)
 try {
 	Mutex mutex;
 
@@ -72,8 +116,12 @@ try {
 	if (playlist == nullptr)
 		throw PlaylistError::NoSuchList();
 
-	playlist_provider_print(r, loader, uri.canonical_uri, *playlist,
+	if (filter == nullptr)
-				start_index, end_index, detail);
+		playlist_provider_print(r, loader, uri.canonical_uri, *playlist,
+					start_index, end_index, detail);
+	else
+		playlist_provider_search_print(r, loader, uri.canonical_uri, *playlist,
+					start_index, end_index, filter);
 } catch (...) {
 	if (IsFileNotFound(std::current_exception()))
 		throw PlaylistError::NoSuchList();

src/playlist/Print.hxx

@@ -5,6 +5,7 @@
 
 class Response;
 class SongLoader;
+class SongFilter;
 struct Partition;
 
 /**
@@ -20,4 +21,6 @@ playlist_file_print(Response &r, Partition &partition,
 		    const SongLoader &loader,
 		    const LocatedUri &uri,
 		    unsigned start_index, unsigned end_index,
-		    bool detail);
+		    bool detail,
+		    SongFilter *filter);
+