playlist/*: convert to C++

src/playlist/XspfPlaylistPlugin.cxx

@@ -0,0 +1,348 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "XspfPlaylistPlugin.hxx"
+#include "PlaylistPlugin.hxx"
+#include "input_stream.h"
+#include "uri.h"
+#include "song.h"
+#include "tag.h"
+
+#include <glib.h>
+
+#include <assert.h>
+#include <string.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "xspf"
+
+/**
+ * This is the state object for the GLib XML parser.
+ */
+struct XspfParser {
+	/**
+	 * The list of songs (in reverse order because that's faster
+	 * while adding).
+	 */
+	GSList *songs;
+
+	/**
+	 * The current position in the XML file.
+	 */
+	enum {
+		ROOT, PLAYLIST, TRACKLIST, TRACK,
+		LOCATION,
+	} state;
+
+	/**
+	 * The current tag within the "track" element.  This is only
+	 * valid if state==TRACK.  TAG_NUM_OF_ITEM_TYPES means there
+	 * is no (known) tag.
+	 */
+	enum tag_type tag;
+
+	/**
+	 * The current song.  It is allocated after the "location"
+	 * element.
+	 */
+	struct song *song;
+
+	XspfParser()
+		:songs(nullptr), state(ROOT) {}
+};
+
+static void
+xspf_start_element(G_GNUC_UNUSED GMarkupParseContext *context,
+		   const gchar *element_name,
+		   G_GNUC_UNUSED const gchar **attribute_names,
+		   G_GNUC_UNUSED const gchar **attribute_values,
+		   gpointer user_data, G_GNUC_UNUSED GError **error)
+{
+	XspfParser *parser = (XspfParser *)user_data;
+
+	switch (parser->state) {
+	case XspfParser::ROOT:
+		if (strcmp(element_name, "playlist") == 0)
+			parser->state = XspfParser::PLAYLIST;
+
+		break;
+
+	case XspfParser::PLAYLIST:
+		if (strcmp(element_name, "trackList") == 0)
+			parser->state = XspfParser::TRACKLIST;
+
+		break;
+
+	case XspfParser::TRACKLIST:
+		if (strcmp(element_name, "track") == 0) {
+			parser->state = XspfParser::TRACK;
+			parser->song = NULL;
+			parser->tag = TAG_NUM_OF_ITEM_TYPES;
+		}
+
+		break;
+
+	case XspfParser::TRACK:
+		if (strcmp(element_name, "location") == 0)
+			parser->state = XspfParser::LOCATION;
+		else if (strcmp(element_name, "title") == 0)
+			parser->tag = TAG_TITLE;
+		else if (strcmp(element_name, "creator") == 0)
+			/* TAG_COMPOSER would be more correct
+			   according to the XSPF spec */
+			parser->tag = TAG_ARTIST;
+		else if (strcmp(element_name, "annotation") == 0)
+			parser->tag = TAG_COMMENT;
+		else if (strcmp(element_name, "album") == 0)
+			parser->tag = TAG_ALBUM;
+		else if (strcmp(element_name, "trackNum") == 0)
+			parser->tag = TAG_TRACK;
+
+		break;
+
+	case XspfParser::LOCATION:
+		break;
+	}
+}
+
+static void
+xspf_end_element(G_GNUC_UNUSED GMarkupParseContext *context,
+		 const gchar *element_name,
+		 gpointer user_data, G_GNUC_UNUSED GError **error)
+{
+	XspfParser *parser = (XspfParser *)user_data;
+
+	switch (parser->state) {
+	case XspfParser::ROOT:
+		break;
+
+	case XspfParser::PLAYLIST:
+		if (strcmp(element_name, "playlist") == 0)
+			parser->state = XspfParser::ROOT;
+
+		break;
+
+	case XspfParser::TRACKLIST:
+		if (strcmp(element_name, "tracklist") == 0)
+			parser->state = XspfParser::PLAYLIST;
+
+		break;
+
+	case XspfParser::TRACK:
+		if (strcmp(element_name, "track") == 0) {
+			if (parser->song != NULL)
+				parser->songs = g_slist_prepend(parser->songs,
+								parser->song);
+
+			parser->state = XspfParser::TRACKLIST;
+		} else
+			parser->tag = TAG_NUM_OF_ITEM_TYPES;
+
+		break;
+
+	case XspfParser::LOCATION:
+		parser->state = XspfParser::TRACK;
+		break;
+	}
+}
+
+static void
+xspf_text(G_GNUC_UNUSED GMarkupParseContext *context,
+	  const gchar *text, gsize text_len,
+	  gpointer user_data, G_GNUC_UNUSED GError **error)
+{
+	XspfParser *parser = (XspfParser *)user_data;
+
+	switch (parser->state) {
+	case XspfParser::ROOT:
+	case XspfParser::PLAYLIST:
+	case XspfParser::TRACKLIST:
+		break;
+
+	case XspfParser::TRACK:
+		if (parser->song != NULL &&
+		    parser->tag != TAG_NUM_OF_ITEM_TYPES) {
+			if (parser->song->tag == NULL)
+				parser->song->tag = tag_new();
+			tag_add_item_n(parser->song->tag, parser->tag,
+				       text, text_len);
+		}
+
+		break;
+
+	case XspfParser::LOCATION:
+		if (parser->song == NULL) {
+			char *uri = g_strndup(text, text_len);
+			parser->song = song_remote_new(uri);
+			g_free(uri);
+		}
+
+		break;
+	}
+}
+
+static const GMarkupParser xspf_parser = {
+	xspf_start_element,
+	xspf_end_element,
+	xspf_text,
+	nullptr,
+	nullptr,
+};
+
+static void
+song_free_callback(gpointer data, G_GNUC_UNUSED gpointer user_data)
+{
+	struct song *song = (struct song *)data;
+
+	song_free(song);
+}
+
+static void
+xspf_parser_destroy(gpointer data)
+{
+	XspfParser *parser = (XspfParser *)data;
+
+	if (parser->state >= XspfParser::TRACK && parser->song != NULL)
+		song_free(parser->song);
+
+	g_slist_foreach(parser->songs, song_free_callback, NULL);
+	g_slist_free(parser->songs);
+}
+
+/*
+ * The playlist object
+ *
+ */
+
+struct XspfPlaylist {
+	struct playlist_provider base;
+
+	GSList *songs;
+};
+
+static struct playlist_provider *
+xspf_open_stream(struct input_stream *is)
+{
+	XspfParser parser;
+	XspfPlaylist *playlist;
+	GMarkupParseContext *context;
+	char buffer[1024];
+	size_t nbytes;
+	bool success;
+	GError *error = NULL;
+
+	/* parse the XSPF XML file */
+
+	context = g_markup_parse_context_new(&xspf_parser,
+					     G_MARKUP_TREAT_CDATA_AS_TEXT,
+					     &parser, xspf_parser_destroy);
+
+	while (true) {
+		nbytes = input_stream_lock_read(is, buffer, sizeof(buffer),
+						&error);
+		if (nbytes == 0) {
+			if (error != NULL) {
+				g_markup_parse_context_free(context);
+				g_warning("%s", error->message);
+				g_error_free(error);
+				return NULL;
+			}
+
+			break;
+		}
+
+		success = g_markup_parse_context_parse(context, buffer, nbytes,
+						       &error);
+		if (!success) {
+			g_warning("XML parser failed: %s", error->message);
+			g_error_free(error);
+			g_markup_parse_context_free(context);
+			return NULL;
+		}
+	}
+
+	success = g_markup_parse_context_end_parse(context, &error);
+	if (!success) {
+		g_warning("XML parser failed: %s", error->message);
+		g_error_free(error);
+		g_markup_parse_context_free(context);
+		return NULL;
+	}
+
+	/* create a #xspf_playlist object from the parsed song list */
+
+	playlist = g_new(XspfPlaylist, 1);
+	playlist_provider_init(&playlist->base, &xspf_playlist_plugin);
+	playlist->songs = g_slist_reverse(parser.songs);
+	parser.songs = NULL;
+
+	g_markup_parse_context_free(context);
+
+	return &playlist->base;
+}
+
+static void
+xspf_close(struct playlist_provider *_playlist)
+{
+	XspfPlaylist *playlist = (XspfPlaylist *)_playlist;
+
+	g_slist_foreach(playlist->songs, song_free_callback, NULL);
+	g_slist_free(playlist->songs);
+	g_free(playlist);
+}
+
+static struct song *
+xspf_read(struct playlist_provider *_playlist)
+{
+	XspfPlaylist *playlist = (XspfPlaylist *)_playlist;
+
+	if (playlist->songs == NULL)
+		return NULL;
+
+	struct song *song = (struct song *)playlist->songs->data;
+	playlist->songs = g_slist_remove(playlist->songs, song);
+
+	return song;
+}
+
+static const char *const xspf_suffixes[] = {
+	"xspf",
+	NULL
+};
+
+static const char *const xspf_mime_types[] = {
+	"application/xspf+xml",
+	NULL
+};
+
+const struct playlist_plugin xspf_playlist_plugin = {
+	"xspf",
+
+	nullptr,
+	nullptr,
+	nullptr,
+	xspf_open_stream,
+	xspf_close,
+	xspf_read,
+
+	nullptr,
+	xspf_suffixes,
+	xspf_mime_types,
+};