mpd/src/playlist/rss_playlist_plugin.c

323 lines
7.1 KiB
C
Raw Normal View History

/*
2011-01-29 10:13:54 +01:00
* Copyright (C) 2003-2011 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 "playlist/rss_playlist_plugin.h"
#include "playlist_plugin.h"
#include "input_stream.h"
#include "song.h"
#include "tag.h"
#include <glib.h>
#include <assert.h>
#include <string.h>
#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "rss"
/**
* This is the state object for the GLib XML parser.
*/
struct rss_parser {
/**
* The list of songs (in reverse order because that's faster
* while adding).
*/
GSList *songs;
/**
* The current position in the XML file.
*/
enum {
ROOT, ITEM,
} state;
/**
* The current tag within the "entry" element. This is only
* valid if state==ITEM. 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;
};
static const gchar *
get_attribute(const gchar **attribute_names, const gchar **attribute_values,
const gchar *name)
{
for (unsigned i = 0; attribute_names[i] != NULL; ++i)
if (g_ascii_strcasecmp(attribute_names[i], name) == 0)
return attribute_values[i];
return NULL;
}
static void
rss_start_element(G_GNUC_UNUSED GMarkupParseContext *context,
const gchar *element_name,
const gchar **attribute_names,
const gchar **attribute_values,
gpointer user_data, G_GNUC_UNUSED GError **error)
{
struct rss_parser *parser = user_data;
switch (parser->state) {
case ROOT:
if (g_ascii_strcasecmp(element_name, "item") == 0) {
parser->state = ITEM;
parser->song = song_remote_new("rss:");
parser->tag = TAG_NUM_OF_ITEM_TYPES;
}
break;
case ITEM:
if (g_ascii_strcasecmp(element_name, "enclosure") == 0) {
const gchar *href = get_attribute(attribute_names,
attribute_values,
"url");
if (href != NULL) {
/* create new song object, and copy
the existing tag over; we cannot
replace the existing song's URI,
because that attribute is
immutable */
struct song *song = song_remote_new(href);
if (parser->song != NULL) {
song->tag = parser->song->tag;
parser->song->tag = NULL;
song_free(parser->song);
}
parser->song = song;
}
} else if (g_ascii_strcasecmp(element_name, "title") == 0)
parser->tag = TAG_TITLE;
else if (g_ascii_strcasecmp(element_name, "itunes:author") == 0)
parser->tag = TAG_ARTIST;
break;
}
}
static void
rss_end_element(G_GNUC_UNUSED GMarkupParseContext *context,
const gchar *element_name,
gpointer user_data, G_GNUC_UNUSED GError **error)
{
struct rss_parser *parser = user_data;
switch (parser->state) {
case ROOT:
break;
case ITEM:
if (g_ascii_strcasecmp(element_name, "item") == 0) {
if (strcmp(parser->song->uri, "rss:") != 0)
parser->songs = g_slist_prepend(parser->songs,
parser->song);
else
song_free(parser->song);
parser->state = ROOT;
} else
parser->tag = TAG_NUM_OF_ITEM_TYPES;
break;
}
}
static void
rss_text(G_GNUC_UNUSED GMarkupParseContext *context,
const gchar *text, gsize text_len,
gpointer user_data, G_GNUC_UNUSED GError **error)
{
struct rss_parser *parser = user_data;
switch (parser->state) {
case ROOT:
break;
case ITEM:
if (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;
}
}
static const GMarkupParser rss_parser = {
.start_element = rss_start_element,
.end_element = rss_end_element,
.text = rss_text,
};
static void
song_free_callback(gpointer data, G_GNUC_UNUSED gpointer user_data)
{
struct song *song = data;
song_free(song);
}
static void
rss_parser_destroy(gpointer data)
{
struct rss_parser *parser = data;
if (parser->state >= ITEM)
song_free(parser->song);
g_slist_foreach(parser->songs, song_free_callback, NULL);
g_slist_free(parser->songs);
}
/*
* The playlist object
*
*/
struct rss_playlist {
struct playlist_provider base;
GSList *songs;
};
static struct playlist_provider *
rss_open_stream(struct input_stream *is)
{
struct rss_parser parser = {
.songs = NULL,
.state = ROOT,
};
struct rss_playlist *playlist;
GMarkupParseContext *context;
char buffer[1024];
size_t nbytes;
bool success;
GError *error = NULL;
/* parse the RSS XML file */
context = g_markup_parse_context_new(&rss_parser,
G_MARKUP_TREAT_CDATA_AS_TEXT,
&parser, rss_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 #rss_playlist object from the parsed song list */
playlist = g_new(struct rss_playlist, 1);
playlist_provider_init(&playlist->base, &rss_playlist_plugin);
playlist->songs = g_slist_reverse(parser.songs);
parser.songs = NULL;
g_markup_parse_context_free(context);
return &playlist->base;
}
static void
rss_close(struct playlist_provider *_playlist)
{
struct rss_playlist *playlist = (struct rss_playlist *)_playlist;
g_slist_foreach(playlist->songs, song_free_callback, NULL);
g_slist_free(playlist->songs);
g_free(playlist);
}
static struct song *
rss_read(struct playlist_provider *_playlist)
{
struct rss_playlist *playlist = (struct rss_playlist *)_playlist;
struct song *song;
if (playlist->songs == NULL)
return NULL;
song = playlist->songs->data;
playlist->songs = g_slist_remove(playlist->songs, song);
return song;
}
static const char *const rss_suffixes[] = {
"rss",
NULL
};
static const char *const rss_mime_types[] = {
"application/rss+xml",
"text/xml",
NULL
};
const struct playlist_plugin rss_playlist_plugin = {
.name = "rss",
.open_stream = rss_open_stream,
.close = rss_close,
.read = rss_read,
.suffixes = rss_suffixes,
.mime_types = rss_mime_types,
};