input_stream: non-blocking I/O

Add GMutex, GCond attributes which will be used by callers to
conditionally wait on the stream.

Remove the (now-useless) plugin method buffer(), wait on GCond
instead.  Lock the input_stream before each method call.  Do the same
with the playlist plugins.

src/archive/bz2_archive_plugin.c

@@ -114,7 +114,11 @@ bz2_open(const char *pathname, GError **error_r)
 	refcount_init(&context->ref);
 
 	//open archive
-	context->istream = input_stream_open(pathname, error_r);
+	static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
+	context->istream = input_stream_open(pathname,
+					     g_static_mutex_get_mutex(&mutex),
+					     NULL,
+					     error_r);
 	if (context->istream == NULL) {
 		g_free(context);
 		return NULL;
@@ -169,12 +173,15 @@ bz2_close(struct archive_file *file)
 /* single archive handling */
 
 static struct input_stream *
-bz2_open_stream(struct archive_file *file, const char *path, GError **error_r)
+bz2_open_stream(struct archive_file *file, const char *path,
+		GMutex *mutex, GCond *cond,
+		GError **error_r)
 {
 	struct bz2_archive_file *context = (struct bz2_archive_file *) file;
 	struct bz2_input_stream *bis = g_new(struct bz2_input_stream, 1);
 
-	input_stream_init(&bis->base, &bz2_inputplugin, path);
+	input_stream_init(&bis->base, &bz2_inputplugin, path,
+			  mutex, cond);
 
 	bis->archive = context;
 

src/archive/iso9660_archive_plugin.c

@@ -173,15 +173,17 @@ struct iso9660_input_stream {
 };
 
 static struct input_stream *
-iso9660_archive_open_stream(struct archive_file *file,
-		const char *pathname, GError **error_r)
+iso9660_archive_open_stream(struct archive_file *file, const char *pathname,
+			    GMutex *mutex, GCond *cond,
+			    GError **error_r)
 {
 	struct iso9660_archive_file *context =
 		(struct iso9660_archive_file *)file;
 	struct iso9660_input_stream *iis;
 
 	iis = g_new(struct iso9660_input_stream, 1);
-	input_stream_init(&iis->base, &iso9660_input_plugin, pathname);
+	input_stream_init(&iis->base, &iso9660_input_plugin, pathname,
+			  mutex, cond);
 
 	iis->archive = context;
 	iis->statbuf = iso9660_ifs_stat_translate(context->iso, pathname);

src/archive/zzip_archive_plugin.c

@@ -135,14 +135,17 @@ struct zzip_input_stream {
 
 static struct input_stream *
 zzip_archive_open_stream(struct archive_file *file,
-			 const char *pathname, GError **error_r)
+			 const char *pathname,
+			 GMutex *mutex, GCond *cond,
+			 GError **error_r)
 {
 	struct zzip_archive *context = (struct zzip_archive *) file;
 	struct zzip_input_stream *zis;
 	ZZIP_STAT z_stat;
 
 	zis = g_new(struct zzip_input_stream, 1);
-	input_stream_init(&zis->base, &zzip_input_plugin, pathname);
+	input_stream_init(&zis->base, &zzip_input_plugin, pathname,
+			  mutex, cond);
 
 	zis->archive = context;
 	zis->file = zzip_file_open(context->dir, pathname, 0);