db_plugin: add method visit()

3 files changed, 121 insertions, 0 deletions

diff --git a/src/db/simple_db_plugin.c b/src/db/simple_db_plugin.c
index 8218635fc..e359b5e65 100644
--- a/src/db/simple_db_plugin.c
+++ b/src/db/simple_db_plugin.c
@@ -21,6 +21,8 @@
 #include "simple_db_plugin.h"
 #include "db_internal.h"
 #include "db_error.h"
+#include "db_selection.h"
+#include "db_visitor.h"
 #include "db_save.h"
 #include "conf.h"
 #include "glib_compat.h"
@@ -48,6 +50,17 @@ simple_db_quark(void)
 	return g_quark_from_static_string("simple_db");
 }
 
+G_GNUC_PURE
+static const struct directory *
+simple_db_lookup_directory(const struct simple_db *db, const char *uri)
+{
+	assert(db != NULL);
+	assert(db->root != NULL);
+	assert(uri != NULL);
+
+	return directory_lookup_directory(db->root, uri);
+}
+
 static struct db *
 simple_db_init(const struct config_param *param, GError **error_r)
 {
@@ -230,6 +243,33 @@ simple_db_get_song(struct db *_db, const char *uri, GError **error_r)
 	return song;
 }
 
+static bool
+simple_db_visit(struct db *_db, const struct db_selection *selection,
+		const struct db_visitor *visitor, void *ctx,
+		GError **error_r)
+{
+	const struct simple_db *db = (const struct simple_db *)_db;
+	const struct directory *directory =
+		simple_db_lookup_directory(db, selection->uri);
+	if (directory == NULL) {
+		struct song *song;
+		if (visitor->song != NULL &&
+		    (song = simple_db_get_song(_db, selection->uri, NULL)) != NULL)
+			return visitor->song(song, ctx, error_r);
+
+		g_set_error(error_r, db_quark(), DB_NOT_FOUND,
+			    "No such directory");
+		return false;
+	}
+
+	if (selection->recursive && visitor->directory != NULL &&
+	    !visitor->directory(directory, ctx, error_r))
+		return false;
+
+	return directory_walk(directory, selection->recursive,
+			      visitor, ctx, error_r);
+}
+
 const struct db_plugin simple_db_plugin = {
 	.name = "simple",
 	.init = simple_db_init,
@@ -237,6 +277,7 @@ const struct db_plugin simple_db_plugin = {
 	.open = simple_db_open,
 	.close = simple_db_close,
 	.get_song = simple_db_get_song,
+	.visit = simple_db_visit,
 };
 
 struct directory *
diff --git a/src/db_plugin.h b/src/db_plugin.h
index 5fec2529e..1c7e14ede 100644
--- a/src/db_plugin.h
+++ b/src/db_plugin.h
@@ -31,6 +31,8 @@
 #include <stdbool.h>
 
 struct config_param;
+struct db_selection;
+struct db_visitor;
 
 struct db {
 	const struct db_plugin *plugin;
@@ -67,6 +69,13 @@ struct db_plugin {
 	 */
 	struct song *(*get_song)(struct db *db, const char *uri,
 				 GError **error_r);
+
+	/**
+	 * Visit the selected entities.
+	 */
+	bool (*visit)(struct db *db, const struct db_selection *selection,
+		      const struct db_visitor *visitor, void *ctx,
+		      GError **error_r);
 };
 
 G_GNUC_MALLOC
@@ -78,6 +87,7 @@ db_plugin_new(const struct db_plugin *plugin, const struct config_param *param,
 	assert(plugin->init != NULL);
 	assert(plugin->finish != NULL);
 	assert(plugin->get_song != NULL);
+	assert(plugin->visit != NULL);
 	assert(error_r == NULL || *error_r == NULL);
 
 	struct db *db = plugin->init(param, error_r);
@@ -129,4 +139,18 @@ db_plugin_get_song(struct db *db, const char *uri, GError **error_r)
 	return db->plugin->get_song(db, uri, error_r);
 }
 
+static inline bool
+db_plugin_visit(struct db *db, const struct db_selection *selection,
+		const struct db_visitor *visitor, void *ctx,
+		GError **error_r)
+{
+	assert(db != NULL);
+	assert(db->plugin != NULL);
+	assert(selection != NULL);
+	assert(visitor != NULL);
+	assert(error_r == NULL || *error_r == NULL);
+
+	return db->plugin->visit(db, selection, visitor, ctx, error_r);
+}
+
 #endif
diff --git a/src/db_selection.h b/src/db_selection.h
new file mode 100644
index 000000000..2cebb4907
--- /dev/null
+++ b/src/db_selection.h
@@ -0,0 +1,56 @@
+/*
+ * 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.
+ */
+
+#ifndef MPD_DB_SELECTION_H
+#define MPD_DB_SELECTION_H
+
+#include "gcc.h"
+
+#include <assert.h>
+
+struct directory;
+struct song;
+
+struct db_selection {
+	/**
+	 * The base URI of the search (UTF-8).  Must not begin or end
+	 * with a slash.  NULL or an empty string searches the whole
+	 * database.
+	 */
+	const char *uri;
+
+	/**
+	 * Recursively search all sub directories?
+	 */
+	bool recursive;
+};
+
+gcc_nonnull(1,2)
+static inline void
+db_selection_init(struct db_selection *selection,
+		  const char *uri, bool recursive)
+{
+	assert(selection != NULL);
+	assert(uri != NULL);
+
+	selection->uri = uri;
+	selection->recursive = recursive;
+}
+
+#endif