db_plugin: convert to C++

1 files changed, 315 insertions, 0 deletions

diff --git a/src/db/SimpleDatabasePlugin.cxx b/src/db/SimpleDatabasePlugin.cxx
new file mode 100644
index 00000000..8398eedc
--- /dev/null
+++ b/src/db/SimpleDatabasePlugin.cxx
@@ -0,0 +1,315 @@
+/*
+ * 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 "SimpleDatabasePlugin.hxx"
+
+extern "C" {
+#include "db_error.h"
+#include "db_selection.h"
+#include "db_visitor.h"
+#include "db_save.h"
+#include "db_lock.h"
+#include "conf.h"
+}
+
+#include "directory.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+
+G_GNUC_CONST
+static inline GQuark
+simple_db_quark(void)
+{
+	return g_quark_from_static_string("simple_db");
+}
+
+Database *
+SimpleDatabase::Create(const struct config_param *param, GError **error_r)
+{
+	SimpleDatabase *db = new SimpleDatabase();
+	if (!db->Configure(param, error_r)) {
+		delete db;
+		db = NULL;
+	}
+
+	return db;
+}
+
+bool
+SimpleDatabase::Configure(const struct config_param *param, GError **error_r)
+{
+	GError *error = NULL;
+
+	char *_path = config_dup_block_path(param, "path", &error);
+	if (_path == NULL) {
+		if (error != NULL)
+			g_propagate_error(error_r, error);
+		else
+			g_set_error(error_r, simple_db_quark(), 0,
+				    "No \"path\" parameter specified");
+		return false;
+	}
+
+	path = _path;
+	free(_path);
+
+	return true;
+}
+
+bool
+SimpleDatabase::Check(GError **error_r) const
+{
+	assert(!path.empty());
+
+	/* Check if the file exists */
+	if (access(path.c_str(), F_OK)) {
+		/* If the file doesn't exist, we can't check if we can write
+		 * it, so we are going to try to get the directory path, and
+		 * see if we can write a file in that */
+		char *dirPath = g_path_get_dirname(path.c_str());
+
+		/* Check that the parent part of the path is a directory */
+		struct stat st;
+		if (stat(dirPath, &st) < 0) {
+			g_free(dirPath);
+			g_set_error(error_r, simple_db_quark(), errno,
+				    "Couldn't stat parent directory of db file "
+				    "\"%s\": %s",
+				    path.c_str(), g_strerror(errno));
+			return false;
+		}
+
+		if (!S_ISDIR(st.st_mode)) {
+			g_free(dirPath);
+			g_set_error(error_r, simple_db_quark(), 0,
+				    "Couldn't create db file \"%s\" because the "
+				    "parent path is not a directory",
+				    path.c_str());
+			return false;
+		}
+
+		/* Check if we can write to the directory */
+		if (access(dirPath, X_OK | W_OK)) {
+			g_set_error(error_r, simple_db_quark(), errno,
+				    "Can't create db file in \"%s\": %s",
+				    dirPath, g_strerror(errno));
+			g_free(dirPath);
+			return false;
+		}
+
+		g_free(dirPath);
+
+		return true;
+	}
+
+	/* Path exists, now check if it's a regular file */
+	struct stat st;
+	if (stat(path.c_str(), &st) < 0) {
+		g_set_error(error_r, simple_db_quark(), errno,
+			    "Couldn't stat db file \"%s\": %s",
+			    path.c_str(), g_strerror(errno));
+		return false;
+	}
+
+	if (!S_ISREG(st.st_mode)) {
+		g_set_error(error_r, simple_db_quark(), 0,
+			    "db file \"%s\" is not a regular file",
+			    path.c_str());
+		return false;
+	}
+
+	/* And check that we can write to it */
+	if (access(path.c_str(), R_OK | W_OK)) {
+		g_set_error(error_r, simple_db_quark(), errno,
+			    "Can't open db file \"%s\" for reading/writing: %s",
+			    path.c_str(), g_strerror(errno));
+		return false;
+	}
+
+	return true;
+}
+
+bool
+SimpleDatabase::Load(GError **error_r)
+{
+	assert(!path.empty());
+	assert(root != NULL);
+
+	FILE *fp = fopen(path.c_str(), "r");
+	if (fp == NULL) {
+		g_set_error(error_r, simple_db_quark(), errno,
+			    "Failed to open database file \"%s\": %s",
+			    path.c_str(), g_strerror(errno));
+		return false;
+	}
+
+	if (!db_load_internal(fp, root, error_r)) {
+		fclose(fp);
+		return false;
+	}
+
+	fclose(fp);
+
+	struct stat st;
+	if (stat(path.c_str(), &st) == 0)
+		mtime = st.st_mtime;
+
+	return true;
+}
+
+bool
+SimpleDatabase::Open(GError **error_r)
+{
+	root = directory_new_root();
+	mtime = 0;
+
+	GError *error = NULL;
+	if (!Load(&error)) {
+		directory_free(root);
+
+		g_warning("Failed to load database: %s", error->message);
+		g_error_free(error);
+
+		if (!Check(error_r))
+			return false;
+
+		root = directory_new_root();
+	}
+
+	return true;
+}
+
+void
+SimpleDatabase::Close()
+{
+	assert(root != NULL);
+
+	directory_free(root);
+}
+
+struct song *
+SimpleDatabase::GetSong(const char *uri, GError **error_r)
+{
+	assert(root != NULL);
+
+	db_lock();
+	struct song *song = directory_lookup_song(root, uri);
+	db_unlock();
+	if (song == NULL)
+		g_set_error(error_r, db_quark(), DB_NOT_FOUND,
+			    "No such song: %s", uri);
+
+	return song;
+}
+
+G_GNUC_PURE
+const struct directory *
+SimpleDatabase::LookupDirectory(const char *uri) const
+{
+	assert(root != NULL);
+	assert(uri != NULL);
+
+	db_lock();
+	struct directory *directory =
+		directory_lookup_directory(root, uri);
+	db_unlock();
+	return directory;
+}
+
+bool
+SimpleDatabase::Visit(const struct db_selection *selection,
+		      VisitDirectory visit_directory,
+		      VisitSong visit_song,
+		      VisitPlaylist visit_playlist,
+		      GError **error_r)
+{
+	const struct directory *directory = LookupDirectory(selection->uri);
+	if (directory == NULL) {
+		struct song *song;
+		if (visit_song &&
+		    (song = GetSong(selection->uri, NULL)) != NULL)
+			return visit_song(song, error_r);
+
+		g_set_error(error_r, db_quark(), DB_NOT_FOUND,
+			    "No such directory");
+		return false;
+	}
+
+	if (selection->recursive && visit_directory &&
+	    !visit_directory(directory, error_r))
+		return false;
+
+	db_lock();
+	bool ret = directory->Walk(selection->recursive,
+				   visit_directory, visit_song, visit_playlist,
+				   error_r);
+	db_unlock();
+	return ret;
+}
+
+bool
+SimpleDatabase::Save(GError **error_r)
+{
+	db_lock();
+
+	g_debug("removing empty directories from DB");
+	directory_prune_empty(root);
+
+	g_debug("sorting DB");
+	directory_sort(root);
+
+	db_unlock();
+
+	g_debug("writing DB");
+
+	FILE *fp = fopen(path.c_str(), "w");
+	if (!fp) {
+		g_set_error(error_r, simple_db_quark(), errno,
+			    "unable to write to db file \"%s\": %s",
+			    path.c_str(), g_strerror(errno));
+		return false;
+	}
+
+	db_save_internal(fp, root);
+
+	if (ferror(fp)) {
+		g_set_error(error_r, simple_db_quark(), errno,
+			    "Failed to write to database file: %s",
+			    g_strerror(errno));
+		fclose(fp);
+		return false;
+	}
+
+	fclose(fp);
+
+	struct stat st;
+	if (stat(path.c_str(), &st) == 0)
+		mtime = st.st_mtime;
+
+	return true;
+}
+
+const DatabasePlugin simple_db_plugin = {
+	"simple",
+	SimpleDatabase::Create,
+};