Standardize state_file handling routines.

This way it's easier to manage and extend.

git-svn-id: https://svn.musicpd.org/mpd/trunk@4494 09075e82-0dd4-0310-85a5-a0d7c8717e4f

1 files changed, 112 insertions, 0 deletions

diff --git a/src/state_file.c b/src/state_file.c
new file mode 100644
index 000000000..1307faa54
--- /dev/null
+++ b/src/state_file.c
@@ -0,0 +1,112 @@
+/* the Music Player Daemon (MPD)
+ * (c)2003-2006 by Warren Dukes (warren.dukes@gmail.com)
+ * This project's homepage is: 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "../config.h"
+#include "state_file.h"
+#include "conf.h"
+#include "gcc.h"
+#include "log.h"
+#include "audio.h"
+#include "playlist.h"
+#include "utils.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+static struct _sf_cb {
+	void (*reader)(FILE *);
+	void (*writer)(FILE *);
+} sf_callbacks [] = {
+	{ readAudioDevicesState, saveAudioDevicesState },
+	{ readPlaylistState, savePlaylistState },
+};
+
+static const char *sfpath = NULL;
+
+static void get_state_file_path(void)
+{
+	ConfigParam *param;
+	if (sfpath)
+		return;
+	param = parseConfigFilePath(CONF_STATE_FILE, 0);
+	if (param)
+		sfpath = (const char *)param->value;
+}
+
+void write_state_file(void)
+{
+	int i;
+	FILE *fp;
+
+	if (!sfpath)
+		return;
+	while (!(fp = fopen(sfpath, "w")) && errno == EINTR);
+
+	if (mpd_unlikely(!fp)) {
+		ERROR("problems opening state file \"%s\" for writing: %s\n",
+		      sfpath, strerror(errno));
+		return;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(sf_callbacks); i++)
+		sf_callbacks[i].writer(fp);
+
+	while(fclose(fp) && errno == EINTR) /* nothing */;
+}
+
+void read_state_file(void)
+{
+	struct stat st;
+	int i;
+	FILE *fp;
+
+	get_state_file_path();
+	if (!sfpath)
+		return;
+	if (stat(sfpath, &st) < 0) {
+		DEBUG("failed to stat state file: %s\n", sfpath);
+		return;
+	}
+	if (!S_ISREG(st.st_mode)) {
+		ERROR("state file \"%s\" is not a regular file\n", sfpath);
+		exit(EXIT_FAILURE);
+	}
+
+	while (!(fp = fopen(sfpath, "r")) && errno == EINTR);
+	if (mpd_unlikely(!fp)) {
+		ERROR("problems opening state file \"%s\" for reading: %s\n",
+		      sfpath, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+	for (i = 0; i < ARRAY_SIZE(sf_callbacks); i++) {
+		sf_callbacks[i].reader(fp);
+		rewind(fp);
+	}
+
+	while(fclose(fp) && errno == EINTR) /* nothing */;
+}
+
+void mpd_noreturn state_file_fatal(void)
+{
+	ERROR("error parsing state file \"%s\"\n", sfpath);
+	exit(EXIT_FAILURE);
+}
+