added string set library

"struct strset" is a hashed string set: you can add strings to this
library, and it stores them as a set of unique strings.  You can get
the size of the set, and you can enumerate through all values.

This will be used to replace the linear tagTracker library.

1 files changed, 49 insertions, 0 deletions

diff --git a/src/strset.h b/src/strset.h
new file mode 100644
index 000000000..41ef0e1bd
--- /dev/null
+++ b/src/strset.h
@@ -0,0 +1,49 @@
+/* the Music Player Daemon (MPD)
+ * Copyright (C) 2008 Max Kellermann <max@duempel.org>
+ * 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
+ */
+
+/**
+ * "struct strset" is a hashed string set: you can add strings to this
+ * library, and it stores them as a set of unique strings.  You can
+ * get the size of the set, and you can enumerate through all values.
+ *
+ * It is important to note that the strset does not copy the string
+ * values - it stores the exact pointers it was given in strset_add().
+ */
+
+#ifndef STRSET_H
+#define STRSET_H
+
+#include "gcc.h"
+
+struct strset;
+
+mpd_malloc struct strset *strset_new(void);
+
+void strset_free(struct strset *set);
+
+void strset_add(struct strset *set, const char *value);
+
+int strset_get(const struct strset *set, const char *value);
+
+unsigned strset_size(const struct strset *set);
+
+void strset_rewind(struct strset *set);
+
+const char *strset_next(struct strset *set);
+
+#endif