add BSEARCH() macros in obt/bsearch.h that to a binary search on an array, use it...

[chaz/openbox] / obt / bsearch.h

diff --git a/obt/bsearch.h b/obt/bsearch.h
new file mode 100644 (file)
index 0000000..ca5ae5b
--- /dev/null
+++ b/obt/bsearch.h
@@ -0,0 +1,54 @@
+/* -*- indent-tabs-mode: nil; tab-width: 4; c-basic-offset: 4; -*-
+ 
+   obt/bsearch.h for the Openbox window manager
+   Copyright (c) 2010        Dana Jansens
+ 
+   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.
+ 
+   See the COPYING file for a copy of the GNU General Public License.
+*/
+
+#ifndef __obt_bsearch_h
+#define __obt_bsearch_h
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+#define BSEARCH_SETUP(t) \
+    register t l_BSEARCH, r_BSEARCH, out_BSEARCH;
+
+#define BSEARCH(t, ar, start, size, val)         \
+{ \
+    l_BSEARCH = (start);              \
+    r_BSEARCH = (start)+(size)-1;     \
+    while (l_BSEARCH <= r_BSEARCH) { \
+        /* m is in the middle, but to the left if there's an even number \
+           of elements */ \
+        out_BSEARCH = l_BSEARCH + (r_BSEARCH - l_BSEARCH)/2;      \
+        if ((val) == (ar)[out_BSEARCH]) {                           \
+            break; \
+        } \
+        else if ((val) < (ar)[out_BSEARCH])                       \
+            r_BSEARCH = out_BSEARCH-1; /* search to the left side */ \
+        else \
+            l_BSEARCH = out_BSEARCH+1; /* search to the left side */ \
+    } \
+}
+
+#define BSEARCH_FOUND() (l_BSEARCH <= r_BSEARCH)
+#define BSEARCH_AT() (out_BSEARCH)
+
+
+
+G_END_DECLS
+
+#endif