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

3 files changed, 71 insertions, 4 deletions

diff --git a/Makefile.am b/Makefile.am
index d919f65b..e8d5b462 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -126,6 +126,7 @@ obt_libobt_la_LIBADD = \
 	$(GLIB_LIBS) \
 	$(XML_LIBS)
 obt_libobt_la_SOURCES = \
+	obt/bsearch.h \
 	obt/display.h \
 	obt/display.c \
 	obt/internal.h \
diff --git a/obt/bsearch.h b/obt/bsearch.h
new file mode 100644
index 00000000..ca5ae5b2
--- /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
diff --git a/obt/paths.c b/obt/paths.c
index f723ae2c..e2e4859b 100644
--- a/obt/paths.c
+++ b/obt/paths.c
@@ -16,9 +16,13 @@
    See the COPYING file for a copy of the GNU General Public License.
 */
 
+#include "obt/bsearch.h"
 #include "obt/paths.h"
 #include "obt/util.h"
 
+#ifdef HAVE_STDLIB_H
+#  include <stdlib.h>
+#endif
 #ifdef HAVE_SYS_STAT_H
 #  include <sys/stat.h>
 #endif
@@ -90,6 +94,12 @@ static GSList* split_paths(const gchar *paths)
     return list;
 }
 
+int gid_cmp(const void *va, const void *vb)
+{
+    const gid_t a = *(const gid_t*)va, b = *(const gid_t*)vb;
+    return a>b ? 1 : (a == b ? 0 : -1);
+}
+
 static void find_uid_gid(uid_t *u, gid_t **g, guint *n)
 {
     struct passwd *pw;
@@ -115,6 +125,8 @@ static void find_uid_gid(uid_t *u, gid_t **g, guint *n)
         }
     }
     endgrent();
+
+    qsort(*g, sizeof(gid_t), *n, gid_cmp);
 }
 
 ObtPaths* obt_paths_new(void)
@@ -317,7 +329,7 @@ static inline gboolean try_exec(const ObtPaths *const p,
                                 const gchar *const path)
 {
     struct stat st;
-    guint i;
+    BSEARCH_SETUP(guint);
 
     stat(path, &st);
 
@@ -325,9 +337,9 @@ static inline gboolean try_exec(const ObtPaths *const p,
         return FALSE;
     if (st.st_uid == p->uid)
         return st.st_mode & S_IXUSR;
-    for (i = 0; i < p->n_gid; ++i)
-        if (st.st_gid == p->gid[i])
-            return st.st_mode & S_IXGRP;
+    BSEARCH(guint, p->gid, 0, p->n_gid, st.st_gid);
+    if (BSEARCH_FOUND())
+        return st.st_mode & S_IXGRP;
     return st.st_mode & S_IXOTH;
 }