Added optional binary search

core/loader/symtab.c

@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * @(#)$Id: symtab.c,v 1.3 2006/12/18 15:27:18 fros4943 Exp $
+ * @(#)$Id: symtab.c,v 1.4 2006/12/19 09:31:37 adamdunkels Exp $
  */
 
 #include "symtab.h"
@@ -37,8 +37,44 @@
 
 #include <string.h>
 
+#define SYMTAB_CONF_BINARY_SEARCH 0
+
 /*---------------------------------------------------------------------------*/
-void *
+#if SYMTAB_CONF_BINARY_SEARCH
+const char *
+symtab_lookup(const char *name)
+{
+  int start, middle, end;
+  int r;
+  
+  start = 0;
+  end = sizeof(symbols) / sizeof(struct symbols);
+
+  do {
+    /* Check middle, divide */
+    middle = (end + start) / 2;
+
+    if(symbols[middle].name == NULL) {
+      return NULL;
+    }
+    r = strcmp(name, symbols[middle].name);
+    if(r == 0) {
+      return symbols[middle].value;   
+    }
+    if(end == middle || start == middle) {
+      return NULL;
+    }
+    if(r < 0) {
+      end = middle;
+    }
+    if(r > 0) {
+      start = middle;
+    }
+  } while(1);
+
+}
+#else /* SYMTAB_CONF_BINARY_SEARCH */
+const char *
 symtab_lookup(const char *name)
 {
   const struct symbols *s;
@@ -49,4 +85,5 @@ symtab_lookup(const char *name)
   }
   return 0;
 }
+#endif /* SYMTAB_CONF_BINARY_SEARCH */
 /*---------------------------------------------------------------------------*/