Added optional binary search

This commit is contained in:
adamdunkels 2006-12-19 09:31:37 +00:00
parent 419c5f3c17
commit 946e11a0fc

View file

@ -1,34 +1,34 @@
/* /*
* Copyright (c) 2005, Swedish Institute of Computer Science * Copyright (c) 2005, Swedish Institute of Computer Science
* All rights reserved. * All rights reserved.
* *
* Redistribution and use in source and binary forms, with or without * Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions * modification, are permitted provided that the following conditions
* are met: * are met:
* 1. Redistributions of source code must retain the above copyright * 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer. * notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright * 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the * notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution. * documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors * 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software * may be used to endorse or promote products derived from this software
* without specific prior written permission. * without specific prior written permission.
* *
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE. * SUCH DAMAGE.
* *
* This file is part of the Contiki operating system. * 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" #include "symtab.h"
@ -37,8 +37,44 @@
#include <string.h> #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) symtab_lookup(const char *name)
{ {
const struct symbols *s; const struct symbols *s;
@ -49,4 +85,5 @@ symtab_lookup(const char *name)
} }
return 0; return 0;
} }
#endif /* SYMTAB_CONF_BINARY_SEARCH */
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/