00001 /* 00002 * Copyright Droids Corporation (2007) 00003 * Olivier MATZ <zer0@droids-corp.org> 00004 * 00005 * This program is free software; you can redistribute it and/or modify 00006 * it under the terms of the GNU General Public License as published by 00007 * the Free Software Foundation; either version 2 of the License, or 00008 * (at your option) any later version. 00009 * 00010 * This program is distributed in the hope that it will be useful, 00011 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00013 * GNU General Public License for more details. 00014 * 00015 * You should have received a copy of the GNU General Public License 00016 * along with this program; if not, write to the Free Software 00017 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 00018 * 00019 * Revision : $Id: cirbuf_del_buf_head.c,v 1.2 2008-01-08 20:05:02 zer0 Exp $ 00020 * 00021 */ 00022 00023 #include <string.h> 00024 00025 #include <cirbuf.h> 00026 00027 /* buffer del */ 00028 00029 cirbuf_int 00030 cirbuf_del_buf_head(struct cirbuf * cbuf, cirbuf_uint size) 00031 { 00032 if (!size || size > CIRBUF_GET_LEN(cbuf)) 00033 return -EINVAL; 00034 00035 cbuf->len -= size; 00036 if (CIRBUF_IS_EMPTY(cbuf)) { 00037 cbuf->start += size - 1; 00038 cbuf->start %= cbuf->maxlen; 00039 } 00040 else { 00041 cbuf->start += size; 00042 cbuf->start %= cbuf->maxlen; 00043 } 00044 return 0; 00045 }
1.5.6