Return to zip_filerange_crc.c CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / php / ext / zip / lib

Annotation of embedaddon/php/ext/zip/lib/zip_filerange_crc.c, revision 1.1.1.1

1.1       misho       1: /*
                      2:   zip_filerange_crc.c -- compute CRC32 for a range of a file
                      3:   Copyright (C) 2008-2009 Dieter Baron and Thomas Klausner
                      4: 
                      5:   This file is part of libzip, a library to manipulate ZIP archives.
                      6:   The authors can be contacted at <libzip@nih.at>
                      7: 
                      8:   Redistribution and use in source and binary forms, with or without
                      9:   modification, are permitted provided that the following conditions
                     10:   are met:
                     11:   1. Redistributions of source code must retain the above copyright
                     12:      notice, this list of conditions and the following disclaimer.
                     13:   2. Redistributions in binary form must reproduce the above copyright
                     14:      notice, this list of conditions and the following disclaimer in
                     15:      the documentation and/or other materials provided with the
                     16:      distribution.
                     17:   3. The names of the authors may not be used to endorse or promote
                     18:      products derived from this software without specific prior
                     19:      written permission.
                     20:  
                     21:   THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
                     22:   OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
                     23:   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     24:   ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
                     25:   DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     26:   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
                     27:   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
                     28:   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
                     29:   IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
                     30:   OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
                     31:   IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
                     32: */
                     33: 
                     34: 
                     35: 
                     36: #include <stdio.h>
                     37: #include <errno.h>
                     38: 
                     39: #include "zipint.h"
                     40: 
                     41: 
                     42: 
                     43: 
                     44: int
                     45: _zip_filerange_crc(FILE *fp, off_t start, off_t len, uLong *crcp,
                     46:                   struct zip_error *errp)
                     47: {
                     48:     Bytef buf[BUFSIZE];
                     49:     size_t n;
                     50: 
                     51:     *crcp = crc32(0L, Z_NULL, 0);
                     52: 
                     53:     if (fseeko(fp, start, SEEK_SET) != 0) {
                     54:        _zip_error_set(errp, ZIP_ER_SEEK, errno);
                     55:        return -1;
                     56:     }
                     57:     
                     58:     while (len > 0) {
                     59:        n = len > BUFSIZE ? BUFSIZE : len;
                     60:        if ((n=fread(buf, 1, n, fp)) <= 0) {
                     61:            _zip_error_set(errp, ZIP_ER_READ, errno);
                     62:            return -1;
                     63:        }
                     64: 
                     65:        *crcp = crc32(*crcp, buf, n);
                     66: 
                     67:        len-= n;
                     68:     }
                     69: 
                     70:     return 0;
                     71: }