XADMaster/XADChecksumHandle.m
2018-03-21 14:24:50 +02:00

61 lines
1.6 KiB
Objective-C

/*
* XADChecksumHandle.m
*
* Copyright (c) 2017-present, MacPaw Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#import "XADChecksumHandle.h"
@implementation XADChecksumHandle
-(id)initWithHandle:(CSHandle *)handle length:(off_t)length correctChecksum:(int)correct mask:(int)mask
{
if((self=[super initWithParentHandle:handle length:length]))
{
correctchecksum=correct;
summask=mask;
}
return self;
}
-(void)resetStream
{
[parent seekToFileOffset:0];
checksum=0;
}
-(int)streamAtMost:(int)num toBuffer:(void *)buffer
{
int actual=[parent readAtMost:num toBuffer:buffer];
uint8_t *bytes=buffer;
for(int i=0;i<actual;i++) checksum+=bytes[i];
return actual;
}
-(BOOL)hasChecksum { return YES; }
-(BOOL)isChecksumCorrect
{
return (checksum&summask)==(correctchecksum&summask);
}
-(double)estimatedProgress { return [parent estimatedProgress]; }
@end