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

155 lines
3.4 KiB
Objective-C

/*
* CSZlibHandle.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 "CSZlibHandle.h"
NSString *CSZlibException=@"CSZlibException";
@implementation CSZlibHandle
+(CSZlibHandle *)zlibHandleWithHandle:(CSHandle *)handle
{
return [[[CSZlibHandle alloc] initWithHandle:handle length:CSHandleMaxLength header:YES] autorelease];
}
+(CSZlibHandle *)zlibHandleWithHandle:(CSHandle *)handle length:(off_t)length
{
return [[[CSZlibHandle alloc] initWithHandle:handle length:length header:YES] autorelease];
}
+(CSZlibHandle *)deflateHandleWithHandle:(CSHandle *)handle
{
return [[[CSZlibHandle alloc] initWithHandle:handle length:CSHandleMaxLength header:NO] autorelease];
}
+(CSZlibHandle *)deflateHandleWithHandle:(CSHandle *)handle length:(off_t)length
{
return [[[CSZlibHandle alloc] initWithHandle:handle length:length header:NO] autorelease];
}
-(id)initWithHandle:(CSHandle *)handle length:(off_t)length header:(BOOL)header
{
if(self=[super initWithParentHandle:handle length:length])
{
startoffs=[parent offsetInFile];
inited=YES;
seekback=NO;
memset(&zs,0,sizeof(zs));
if(header) inflateInit(&zs);
else inflateInit2(&zs,-MAX_WBITS);
}
return self;
}
-(id)initAsCopyOf:(CSZlibHandle *)other
{
if(self=[super initAsCopyOf:other])
{
startoffs=other->startoffs;
inited=NO;
seekback=other->seekback;
memset(&zs,0,sizeof(zs));
if(inflateCopy(&zs,&other->zs)==Z_OK)
{
zs.next_in=inbuffer;
memcpy(inbuffer,other->zs.next_in,zs.avail_in);
inited=YES;
return self;
}
[self release];
}
return nil;
}
-(void)dealloc
{
if(inited) inflateEnd(&zs);
[super dealloc];
}
-(void)setSeekBackAtEOF:(BOOL)seekateof { seekback=seekateof; }
-(void)setEndStreamAtInputEOF:(BOOL)endateof { endstreamateof=endateof; } // Hack for NSIS's broken zlib usage
-(void)resetStream
{
[parent seekToFileOffset:startoffs];
zs.avail_in=0;
inflateReset(&zs);
}
-(int)streamAtMost:(int)num toBuffer:(void *)buffer
{
zs.next_out=buffer;
zs.avail_out=num;
for(;;)
{
int err=inflate(&zs,0);
if(err==Z_STREAM_END)
{
if(seekback) [parent skipBytes:-(off_t)zs.avail_in];
[self endStream];
return num-zs.avail_out;
}
else if(err!=Z_OK && err!=Z_BUF_ERROR) [self _raiseZlib];
if(!zs.avail_out) return num;
if(!zs.avail_in)
{
zs.avail_in=[parent readAtMost:sizeof(inbuffer) toBuffer:inbuffer];
zs.next_in=(void *)inbuffer;
if(!zs.avail_in)
{
if(endstreamateof)
{
[self endStream];
return num-zs.avail_out;
}
else [parent _raiseEOF];
}
}
}
}
-(void)_raiseZlib
{
[NSException raise:CSZlibException
format:@"Zlib error while attepting to read from \"%@\": %s.",[self name],zs.msg];
}
@end