Adding large filles problem

[GoogleCodeExporter]

1. On some devices (iPad in my case) trying to add a large file in 
     -(BOOL) addFileToZip:(NSString*) file newname:(NSString*) newname;
     will crash the app because the method
     [NSData dataWithContentsOfFile:] 
     will use up all the memory.

I fixed the issue for my particular problem with zip files that have no 
password by changing the addFileToZip method a bit. You might want to take a 
look at it and change it universally... Also there is no internal autorelease 
pool needed when adding multiple files.

The methode:

#define M_FRAGMENT_SIZE 10000000
-(BOOL) addFileToZip:(NSString*) file newname:(NSString*) newname;
{
    if( !_zipFile )
        return NO;

//  tm_zip filetime;
    time_t current;
    time( &current );

    zip_fileinfo zipInfo = {0};
//  zipInfo.dosDate = (unsigned long) current;

    NSDictionary* attr = [[NSFileManager defaultManager] attributesOfItemAtPath:file error:nil];
    if( attr )
    {
        NSDate* fileDate = (NSDate*)[attr objectForKey:NSFileModificationDate];
        if( fileDate )
        {
            // some application does use dosDate, but tmz_date instead
        //  zipInfo.dosDate = [fileDate timeIntervalSinceDate:[self Date1980] ];
            NSCalendar* currCalendar = [NSCalendar currentCalendar];
            uint flags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | 
                NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit ;
            NSDateComponents* dc = [currCalendar components:flags fromDate:fileDate];
            zipInfo.tmz_date.tm_sec = [dc second];
            zipInfo.tmz_date.tm_min = [dc minute];
            zipInfo.tmz_date.tm_hour = [dc hour];
            zipInfo.tmz_date.tm_mday = [dc day];
            zipInfo.tmz_date.tm_mon = [dc month] - 1;
            zipInfo.tmz_date.tm_year = [dc year];
        }
    }

    int ret ;
    NSData* data = nil;
    if( [_password length] == 0 )
    {
        ret = zipOpenNewFileInZip( _zipFile,
                                  (const char*) [newname UTF8String],
                                  &zipInfo,
                                  NULL,0,
                                  NULL,0,
                                  NULL,//comment
                                  Z_DEFLATED,
                                  Z_DEFAULT_COMPRESSION );
    }
    else
    {
        FILE *f = fopen([file cStringUsingEncoding:NSUTF8StringEncoding], "r");
        fseek(f, 0, SEEK_END);
        long fLenght = ftell(f);
        void *fBuffer = malloc(fLenght);
        fread(fBuffer, 1, fLenght, f);
        fclose(f);
        data = [[NSData alloc] initWithBytesNoCopy:fBuffer length:fLenght];
        uLong crcValue = crc32( 0L,NULL, 0L );
        crcValue = crc32( crcValue, (const Bytef*)[data bytes], [data length] );
        ret = zipOpenNewFileInZip3( _zipFile,
                                  (const char*) [newname UTF8String],
                                  &zipInfo,
                                  NULL,0,
                                  NULL,0,
                                  NULL,//comment
                                  Z_DEFLATED,
                                  Z_DEFAULT_COMPRESSION,
                                  0,
                                  15,
                                  8,
                                  Z_DEFAULT_STRATEGY,
                                  [_password cStringUsingEncoding:NSASCIIStringEncoding],
                                  crcValue );
    }
    if( ret!=Z_OK )
    {
        [data release];
        return NO;
    }

// M_FRAGMENT_SIZE 10000000 (10MB)
    FILE *f = fopen([file cStringUsingEncoding:NSUTF8StringEncoding], "r");
    if(!f)
        return NO;

    fseek(f, 0, SEEK_END);
    long fLenght = ftell(f);
    rewind(f);
    void *fBuffer = malloc(M_FRAGMENT_SIZE);

    for (;fLenght > M_FRAGMENT_SIZE; fLenght-=M_FRAGMENT_SIZE) {        
        fread(fBuffer, 1, M_FRAGMENT_SIZE, f);
        ret = zipWriteInFileInZip( _zipFile, (const void*)fBuffer, M_FRAGMENT_SIZE);
    }   
    if(fLenght) {
        fread(fBuffer, 1, fLenght, f);
        ret = zipWriteInFileInZip( _zipFile, (const void*)fBuffer, fLenght);
        if( ret!=Z_OK )
        {
            free(fBuffer);
            fclose(f);
            return NO;
        }
    }
    free(fBuffer);
    fclose(f);

    if( ret!=Z_OK )
    {
        return NO;
    }
    ret = zipCloseFileInZip( _zipFile );
    if( ret!=Z_OK )
        return NO;
    return YES;
}

Now the memory consumption is restricted by M_FRAGMENT_SIZE in bytes, currently 
10MB and it seems to work great...

Original issue reported on code.google.com by [email protected] on 21 Apr 2011 at 10:02