decompressing .gZ file from Document directory?
- by senthilmuthu
hi, i am having .gZ (zip file) in document directory.i want unZip it.but i am using libz.dylib framework .will it decompress and save all data to that file path?how can i get that extracted data?any has experienced in doing this?any help?when i use the method,but
when i put break point, it returns data error(used in NSLog)--Z_DATA_ERROR--
- (id)initWithGzippedData: (NSData *)gzippedData;
{
[gzippedData retain];
if ([gzippedData length] == 0) return nil;
unsigned full_length = [gzippedData length];
unsigned half_length = [gzippedData length] / 2;
NSMutableData *decompressed = [[NSMutableData alloc] initWithLength:(full_length + half_length)];
BOOL done = NO;
int status;
z_stream strm;
strm.next_in = (Bytef *)[gzippedData bytes];
strm.avail_in = [gzippedData length];
strm.total_out = 0;
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
if (inflateInit2(&strm, (15+32)) != Z_OK)
{
[gzippedData release];
[decompressed release];
return nil;
}
while (!done)
{
// Make sure we have enough room and reset the lengths.
if (strm.total_out >= [decompressed length])
[decompressed increaseLengthBy: half_length];
strm.next_out = [decompressed mutableBytes] + strm.total_out;
strm.avail_out = [decompressed length] - strm.total_out;
// Inflate another chunk.
status = inflate (&strm, Z_SYNC_FLUSH);
if(status == Z_DATA_ERROR)
{
NSLog(@"data error");
}
if (status == Z_STREAM_END)
done = YES;
else if (status != Z_OK) break;
}
if (inflateEnd (&strm) != Z_OK)
{
[decompressed release];
return nil;
}
// Set real length.
[decompressed setLength: strm.total_out];
id newObject = [self initWithBytes:[decompressed bytes] length:[decompressed length]];
[decompressed release];
[gzippedData release];
return newObject;
}
