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373769682e
git-subtree-dir: submodules/MtProtoKit git-subtree-mainline: 3b155750f5a4894ff3dedf1860a37e94e0ea9571 git-subtree-split: 14ab734b977fd4f1686a2a13415f6a4c9b9fdd6d
54 lines
1.5 KiB
Objective-C
54 lines
1.5 KiB
Objective-C
#import "MTGzip.h"
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#import <zlib.h>
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@implementation MTGzip
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+ (NSData * _Nullable)decompress:(NSData *)data {
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const int kMemoryChunkSize = 1024;
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NSUInteger length = [data length];
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int windowBits = 15 + 32; //Default + gzip header instead of zlib header
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int retCode;
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unsigned char output[kMemoryChunkSize];
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uInt gotBack;
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NSMutableData *result;
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z_stream stream;
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if ((length == 0) || (length > UINT_MAX)) //FIXME: Support 64 bit inputs
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return nil;
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bzero(&stream, sizeof(z_stream));
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stream.avail_in = (uInt)length;
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stream.next_in = (unsigned char*)[data bytes];
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retCode = inflateInit2(&stream, windowBits);
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if(retCode != Z_OK)
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{
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NSLog(@"%s: inflateInit2() failed with error %i", __PRETTY_FUNCTION__, retCode);
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return nil;
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}
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result = [NSMutableData dataWithCapacity:(length * 4)];
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do
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{
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stream.avail_out = kMemoryChunkSize;
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stream.next_out = output;
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retCode = inflate(&stream, Z_NO_FLUSH);
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if ((retCode != Z_OK) && (retCode != Z_STREAM_END))
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{
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NSLog(@"%s: inflate() failed with error %i", __PRETTY_FUNCTION__, retCode);
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inflateEnd(&stream);
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return nil;
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}
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gotBack = kMemoryChunkSize - stream.avail_out;
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if (gotBack > 0)
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[result appendBytes:output length:gotBack];
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} while( retCode == Z_OK);
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inflateEnd(&stream);
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return (retCode == Z_STREAM_END ? result : nil);
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}
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@end
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