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130 lines
3.7 KiB
Objective-C
130 lines
3.7 KiB
Objective-C
#import "NSData+GZip.h"
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#import <zlib.h>
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#import "NSData+GZip.h"
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#import "lz4.h"
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#define kMemoryChunkSize 1024
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@implementation NSData (GZip)
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- (NSData *)compressGZip
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{
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NSUInteger length = [self length];
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int windowBits = 15 + 16; //Default + gzip header instead of zlib header
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int memLevel = 8; //Default
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int retCode;
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NSMutableData *result;
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z_stream stream;
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unsigned char output[kMemoryChunkSize];
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uInt gotBack;
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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*)[self bytes];
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retCode = deflateInit2(&stream, Z_BEST_COMPRESSION, Z_DEFLATED, windowBits, memLevel, Z_DEFAULT_STRATEGY);
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if(retCode != Z_OK)
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{
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NSLog(@"%s: deflateInit2() failed with error %i", __PRETTY_FUNCTION__, retCode);
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return nil;
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}
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result = [[NSMutableData alloc] initWithCapacity:(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 = deflate(&stream, Z_FINISH);
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if((retCode != Z_OK) && (retCode != Z_STREAM_END))
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{
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NSLog(@"%s: deflate() failed with error %i", __PRETTY_FUNCTION__, retCode);
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deflateEnd(&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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deflateEnd(&stream);
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return (retCode == Z_STREAM_END ? result : nil);
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}
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- (NSData *)decompressGZip
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{
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NSUInteger length = [self 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*)[self 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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- (NSData *)compressLZ4
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{
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uint8_t *bytes = malloc(4 + LZ4_compressBound((int)self.length));
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int32_t length = LZ4_compress(self.bytes, (char *)bytes + 4, (int)self.length);
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bytes = realloc(bytes, 4 + length);
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int32_t originalLength = (int32_t)self.length;
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memcpy(bytes, &originalLength, 4);
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return [[NSData alloc] initWithBytesNoCopy:bytes length:4 + length freeWhenDone:true];
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}
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- (NSData *)decompressLZ4
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{
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int32_t length = 0;
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memcpy(&length, self.bytes, 4);
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uint8_t *bytes = malloc(length);
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if (LZ4_decompress_safe(((char *)self.bytes) + 4, (char *)bytes, (int)(self.length - 4), length) != length)
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{
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free(bytes);
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return nil;
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}
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return [[NSData alloc] initWithBytesNoCopy:bytes length:length freeWhenDone:true];
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}
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@end
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