101 lines
2.3 KiB
Objective-C
101 lines
2.3 KiB
Objective-C
//
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// NSData+CocoaDevAdditions.m
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// InsideJob
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//
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// Created by Adam Preble on 10/6/10.
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//
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// Source: http://www.cocoadev.com/index.pl?NSDataCategory
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#import "NSData+CocoaDevAdditions.h"
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#import <zlib.h>
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@implementation NSData (CocoaDevAdditions)
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- (NSData *)gzipInflate
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{
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if ([self length] == 0) return self;
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unsigned full_length = [self length];
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unsigned half_length = [self length] / 2;
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NSMutableData *decompressed = [NSMutableData dataWithLength: full_length + half_length];
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BOOL done = NO;
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int status;
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z_stream strm;
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strm.next_in = (Bytef *)[self bytes];
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strm.avail_in = [self length];
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strm.total_out = 0;
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strm.zalloc = Z_NULL;
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strm.zfree = Z_NULL;
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if (inflateInit2(&strm, (15+32)) != Z_OK) return nil;
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while (!done)
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{
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// Make sure we have enough room and reset the lengths.
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if (strm.total_out >= [decompressed length])
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[decompressed increaseLengthBy: half_length];
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strm.next_out = [decompressed mutableBytes] + strm.total_out;
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strm.avail_out = [decompressed length] - strm.total_out;
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// Inflate another chunk.
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status = inflate (&strm, Z_SYNC_FLUSH);
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if (status == Z_STREAM_END) done = YES;
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else if (status != Z_OK) break;
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}
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if (inflateEnd (&strm) != Z_OK) return nil;
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// Set real length.
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if (done)
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{
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[decompressed setLength: strm.total_out];
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return [NSData dataWithData: decompressed];
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}
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else return nil;
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}
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- (NSData *)gzipDeflate
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{
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if ([self length] == 0) return self;
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z_stream strm;
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strm.zalloc = Z_NULL;
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strm.zfree = Z_NULL;
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strm.opaque = Z_NULL;
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strm.total_out = 0;
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strm.next_in=(Bytef *)[self bytes];
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strm.avail_in = [self length];
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// Compresssion Levels:
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// Z_NO_COMPRESSION
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// Z_BEST_SPEED
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// Z_BEST_COMPRESSION
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// Z_DEFAULT_COMPRESSION
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if (deflateInit2(&strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED, (15+16), 8, Z_DEFAULT_STRATEGY) != Z_OK) return nil;
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NSMutableData *compressed = [NSMutableData dataWithLength:16384]; // 16K chunks for expansion
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do {
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if (strm.total_out >= [compressed length])
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[compressed increaseLengthBy: 16384];
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strm.next_out = [compressed mutableBytes] + strm.total_out;
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strm.avail_out = [compressed length] - strm.total_out;
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deflate(&strm, Z_FINISH);
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} while (strm.avail_out == 0);
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deflateEnd(&strm);
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[compressed setLength: strm.total_out];
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return [NSData dataWithData:compressed];
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}
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@end
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