mirror of
https://github.com/samsonjs/arq_restore.git
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131 lines
4.1 KiB
Objective-C
131 lines
4.1 KiB
Objective-C
/*
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Copyright (c) 2009-2011, Stefan Reitshamer http://www.haystacksoftware.com
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the names of PhotoMinds LLC or Haystack Software, nor the names of
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their contributors may be used to endorse or promote products derived from
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this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#import "NSData-GZip.h"
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#include <zlib.h>
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@implementation NSData (GZip)
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- (NSData *)gzipInflate {
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if ([self length] == 0) {
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return self;
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}
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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 stream;
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stream.next_in = (Bytef *)[self bytes];
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stream.avail_in = [self length];
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stream.total_out = 0;
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stream.zalloc = Z_NULL;
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stream.zfree = Z_NULL;
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if (inflateInit2(&stream, (15+32)) != Z_OK) {
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return nil;
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}
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while (!done) {
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// Make sure we have enough room and reset the lengths.
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if (stream.total_out >= [decompressed length]) {
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[decompressed increaseLengthBy: half_length];
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}
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stream.next_out = [decompressed mutableBytes] + stream.total_out;
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stream.avail_out = [decompressed length] - stream.total_out;
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// Inflate another chunk.
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status = inflate (&stream, Z_SYNC_FLUSH);
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if (status == Z_STREAM_END) {
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done = YES;
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} else if (status != Z_OK) {
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break;
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}
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}
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if (inflateEnd (&stream) != Z_OK) {
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return nil;
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}
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// Set real length.
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if (done) {
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[decompressed setLength: stream.total_out];
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return [NSData dataWithData: decompressed];
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} else {
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return nil;
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}
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}
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- (NSData *)gzipDeflate {
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if ([self length] == 0) {
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return self;
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}
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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) {
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return nil;
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}
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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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}
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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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