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//// GTMNSData+zlib.m//// Copyright 2007-2008 Google Inc.//// Licensed under the Apache License, Version 2.0 (the "License"); you may not// use this file except in compliance with the License. You may obtain a copy// of the License at//// http://www.apache.org/licenses/LICENSE-2.0//// Unless required by applicable law or agreed to in writing, software// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the// License for the specific language governing permissions and limitations under// the License.//
#import "GTMNSData+zlib.h"#import <zlib.h>#import "GTMDefines.h"
#define kChunkSize 1024
NSString *const GTMNSDataZlibErrorDomain = @"com.google.GTMNSDataZlibErrorDomain";NSString *const GTMNSDataZlibErrorKey = @"GTMNSDataZlibErrorKey";NSString *const GTMNSDataZlibRemainingBytesKey = @"GTMNSDataZlibRemainingBytesKey";
typedef enum { CompressionModeZlib, CompressionModeGzip, CompressionModeRaw,} CompressionMode;
@interface NSData (GTMZlibAdditionsPrivate)+ (NSData *)gtm_dataByCompressingBytes:(const void *)bytes length:(NSUInteger)length compressionLevel:(int)level mode:(CompressionMode)mode error:(NSError **)error;+ (NSData *)gtm_dataByInflatingBytes:(const void *)bytes length:(NSUInteger)length isRawData:(BOOL)isRawData error:(NSError **)error;@end
@implementation NSData (GTMZlibAdditionsPrivate)
+ (NSData *)gtm_dataByCompressingBytes:(const void *)bytes length:(NSUInteger)length compressionLevel:(int)level mode:(CompressionMode)mode error:(NSError **)error { if (!bytes || !length) { return nil; }
#if defined(__LP64__) && __LP64__ // Don't support > 32bit length for 64 bit, see note in header. if (length > UINT_MAX) { if (error) { *error = [NSError errorWithDomain:GTMNSDataZlibErrorDomain code:GTMNSDataZlibErrorGreaterThan32BitsToCompress userInfo:nil]; } return nil; }#endif
if (level == Z_DEFAULT_COMPRESSION) { // the default value is actually outside the range, so we have to let it // through specifically. } else if (level < Z_BEST_SPEED) { level = Z_BEST_SPEED; } else if (level > Z_BEST_COMPRESSION) { level = Z_BEST_COMPRESSION; }
z_stream strm; bzero(&strm, sizeof(z_stream));
int memLevel = 8; // the default int windowBits = 15; // the default switch (mode) { case CompressionModeZlib: // nothing to do break;
case CompressionModeGzip: windowBits += 16; // enable gzip header instead of zlib header break;
case CompressionModeRaw: windowBits *= -1; // Negative to mean no header. break; } int retCode; if ((retCode = deflateInit2(&strm, level, Z_DEFLATED, windowBits, memLevel, Z_DEFAULT_STRATEGY)) != Z_OK) { // COV_NF_START - no real way to force this in a unittest (we guard all args) if (error) { NSDictionary *userInfo = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:retCode] forKey:GTMNSDataZlibErrorKey]; *error = [NSError errorWithDomain:GTMNSDataZlibErrorDomain code:GTMNSDataZlibErrorInternal userInfo:userInfo]; } return nil; // COV_NF_END }
// hint the size at 1/4 the input size NSMutableData *result = [NSMutableData dataWithCapacity:(length/4)]; unsigned char output[kChunkSize];
// setup the input strm.avail_in = (unsigned int)length; strm.next_in = (unsigned char*)bytes;
// loop to collect the data do { // update what we're passing in strm.avail_out = kChunkSize; strm.next_out = output; retCode = deflate(&strm, Z_FINISH); if ((retCode != Z_OK) && (retCode != Z_STREAM_END)) { // COV_NF_START - no real way to force this in a unittest // (in inflate, we can feed bogus/truncated data to test, but an error // here would be some internal issue w/in zlib, and there isn't any real // way to test it) if (error) { NSDictionary *userInfo = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:retCode] forKey:GTMNSDataZlibErrorKey]; *error = [NSError errorWithDomain:GTMNSDataZlibErrorDomain code:GTMNSDataZlibErrorInternal userInfo:userInfo]; } deflateEnd(&strm); return nil; // COV_NF_END } // collect what we got unsigned gotBack = kChunkSize - strm.avail_out; if (gotBack > 0) { [result appendBytes:output length:gotBack]; }
} while (retCode == Z_OK);
// if the loop exits, we used all input and the stream ended _GTMDevAssert(strm.avail_in == 0, @"thought we finished deflate w/o using all input, %u bytes left", strm.avail_in); _GTMDevAssert(retCode == Z_STREAM_END, @"thought we finished deflate w/o getting a result of stream end, code %d", retCode);
// clean up deflateEnd(&strm);
return result;} // gtm_dataByCompressingBytes:length:compressionLevel:useGzip:
+ (NSData *)gtm_dataByInflatingBytes:(const void *)bytes length:(NSUInteger)length isRawData:(BOOL)isRawData error:(NSError **)error { if (!bytes || !length) { return nil; }
#if defined(__LP64__) && __LP64__ // Don't support > 32bit length for 64 bit, see note in header. if (length > UINT_MAX) { return nil; }#endif
z_stream strm; bzero(&strm, sizeof(z_stream));
// setup the input strm.avail_in = (unsigned int)length; strm.next_in = (unsigned char*)bytes;
int windowBits = 15; // 15 to enable any window size if (isRawData) { windowBits *= -1; // make it negative to signal no header. } else { windowBits += 32; // and +32 to enable zlib or gzip header detection. }
int retCode; if ((retCode = inflateInit2(&strm, windowBits)) != Z_OK) { // COV_NF_START - no real way to force this in a unittest (we guard all args) if (error) { NSDictionary *userInfo = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:retCode] forKey:GTMNSDataZlibErrorKey]; *error = [NSError errorWithDomain:GTMNSDataZlibErrorDomain code:GTMNSDataZlibErrorInternal userInfo:userInfo]; } return nil; // COV_NF_END }
// hint the size at 4x the input size NSMutableData *result = [NSMutableData dataWithCapacity:(length*4)]; unsigned char output[kChunkSize];
// loop to collect the data do { // update what we're passing in strm.avail_out = kChunkSize; strm.next_out = output; retCode = inflate(&strm, Z_NO_FLUSH); if ((retCode != Z_OK) && (retCode != Z_STREAM_END)) { if (error) { NSMutableDictionary *userInfo = [NSMutableDictionary dictionaryWithObject:[NSNumber numberWithInt:retCode] forKey:GTMNSDataZlibErrorKey]; if (strm.msg) { NSString *message = [NSString stringWithUTF8String:strm.msg]; if (message) { [userInfo setObject:message forKey:NSLocalizedDescriptionKey]; } } *error = [NSError errorWithDomain:GTMNSDataZlibErrorDomain code:GTMNSDataZlibErrorInternal userInfo:userInfo]; } inflateEnd(&strm); return nil; } // collect what we got unsigned gotBack = kChunkSize - strm.avail_out; if (gotBack > 0) { [result appendBytes:output length:gotBack]; }
} while (retCode == Z_OK);
// make sure there wasn't more data tacked onto the end of a valid compressed // stream. if (strm.avail_in != 0) { if (error) { NSDictionary *userInfo = [NSDictionary dictionaryWithObject:[NSNumber numberWithUnsignedInt:strm.avail_in] forKey:GTMNSDataZlibRemainingBytesKey]; *error = [NSError errorWithDomain:GTMNSDataZlibErrorDomain code:GTMNSDataZlibErrorDataRemaining userInfo:userInfo]; } result = nil; } // the only way out of the loop was by hitting the end of the stream _GTMDevAssert(retCode == Z_STREAM_END, @"thought we finished inflate w/o getting a result of stream end, code %d", retCode);
// clean up inflateEnd(&strm);
return result;} // gtm_dataByInflatingBytes:length:windowBits:
@end
@implementation NSData (GTMZLibAdditions)
+ (NSData *)gtm_dataByGzippingBytes:(const void *)bytes length:(NSUInteger)length { return [self gtm_dataByGzippingBytes:bytes length:length error:NULL];} // gtm_dataByGzippingBytes:length:
+ (NSData *)gtm_dataByGzippingBytes:(const void *)bytes length:(NSUInteger)length error:(NSError **)error { return [self gtm_dataByCompressingBytes:bytes length:length compressionLevel:Z_DEFAULT_COMPRESSION mode:CompressionModeGzip error:error];} // gtm_dataByGzippingBytes:length:error:
+ (NSData *)gtm_dataByGzippingData:(NSData *)data { return [self gtm_dataByGzippingData:data error:NULL];} // gtm_dataByGzippingData:
+ (NSData *)gtm_dataByGzippingData:(NSData *)data error:(NSError **)error { return [self gtm_dataByCompressingBytes:[data bytes] length:[data length] compressionLevel:Z_DEFAULT_COMPRESSION mode:CompressionModeGzip error:error];} // gtm_dataByGzippingData:error:
+ (NSData *)gtm_dataByGzippingBytes:(const void *)bytes length:(NSUInteger)length compressionLevel:(int)level { return [self gtm_dataByGzippingBytes:bytes length:length compressionLevel:level error:NULL];} // gtm_dataByGzippingBytes:length:level:
+ (NSData *)gtm_dataByGzippingBytes:(const void *)bytes length:(NSUInteger)length compressionLevel:(int)level error:(NSError **)error{ return [self gtm_dataByCompressingBytes:bytes length:length compressionLevel:level mode:CompressionModeGzip error:error];} // gtm_dataByGzippingBytes:length:level:error
+ (NSData *)gtm_dataByGzippingData:(NSData *)data compressionLevel:(int)level { return [self gtm_dataByGzippingData:data compressionLevel:level error:NULL];} // gtm_dataByGzippingData:level:
+ (NSData *)gtm_dataByGzippingData:(NSData *)data compressionLevel:(int)level error:(NSError **)error{ return [self gtm_dataByCompressingBytes:[data bytes] length:[data length] compressionLevel:level mode:CompressionModeGzip error:error];} // gtm_dataByGzippingData:level:error
#pragma mark -
+ (NSData *)gtm_dataByDeflatingBytes:(const void *)bytes length:(NSUInteger)length { return [self gtm_dataByDeflatingBytes:bytes length:length error:NULL];} // gtm_dataByDeflatingBytes:length:
+ (NSData *)gtm_dataByDeflatingBytes:(const void *)bytes length:(NSUInteger)length error:(NSError **)error{ return [self gtm_dataByCompressingBytes:bytes length:length compressionLevel:Z_DEFAULT_COMPRESSION mode:CompressionModeZlib error:error];} // gtm_dataByDeflatingBytes:length:error
+ (NSData *)gtm_dataByDeflatingData:(NSData *)data { return [self gtm_dataByDeflatingData:data error:NULL];} // gtm_dataByDeflatingData:
+ (NSData *)gtm_dataByDeflatingData:(NSData *)data error:(NSError **)error { return [self gtm_dataByCompressingBytes:[data bytes] length:[data length] compressionLevel:Z_DEFAULT_COMPRESSION mode:CompressionModeZlib error:error];} // gtm_dataByDeflatingData:
+ (NSData *)gtm_dataByDeflatingBytes:(const void *)bytes length:(NSUInteger)length compressionLevel:(int)level { return [self gtm_dataByDeflatingBytes:bytes length:length compressionLevel:level error:NULL];} // gtm_dataByDeflatingBytes:length:level:
+ (NSData *)gtm_dataByDeflatingBytes:(const void *)bytes length:(NSUInteger)length compressionLevel:(int)level error:(NSError **)error { return [self gtm_dataByCompressingBytes:bytes length:length compressionLevel:level mode:CompressionModeZlib error:error];} // gtm_dataByDeflatingBytes:length:level:error:
+ (NSData *)gtm_dataByDeflatingData:(NSData *)data compressionLevel:(int)level { return [self gtm_dataByDeflatingData:data compressionLevel:level error:NULL];} // gtm_dataByDeflatingData:level:
+ (NSData *)gtm_dataByDeflatingData:(NSData *)data compressionLevel:(int)level error:(NSError **)error { return [self gtm_dataByCompressingBytes:[data bytes] length:[data length] compressionLevel:level mode:CompressionModeZlib error:error];} // gtm_dataByDeflatingData:level:error:
#pragma mark -
+ (NSData *)gtm_dataByInflatingBytes:(const void *)bytes length:(NSUInteger)length { return [self gtm_dataByInflatingBytes:bytes length:length error:NULL];} // gtm_dataByInflatingBytes:length:
+ (NSData *)gtm_dataByInflatingBytes:(const void *)bytes length:(NSUInteger)length error:(NSError **)error { return [self gtm_dataByInflatingBytes:bytes length:length isRawData:NO error:error];} // gtm_dataByInflatingBytes:length:error:
+ (NSData *)gtm_dataByInflatingData:(NSData *)data { return [self gtm_dataByInflatingData:data error:NULL];} // gtm_dataByInflatingData:
+ (NSData *)gtm_dataByInflatingData:(NSData *)data error:(NSError **)error { return [self gtm_dataByInflatingBytes:[data bytes] length:[data length] isRawData:NO error:error];} // gtm_dataByInflatingData:
#pragma mark -
+ (NSData *)gtm_dataByRawDeflatingBytes:(const void *)bytes length:(NSUInteger)length { return [self gtm_dataByRawDeflatingBytes:(const void *)bytes length:(NSUInteger)length error:NULL];} // gtm_dataByRawDeflatingBytes:length:
+ (NSData *)gtm_dataByRawDeflatingBytes:(const void *)bytes length:(NSUInteger)length error:(NSError **)error { return [self gtm_dataByCompressingBytes:bytes length:length compressionLevel:Z_DEFAULT_COMPRESSION mode:CompressionModeRaw error:error];} // gtm_dataByRawDeflatingBytes:length:error:
+ (NSData *)gtm_dataByRawDeflatingData:(NSData *)data { return [self gtm_dataByRawDeflatingData:data error:NULL];} // gtm_dataByRawDeflatingData:
+ (NSData *)gtm_dataByRawDeflatingData:(NSData *)data error:(NSError **)error { return [self gtm_dataByCompressingBytes:[data bytes] length:[data length] compressionLevel:Z_DEFAULT_COMPRESSION mode:CompressionModeRaw error:error];} // gtm_dataByRawDeflatingData:error:
+ (NSData *)gtm_dataByRawDeflatingBytes:(const void *)bytes length:(NSUInteger)length compressionLevel:(int)level { return [self gtm_dataByRawDeflatingBytes:bytes length:length compressionLevel:level error:NULL];} // gtm_dataByRawDeflatingBytes:length:compressionLevel:
+ (NSData *)gtm_dataByRawDeflatingBytes:(const void *)bytes length:(NSUInteger)length compressionLevel:(int)level error:(NSError **)error{ return [self gtm_dataByCompressingBytes:bytes length:length compressionLevel:level mode:CompressionModeRaw error:error];} // gtm_dataByRawDeflatingBytes:length:compressionLevel:error:
+ (NSData *)gtm_dataByRawDeflatingData:(NSData *)data compressionLevel:(int)level { return [self gtm_dataByRawDeflatingData:data compressionLevel:level error:NULL];} // gtm_dataByRawDeflatingData:compressionLevel:
+ (NSData *)gtm_dataByRawDeflatingData:(NSData *)data compressionLevel:(int)level error:(NSError **)error { return [self gtm_dataByCompressingBytes:[data bytes] length:[data length] compressionLevel:level mode:CompressionModeRaw error:error];} // gtm_dataByRawDeflatingData:compressionLevel:error:
+ (NSData *)gtm_dataByRawInflatingBytes:(const void *)bytes length:(NSUInteger)length { return [self gtm_dataByInflatingBytes:bytes length:length error:NULL];} // gtm_dataByRawInflatingBytes:length:
+ (NSData *)gtm_dataByRawInflatingBytes:(const void *)bytes length:(NSUInteger)length error:(NSError **)error{ return [self gtm_dataByInflatingBytes:bytes length:length isRawData:YES error:error];} // gtm_dataByRawInflatingBytes:length:error:
+ (NSData *)gtm_dataByRawInflatingData:(NSData *)data { return [self gtm_dataByRawInflatingData:data error:NULL];} // gtm_dataByRawInflatingData:
+ (NSData *)gtm_dataByRawInflatingData:(NSData *)data error:(NSError **)error { return [self gtm_dataByInflatingBytes:[data bytes] length:[data length] isRawData:YES error:error];} // gtm_dataByRawInflatingData:error:
@end
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