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| | |
| | | // |
| | | // ASIDataDecompressor.m |
| | | // Part of ASIHTTPRequest -> http://allseeing-i.com/ASIHTTPRequest |
| | | // |
| | | // Created by Ben Copsey on 17/08/2010. |
| | | // Copyright 2010 All-Seeing Interactive. All rights reserved. |
| | | // |
| | | |
| | | #import "ASIDataDecompressor.h" |
| | | #import "ASIHTTPRequest.h" |
| | | |
| | | #define DATA_CHUNK_SIZE 262144 // Deal with gzipped data in 256KB chunks |
| | | |
| | | @interface ASIDataDecompressor () |
| | | + (NSError *)inflateErrorWithCode:(int)code; |
| | | @end; |
| | | |
| | | @implementation ASIDataDecompressor |
| | | |
| | | + (id)decompressor |
| | | { |
| | | ASIDataDecompressor *decompressor = [[[self alloc] init] autorelease]; |
| | | [decompressor setupStream]; |
| | | return decompressor; |
| | | } |
| | | |
| | | - (void)dealloc |
| | | { |
| | | if (streamReady) { |
| | | [self closeStream]; |
| | | } |
| | | [super dealloc]; |
| | | } |
| | | |
| | | - (NSError *)setupStream |
| | | { |
| | | if (streamReady) { |
| | | return nil; |
| | | } |
| | | // Setup the inflate stream |
| | | zStream.zalloc = Z_NULL; |
| | | zStream.zfree = Z_NULL; |
| | | zStream.opaque = Z_NULL; |
| | | zStream.avail_in = 0; |
| | | zStream.next_in = 0; |
| | | int status = inflateInit2(&zStream, (15+32)); |
| | | if (status != Z_OK) { |
| | | return [[self class] inflateErrorWithCode:status]; |
| | | } |
| | | streamReady = YES; |
| | | return nil; |
| | | } |
| | | |
| | | - (NSError *)closeStream |
| | | { |
| | | if (!streamReady) { |
| | | return nil; |
| | | } |
| | | // Close the inflate stream |
| | | streamReady = NO; |
| | | int status = inflateEnd(&zStream); |
| | | if (status != Z_OK) { |
| | | return [[self class] inflateErrorWithCode:status]; |
| | | } |
| | | return nil; |
| | | } |
| | | |
| | | - (NSData *)uncompressBytes:(Bytef *)bytes length:(NSUInteger)length error:(NSError **)err |
| | | { |
| | | if (length == 0) return nil; |
| | | |
| | | NSUInteger halfLength = length/2; |
| | | NSMutableData *outputData = [NSMutableData dataWithLength:length+halfLength]; |
| | | |
| | | int status; |
| | | |
| | | zStream.next_in = bytes; |
| | | zStream.avail_in = (unsigned int)length; |
| | | zStream.avail_out = 0; |
| | | |
| | | NSInteger bytesProcessedAlready = zStream.total_out; |
| | | while (zStream.avail_in != 0) { |
| | | |
| | | if (zStream.total_out-bytesProcessedAlready >= [outputData length]) { |
| | | [outputData increaseLengthBy:halfLength]; |
| | | } |
| | | |
| | | zStream.next_out = (Bytef*)[outputData mutableBytes] + zStream.total_out-bytesProcessedAlready; |
| | | zStream.avail_out = (unsigned int)([outputData length] - (zStream.total_out-bytesProcessedAlready)); |
| | | |
| | | status = inflate(&zStream, Z_NO_FLUSH); |
| | | |
| | | if (status == Z_STREAM_END) { |
| | | break; |
| | | } else if (status != Z_OK) { |
| | | if (err) { |
| | | *err = [[self class] inflateErrorWithCode:status]; |
| | | } |
| | | return nil; |
| | | } |
| | | } |
| | | |
| | | // Set real length |
| | | [outputData setLength: zStream.total_out-bytesProcessedAlready]; |
| | | return outputData; |
| | | } |
| | | |
| | | |
| | | + (NSData *)uncompressData:(NSData*)compressedData error:(NSError **)err |
| | | { |
| | | NSError *theError = nil; |
| | | NSData *outputData = [[ASIDataDecompressor decompressor] uncompressBytes:(Bytef *)[compressedData bytes] length:[compressedData length] error:&theError]; |
| | | if (theError) { |
| | | if (err) { |
| | | *err = theError; |
| | | } |
| | | return nil; |
| | | } |
| | | return outputData; |
| | | } |
| | | |
| | | + (BOOL)uncompressDataFromFile:(NSString *)sourcePath toFile:(NSString *)destinationPath error:(NSError **)err |
| | | { |
| | | NSFileManager *fileManager = [[[NSFileManager alloc] init] autorelease]; |
| | | |
| | | // Create an empty file at the destination path |
| | | if (![fileManager createFileAtPath:destinationPath contents:[NSData data] attributes:nil]) { |
| | | if (err) { |
| | | *err = [NSError errorWithDomain:NetworkRequestErrorDomain code:ASICompressionError userInfo:[NSDictionary dictionaryWithObjectsAndKeys:[NSString stringWithFormat:@"Decompression of %@ failed because we were to create a file at %@",sourcePath,destinationPath],NSLocalizedDescriptionKey,nil]]; |
| | | } |
| | | return NO; |
| | | } |
| | | |
| | | // Ensure the source file exists |
| | | if (![fileManager fileExistsAtPath:sourcePath]) { |
| | | if (err) { |
| | | *err = [NSError errorWithDomain:NetworkRequestErrorDomain code:ASICompressionError userInfo:[NSDictionary dictionaryWithObjectsAndKeys:[NSString stringWithFormat:@"Decompression of %@ failed the file does not exist",sourcePath],NSLocalizedDescriptionKey,nil]]; |
| | | } |
| | | return NO; |
| | | } |
| | | |
| | | UInt8 inputData[DATA_CHUNK_SIZE]; |
| | | NSData *outputData; |
| | | NSInteger readLength; |
| | | NSError *theError = nil; |
| | | |
| | | |
| | | ASIDataDecompressor *decompressor = [ASIDataDecompressor decompressor]; |
| | | |
| | | NSInputStream *inputStream = [NSInputStream inputStreamWithFileAtPath:sourcePath]; |
| | | [inputStream open]; |
| | | NSOutputStream *outputStream = [NSOutputStream outputStreamToFileAtPath:destinationPath append:NO]; |
| | | [outputStream open]; |
| | | |
| | | while ([decompressor streamReady]) { |
| | | |
| | | // Read some data from the file |
| | | readLength = [inputStream read:inputData maxLength:DATA_CHUNK_SIZE]; |
| | | |
| | | // Make sure nothing went wrong |
| | | if ([inputStream streamStatus] == NSStreamStatusError) { |
| | | if (err) { |
| | | *err = [NSError errorWithDomain:NetworkRequestErrorDomain code:ASICompressionError userInfo:[NSDictionary dictionaryWithObjectsAndKeys:[NSString stringWithFormat:@"Decompression of %@ failed because we were unable to read from the source data file",sourcePath],NSLocalizedDescriptionKey,[inputStream streamError],NSUnderlyingErrorKey,nil]]; |
| | | } |
| | | [decompressor closeStream]; |
| | | return NO; |
| | | } |
| | | // Have we reached the end of the input data? |
| | | if (!readLength) { |
| | | break; |
| | | } |
| | | |
| | | // Attempt to inflate the chunk of data |
| | | outputData = [decompressor uncompressBytes:inputData length:readLength error:&theError]; |
| | | if (theError) { |
| | | if (err) { |
| | | *err = theError; |
| | | } |
| | | [decompressor closeStream]; |
| | | return NO; |
| | | } |
| | | |
| | | // Write the inflated data out to the destination file |
| | | [outputStream write:(Bytef*)[outputData bytes] maxLength:[outputData length]]; |
| | | |
| | | // Make sure nothing went wrong |
| | | if ([inputStream streamStatus] == NSStreamStatusError) { |
| | | if (err) { |
| | | *err = [NSError errorWithDomain:NetworkRequestErrorDomain code:ASICompressionError userInfo:[NSDictionary dictionaryWithObjectsAndKeys:[NSString stringWithFormat:@"Decompression of %@ failed because we were unable to write to the destination data file at %@",sourcePath,destinationPath],NSLocalizedDescriptionKey,[outputStream streamError],NSUnderlyingErrorKey,nil]]; |
| | | } |
| | | [decompressor closeStream]; |
| | | return NO; |
| | | } |
| | | |
| | | } |
| | | |
| | | [inputStream close]; |
| | | [outputStream close]; |
| | | |
| | | NSError *error = [decompressor closeStream]; |
| | | if (error) { |
| | | if (err) { |
| | | *err = error; |
| | | } |
| | | return NO; |
| | | } |
| | | |
| | | return YES; |
| | | } |
| | | |
| | | |
| | | + (NSError *)inflateErrorWithCode:(int)code |
| | | { |
| | | return [NSError errorWithDomain:NetworkRequestErrorDomain code:ASICompressionError userInfo:[NSDictionary dictionaryWithObjectsAndKeys:[NSString stringWithFormat:@"Decompression of data failed with code %d",code],NSLocalizedDescriptionKey,nil]]; |
| | | } |
| | | |
| | | @synthesize streamReady; |
| | | @end |