NSDataAdditions.m

#import "NSDataAdditions.h"

#import <zlib.h>

@implementation NSData (NSDataAdditions)

// ================================================================================================
//  Created by Tom Bradley on 21/10/2009.
//  Version 1.3
//
//  Copyright (c) 2009 Tom Bradley
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.
// ================================================================================================

+ (NSData *) dataWithUncompressedContentsOfFile:(NSString *)aFile {

    NSData * result;

    if ([[aFile pathExtension] isEqualToString:@"gz"]) {
        NSData * compressedData = [NSData dataWithContentsOfFile:aFile];
        result = [compressedData gzipInflate];
    }
    else
        result = [NSData dataWithContentsOfFile:aFile];

    return result;
}


// ================================================================================================
//  base64.m
//  ViewTransitions
//
//  Created by Neo on 5/11/08.
//  Copyright 2008 Kaliware, LLC. All rights reserved.
//
//  Created by khammond on Mon Oct 29 2001.
//  Formatted by Timothy Hatcher on Sun Jul 4 2004.
//  Copyright (c) 2001 Kyle Hammond. All rights reserved.
//  Original development by Dave Winer.
//
//  FOUND HERE http://idevkit.com/forums/tutorials-code-samples-sdk/8-nsdata-base64-extension.html
// ================================================================================================

static char encodingTable[64] = {
    'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
    'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
    'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
    'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/' };


+ (NSData *) dataWithBase64EncodedString:(NSString *) string {
    NSData *result = [[NSData alloc] initWithBase64EncodedString:string];
    return [result autorelease];
}

- (id) initWithBase64EncodedString:(NSString *) string {
    NSMutableData *mutableData = nil;

    if( string ) {
        unsigned long ixtext = 0;
        unsigned long lentext = 0;
        unsigned char ch = 0;
        unsigned char inbuf[4], outbuf[3];
        short i = 0, ixinbuf = 0;
        BOOL flignore = NO;
        BOOL flendtext = NO;
        NSData *base64Data = nil;
        const unsigned char *base64Bytes = nil;

        // Convert the string to ASCII data.
        base64Data = [string dataUsingEncoding:NSASCIIStringEncoding];
        base64Bytes = [base64Data bytes];
        mutableData = [NSMutableData dataWithCapacity:[base64Data length]];
        lentext = [base64Data length];

        while( YES ) {
            if( ixtext >= lentext ) break;
            ch = base64Bytes[ixtext++];
            flignore = NO;

            if( ( ch >= 'A' ) && ( ch <= 'Z' ) ) ch = ch - 'A';
            else if( ( ch >= 'a' ) && ( ch <= 'z' ) ) ch = ch - 'a' + 26;
            else if( ( ch >= '0' ) && ( ch <= '9' ) ) ch = ch - '0' + 52;
            else if( ch == '+' ) ch = 62;
            else if( ch == '=' ) flendtext = YES;
            else if( ch == '/' ) ch = 63;
            else flignore = YES;

            if( ! flignore ) {
                short ctcharsinbuf = 3;
                BOOL flbreak = NO;

                if( flendtext ) {
                    if( ! ixinbuf ) break;
                    if( ( ixinbuf == 1 ) || ( ixinbuf == 2 ) ) ctcharsinbuf = 1;
                    else ctcharsinbuf = 2;
                    ixinbuf = 3;
                    flbreak = YES;
                }

                inbuf [ixinbuf++] = ch;

                if( ixinbuf == 4 ) {
                    ixinbuf = 0;
                    outbuf [0] = ( inbuf[0] << 2 ) | ( ( inbuf[1] & 0x30) >> 4 );
                    outbuf [1] = ( ( inbuf[1] & 0x0F ) << 4 ) | ( ( inbuf[2] & 0x3C ) >> 2 );
                    outbuf [2] = ( ( inbuf[2] & 0x03 ) << 6 ) | ( inbuf[3] & 0x3F );

                    for( i = 0; i < ctcharsinbuf; i++ )
                        [mutableData appendBytes:&outbuf[i] length:1];
                }

                if( flbreak )  break;
            }
        }
    }

    self = [self initWithData:mutableData];
    return self;
}

#pragma mark -

- (NSString *) base64Encoding {
    return [self base64EncodingWithLineLength:0];
}

- (NSString *) base64EncodingWithLineLength:(unsigned int) lineLength {
    const unsigned char    *bytes = [self bytes];
    NSMutableString *result = [NSMutableString stringWithCapacity:[self length]];
    unsigned long ixtext = 0;
    unsigned long lentext = [self length];
    long ctremaining = 0;
    unsigned char inbuf[3], outbuf[4];
    short i = 0;
    short charsonline = 0, ctcopy = 0;
    unsigned long ix = 0;

    while( YES ) {
        ctremaining = lentext - ixtext;
        if( ctremaining <= 0 ) break;

        for( i = 0; i < 3; i++ ) {
            ix = ixtext + i;
            if( ix < lentext ) inbuf[i] = bytes[ix];
            else inbuf [i] = 0;
        }

        outbuf [0] = (inbuf [0] & 0xFC) >> 2;
        outbuf [1] = ((inbuf [0] & 0x03) << 4) | ((inbuf [1] & 0xF0) >> 4);
        outbuf [2] = ((inbuf [1] & 0x0F) << 2) | ((inbuf [2] & 0xC0) >> 6);
        outbuf [3] = inbuf [2] & 0x3F;
        ctcopy = 4;

        switch( ctremaining ) {
            case 1:
                ctcopy = 2;
                break;
            case 2:
                ctcopy = 3;
                break;
        }

        for( i = 0; i < ctcopy; i++ )
            [result appendFormat:@"%c", encodingTable[outbuf[i]]];

        for( i = ctcopy; i < 4; i++ )
            [result appendFormat:@"%c",'='];

        ixtext += 3;
        charsonline += 4;

        if( lineLength > 0 ) {
            if (charsonline >= lineLength) {
                charsonline = 0;
                [result appendString:@"\n"];
            }
        }
    }

    return result;
}


// ================================================================================================
//  NSData+gzip.m
//  Drip
//
//  Created by Nur Monson on 8/21/07.
//  Copyright 2007 theidiotproject. All rights reserved.
//
//  FOUND HERE http://code.google.com/p/drop-osx/source/browse/trunk/Source/NSData%2Bgzip.m
//
//  Also Check http://deusty.blogspot.com/2007/07/gzip-compressiondecompression.html
// ================================================================================================

#pragma mark -
#pragma mark GZIP

- (NSData *)gzipDeflate
{
    if ([self length] == 0) return self;

    z_stream strm;

    strm.zalloc = Z_NULL;
    strm.zfree = Z_NULL;
    strm.opaque = Z_NULL;
    strm.total_out = 0;
    strm.next_in=(Bytef *)[self bytes];
    strm.avail_in = [self length];

    // Compresssion Levels:
    //   Z_NO_COMPRESSION
    //   Z_BEST_SPEED
    //   Z_BEST_COMPRESSION
    //   Z_DEFAULT_COMPRESSION

    if (deflateInit2(&strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED, (15+16), 8, Z_DEFAULT_STRATEGY) != Z_OK) return nil;

    NSMutableData *compressed = [NSMutableData dataWithLength:16384];  // 16K chunks for expansion

    do {

        if (strm.total_out >= [compressed length])
            [compressed increaseLengthBy: 16384];

        strm.next_out = [compressed mutableBytes] + strm.total_out;
        strm.avail_out = [compressed length] - strm.total_out;

        deflate(&strm, Z_FINISH);

    } while (strm.avail_out == 0);

    deflateEnd(&strm);

    [compressed setLength: strm.total_out];
    return [NSData dataWithData:compressed];
}

- (NSData *)gzipInflate
{
    if ([self length] == 0) return self;

    unsigned full_length = [self length];
    unsigned half_length = [self length] / 2;

    NSMutableData *decompressed = [NSMutableData dataWithLength: full_length + half_length];
    BOOL done = NO;
    int status;

    z_stream strm;
    strm.next_in = (Bytef *)[self bytes];
    strm.avail_in = [self length];
    strm.total_out = 0;
    strm.zalloc = Z_NULL;
    strm.zfree = Z_NULL;

    if (inflateInit2(&strm, (15+32)) != Z_OK) return nil;
    while (!done)
    {
        // Make sure we have enough room and reset the lengths.
        if (strm.total_out >= [decompressed length])
            [decompressed increaseLengthBy: half_length];
        strm.next_out = [decompressed mutableBytes] + strm.total_out;
        strm.avail_out = [decompressed length] - strm.total_out;

        // Inflate another chunk.
        status = inflate (&strm, Z_SYNC_FLUSH);
        if (status == Z_STREAM_END) done = YES;
        else if (status != Z_OK) break;
    }
    if (inflateEnd (&strm) != Z_OK) return nil;

    // Set real length.
    if (done)
    {
        [decompressed setLength: strm.total_out];
        return [NSData dataWithData: decompressed];
    }
    else return nil;
}

@end