Objective-Cのでzipファイルに

Question

可能な重複のNSDataを変換する方法：
How can I create a zip file by using Objective C?

は、私がデータを保存するためのNSDataを使用して、私のサーバーからzipファイルを要求します。そして、これらのデータをzipファイルに保存したいのですが、どうすればobjective-cで行うことができますか？

Answer 1

私は以下の2つの方法を使用します。

圧縮：

+(NSData*) compressData:(NSData*) uncompressedData { 
if ([uncompressedData length] == 0) return uncompressedData; 

z_stream strm; 

strm.zalloc = Z_NULL; 
strm.zfree = Z_NULL; 
strm.opaque = Z_NULL; 
strm.total_out = 0; 
strm.next_in=(Bytef *)[uncompressedData bytes]; 
strm.avail_in = (unsigned int)[uncompressedData 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 = (unsigned int)([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]; 
} 

解凍：保管場所がどうなるか

+(NSData*) uncompressGZip(NSData*) compressedData { 
if ([compressedData length] == 0) return compressedData; 

NSUInteger full_length = [compressedData length]; 
NSUInteger half_length = [compressedData length]/2; 

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

z_stream strm; 
strm.next_in = (Bytef *)[compressedData bytes]; 
strm.avail_in = (unsigned int)[compressedData 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 = (unsigned int)([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; 
} 
}