python的zlib压缩解压缩对应的c语言方式 解压

文章目录
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enData = zlib.compress(data)[2:-4]

对应:

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compress2(dstbuf, &dstLen, strSrc, srcLen, 6);

解压

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deData = zlib.decompress(enData, -zlib.MAX_WBITS)

对应:

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bool ( const std::string& compressedBytes, std::string& uncompressedBytes ) {
if ( compressedBytes.size() == 0 ) {
uncompressedBytes = compressedBytes ;
return true ;
}

uncompressedBytes.clear() ;

unsigned full_length = compressedBytes.size() ;
unsigned half_length = compressedBytes.size() / 2;

unsigned uncompLength = full_length ;
char* uncomp = (char*) calloc( sizeof(char), uncompLength );

z_stream strm;
strm.next_in = (Bytef *) compressedBytes.c_str();
strm.avail_in = compressedBytes.size() ;
strm.total_out = 0;
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;

bool done = false ;


if (inflateInit2(&strm, -MAX_WBITS) != Z_OK)
{
free( uncomp );
return false;
}

while (!done) {
// If our output buffer is too small
if (strm.total_out >= uncompLength ) {
// Increase size of output buffer
char* uncomp2 = (char*) calloc( sizeof(char), uncompLength + half_length );
memcpy( uncomp2, uncomp, uncompLength );
uncompLength += half_length ;
free( uncomp );
uncomp = uncomp2 ;
}

strm.next_out = (Bytef *) (uncomp + strm.total_out);
strm.avail_out = uncompLength - strm.total_out;

// Inflate another chunk.
int err = inflate (&strm, Z_SYNC_FLUSH);
if (err == Z_STREAM_END) done = true;
else if (err != Z_OK) {
break;
}
}

if (inflateEnd (&strm) != Z_OK) {
free( uncomp );
return false;
}

for ( size_t i=0; i<strm.total_out; ++i ) {
uncompressedBytes += uncomp[ i ];
}
free( uncomp );
return true ;
}