shared_data xcc_z::gzip(data_ref s)
{
unsigned long cb_d = s.size() + (s.size() + 999) / 1000 + 12;
shared_data d(10 + cb_d + 8);
unsigned char* w = d.data();
*w++ = 0x1f;
*w++ = 0x8b;
*w++ = Z_DEFLATED;
*w++ = 0;
*w++ = 0;
*w++ = 0;
*w++ = 0;
*w++ = 0;
*w++ = 0;
*w++ = 3;
{
z_stream stream;
stream.zalloc = NULL;
stream.zfree = NULL;
stream.opaque = NULL;
deflateInit2(&stream, Z_DEFAULT_COMPRESSION, Z_DEFLATED, -MAX_WBITS, MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
stream.next_in = const_cast<unsigned char*>(s.begin());
stream.avail_in = s.size();
stream.next_out = w;
stream.avail_out = cb_d;
deflate(&stream, Z_FINISH);
deflateEnd(&stream);
w = stream.next_out;
}
w = write_int_le(4, w, crc32(crc32(0, NULL, 0), s.data(), s.size()));
w = write_int_le(4, w, s.size());
return d.substr(0, w - d.data());
}
void Cvirtual_binary::assign(data_ref v)
{
if (v.size())
{
m_source = boost::make_shared<Cvirtual_binary_source>(v.size());
if (v.begin())
memcpy(data_edit(), v.data(), v.size());
}
else
m_source.reset();
}
shared_data xcc_z::gunzip(data_ref s)
{
if (s.size() < 18)
return shared_data();
shared_data d(read_int_le(4, s.end() - 4));
z_stream stream;
stream.zalloc = NULL;
stream.zfree = NULL;
stream.opaque = NULL;
stream.next_in = const_cast<unsigned char*>(s.begin()) + 10;
stream.avail_in = s.size() - 18;
stream.next_out = d.data();
stream.avail_out = d.size();
return stream.next_out
&& Z_OK == inflateInit2(&stream, -MAX_WBITS)
&& Z_STREAM_END == inflate(&stream, Z_FINISH)
&& Z_OK == inflateEnd(&stream)
? d
: shared_data();
}