metaforce/Runtime/IOStreams.cpp

90 lines
2.2 KiB
C++

#include "IOStreams.hpp"
#include "CMemory.hpp"
namespace urde
{
s32 DecryptionCtx::DecryptRead(CInputStream& in, s32 key)
{
int ret = 0;
if (x20_encShift >= key)
{
int diff = x20_encShift - 0x20;
int baseVal = -1;
if (x20_encShift != 0x20)
baseVal = 1 << (x20_encShift - 1);
x20_encShift = key - x20_encShift;
ret = baseVal | (x1c_encVal >> diff);
}
else
{
int diff = x20_encShift - key;
int rem = x20_encShift - 0x20;
int baseVal1 = -1;
if (x20_encShift != 0x20)
baseVal1 = 1 << (x20_encShift - 1);
int bit = diff & 7;
x20_encShift = 0;
int count = (diff >> 3) + ((-bit | bit) >> 31);
int baseVal2 = (baseVal1 & (x1c_encVal >> rem)) << diff;
in.readBytesToBuf(&x1c_encVal, count);
int baseVal3 = -1;
if (diff != 0x20)
baseVal3 = 1 << (diff - 1);
int tmpShift = x20_encShift;
x20_encShift = (count << 3);
ret = baseVal2 | (baseVal3 & (x1c_encVal >> (diff - 0x20))) << tmpShift;
x20_encShift = diff - x20_encShift;
x1c_encVal = x1c_encVal >> diff;
}
return ret;
}
class CZipSupport
{
public:
static void* Alloc(void*, u32 c, u32 n)
{
return new u8[c*n];
}
static void Free(void*, void* buf)
{
delete[] static_cast<u8*>(buf);
}
};
CZipInputStream::CZipInputStream(std::unique_ptr<CInputStream>&& strm)
: x24_compBuf(new u8[4096]), x28_strm(std::move(strm))
{
x30_zstrm.next_in = x24_compBuf.get();
x30_zstrm.avail_in = 0;
x30_zstrm.zalloc = CZipSupport::Alloc;
x30_zstrm.zfree = CZipSupport::Free;
inflateInit(&x30_zstrm);
}
CZipInputStream::~CZipInputStream()
{
inflateEnd(&x30_zstrm);
}
atUint64 CZipInputStream::readUBytesToBuf(void *buf, atUint64 len)
{
x30_zstrm.next_out = (Bytef*)buf;
x30_zstrm.avail_out = len;
if (!x30_zstrm.avail_in)
{
atUint64 readSz = x28_strm->readUBytesToBuf(x24_compBuf.get(), 4096);
x30_zstrm.avail_in = readSz;
x30_zstrm.next_in = x24_compBuf.get();
}
inflate(&x30_zstrm, Z_NO_FLUSH);
return x30_zstrm.total_out;
}
}