void Inflator::MessageEnd(int propagation)
{
ProcessInput(true);
if (!(m_state == PRE_STREAM || m_state == AFTER_END))
throw UnexpectedEndErr();
Filter::MessageEnd(propagation);
}
size_t Inflator::Put2(const byte *inString, size_t length, int messageEnd, bool blocking)
{
if (!blocking)
throw BlockingInputOnly("Inflator");
LazyPutter lp(m_inQueue, inString, length);
ProcessInput(messageEnd != 0);
if (messageEnd)
if (!(m_state == PRE_STREAM || m_state == AFTER_END))
throw UnexpectedEndErr();
Output(0, NULL, 0, messageEnd, blocking);
return 0;
}
void Inflator::DecodeHeader()
{
if (!m_reader.FillBuffer(3))
throw UnexpectedEndErr();
m_eof = m_reader.GetBits(1) != 0;
m_blockType = (byte)m_reader.GetBits(2);
switch (m_blockType)
{
case 0: // stored
{
m_reader.SkipBits(m_reader.BitsBuffered() % 8);
if (!m_reader.FillBuffer(32))
throw UnexpectedEndErr();
m_storedLen = (word16)m_reader.GetBits(16);
word16 nlen = (word16)m_reader.GetBits(16);
if (nlen != (word16)~m_storedLen)
throw BadBlockErr();
break;
}
case 1: // fixed codes
m_nextDecode = LITERAL;
break;
case 2: // dynamic codes
{
if (!m_reader.FillBuffer(5+5+4))
throw UnexpectedEndErr();
unsigned int hlit = m_reader.GetBits(5);
unsigned int hdist = m_reader.GetBits(5);
unsigned int hclen = m_reader.GetBits(4);
FixedSizeSecBlock<unsigned int, 286+32> codeLengths;
unsigned int i;
static const unsigned int border[] = { // Order of the bit length code lengths
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
};
std::fill(codeLengths.begin(), codeLengths+19, 0);
for (i=0; i<hclen+4; i++)
codeLengths[border[i]] = m_reader.GetBits(3);
try
{
HuffmanDecoder codeLengthDecoder(codeLengths, 19);
for (i = 0; i < hlit+257+hdist+1; )
{
unsigned int k, count, repeater;
bool result = codeLengthDecoder.Decode(m_reader, k);
if (!result)
throw UnexpectedEndErr();
if (k <= 15)
{
count = 1;
repeater = k;
}
else switch (k)
{
case 16:
if (!m_reader.FillBuffer(2))
throw UnexpectedEndErr();
count = 3 + m_reader.GetBits(2);
if (i == 0)
throw BadBlockErr();
repeater = codeLengths[i-1];
break;
case 17:
if (!m_reader.FillBuffer(3))
throw UnexpectedEndErr();
count = 3 + m_reader.GetBits(3);
repeater = 0;
break;
case 18:
if (!m_reader.FillBuffer(7))
throw UnexpectedEndErr();
count = 11 + m_reader.GetBits(7);
repeater = 0;
break;
}
if (i + count > hlit+257+hdist+1)
throw BadBlockErr();
std::fill(codeLengths + i, codeLengths + i + count, repeater);
i += count;
}
m_dynamicLiteralDecoder.Initialize(codeLengths, hlit+257);
if (hdist == 0 && codeLengths[hlit+257] == 0)
{
if (hlit != 0) // a single zero distance code length means all literals
throw BadBlockErr();
}
else
m_dynamicDistanceDecoder.Initialize(codeLengths+hlit+257, hdist+1);
m_nextDecode = LITERAL;
}
catch (HuffmanDecoder::Err &)
{
throw BadBlockErr();
}
break;
}
default:
throw BadBlockErr(); // reserved block type
}
m_state = DECODING_BODY;
}