private void DecompressAllTags()
{
Pointer ip = _ip;
// We could have put this refill fragment only at the beginning of the loop.
// However, duplicating it at the end of each branch gives the compiler more
// scope to optimize the <ip_limit_ - ip> expression based on the local
// context, which overall increases speed.
Func <bool> maybeRefill = () =>
{
if (_ipLimit - ip < 5)
{
_ip = ip;
if (!RefillTag())
{
return(false);
}
ip = _ip;
}
return(true);
};
if (!maybeRefill())
{
return;
}
for (; ;)
{
byte c = ip[0];
ip = ip + 1;
if ((c & 0x3) == CompressorTag.Literal)
{
int literalLength = ((c >> 2) + 1);
if (_output.TryFastAppend(ip, _ipLimit - ip, literalLength))
{
Debug.Assert(literalLength < 61);
ip += literalLength;
if (!maybeRefill())
{
return;
}
continue;
}
if (literalLength >= 61)
{
int longLiteral = literalLength - 60;
literalLength = (int)((ip.ToUInt32() & Wordmask[longLiteral]) + 1);
ip += longLiteral;
}
int avail = _ipLimit - ip;
while (avail < literalLength)
{
if (!_output.Append(ip, avail))
{
return;
}
literalLength -= avail;
Skip(_peeked);
int n;
ip = Peek(out n);
avail = n;
_peeked = avail;
if (avail == 0)
{
return; // Premature end of input
}
_ipLimit = ip + avail;
}
if (!_output.Append(ip, literalLength))
{
return;
}
ip += literalLength;
if (!maybeRefill())
{
return;
}
}
else
{
int entry = CharTable[c];
int trailer = (int)(ip.ToUInt32() & Wordmask[entry >> 11]);
int length = entry & 0xff;
ip += entry >> 11;
// copy_offset/256 is encoded in bits 8..10. By just fetching
// those bits, we get copy_offset (since the bit-field starts at
// bit 8).
int copyOffset = entry & 0x700;
if (!_output.AppendFromSelf(copyOffset + trailer, length))
{
return;
}
if (!maybeRefill())
{
return;
}
}
}
}
private void Skip(int peeked)
{
_ip += peeked;
}