/// <summary>Flush the cache to <see cref="BaseStream"/> with <see cref="kWordByteCount"/> or fewer bytes bytes</summary>
void FlushCache()
{
#if !CONTRACTS_FULL_SHIM // can't do this with our shim! ValueAtReturn sets out param to default ON ENTRY
Contract.Ensures(Contract.ValueAtReturn(out mCache) == 0);
Contract.Ensures(Contract.ValueAtReturn(out mCacheBitIndex) == 0);
#endif
if (mCacheBitIndex == 0) // no bits to flush!
{
Contract.Assert(mCache == 0, "Why is there data in the cache?");
return;
}
mCacheBitsStreamedCount = 0;
int byte_count = (mCacheBitIndex - 1) >> Bits.kByteBitShift; // number of bytes to try and write
int shift = kWordBitCount - Bits.kByteBitCount; // start shifting from the MSB
while ( /*!IsEndOfStream &&*/
byte_count >= 0)
{
mIoBuffer[0] = (byte)(mCache >> shift);
BaseStream.Write(mIoBuffer, 0, sizeof(byte));
--byte_count;
shift -= Bits.kByteBitCount;
mCacheBitsStreamedCount += Bits.kByteBitCount;
}
if (byte_count != -1 && ThrowOnOverflow.CanWrite())
{
throw new System.IO.EndOfStreamException("Tried to write more bits than the stream has/can see");
}
mCache = 0;
mCacheBitIndex = 0;
}
// #REVIEW: change mIoBuffer to be kWordByteCount and do an entire Read/Write() instead of looping?
// #REVIEW: maybe change the ReadWord implementation to not automatically populate the next word...
#region Cache operations
/// <summary>Fill the cache with <see cref="kWordByteCount"/> or fewer bytes bytes</summary>
void FillCache()
{
mCache = 0;
mCacheBitIndex = 0;
mCacheBitsStreamedCount = 0;
int byte_count = kWordByteCount - 1; // number of bytes to try and read
int shift = kWordBitCount - Bits.kByteBitCount; // start shifting to the MSB
while (!IsEndOfStream &&
byte_count >= 0 &&
BaseStream.Read(mIoBuffer, 0, sizeof(byte)) != 0)
{
mCache |= ((TWord)mIoBuffer[0]) << shift;
--byte_count;
shift -= Bits.kByteBitCount;
mCacheBitsStreamedCount += Bits.kByteBitCount;
}
if (byte_count != -1 && ThrowOnOverflow.CanRead())
{
throw new System.IO.EndOfStreamException("Tried to read more bits than the stream has/can see");
}
}
