void VP8LBitReaderSetBuffer(VP8LBitReader* const br,
const uint8_t* const buf, size_t len) {
assert(br != NULL);
assert(buf != NULL);
assert(len < 0xfffffff8u); // can't happen with a RIFF chunk.
br->buf_ = buf;
br->len_ = len;
br->eos_ = IsEndOfStream(br);
}
int CMemoryStream::Read(void *lpDest, DWORD dwBytes)
{
if (IsEndOfStream())
return 0;
DWORD dwMaxBytes = static_cast<DWORD>(GetSize() - GetPos());
DWORD dwBytesToCopy = min(dwBytes, dwMaxBytes);
memcpy(lpDest, &m_data[static_cast<int>(m_currentPosition)], dwBytesToCopy);
m_currentPosition += dwBytesToCopy;
return dwBytesToCopy;
}
std::size_t InMemoryDataStream::Read(char* bytes, std::size_t numBytesToRead)
{
if (IsEndOfStream())
{
return 0;
}
std::size_t bytesRemaining = BytesRemaining();
std::size_t bytesRead = (numBytesToRead > bytesRemaining) ? bytesRemaining : numBytesToRead;
for (std::size_t readByteIndex = 0; readByteIndex < bytesRead; ++readByteIndex)
{
bytes[readByteIndex] = data[streamPosition];
++streamPosition;
}
return bytesRead;
}
// Returns TRUE if all data was written successfully,
// FALSE if data was dropped.
bool ByteQueue::WriteData( const char *data, size_t length )
{
size_t bytesToCopy;
bool noDrop = true, wasEmpty;
int err;
LOG_DEBUG( LOG_DEBUG_ARG, "%p->WriteData( %p, %d )", this, data, length );
assert( !IsEndOfStream() );
err = pthread_mutex_lock( &(mutex) );
assert( err == 0 );
wasEmpty = this->IsEmpty();
#if DEBUG
fprintf( debugLogFile, "Before WriteData( %p, %p, %d ): head=%d, tail=%d, "
"isEmpty=%d, isFull=%d.\n", this, data, (int) length, head, tail,
wasEmpty, this->IsFull() );
#endif
while( length > 0 )
{
if( this->IsFull() )
{
noDrop = false;
break; // drop
}
// Copy source from TAIL to (HEAD - 1 or end of buffer) whichever comes first
if( head > tail )
bytesToCopy = head - tail;
else
bytesToCopy = size - tail;
if( bytesToCopy > length )
bytesToCopy = length;
assert( bytesToCopy > 0 );
memcpy( &(buffer[ tail ]), data, bytesToCopy );
data += bytesToCopy;
tail += bytesToCopy;
assert( tail <= size );
if( tail == size )
tail = 0;
length -= bytesToCopy;
if( head == tail )
isFull = true;
if( wasEmpty )
{
assert( !IsEmpty() );
pthread_cond_broadcast( &condition );
wasEmpty = false;
}
}
#if DEBUG
fprintf( debugLogFile, "After WriteData( %p, %p, %d ): head=%d, tail=%d, "
"isEmpty=%d, isFull=%d, noDrop=%d.\n", this, data, (int) length, head, tail,
this->IsEmpty(), this->IsFull(), noDrop );
fflush( debugLogFile );
#endif
err = pthread_mutex_unlock( &mutex );
assert( err == 0 );
return noDrop;
}
// Behaviour: block on read
size_t ByteQueue::ReadData( char *data, size_t readRequest )
{
size_t bytesToCopy;
int err;
size_t result;
size_t length;
LOG_DEBUG( LOG_DEBUG_ARG, "%p->ReadData( %p, %d )", (void *) this, data,
readRequest );
length = readRequest;
err = pthread_mutex_lock( &mutex );
assert( err == 0 );
assert( length > 0 );
#if DEBUG
fprintf( debugLogFile, "Before ReadData( %p, %p, %d ): head=%d, tail=%d, "
"isEmpty=%d, isFull=%d.\n", this, data, (int) length, head, tail,
IsEmpty(), IsFull() );
#endif
result = 0;
while( length > 0 )
{
if( IsEmpty() )
{
LOG_TRACE( LOG_TRACE_ARG, "%p->ReadData: IsEmpty, eos=%d, "
"eosReported=%d", this, IsEndOfStream(),
endOfStreamReported );
if( IsEndOfStream() && !endOfStreamReported )
break;
else
{
LOG_TRACE( LOG_TRACE_ARG, "%p->ReadData: waiting for data", this );
pthread_cond_wait( &condition, &mutex );
LOG_TRACE( LOG_TRACE_ARG, "%p->ReadData: got condition change", this );
// the condition may have been signalled from the end of stream
// function, in which case we should do the IsEmpty check again
continue;
}
}
if( tail <= head )
bytesToCopy = size - head;
else
bytesToCopy = tail - head;
if( bytesToCopy > length )
bytesToCopy = length;
assert( bytesToCopy > 0 );
memcpy( data, &(buffer[head]), bytesToCopy );
if( head == tail ) // then it was full, because it was not empty
{
assert( isFull );
isFull = false;
}
data += bytesToCopy;
head += bytesToCopy;
result += bytesToCopy;
assert( head <= size );
if( head == size )
head = 0;
length -= bytesToCopy;
}
#if DEBUG
fprintf( debugLogFile, "After ReadData( %p, %p, %d ): head=%d, tail=%d, "
"isEmpty=%d, isFull=%d.\n", this, data, (int) length, head, tail,
IsEmpty(), IsFull() );
fflush( debugLogFile );
#endif
if( result < readRequest )
{
assert( IsEndOfStream() );
endOfStreamReported = true;
// broadcast because eos is now reported
pthread_cond_broadcast( &condition );
}
pthread_mutex_unlock( &mutex );
return result;
}
