engine::want operator()(engine& eng,
asio::error_code& ec,
std::size_t& bytes_transferred) const
{
bytes_transferred = 0;
return eng.handshake(type_, ec);
}
engine::want operator()(engine& eng,
asio::error_code& ec,
std::size_t& bytes_transferred) const
{
typename ConstBufferSequence::const_iterator iter = buffers_.begin();
typename ConstBufferSequence::const_iterator end = buffers_.end();
std::size_t accumulated_size = 0;
for (;;)
{
engine::want want = eng.handshake(type_, ec);
if (want != engine::want_input_and_retry
|| bytes_transferred == total_buffer_size_)
return want;
// Find the next buffer piece to be fed to the engine.
while (iter != end)
{
const_buffer buffer(*iter);
// Skip over any buffers which have already been consumed by the engine.
if (bytes_transferred >= accumulated_size + buffer_size(buffer))
{
accumulated_size += buffer_size(buffer);
++iter;
continue;
}
// The current buffer may have been partially consumed by the engine on
// a previous iteration. If so, adjust the buffer to point to the
// unused portion.
if (bytes_transferred > accumulated_size)
buffer = buffer + (bytes_transferred - accumulated_size);
// Pass the buffer to the engine, and update the bytes transferred to
// reflect the total number of bytes consumed so far.
bytes_transferred += buffer_size(buffer);
buffer = eng.put_input(buffer);
bytes_transferred -= buffer_size(buffer);
break;
}
}
}