//! \brief Return the smallest contiguous area that needs to be
//! uploaded. If there is no pending data, pos_start will be set to
//! -1. You can call hasPendingData() before this method.
std::pair<size_t, size_t> getPendingData() const
{
if (hasPendingData())
{
return std::make_pair(m_pending_start, m_pending_end);
}
else
{
return std::make_pair(0_z, 0_z);
}
}
//! \brief Update the range indexes of changed elements with a new range.
void tagAsPending(const size_t pos_start, const size_t pos_end)
{
if (!hasPendingData())
{
m_pending_start = pos_start;
m_pending_end = pos_end;
}
else
{
m_pending_start = maths::min(m_pending_start, pos_start);
m_pending_end = maths::max(m_pending_end, pos_end);
}
}
//! \brief Return the smallest contiguous area that needs to be
//! uploaded. If there is no pending data, pos_start will be set to
//! -1. You can call hasPendingData() before this method.
void getPendingData(size_t &pos_start, size_t &pos_end) const
{
if (hasPendingData())
{
pos_start = m_pending_start;
pos_end = m_pending_end;
}
else
{
pos_start = 0_z;
pos_end = 0_z;
}
}
off_t ReadBufferAIO::doSeek(off_t off, int whence)
{
off_t new_pos_in_file;
if (whence == SEEK_SET)
{
if (off < 0)
throw Exception("SEEK_SET underflow", ErrorCodes::ARGUMENT_OUT_OF_BOUND);
new_pos_in_file = off;
}
else if (whence == SEEK_CUR)
{
if (off >= 0)
{
if (off > (std::numeric_limits<off_t>::max() - getPositionInFile()))
throw Exception("SEEK_CUR overflow", ErrorCodes::ARGUMENT_OUT_OF_BOUND);
}
else if (off < -getPositionInFile())
throw Exception("SEEK_CUR underflow", ErrorCodes::ARGUMENT_OUT_OF_BOUND);
new_pos_in_file = getPositionInFile() + off;
}
else
throw Exception("ReadBufferAIO::seek expects SEEK_SET or SEEK_CUR as whence", ErrorCodes::ARGUMENT_OUT_OF_BOUND);
if (new_pos_in_file != getPositionInFile())
{
off_t first_read_pos_in_file = first_unread_pos_in_file - static_cast<off_t>(working_buffer.size());
if (hasPendingData() && (new_pos_in_file >= first_read_pos_in_file) && (new_pos_in_file <= first_unread_pos_in_file))
{
/// Moved, but remained within the buffer.
pos = working_buffer.begin() + (new_pos_in_file - first_read_pos_in_file);
}
else
{
/// Moved past the buffer.
pos = working_buffer.end();
first_unread_pos_in_file = new_pos_in_file;
/// We can not use the result of the current asynchronous request.
skip();
}
}
return new_pos_in_file;
}
