Files
MaxScale/server/modules/routing/cat/catsession.cc

126 lines
2.8 KiB
C++

/*
* Copyright (c) 2016 MariaDB Corporation Ab
*
* Use of this software is governed by the Business Source License included
* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
*
* Change Date: 2022-01-01
*
* On the date above, in accordance with the Business Source License, use
* of this software will be governed by version 2 or later of the General
* Public License.
*/
#include "cat.hh"
#include "catsession.hh"
#include <maxscale/protocol/mysql.h>
#include <maxscale/modutil.hh>
using namespace maxscale;
CatSession::CatSession(MXS_SESSION* session, Cat* router, SRWBackendList& backends)
: RouterSession(session)
, m_session(session)
, m_backends(backends)
, m_completed(0)
, m_packet_num(0)
, m_query(NULL)
{
}
CatSession::~CatSession()
{
}
void CatSession::close()
{
}
bool CatSession::next_backend()
{
// Skip unused backends
while (m_current != m_backends.end() && !(*m_current)->in_use())
{
m_current++;
}
return m_current != m_backends.end();
}
int32_t CatSession::routeQuery(GWBUF* pPacket)
{
int32_t rval = 0;
m_completed = 0;
m_packet_num = 0;
m_query = pPacket;
m_current = m_backends.begin();
if (next_backend())
{
// We have a backend, write the query only to this one. It will be
// propagated onwards in clientReply.
rval = (*m_current)->write(gwbuf_clone(pPacket));
}
return rval;
}
void CatSession::clientReply(GWBUF* pPacket, DCB* pDcb)
{
auto backend = *m_current;
mxb_assert(backend->dcb() == pDcb);
bool send = false;
backend->process_reply(pPacket);
if (backend->reply_is_complete())
{
m_completed++;
m_current++;
if (!next_backend())
{
send = true;
gwbuf_free(m_query);
m_query = NULL;
}
else
{
(*m_current)->write(gwbuf_clone(m_query));
}
}
if (m_completed == 0)
{
send = backend->get_reply_state() != REPLY_STATE_DONE;
}
else if (backend->get_reply_state() == REPLY_STATE_RSET_ROWS
&& mxs_mysql_get_command(pPacket) != MYSQL_REPLY_EOF)
{
send = true;
}
if (send)
{
// Increment the packet sequence number and send it to the client
mxb_assert(modutil_count_packets(pPacket) > 0);
GWBUF_DATA(pPacket)[3] = m_packet_num++;
MXS_SESSION_ROUTE_REPLY(pDcb->session, pPacket);
}
else
{
gwbuf_free(pPacket);
}
}
void CatSession::handleError(GWBUF* pMessage, DCB* pProblem, mxs_error_action_t action, bool* pSuccess)
{
/**
* The simples thing to do here is to close the connection. Anything else
* would still require extra processing on the client side and reconnecting
* will cause things to fix themselves.
*/
*pSuccess = false;
}