SQLerror Query(const SQLrequest &req)
{
queue.push(req);
if(!qinprog && queue.totalsize())
{
/* There's no query currently in progress, and there's queries in the queue. */
SQLrequest& query = queue.front();
return DoQuery(query);
}
else
{
return SQLerror();
}
}
void Worker::run()
{
QueryQueue query_queue;
QueryPtr follower_query;
while (working_)
{
assert(query_queue.empty());
{
std::unique_lock<std::mutex> lock(mutex_);
if (!follower_query_ && query_queue_.empty())
{
cond_.wait(lock);
}
if (follower_query_)
{
follower_query = follower_query_;
follower_query_.reset();
}
if (!query_queue_.empty())
{
query_queue_.swap(query_queue);
}
}
while (!query_queue.empty())
{
handle_query(query_queue.front());
query_queue.pop_front();
}
if (follower_query != nullptr)
{
handle_query(follower_query);
follower_query.reset();
on_query_finished(shared_from_this());
}
}
}
void Worker::post_to_queue(const QueryPtr& query)
{
if (!working_) return;
{
std::lock_guard<std::mutex> guard(mutex_);
query_queue_.push_back(query);
}
cond_.notify_one();
}
void OnUnloadModule(Module* mod)
{
queue.PurgeModule(mod);
}
bool DoConnectedPoll()
{
if(!qinprog && queue.totalsize())
{
/* There's no query currently in progress, and there's queries in the queue. */
SQLrequest& query = queue.front();
DoQuery(query);
}
if(PQconsumeInput(sql))
{
/* We just read stuff from the server, that counts as it being alive
* so update the idle-since time :p
*/
idle = this->ServerInstance->Time();
if (PQisBusy(sql))
{
/* Nothing happens here */
}
else if (qinprog)
{
/* Grab the request we're processing */
SQLrequest& query = queue.front();
/* Get a pointer to the module we're about to return the result to */
Module* to = query.GetSource();
/* Fetch the result.. */
PGresult* result = PQgetResult(sql);
/* PgSQL would allow a query string to be sent which has multiple
* queries in it, this isn't portable across database backends and
* we don't want modules doing it. But just in case we make sure we
* drain any results there are and just use the last one.
* If the module devs are behaving there will only be one result.
*/
while (PGresult* temp = PQgetResult(sql))
{
PQclear(result);
result = temp;
}
if(to)
{
/* ..and the result */
PgSQLresult reply(us, to, query.id, result);
/* Fix by brain, make sure the original query gets sent back in the reply */
reply.query = query.query.q;
switch(PQresultStatus(result))
{
case PGRES_EMPTY_QUERY:
case PGRES_BAD_RESPONSE:
case PGRES_FATAL_ERROR:
reply.error.Id(SQL_QREPLY_FAIL);
reply.error.Str(PQresultErrorMessage(result));
default:
;
/* No action, other values are not errors */
}
reply.Send();
/* PgSQLresult's destructor will free the PGresult */
}
else
{
/* If the client module is unloaded partway through a query then the provider will set
* the pointer to NULL. We cannot just cancel the query as the result will still come
* through at some point...and it could get messy if we play with invalid pointers...
*/
PQclear(result);
}
qinprog = false;
queue.pop();
DoConnectedPoll();
}
return true;
}
else
{
/* I think we'll assume this means the server died...it might not,
* but I think that any error serious enough we actually get here
* deserves to reconnect [/excuse]
* Returning true so the core doesn't try and close the connection.
*/
DelayReconnect();
return true;
}
}
void DoLeadingQuery()
{
SQLrequest* req = queue.front();
req->error = Query(req);
}
unsigned int Worker::get_query_queue_size()
{
std::lock_guard<std::mutex> guard(mutex_);
return query_queue_.size();
}
