/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
* Copyright (C) 2006-2007, 2009 Dennis Friis <peavey@inspircd.org>
* Copyright (C) 2006-2009 Craig Edwards <craigedwards@brainbox.cc>
* Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
*
* This file is part of InspIRCd. InspIRCd is free software: you can
* redistribute it and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* Stop mysql wanting to use long long */
#define NO_CLIENT_LONG_LONG
#include "inspircd.h"
#include <mysql.h>
#include "sql.h"
#ifdef WINDOWS
# pragma comment(lib, "mysqlclient.lib")
# pragma comment(lib, "advapi32.lib")
# pragma comment(linker, "/NODEFAULTLIB:LIBCMT")
#endif
/* VERSION 3 API: With nonblocking (threaded) requests */
/* $ModDesc: SQL Service Provider module for all other m_sql* modules */
/* $CompileFlags: exec("mysql_config --include") */
/* $LinkerFlags: exec("mysql_config --libs_r") rpath("mysql_config --libs_r") */
/* THE NONBLOCKING MYSQL API!
*
* MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
* that instead, you should thread your program. This is what i've done here to allow for
* asyncronous SQL requests via mysql. The way this works is as follows:
*
* The module spawns a thread via class Thread, and performs its mysql queries in this thread,
* using a queue with priorities. There is a mutex on either end which prevents two threads
* adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
* worker thread wakes up, and checks if there is a request at the head of its queue.
* If there is, it processes this request, blocking the worker thread but leaving the ircd
* thread to go about its business as usual. During this period, the ircd thread is able
* to insert futher pending requests into the queue.
*
* Once the processing of a request is complete, it is removed from the incoming queue to
* an outgoing queue, and initialized as a 'response'. The worker thread then signals the
* ircd thread (via a loopback socket) of the fact a result is available, by sending the
* connection ID through the connection.
*
* The ircd thread then mutexes the queue once more, reads the outbound response off the head
* of the queue, and sends it on its way to the original calling module.
*
* XXX: You might be asking "why doesnt he just send the response from within the worker thread?"
* The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
* threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
* however, if we were to call a module's OnRequest even from within a thread which was not the
* one the module was originally instantiated upon, there is a chance of all hell breaking loose
* if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
* corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
* gauranteed threadsafe!)
*
* For a diagram of this system please see http://wiki.inspircd.org/Mysql2
*/
class SQLConnection;
class MySQLresult;
class DispatcherThread;
struct QQueueItem
{
SQLQuery* q;
std::string query;
SQLConnection* c;
QQueueItem(SQLQuery* Q, const std::string& S, SQLConnection* C) : q(Q), query(S), c(C) {}
};
struct RQueueItem
{
SQLQuery* q;
MySQLresult* r;
RQueueItem(SQLQuery* Q, MySQLresult* R) : q(Q), r(R) {}
};
typedef std::map<std::string, SQLConnection*> ConnMap;
typedef std::deque<QQueueItem> QueryQueue;
typedef std::deque<RQueueItem> ResultQueue;
/** MySQL module
* */
class ModuleSQL : public Module
{
public:
DispatcherThread* Dispatcher;
QueryQueue qq; // MUST HOLD MUTEX
ResultQueue rq; // MUST HOLD MUTEX
ConnMap connections; // main thread only
ModuleSQL();
void init();
~ModuleSQL();
void OnRehash(User* user);
void OnUnloadModule(Module* mod);
Version GetVersion();
};
class DispatcherThread : public SocketThread
{
private:
ModuleSQL* const Parent;
public:
DispatcherThread(ModuleSQL* CreatorModule) : Parent(CreatorModule) { }
~DispatcherThread() { }
virtual void Run();
virtual void OnNotify();
};
#if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
#define mysql_field_count mysql_num_fields
#endif
/** Represents a mysql result set
*/
class MySQLresult : public SQLResult
{
public:
SQLerror err;
int currentrow;
int rows;
std::vector<std::string> colnames;
std::vector<SQLEntries> fieldlists;
MySQLresult(MYSQL_RES* res, int affected_rows) : err(SQL_NO_ERROR), currentrow(0), rows(0)
{
if (affected_rows >= 1)
{
rows = affected_rows;
fieldlists.resize(rows);
}
unsigned int field_count = 0;
if (res)
{
MYSQL_ROW row;
int n = 0;
while ((row = mysql_fetch_row(res)))
{
if (fieldlists.size() < (unsigned int)rows+1)
{
fieldlists.resize(fieldlists.size()+1);
}
field_count = 0;
MYSQL_FIELD *fields = mysql_fetch_fields(res);
if(mysql_num_fields(res) == 0)
break;
if (fields && mysql_num_fields(res))
{
colnames.clear();
while (field_count < mysql_num_fields(res))
{
std::string a = (fields[field_count].name ? fields[field_count].name : "");
if (row[field_count])
fieldlists[n].push_back(SQLEntry(row[field_count]));
else
fieldlists[n].push_back(SQLEntry());
colnames.push_back(a);
field_count++;
}
n++;
}
rows++;
}
mysql_free_result(res);
res = NULL;
}
}
MySQLresult(SQLerror& e) : err(e)
{
}
~MySQLresult()
{
}
virtual int Rows()
{
return rows;
}
virtual void GetCols(std::vector<std::string>& result)
{
result.assign(colnames.begin(), colnames.end());
}
virtual SQLEntry GetValue(int row, int column)
{
if ((row >= 0) && (row < rows) && (column >= 0) && (column < (int)fieldlists[row].size()))
{
return fieldlists[row][column];
}
return SQLEntry();
}
virtual bool GetRow(SQLEntries& result)
{
if (currentrow < rows)
{
result.assign(fieldlists[currentrow].begin(), fieldlists[currentrow].end());
currentrow++;
return true;
}
else
{
result.clear();
return false;
}
}
};
/** Represents a connection to a mysql database
*/
class SQLConnection : public SQLProvider
{
public:
reference<ConfigTag> config;
MYSQL *connection;
Mutex lock;
// This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
SQLConnection(Module* p, ConfigTag* tag) : SQLProvider(p, "SQL/" + tag->getString("id")),
config(tag), connection(NULL)
{
}
~SQLConnection()
{
Close();
}
// This method connects to the database using the credentials supplied to the constructor, and returns
// true upon success.
bool Connect()
{
unsigned int timeout = 1;
connection = mysql_init(connection);
mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
std::string host = config->getString("host");
std::string user = config->getString("user");
std::string pass = config->getString("pass");
std::string dbname = config->getString("name");
int port = config->getInt("port");
bool rv = mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, 0);
if (!rv)
return rv;
std::string initquery;
if (config->readString("initialquery", initquery))
{
mysql_query(connection,initquery.c_str());
}
return true;
}
ModuleSQL* Parent()
{
return (ModuleSQL*)(Module*)creator;
}
MySQLresult* DoBlockingQuery(const std::string& query)
{
/* Parse the command string and dispatch it to mysql */
if (CheckConnection() && !mysql_real_query(connection, query.data(), query.length()))
{
/* Successfull query */
MYSQL_RES* res = mysql_use_result(connection);
unsigned long rows = mysql_affected_rows(connection);
return new MySQLresult(res, rows);
}
else
{
/* XXX: See /usr/include/mysql/mysqld_error.h for a list of
* possible error numbers and error messages */
SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + std::string(": ") + mysql_error(connection));
return new MySQLresult(e);
}
}
bool CheckConnection()
{
if (!connection || mysql_ping(connection) != 0)
return Connect();
return true;
}
std::string GetError()
{
return mysql_error(connection);
}
void Close()
{
mysql_close(connection);
}
void submit(SQLQuery* q, const std::string& qs)
{
Parent()->Dispatcher->LockQueue();
Parent()->qq.push_back(QQueueItem(q, qs, this));
Parent()->Dispatcher->UnlockQueueWakeup();
}
void submit(SQLQuery* call, const std::string& q, const ParamL& p)
{
std::string res;
unsigned int param = 0;
for(std::string::size_type i = 0; i < q.length(); i++)
{
if (q[i] != '?')
res.push_back(q[i]);
else
{
if (param < p.size())
{
std::string parm = p[param++];
char buffer[MAXBUF];
mysql_escape_string(buffer, parm.c_str(), parm.length());
// mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
res.append(buffer);
}
}
}
submit(call, res);
}
void submit(SQLQuery* call, const std::string& q, const ParamM& p)
{
std::string res;
for(std::string::size_type i = 0; i < q.length(); i++)
{
if (q[i] != '$')
res.push_back(q[i]);
else
{
std::string field;
i++;
while (i < q.length() && isalnum(q[i]))
field.push_back(q[i++]);
i--;
ParamM::const_iterator it = p.find(field);
if (it != p.end())
{
std::string parm = it->second;
char buffer[MAXBUF];
mysql_escape_string(buffer, parm.c_str(), parm.length());
res.append(buffer);
}
}
}
submit(call, res);
}
};
ModuleSQL::ModuleSQL()
{
Dispatcher = NULL;
}
void ModuleSQL::init()
{
Dispatcher = new DispatcherThread(this);
ServerInstance->Threads->Start(Dispatcher);
Implementation eventlist[] = { I_OnRehash, I_OnUnloadModule };
ServerInstance->Modules->Attach(eventlist, this, 2);
OnRehash(NULL);
}
ModuleSQL::~ModuleSQL()
{
if (Dispatcher)
{
Dispatcher->join();
Dispatcher->OnNotify();
delete Dispatcher;
}
for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
{
delete i->second;
}
}
void ModuleSQL::OnRehash(User* user)
{
ConnMap conns;
ConfigTagList tags = ServerInstance->Config->ConfTags("database");
for(ConfigIter i = tags.first; i != tags.second; i++)
{
if (i->second->getString("module", "mysql") != "mysql")
continue;
std::string id = i->second->getString("id");
ConnMap::iterator curr = connections.find(id);
if (curr == connections.end())
{
SQLConnection* conn = new SQLConnection(this, i->second);
conns.insert(std::make_pair(id, conn));
ServerInstance->Modules->AddService(*conn);
}
else
{
conns.insert(*curr);
connections.erase(curr);
}
}
// now clean up the deleted databases
Dispatcher->LockQueue();
SQLerror err(SQL_BAD_DBID);
for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
{
ServerInstance->Modules->DelService(*i->second);
// it might be running a query on this database. Wait for that to complete
i->second->lock.Lock();
i->second->lock.Unlock();
// now remove all active queries to this DB
for(unsigned int j = qq.size() - 1; j >= 0; j--)
{
if (qq[j].c == i->second)
{
qq[j].q->OnError(err);
delete qq[j].q;
qq.erase(qq.begin() + j);
}
}
// finally, nuke the connection
delete i->second;
}
Dispatcher->UnlockQueue();
connections.swap(conns);
}
void ModuleSQL::OnUnloadModule(Module* mod)
{
SQLerror err(SQL_BAD_DBID);
Dispatcher->LockQueue();
unsigned int i = qq.size();
while (i > 0)
{
i--;
if (qq[i].q->creator == mod)
{
if (i == 0)
{
// need to wait until the query is done
// (the result will be discarded)
qq[i].c->lock.Lock();
qq[i].c->lock.Unlock();
}
qq[i].q->OnError(err);
delete qq[i].q;
qq.erase(qq.begin() + i);
}
}
Dispatcher->UnlockQueue();
// clean up any result queue entries
Dispatcher->OnNotify();
}
Version ModuleSQL::GetVersion()
{
return Version("MySQL support", VF_VENDOR);
}
void DispatcherThread::Run()
{
this->LockQueue();
while (!this->GetExitFlag())
{
if (!Parent->qq.empty())
{
QQueueItem i = Parent->qq.front();
i.c->lock.Lock();
this->UnlockQueue();
MySQLresult* res = i.c->DoBlockingQuery(i.query);
i.c->lock.Unlock();
/*
* At this point, the main thread could be working on:
* Rehash - delete i.c out from under us. We don't care about that.
* UnloadModule - delete i.q and the qq item. Need to avoid reporting results.
*/
this->LockQueue();
if (Parent->qq.front().q == i.q)
{
Parent->qq.pop_front();
Parent->rq.push_back(RQueueItem(i.q, res));
NotifyParent();
}
else
{
// UnloadModule ate the query
delete res;
}
}
else
{
/* We know the queue is empty, we can safely hang this thread until
* something happens
*/
this->WaitForQueue();
}
}
this->UnlockQueue();
}
void DispatcherThread::OnNotify()
{
// this could unlock during the dispatch, but OnResult isn't expected to take that long
this->LockQueue();
for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
{
MySQLresult* res = i->r;
if (res->err.id == SQL_NO_ERROR)
i->q->OnResult(*res);
else
i->q->OnError(res->err);
delete i->q;
delete i->r;
}
Parent->rq.clear();
this->UnlockQueue();
}
MODULE_INIT(ModuleSQL)
