src/modules/extra/m_mysql.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *          the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 /* Stop mysql wanting to use long long */
  15 #define NO_CLIENT_LONG_LONG
  16
  17 #include "inspircd.h"
  18 #include <mysql.h>
  19 #include "m_sqlv2.h"
  20
  21 #ifdef WINDOWS
  22 #pragma comment(lib, "mysqlclient.lib")
  23 #endif
  24
  25 /* VERSION 2 API: With nonblocking (threaded) requests */
  26
  27 /* $ModDesc: SQL Service Provider module for all other m_sql* modules */
  28 /* $CompileFlags: exec("mysql_config --include") */
  29 /* $LinkerFlags: exec("mysql_config --libs_r") rpath("mysql_config --libs_r") */
  30 /* $ModDep: m_sqlv2.h */
  31
  32 /* THE NONBLOCKING MYSQL API!
  33  *
  34  * MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
  35  * that instead, you should thread your program. This is what i've done here to allow for
  36  * asyncronous SQL requests via mysql. The way this works is as follows:
  37  *
  38  * The module spawns a thread via class Thread, and performs its mysql queries in this thread,
  39  * using a queue with priorities. There is a mutex on either end which prevents two threads
  40  * adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
  41  * worker thread wakes up, and checks if there is a request at the head of its queue.
  42  * If there is, it processes this request, blocking the worker thread but leaving the ircd
  43  * thread to go about its business as usual. During this period, the ircd thread is able
  44  * to insert futher pending requests into the queue.
  45  *
  46  * Once the processing of a request is complete, it is removed from the incoming queue to
  47  * an outgoing queue, and initialized as a 'response'. The worker thread then signals the
  48  * ircd thread (via a loopback socket) of the fact a result is available, by sending the
  49  * connection ID through the connection.
  50  *
  51  * The ircd thread then mutexes the queue once more, reads the outbound response off the head
  52  * of the queue, and sends it on its way to the original calling module.
  53  *
  54  * XXX: You might be asking "why doesnt he just send the response from within the worker thread?"
  55  * The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
  56  * threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
  57  * however, if we were to call a module's OnRequest even from within a thread which was not the
  58  * one the module was originally instantiated upon, there is a chance of all hell breaking loose
  59  * if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
  60  * corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
  61  * gauranteed threadsafe!)
  62  *
  63  * For a diagram of this system please see http://wiki.inspircd.org/Mysql2
  64  */
  65
  66
  67 class SQLConnection;
  68 class DispatcherThread;
  69
  70 typedef std::map<std::string, SQLConnection*> ConnMap;
  71 typedef std::deque<SQLresult*> ResultQueue;
  72
  73 unsigned long count(const char * const str, char a)
  74 {
  75         unsigned long n = 0;
  76         for (const char *p = str; *p; ++p)
  77         {
  78                 if (*p == '?')
  79                         ++n;
  80         }
  81         return n;
  82 }
  83
  84
  85 /** MySQL module
  86  *  */
  87 class ModuleSQL : public Module
  88 {
  89  public:
  90
  91          ConfigReader *Conf;
  92          int currid;
  93          bool rehashing;
  94          DispatcherThread* Dispatcher;
  95          Mutex ResultsMutex;
  96          Mutex LoggingMutex;
  97          Mutex ConnMutex;
  98
  99          ModuleSQL();
 100          ~ModuleSQL();
 101          unsigned long NewID();
 102          const char* OnRequest(Request* request);
 103          void OnRehash(User* user);
 104          Version GetVersion();
 105 };
 106
 107
 108 #if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
 109 #define mysql_field_count mysql_num_fields
 110 #endif
 111
 112 /** Represents a mysql result set
 113  */
 114 class MySQLresult : public SQLresult
 115 {
 116         int currentrow;
 117         std::vector<std::string> colnames;
 118         std::vector<SQLfieldList> fieldlists;
 119         SQLfieldMap* fieldmap;
 120         SQLfieldMap fieldmap2;
 121         SQLfieldList emptyfieldlist;
 122         int rows;
 123  public:
 124
 125         MySQLresult(Module* self, Module* to, MYSQL_RES* res, int affected_rows, unsigned int rid) : SQLresult(self, to, rid), currentrow(0), fieldmap(NULL)
 126         {
 127                 /* A number of affected rows from from mysql_affected_rows.
 128                  */
 129                 fieldlists.clear();
 130                 rows = 0;
 131                 if (affected_rows >= 1)
 132                 {
 133                         rows = affected_rows;
 134                         fieldlists.resize(rows);
 135                 }
 136                 unsigned int field_count = 0;
 137                 if (res)
 138                 {
 139                         MYSQL_ROW row;
 140                         int n = 0;
 141                         while ((row = mysql_fetch_row(res)))
 142                         {
 143                                 if (fieldlists.size() < (unsigned int)rows+1)
 144                                 {
 145                                         fieldlists.resize(fieldlists.size()+1);
 146                                 }
 147                                 field_count = 0;
 148                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 149                                 if(mysql_num_fields(res) == 0)
 150                                         break;
 151                                 if (fields && mysql_num_fields(res))
 152                                 {
 153                                         colnames.clear();
 154                                         while (field_count < mysql_num_fields(res))
 155                                         {
 156                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 157                                                 std::string b = (row[field_count] ? row[field_count] : "");
 158                                                 SQLfield sqlf(b, !row[field_count]);
 159                                                 colnames.push_back(a);
 160                                                 fieldlists[n].push_back(sqlf);
 161                                                 field_count++;
 162                                         }
 163                                         n++;
 164                                 }
 165                                 rows++;
 166                         }
 167                         mysql_free_result(res);
 168                         res = NULL;
 169                 }
 170         }
 171
 172         MySQLresult(Module* self, Module* to, SQLerror e, unsigned int rid) : SQLresult(self, to, rid), currentrow(0)
 173         {
 174                 rows = 0;
 175                 error = e;
 176         }
 177
 178         ~MySQLresult()
 179         {
 180         }
 181
 182         virtual int Rows()
 183         {
 184                 return rows;
 185         }
 186
 187         virtual int Cols()
 188         {
 189                 return colnames.size();
 190         }
 191
 192         virtual std::string ColName(int column)
 193         {
 194                 if (column < (int)colnames.size())
 195                 {
 196                         return colnames[column];
 197                 }
 198                 else
 199                 {
 200                         throw SQLbadColName();
 201                 }
 202                 return "";
 203         }
 204
 205         virtual int ColNum(const std::string &column)
 206         {
 207                 for (unsigned int i = 0; i < colnames.size(); i++)
 208                 {
 209                         if (column == colnames[i])
 210                                 return i;
 211                 }
 212                 throw SQLbadColName();
 213                 return 0;
 214         }
 215
 216         virtual SQLfield GetValue(int row, int column)
 217         {
 218                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < Cols()))
 219                 {
 220                         return fieldlists[row][column];
 221                 }
 222
 223                 throw SQLbadColName();
 224
 225                 /* XXX: We never actually get here because of the throw */
 226                 return SQLfield("",true);
 227         }
 228
 229         virtual SQLfieldList& GetRow()
 230         {
 231                 if (currentrow < rows)
 232                         return fieldlists[currentrow++];
 233                 else
 234                         return emptyfieldlist;
 235         }
 236
 237         virtual SQLfieldMap& GetRowMap()
 238         {
 239                 fieldmap2.clear();
 240
 241                 if (currentrow < rows)
 242                 {
 243                         for (int i = 0; i < Cols(); i++)
 244                         {
 245                                 fieldmap2.insert(std::make_pair(colnames[i],GetValue(currentrow, i)));
 246                         }
 247                         currentrow++;
 248                 }
 249
 250                 return fieldmap2;
 251         }
 252
 253         virtual SQLfieldList* GetRowPtr()
 254         {
 255                 SQLfieldList* fieldlist = new SQLfieldList();
 256
 257                 if (currentrow < rows)
 258                 {
 259                         for (int i = 0; i < Rows(); i++)
 260                         {
 261                                 fieldlist->push_back(fieldlists[currentrow][i]);
 262                         }
 263                         currentrow++;
 264                 }
 265                 return fieldlist;
 266         }
 267
 268         virtual SQLfieldMap* GetRowMapPtr()
 269         {
 270                 fieldmap = new SQLfieldMap();
 271
 272                 if (currentrow < rows)
 273                 {
 274                         for (int i = 0; i < Cols(); i++)
 275                         {
 276                                 fieldmap->insert(std::make_pair(colnames[i],GetValue(currentrow, i)));
 277                         }
 278                         currentrow++;
 279                 }
 280
 281                 return fieldmap;
 282         }
 283
 284         virtual void Free(SQLfieldMap* fm)
 285         {
 286                 delete fm;
 287         }
 288
 289         virtual void Free(SQLfieldList* fl)
 290         {
 291                 delete fl;
 292         }
 293 };
 294
 295 /** Represents a connection to a mysql database
 296  */
 297 class SQLConnection : public classbase
 298 {
 299  protected:
 300         MYSQL *connection;
 301         MYSQL_RES *res;
 302         MYSQL_ROW *row;
 303         SQLhost host;
 304         std::map<std::string,std::string> thisrow;
 305         bool Enabled;
 306         ModuleSQL* Parent;
 307         std::string initquery;
 308
 309  public:
 310
 311         QueryQueue queue;
 312         ResultQueue rq;
 313
 314         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 315         SQLConnection(const SQLhost &hi, ModuleSQL* Creator) : connection(NULL), host(hi), Enabled(false), Parent(Creator)
 316         {
 317         }
 318
 319         ~SQLConnection()
 320         {
 321                 Close();
 322         }
 323
 324         // This method connects to the database using the credentials supplied to the constructor, and returns
 325         // true upon success.
 326         bool Connect()
 327         {
 328                 unsigned int timeout = 1;
 329                 connection = mysql_init(connection);
 330                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 331                 return mysql_real_connect(connection, host.host.c_str(), host.user.c_str(), host.pass.c_str(), host.name.c_str(), host.port, NULL, 0);
 332         }
 333
 334         void DoLeadingQuery()
 335         {
 336                 if (!CheckConnection())
 337                         return;
 338
 339                 if( !initquery.empty() )
 340                         mysql_query(connection,initquery.c_str());
 341
 342                 /* Parse the command string and dispatch it to mysql */
 343                 SQLrequest& req = queue.front();
 344
 345                 /* Pointer to the buffer we screw around with substitution in */
 346                 char* query;
 347
 348                 /* Pointer to the current end of query, where we append new stuff */
 349                 char* queryend;
 350
 351                 /* Total length of the unescaped parameters */
 352                 unsigned long maxparamlen, paramcount;
 353
 354                 /* The length of the longest parameter */
 355                 maxparamlen = 0;
 356
 357                 for(ParamL::iterator i = req.query.p.begin(); i != req.query.p.end(); i++)
 358                 {
 359                         if (i->size() > maxparamlen)
 360                                 maxparamlen = i->size();
 361                 }
 362
 363                 /* How many params are there in the query? */
 364                 paramcount = count(req.query.q.c_str(), '?');
 365
 366                 /* This stores copy of params to be inserted with using numbered params 1;3B*/
 367                 ParamL paramscopy(req.query.p);
 368
 369                 /* To avoid a lot of allocations, allocate enough memory for the biggest the escaped query could possibly be.
 370                  * sizeofquery + (maxtotalparamlength*2) + 1
 371                  *
 372                  * The +1 is for null-terminating the string for mysql_real_escape_string
 373                  */
 374
 375                 query = new char[req.query.q.length() + (maxparamlen*paramcount*2) + 1];
 376                 queryend = query;
 377
 378                 /* Okay, now we have a buffer large enough we need to start copying the query into it and escaping and substituting
 379                  * the parameters into it...
 380                  */
 381
 382                 for(unsigned long i = 0; i < req.query.q.length(); i++)
 383                 {
 384                         if(req.query.q[i] == '?')
 385                         {
 386                                 /* We found a place to substitute..what fun.
 387                                  * use mysql calls to escape and write the
 388                                  * escaped string onto the end of our query buffer,
 389                                  * then we "just" need to make sure queryend is
 390                                  * pointing at the right place.
 391                                  */
 392
 393                                 /* Is it numbered parameter?
 394                                  */
 395
 396                                 bool numbered;
 397                                 numbered = false;
 398
 399                                 /* Numbered parameter number :|
 400                                  */
 401                                 unsigned int paramnum;
 402                                 paramnum = 0;
 403
 404                                 /* Let's check if it's a numbered param. And also calculate it's number.
 405                                  */
 406
 407                                 while ((i < req.query.q.length() - 1) && (req.query.q[i+1] >= '0') && (req.query.q[i+1] <= '9'))
 408                                 {
 409                                         numbered = true;
 410                                         ++i;
 411                                         paramnum = paramnum * 10 + req.query.q[i] - '0';
 412                                 }
 413
 414                                 if (paramnum > paramscopy.size() - 1)
 415                                 {
 416                                         /* index is out of range!
 417                                          */
 418                                         numbered = false;
 419                                 }
 420
 421                                 if (numbered)
 422                                 {
 423                                         unsigned long len = mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 424
 425                                         queryend += len;
 426                                 }
 427                                 else if (req.query.p.size())
 428                                 {
 429                                         unsigned long len = mysql_real_escape_string(connection, queryend, req.query.p.front().c_str(), req.query.p.front().length());
 430
 431                                         queryend += len;
 432                                         req.query.p.pop_front();
 433                                 }
 434                                 else
 435                                         break;
 436                         }
 437                         else
 438                         {
 439                                 *queryend = req.query.q[i];
 440                                 queryend++;
 441                         }
 442                 }
 443
 444                 *queryend = 0;
 445
 446                 req.query.q = query;
 447
 448                 if (!mysql_real_query(connection, req.query.q.data(), req.query.q.length()))
 449                 {
 450                         /* Successfull query */
 451                         res = mysql_use_result(connection);
 452                         unsigned long rows = mysql_affected_rows(connection);
 453                         MySQLresult* r = new MySQLresult(Parent, req.GetSource(), res, rows, req.id);
 454                         r->dbid = this->GetID();
 455                         r->query = req.query.q;
 456                         /* Put this new result onto the results queue.
 457                          * XXX: Remember to mutex the queue!
 458                          */
 459                         Parent->ResultsMutex.Lock();
 460                         rq.push_back(r);
 461                         Parent->ResultsMutex.Unlock();
 462                 }
 463                 else
 464                 {
 465                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 466                          * possible error numbers and error messages */
 467                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + std::string(": ") + mysql_error(connection));
 468                         MySQLresult* r = new MySQLresult(Parent, req.GetSource(), e, req.id);
 469                         r->dbid = this->GetID();
 470                         r->query = req.query.q;
 471
 472                         Parent->ResultsMutex.Lock();
 473                         rq.push_back(r);
 474                         Parent->ResultsMutex.Unlock();
 475                 }
 476
 477                 delete[] query;
 478         }
 479
 480         bool ConnectionLost()
 481         {
 482                 if (&connection)
 483                 {
 484                         return (mysql_ping(connection) != 0);
 485                 }
 486                 else return false;
 487         }
 488
 489         bool CheckConnection()
 490         {
 491                 if (ConnectionLost())
 492                 {
 493                         return Connect();
 494                 }
 495                 else return true;
 496         }
 497
 498         std::string GetError()
 499         {
 500                 return mysql_error(connection);
 501         }
 502
 503         const std::string& GetID()
 504         {
 505                 return host.id;
 506         }
 507
 508         std::string GetHost()
 509         {
 510                 return host.host;
 511         }
 512
 513         void setInitialQuery(std::string init)
 514         {
 515                 initquery = init;
 516         }
 517
 518         void SetEnable(bool Enable)
 519         {
 520                 Enabled = Enable;
 521         }
 522
 523         bool IsEnabled()
 524         {
 525                 return Enabled;
 526         }
 527
 528         void Close()
 529         {
 530                 mysql_close(connection);
 531         }
 532
 533         const SQLhost& GetConfHost()
 534         {
 535                 return host;
 536         }
 537
 538 };
 539
 540 ConnMap Connections;
 541
 542 bool HasHost(const SQLhost &host)
 543 {
 544         for (ConnMap::iterator iter = Connections.begin(); iter != Connections.end(); iter++)
 545         {
 546                 if (host == iter->second->GetConfHost())
 547                         return true;
 548         }
 549         return false;
 550 }
 551
 552 bool HostInConf(ConfigReader* conf, const SQLhost &h)
 553 {
 554         for(int i = 0; i < conf->Enumerate("database"); i++)
 555         {
 556                 SQLhost host;
 557                 host.id         = conf->ReadValue("database", "id", i);
 558                 host.host       = conf->ReadValue("database", "hostname", i);
 559                 host.port       = conf->ReadInteger("database", "port", i, true);
 560                 host.name       = conf->ReadValue("database", "name", i);
 561                 host.user       = conf->ReadValue("database", "username", i);
 562                 host.pass       = conf->ReadValue("database", "password", i);
 563                 host.ssl        = conf->ReadFlag("database", "ssl", i);
 564                 if (h == host)
 565                         return true;
 566         }
 567         return false;
 568 }
 569
 570 void ClearOldConnections(ConfigReader* conf)
 571 {
 572         ConnMap::iterator i,safei;
 573         for (i = Connections.begin(); i != Connections.end(); i++)
 574         {
 575                 if (!HostInConf(conf, i->second->GetConfHost()))
 576                 {
 577                         delete i->second;
 578                         safei = i;
 579                         --i;
 580                         Connections.erase(safei);
 581                 }
 582         }
 583 }
 584
 585 void ClearAllConnections()
 586 {
 587         ConnMap::iterator i;
 588         while ((i = Connections.begin()) != Connections.end())
 589         {
 590                 Connections.erase(i);
 591                 delete i->second;
 592         }
 593 }
 594
 595 void ConnectDatabases(ModuleSQL* Parent)
 596 {
 597         for (ConnMap::iterator i = Connections.begin(); i != Connections.end(); i++)
 598         {
 599                 if (i->second->IsEnabled())
 600                         continue;
 601
 602                 i->second->SetEnable(true);
 603                 if (!i->second->Connect())
 604                 {
 605                         /* XXX: MUTEX */
 606                         Parent->LoggingMutex.Lock();
 607                         ServerInstance->Logs->Log("m_mysql",DEFAULT,"SQL: Failed to connect database "+i->second->GetHost()+": Error: "+i->second->GetError());
 608                         i->second->SetEnable(false);
 609                         Parent->LoggingMutex.Unlock();
 610                 }
 611         }
 612 }
 613
 614 void LoadDatabases(ConfigReader* conf, ModuleSQL* Parent)
 615 {
 616         Parent->ConnMutex.Lock();
 617         ClearOldConnections(conf);
 618         for (int j =0; j < conf->Enumerate("database"); j++)
 619         {
 620                 SQLhost host;
 621                 host.id         = conf->ReadValue("database", "id", j);
 622                 host.host       = conf->ReadValue("database", "hostname", j);
 623                 host.port       = conf->ReadInteger("database", "port", j, true);
 624                 host.name       = conf->ReadValue("database", "name", j);
 625                 host.user       = conf->ReadValue("database", "username", j);
 626                 host.pass       = conf->ReadValue("database", "password", j);
 627                 host.ssl        = conf->ReadFlag("database", "ssl", j);
 628                 std::string initquery = conf->ReadValue("database", "initialquery", j);
 629
 630                 if (HasHost(host))
 631                         continue;
 632
 633                 if (!host.id.empty() && !host.host.empty() && !host.name.empty() && !host.user.empty() && !host.pass.empty())
 634                 {
 635                         SQLConnection* ThisSQL = new SQLConnection(host, Parent);
 636                         Connections[host.id] = ThisSQL;
 637
 638                         ThisSQL->setInitialQuery(initquery);
 639                 }
 640         }
 641         ConnectDatabases(Parent);
 642         Parent->ConnMutex.Unlock();
 643 }
 644
 645 char FindCharId(const std::string &id)
 646 {
 647         char i = 1;
 648         for (ConnMap::iterator iter = Connections.begin(); iter != Connections.end(); ++iter, ++i)
 649         {
 650                 if (iter->first == id)
 651                 {
 652                         return i;
 653                 }
 654         }
 655         return 0;
 656 }
 657
 658 ConnMap::iterator GetCharId(char id)
 659 {
 660         char i = 1;
 661         for (ConnMap::iterator iter = Connections.begin(); iter != Connections.end(); ++iter, ++i)
 662         {
 663                 if (i == id)
 664                         return iter;
 665         }
 666         return Connections.end();
 667 }
 668
 669 class ModuleSQL;
 670
 671 class DispatcherThread : public SocketThread
 672 {
 673  private:
 674         ModuleSQL* Parent;
 675  public:
 676         DispatcherThread(ModuleSQL* CreatorModule) : SocketThread(Instance), Parent(CreatorModule),{ }
 677         ~DispatcherThread() { }
 678         virtual void Run();
 679         virtual void OnNotify();
 680 };
 681
 682 ModuleSQL::ModuleSQL() : rehashing(false)
 683 {
 684         ServerInstance->Modules->UseInterface("SQLutils");
 685
 686         Conf = new ConfigReader;
 687         PublicServerInstance = ServerInstance;
 688         currid = 0;
 689
 690         Dispatcher = new DispatcherThread(this);
 691         ServerInstance->Threads->Start(Dispatcher);
 692
 693         if (!ServerInstance->Modules->PublishFeature("SQL", this))
 694         {
 695                 Dispatcher->join();
 696                 delete Dispatcher;
 697                 ServerInstance->Modules->DoneWithInterface("SQLutils");
 698                 throw ModuleException("m_mysql: Unable to publish feature 'SQL'");
 699         }
 700
 701         ServerInstance->Modules->PublishInterface("SQL", this);
 702         Implementation eventlist[] = { I_OnRehash, I_OnRequest };
 703         ServerInstance->Modules->Attach(eventlist, this, 2);
 704 }
 705
 706 ModuleSQL::~ModuleSQL()
 707 {
 708         delete Dispatcher;
 709         ClearAllConnections();
 710         delete Conf;
 711         ServerInstance->Modules->UnpublishInterface("SQL", this);
 712         ServerInstance->Modules->UnpublishFeature("SQL");
 713         ServerInstance->Modules->DoneWithInterface("SQLutils");
 714 }
 715
 716 unsigned long ModuleSQL::NewID()
 717 {
 718         if (currid+1 == 0)
 719                 currid++;
 720         return ++currid;
 721 }
 722
 723 const char* ModuleSQL::OnRequest(Request* request)
 724 {
 725         if(strcmp(SQLREQID, request->GetId()) == 0)
 726         {
 727                 SQLrequest* req = (SQLrequest*)request;
 728
 729                 ConnMap::iterator iter;
 730
 731                 const char* returnval = NULL;
 732
 733                 Dispatcher->LockQueue();
 734                 ConnMutex.Lock();
 735                 if((iter = Connections.find(req->dbid)) != Connections.end())
 736                 {
 737                         req->id = NewID();
 738                         iter->second->queue.push(*req);
 739                         returnval = SQLSUCCESS;
 740                 }
 741                 else
 742                 {
 743                         req->error.Id(SQL_BAD_DBID);
 744                 }
 745
 746                 ConnMutex.Unlock();
 747                 Dispatcher->UnlockQueueWakeup();
 748                 /* Yes, it's possible this will generate a spurious wakeup.
 749                  * That's fine, it'll just get ignored.
 750                  */
 751
 752                 return returnval;
 753         }
 754
 755         return NULL;
 756 }
 757
 758 void ModuleSQL::OnRehash(User* user)
 759 {
 760         Dispatcher->LockQueue();
 761         rehashing = true;
 762         Dispatcher->UnlockQueueWakeup();
 763 }
 764
 765 Version ModuleSQL::GetVersion()
 766 {
 767         return Version("SQL Service Provider module for all other m_sql* modules", VF_VENDOR | VF_SERVICEPROVIDER, API_VERSION);
 768 }
 769
 770 void DispatcherThread::Run()
 771 {
 772         LoadDatabases(Parent->Conf, Parent->PublicServerInstance, Parent);
 773
 774         SQLConnection* conn = NULL;
 775
 776         this->LockQueue();
 777         while (!this->GetExitFlag())
 778         {
 779                 if (Parent->rehashing)
 780                 {
 781                         Parent->rehashing = false;
 782                         LoadDatabases(Parent->Conf, Parent->PublicServerInstance, Parent);
 783                 }
 784
 785                 conn = NULL;
 786                 Parent->ConnMutex.Lock();
 787                 for (ConnMap::iterator i = Connections.begin(); i != Connections.end(); i++)
 788                 {
 789                         if (i->second->queue.totalsize())
 790                         {
 791                                 conn = i->second;
 792                                 break;
 793                         }
 794                 }
 795                 Parent->ConnMutex.Unlock();
 796
 797                 if (conn)
 798                 {
 799                         /* There's an item! */
 800                         this->UnlockQueue();
 801                         conn->DoLeadingQuery();
 802                         this->NotifyParent();
 803                         this->LockQueue();
 804                         conn->queue.pop();
 805                 }
 806                 else
 807                 {
 808                         /* We know the queue is empty, we can safely hang this thread until
 809                          * something happens
 810                          */
 811                         this->WaitForQueue();
 812                 }
 813         }
 814         this->UnlockQueue();
 815 }
 816
 817 void DispatcherThread::OnNotify()
 818 {
 819         SQLConnection* conn;
 820         while (1)
 821         {
 822                 conn = NULL;
 823                 Parent->ConnMutex.Lock();
 824                 for (ConnMap::iterator iter = Connections.begin(); iter != Connections.end(); iter++)
 825                 {
 826                         if (!iter->second->rq.empty())
 827                         {
 828                                 conn = iter->second;
 829                                 break;
 830                         }
 831                 }
 832                 Parent->ConnMutex.Unlock();
 833
 834                 if (!conn)
 835                         break;
 836
 837                 Parent->ResultsMutex.Lock();
 838                 ResultQueue::iterator n = conn->rq.begin();
 839                 Parent->ResultsMutex.Unlock();
 840
 841                 (*n)->Send();
 842                 delete (*n);
 843
 844                 Parent->ResultsMutex.Lock();
 845                 conn->rq.pop_front();
 846                 Parent->ResultsMutex.Unlock();
 847         }
 848 }
 849
 850 MODULE_INIT(ModuleSQL)