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          InspIRCd* PublicServerInstance;
  93          int currid;
  94          bool rehashing;
  95          DispatcherThread* Dispatcher;
  96          Mutex ResultsMutex;
  97          Mutex LoggingMutex;
  98          Mutex ConnMutex;
  99
 100          ModuleSQL(InspIRCd* Me);
 101          ~ModuleSQL();
 102          unsigned long NewID();
 103          const char* OnRequest(Request* request);
 104          void OnRehash(User* user);
 105          Version GetVersion();
 106 };
 107
 108
 109 #if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
 110 #define mysql_field_count mysql_num_fields
 111 #endif
 112
 113 /** Represents a mysql result set
 114  */
 115 class MySQLresult : public SQLresult
 116 {
 117         int currentrow;
 118         std::vector<std::string> colnames;
 119         std::vector<SQLfieldList> fieldlists;
 120         SQLfieldMap* fieldmap;
 121         SQLfieldMap fieldmap2;
 122         SQLfieldList emptyfieldlist;
 123         int rows;
 124  public:
 125
 126         MySQLresult(Module* self, Module* to, MYSQL_RES* res, int affected_rows, unsigned int rid) : SQLresult(self, to, rid), currentrow(0), fieldmap(NULL)
 127         {
 128                 /* A number of affected rows from from mysql_affected_rows.
 129                  */
 130                 fieldlists.clear();
 131                 rows = 0;
 132                 if (affected_rows >= 1)
 133                 {
 134                         rows = affected_rows;
 135                         fieldlists.resize(rows);
 136                 }
 137                 unsigned int field_count = 0;
 138                 if (res)
 139                 {
 140                         MYSQL_ROW row;
 141                         int n = 0;
 142                         while ((row = mysql_fetch_row(res)))
 143                         {
 144                                 if (fieldlists.size() < (unsigned int)rows+1)
 145                                 {
 146                                         fieldlists.resize(fieldlists.size()+1);
 147                                 }
 148                                 field_count = 0;
 149                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 150                                 if(mysql_num_fields(res) == 0)
 151                                         break;
 152                                 if (fields && mysql_num_fields(res))
 153                                 {
 154                                         colnames.clear();
 155                                         while (field_count < mysql_num_fields(res))
 156                                         {
 157                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 158                                                 std::string b = (row[field_count] ? row[field_count] : "");
 159                                                 SQLfield sqlf(b, !row[field_count]);
 160                                                 colnames.push_back(a);
 161                                                 fieldlists[n].push_back(sqlf);
 162                                                 field_count++;
 163                                         }
 164                                         n++;
 165                                 }
 166                                 rows++;
 167                         }
 168                         mysql_free_result(res);
 169                         res = NULL;
 170                 }
 171         }
 172
 173         MySQLresult(Module* self, Module* to, SQLerror e, unsigned int rid) : SQLresult(self, to, rid), currentrow(0)
 174         {
 175                 rows = 0;
 176                 error = e;
 177         }
 178
 179         ~MySQLresult()
 180         {
 181         }
 182
 183         virtual int Rows()
 184         {
 185                 return rows;
 186         }
 187
 188         virtual int Cols()
 189         {
 190                 return colnames.size();
 191         }
 192
 193         virtual std::string ColName(int column)
 194         {
 195                 if (column < (int)colnames.size())
 196                 {
 197                         return colnames[column];
 198                 }
 199                 else
 200                 {
 201                         throw SQLbadColName();
 202                 }
 203                 return "";
 204         }
 205
 206         virtual int ColNum(const std::string &column)
 207         {
 208                 for (unsigned int i = 0; i < colnames.size(); i++)
 209                 {
 210                         if (column == colnames[i])
 211                                 return i;
 212                 }
 213                 throw SQLbadColName();
 214                 return 0;
 215         }
 216
 217         virtual SQLfield GetValue(int row, int column)
 218         {
 219                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < Cols()))
 220                 {
 221                         return fieldlists[row][column];
 222                 }
 223
 224                 throw SQLbadColName();
 225
 226                 /* XXX: We never actually get here because of the throw */
 227                 return SQLfield("",true);
 228         }
 229
 230         virtual SQLfieldList& GetRow()
 231         {
 232                 if (currentrow < rows)
 233                         return fieldlists[currentrow++];
 234                 else
 235                         return emptyfieldlist;
 236         }
 237
 238         virtual SQLfieldMap& GetRowMap()
 239         {
 240                 fieldmap2.clear();
 241
 242                 if (currentrow < rows)
 243                 {
 244                         for (int i = 0; i < Cols(); i++)
 245                         {
 246                                 fieldmap2.insert(std::make_pair(colnames[i],GetValue(currentrow, i)));
 247                         }
 248                         currentrow++;
 249                 }
 250
 251                 return fieldmap2;
 252         }
 253
 254         virtual SQLfieldList* GetRowPtr()
 255         {
 256                 SQLfieldList* fieldlist = new SQLfieldList();
 257
 258                 if (currentrow < rows)
 259                 {
 260                         for (int i = 0; i < Rows(); i++)
 261                         {
 262                                 fieldlist->push_back(fieldlists[currentrow][i]);
 263                         }
 264                         currentrow++;
 265                 }
 266                 return fieldlist;
 267         }
 268
 269         virtual SQLfieldMap* GetRowMapPtr()
 270         {
 271                 fieldmap = new SQLfieldMap();
 272
 273                 if (currentrow < rows)
 274                 {
 275                         for (int i = 0; i < Cols(); i++)
 276                         {
 277                                 fieldmap->insert(std::make_pair(colnames[i],GetValue(currentrow, i)));
 278                         }
 279                         currentrow++;
 280                 }
 281
 282                 return fieldmap;
 283         }
 284
 285         virtual void Free(SQLfieldMap* fm)
 286         {
 287                 delete fm;
 288         }
 289
 290         virtual void Free(SQLfieldList* fl)
 291         {
 292                 delete fl;
 293         }
 294 };
 295
 296 /** Represents a connection to a mysql database
 297  */
 298 class SQLConnection : public classbase
 299 {
 300  protected:
 301         MYSQL *connection;
 302         MYSQL_RES *res;
 303         MYSQL_ROW *row;
 304         SQLhost host;
 305         std::map<std::string,std::string> thisrow;
 306         bool Enabled;
 307         ModuleSQL* Parent;
 308         std::string initquery;
 309
 310  public:
 311
 312         QueryQueue queue;
 313         ResultQueue rq;
 314
 315         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 316         SQLConnection(const SQLhost &hi, ModuleSQL* Creator) : connection(NULL), host(hi), Enabled(false), Parent(Creator)
 317         {
 318         }
 319
 320         ~SQLConnection()
 321         {
 322                 Close();
 323         }
 324
 325         // This method connects to the database using the credentials supplied to the constructor, and returns
 326         // true upon success.
 327         bool Connect()
 328         {
 329                 unsigned int timeout = 1;
 330                 connection = mysql_init(connection);
 331                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 332                 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);
 333         }
 334
 335         void DoLeadingQuery()
 336         {
 337                 if (!CheckConnection())
 338                         return;
 339
 340                 if( !initquery.empty() )
 341                         mysql_query(connection,initquery.c_str());
 342
 343                 /* Parse the command string and dispatch it to mysql */
 344                 SQLrequest& req = queue.front();
 345
 346                 /* Pointer to the buffer we screw around with substitution in */
 347                 char* query;
 348
 349                 /* Pointer to the current end of query, where we append new stuff */
 350                 char* queryend;
 351
 352                 /* Total length of the unescaped parameters */
 353                 unsigned long maxparamlen, paramcount;
 354
 355                 /* The length of the longest parameter */
 356                 maxparamlen = 0;
 357
 358                 for(ParamL::iterator i = req.query.p.begin(); i != req.query.p.end(); i++)
 359                 {
 360                         if (i->size() > maxparamlen)
 361                                 maxparamlen = i->size();
 362                 }
 363
 364                 /* How many params are there in the query? */
 365                 paramcount = count(req.query.q.c_str(), '?');
 366
 367                 /* This stores copy of params to be inserted with using numbered params 1;3B*/
 368                 ParamL paramscopy(req.query.p);
 369
 370                 /* To avoid a lot of allocations, allocate enough memory for the biggest the escaped query could possibly be.
 371                  * sizeofquery + (maxtotalparamlength*2) + 1
 372                  *
 373                  * The +1 is for null-terminating the string for mysql_real_escape_string
 374                  */
 375
 376                 query = new char[req.query.q.length() + (maxparamlen*paramcount*2) + 1];
 377                 queryend = query;
 378
 379                 /* Okay, now we have a buffer large enough we need to start copying the query into it and escaping and substituting
 380                  * the parameters into it...
 381                  */
 382
 383                 for(unsigned long i = 0; i < req.query.q.length(); i++)
 384                 {
 385                         if(req.query.q[i] == '?')
 386                         {
 387                                 /* We found a place to substitute..what fun.
 388                                  * use mysql calls to escape and write the
 389                                  * escaped string onto the end of our query buffer,
 390                                  * then we "just" need to make sure queryend is
 391                                  * pointing at the right place.
 392                                  */
 393
 394                                 /* Is it numbered parameter?
 395                                  */
 396
 397                                 bool numbered;
 398                                 numbered = false;
 399
 400                                 /* Numbered parameter number :|
 401                                  */
 402                                 unsigned int paramnum;
 403                                 paramnum = 0;
 404
 405                                 /* Let's check if it's a numbered param. And also calculate it's number.
 406                                  */
 407
 408                                 while ((i < req.query.q.length() - 1) && (req.query.q[i+1] >= '0') && (req.query.q[i+1] <= '9'))
 409                                 {
 410                                         numbered = true;
 411                                         ++i;
 412                                         paramnum = paramnum * 10 + req.query.q[i] - '0';
 413                                 }
 414
 415                                 if (paramnum > paramscopy.size() - 1)
 416                                 {
 417                                         /* index is out of range!
 418                                          */
 419                                         numbered = false;
 420                                 }
 421
 422                                 if (numbered)
 423                                 {
 424                                         unsigned long len = mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 425
 426                                         queryend += len;
 427                                 }
 428                                 else if (req.query.p.size())
 429                                 {
 430                                         unsigned long len = mysql_real_escape_string(connection, queryend, req.query.p.front().c_str(), req.query.p.front().length());
 431
 432                                         queryend += len;
 433                                         req.query.p.pop_front();
 434                                 }
 435                                 else
 436                                         break;
 437                         }
 438                         else
 439                         {
 440                                 *queryend = req.query.q[i];
 441                                 queryend++;
 442                         }
 443                 }
 444
 445                 *queryend = 0;
 446
 447                 req.query.q = query;
 448
 449                 if (!mysql_real_query(connection, req.query.q.data(), req.query.q.length()))
 450                 {
 451                         /* Successfull query */
 452                         res = mysql_use_result(connection);
 453                         unsigned long rows = mysql_affected_rows(connection);
 454                         MySQLresult* r = new MySQLresult(Parent, req.GetSource(), res, rows, req.id);
 455                         r->dbid = this->GetID();
 456                         r->query = req.query.q;
 457                         /* Put this new result onto the results queue.
 458                          * XXX: Remember to mutex the queue!
 459                          */
 460                         Parent->ResultsMutex.Lock();
 461                         rq.push_back(r);
 462                         Parent->ResultsMutex.Unlock();
 463                 }
 464                 else
 465                 {
 466                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 467                          * possible error numbers and error messages */
 468                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + std::string(": ") + mysql_error(connection));
 469                         MySQLresult* r = new MySQLresult(Parent, req.GetSource(), e, req.id);
 470                         r->dbid = this->GetID();
 471                         r->query = req.query.q;
 472
 473                         Parent->ResultsMutex.Lock();
 474                         rq.push_back(r);
 475                         Parent->ResultsMutex.Unlock();
 476                 }
 477
 478                 delete[] query;
 479         }
 480
 481         bool ConnectionLost()
 482         {
 483                 if (&connection)
 484                 {
 485                         return (mysql_ping(connection) != 0);
 486                 }
 487                 else return false;
 488         }
 489
 490         bool CheckConnection()
 491         {
 492                 if (ConnectionLost())
 493                 {
 494                         return Connect();
 495                 }
 496                 else return true;
 497         }
 498
 499         std::string GetError()
 500         {
 501                 return mysql_error(connection);
 502         }
 503
 504         const std::string& GetID()
 505         {
 506                 return host.id;
 507         }
 508
 509         std::string GetHost()
 510         {
 511                 return host.host;
 512         }
 513
 514         void setInitialQuery(std::string init)
 515         {
 516                 initquery = init;
 517         }
 518
 519         void SetEnable(bool Enable)
 520         {
 521                 Enabled = Enable;
 522         }
 523
 524         bool IsEnabled()
 525         {
 526                 return Enabled;
 527         }
 528
 529         void Close()
 530         {
 531                 mysql_close(connection);
 532         }
 533
 534         const SQLhost& GetConfHost()
 535         {
 536                 return host;
 537         }
 538
 539 };
 540
 541 ConnMap Connections;
 542
 543 bool HasHost(const SQLhost &host)
 544 {
 545         for (ConnMap::iterator iter = Connections.begin(); iter != Connections.end(); iter++)
 546         {
 547                 if (host == iter->second->GetConfHost())
 548                         return true;
 549         }
 550         return false;
 551 }
 552
 553 bool HostInConf(ConfigReader* conf, const SQLhost &h)
 554 {
 555         for(int i = 0; i < conf->Enumerate("database"); i++)
 556         {
 557                 SQLhost host;
 558                 host.id         = conf->ReadValue("database", "id", i);
 559                 host.host       = conf->ReadValue("database", "hostname", i);
 560                 host.port       = conf->ReadInteger("database", "port", i, true);
 561                 host.name       = conf->ReadValue("database", "name", i);
 562                 host.user       = conf->ReadValue("database", "username", i);
 563                 host.pass       = conf->ReadValue("database", "password", i);
 564                 host.ssl        = conf->ReadFlag("database", "ssl", i);
 565                 if (h == host)
 566                         return true;
 567         }
 568         return false;
 569 }
 570
 571 void ClearOldConnections(ConfigReader* conf)
 572 {
 573         ConnMap::iterator i,safei;
 574         for (i = Connections.begin(); i != Connections.end(); i++)
 575         {
 576                 if (!HostInConf(conf, i->second->GetConfHost()))
 577                 {
 578                         delete i->second;
 579                         safei = i;
 580                         --i;
 581                         Connections.erase(safei);
 582                 }
 583         }
 584 }
 585
 586 void ClearAllConnections()
 587 {
 588         ConnMap::iterator i;
 589         while ((i = Connections.begin()) != Connections.end())
 590         {
 591                 Connections.erase(i);
 592                 delete i->second;
 593         }
 594 }
 595
 596 void ConnectDatabases(InspIRCd* ServerInstance, ModuleSQL* Parent)
 597 {
 598         for (ConnMap::iterator i = Connections.begin(); i != Connections.end(); i++)
 599         {
 600                 if (i->second->IsEnabled())
 601                         continue;
 602
 603                 i->second->SetEnable(true);
 604                 if (!i->second->Connect())
 605                 {
 606                         /* XXX: MUTEX */
 607                         Parent->LoggingMutex.Lock();
 608                         ServerInstance->Logs->Log("m_mysql",DEFAULT,"SQL: Failed to connect database "+i->second->GetHost()+": Error: "+i->second->GetError());
 609                         i->second->SetEnable(false);
 610                         Parent->LoggingMutex.Unlock();
 611                 }
 612         }
 613 }
 614
 615 void LoadDatabases(ConfigReader* conf, InspIRCd* ServerInstance, ModuleSQL* Parent)
 616 {
 617         Parent->ConnMutex.Lock();
 618         ClearOldConnections(conf);
 619         for (int j =0; j < conf->Enumerate("database"); j++)
 620         {
 621                 SQLhost host;
 622                 host.id         = conf->ReadValue("database", "id", j);
 623                 host.host       = conf->ReadValue("database", "hostname", j);
 624                 host.port       = conf->ReadInteger("database", "port", j, true);
 625                 host.name       = conf->ReadValue("database", "name", j);
 626                 host.user       = conf->ReadValue("database", "username", j);
 627                 host.pass       = conf->ReadValue("database", "password", j);
 628                 host.ssl        = conf->ReadFlag("database", "ssl", j);
 629                 std::string initquery = conf->ReadValue("database", "initialquery", j);
 630
 631                 if (HasHost(host))
 632                         continue;
 633
 634                 if (!host.id.empty() && !host.host.empty() && !host.name.empty() && !host.user.empty() && !host.pass.empty())
 635                 {
 636                         SQLConnection* ThisSQL = new SQLConnection(host, Parent);
 637                         Connections[host.id] = ThisSQL;
 638
 639                         ThisSQL->setInitialQuery(initquery);
 640                 }
 641         }
 642         ConnectDatabases(ServerInstance, Parent);
 643         Parent->ConnMutex.Unlock();
 644 }
 645
 646 char FindCharId(const std::string &id)
 647 {
 648         char i = 1;
 649         for (ConnMap::iterator iter = Connections.begin(); iter != Connections.end(); ++iter, ++i)
 650         {
 651                 if (iter->first == id)
 652                 {
 653                         return i;
 654                 }
 655         }
 656         return 0;
 657 }
 658
 659 ConnMap::iterator GetCharId(char id)
 660 {
 661         char i = 1;
 662         for (ConnMap::iterator iter = Connections.begin(); iter != Connections.end(); ++iter, ++i)
 663         {
 664                 if (i == id)
 665                         return iter;
 666         }
 667         return Connections.end();
 668 }
 669
 670 class ModuleSQL;
 671
 672 class DispatcherThread : public SocketThread
 673 {
 674  private:
 675         ModuleSQL* Parent;
 676         InspIRCd* ServerInstance;
 677  public:
 678         DispatcherThread(InspIRCd* Instance, ModuleSQL* CreatorModule) : SocketThread(Instance), Parent(CreatorModule), ServerInstance(Instance) { }
 679         ~DispatcherThread() { }
 680         virtual void Run();
 681         virtual void OnNotify();
 682 };
 683
 684 ModuleSQL::ModuleSQL(InspIRCd* Me) : Module(Me), rehashing(false)
 685 {
 686         ServerInstance->Modules->UseInterface("SQLutils");
 687
 688         Conf = new ConfigReader(ServerInstance);
 689         PublicServerInstance = ServerInstance;
 690         currid = 0;
 691
 692         Dispatcher = new DispatcherThread(ServerInstance, this);
 693         ServerInstance->Threads->Start(Dispatcher);
 694
 695         if (!ServerInstance->Modules->PublishFeature("SQL", this))
 696         {
 697                 Dispatcher->join();
 698                 delete Dispatcher;
 699                 ServerInstance->Modules->DoneWithInterface("SQLutils");
 700                 throw ModuleException("m_mysql: Unable to publish feature 'SQL'");
 701         }
 702
 703         ServerInstance->Modules->PublishInterface("SQL", this);
 704         Implementation eventlist[] = { I_OnRehash, I_OnRequest };
 705         ServerInstance->Modules->Attach(eventlist, this, 2);
 706 }
 707
 708 ModuleSQL::~ModuleSQL()
 709 {
 710         delete Dispatcher;
 711         ClearAllConnections();
 712         delete Conf;
 713         ServerInstance->Modules->UnpublishInterface("SQL", this);
 714         ServerInstance->Modules->UnpublishFeature("SQL");
 715         ServerInstance->Modules->DoneWithInterface("SQLutils");
 716 }
 717
 718 unsigned long ModuleSQL::NewID()
 719 {
 720         if (currid+1 == 0)
 721                 currid++;
 722         return ++currid;
 723 }
 724
 725 const char* ModuleSQL::OnRequest(Request* request)
 726 {
 727         if(strcmp(SQLREQID, request->GetId()) == 0)
 728         {
 729                 SQLrequest* req = (SQLrequest*)request;
 730
 731                 ConnMap::iterator iter;
 732
 733                 const char* returnval = NULL;
 734
 735                 Dispatcher->LockQueue();
 736                 ConnMutex.Lock();
 737                 if((iter = Connections.find(req->dbid)) != Connections.end())
 738                 {
 739                         req->id = NewID();
 740                         iter->second->queue.push(*req);
 741                         returnval = SQLSUCCESS;
 742                 }
 743                 else
 744                 {
 745                         req->error.Id(SQL_BAD_DBID);
 746                 }
 747
 748                 ConnMutex.Unlock();
 749                 Dispatcher->UnlockQueueWakeup();
 750                 /* Yes, it's possible this will generate a spurious wakeup.
 751                  * That's fine, it'll just get ignored.
 752                  */
 753
 754                 return returnval;
 755         }
 756
 757         return NULL;
 758 }
 759
 760 void ModuleSQL::OnRehash(User* user)
 761 {
 762         Dispatcher->LockQueue();
 763         rehashing = true;
 764         Dispatcher->UnlockQueueWakeup();
 765 }
 766
 767 Version ModuleSQL::GetVersion()
 768 {
 769         return Version("SQL Service Provider module for all other m_sql* modules", VF_VENDOR | VF_SERVICEPROVIDER, API_VERSION);
 770 }
 771
 772 void DispatcherThread::Run()
 773 {
 774         LoadDatabases(Parent->Conf, Parent->PublicServerInstance, Parent);
 775
 776         SQLConnection* conn = NULL;
 777
 778         this->LockQueue();
 779         while (!this->GetExitFlag())
 780         {
 781                 if (Parent->rehashing)
 782                 {
 783                         Parent->rehashing = false;
 784                         LoadDatabases(Parent->Conf, Parent->PublicServerInstance, Parent);
 785                 }
 786
 787                 conn = NULL;
 788                 Parent->ConnMutex.Lock();
 789                 for (ConnMap::iterator i = Connections.begin(); i != Connections.end(); i++)
 790                 {
 791                         if (i->second->queue.totalsize())
 792                         {
 793                                 conn = i->second;
 794                                 break;
 795                         }
 796                 }
 797                 Parent->ConnMutex.Unlock();
 798
 799                 if (conn)
 800                 {
 801                         /* There's an item! */
 802                         this->UnlockQueue();
 803                         conn->DoLeadingQuery();
 804                         this->NotifyParent();
 805                         this->LockQueue();
 806                         conn->queue.pop();
 807                 }
 808                 else
 809                 {
 810                         /* We know the queue is empty, we can safely hang this thread until
 811                          * something happens
 812                          */
 813                         this->WaitForQueue();
 814                 }
 815         }
 816         this->UnlockQueue();
 817 }
 818
 819 void DispatcherThread::OnNotify()
 820 {
 821         SQLConnection* conn;
 822         while (1)
 823         {
 824                 conn = NULL;
 825                 Parent->ConnMutex.Lock();
 826                 for (ConnMap::iterator iter = Connections.begin(); iter != Connections.end(); iter++)
 827                 {
 828                         if (!iter->second->rq.empty())
 829                         {
 830                                 conn = iter->second;
 831                                 break;
 832                         }
 833                 }
 834                 Parent->ConnMutex.Unlock();
 835
 836                 if (!conn)
 837                         break;
 838
 839                 Parent->ResultsMutex.Lock();
 840                 ResultQueue::iterator n = conn->rq.begin();
 841                 Parent->ResultsMutex.Unlock();
 842
 843                 (*n)->Send();
 844                 delete (*n);
 845
 846                 Parent->ResultsMutex.Lock();
 847                 conn->rq.pop_front();
 848                 Parent->ResultsMutex.Unlock();
 849         }
 850 }
 851
 852 MODULE_INIT(ModuleSQL)