src/modules/extra/m_mysql.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd is copyright (C) 2002-2004 ChatSpike-Dev.
   6  *                     E-mail:
   7  *              <brain@chatspike.net>
   8  *                <Craig@chatspike.net>
   9  *
  10  * Written by Craig Edwards, Craig McLure, and others.
  11  * This program is free but copyrighted software; see
  12  *          the file COPYING for details.
  13  *
  14  * ---------------------------------------------------
  15  */
  16
  17 using namespace std;
  18
  19 #include <stdio.h>
  20 #include <string>
  21 #include <mysql.h>
  22 #include <pthread.h>
  23 #include "users.h"
  24 #include "channels.h"
  25 #include "modules.h"
  26 #include "helperfuncs.h"
  27 #include "m_sqlv2.h"
  28
  29 /* VERSION 2 API: With nonblocking (threaded) requests */
  30
  31 /* $ModDesc: SQL Service Provider module for all other m_sql* modules */
  32 /* $CompileFlags: `mysql_config --include` */
  33 /* $LinkerFlags: `mysql_config --libs_r` `perl ../mysql_rpath.pl` */
  34
  35 /* THE NONBLOCKING MYSQL API!
  36  *
  37  * MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
  38  * that instead, you should thread your program. This is what i've done here to allow for
  39  * asyncronous SQL requests via mysql. The way this works is as follows:
  40  *
  41  * The module spawns a thread via pthreads, and performs its mysql queries in this thread,
  42  * using a queue with priorities. There is a mutex on either end which prevents two threads
  43  * adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
  44  * worker thread wakes up, and checks if there is a request at the head of its queue.
  45  * If there is, it processes this request, blocking the worker thread but leaving the ircd
  46  * thread to go about its business as usual. During this period, the ircd thread is able
  47  * to insert futher pending requests into the queue.
  48  *
  49  * Once the processing of a request is complete, it is removed from the incoming queue to
  50  * an outgoing queue, and initialized as a 'response'. The worker thread then signals the
  51  * ircd thread (via a loopback socket) of the fact a result is available, by sending the
  52  * connection ID through the connection.
  53  *
  54  * The ircd thread then mutexes the queue once more, reads the outbound response off the head
  55  * of the queue, and sends it on its way to the original calling module.
  56  *
  57  * XXX: You might be asking "why doesnt he just send the response from within the worker thread?"
  58  * The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
  59  * threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
  60  * however, if we were to call a module's OnRequest even from within a thread which was not the
  61  * one the module was originally instantiated upon, there is a chance of all hell breaking loose
  62  * if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
  63  * corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
  64  * gauranteed threadsafe!)
  65  *
  66  * For a diagram of this system please see http://www.inspircd.org/wiki/Mysql2
  67  */
  68
  69
  70 class SQLConnection;
  71 class Notifier;
  72
  73 extern InspIRCd* ServerInstance;
  74 typedef std::map<std::string, SQLConnection*> ConnMap;
  75 bool giveup = false;
  76 static Module* SQLModule = NULL;
  77 static Notifier* MessagePipe = NULL;
  78 int QueueFD = -1;
  79
  80
  81 #if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
  82 #define mysql_field_count mysql_num_fields
  83 #endif
  84
  85 typedef std::deque<SQLresult*> ResultQueue;
  86
  87 class QueryQueue : public classbase
  88 {
  89 private:
  90         typedef std::deque<SQLrequest> ReqDeque;
  91
  92         ReqDeque priority;      /* The priority queue */
  93         ReqDeque normal;        /* The 'normal' queue */
  94         enum { PRI, NOR, NON } which;   /* Which queue the currently active element is at the front of */
  95
  96 public:
  97         QueryQueue()
  98         : which(NON)
  99         {
 100         }
 101
 102         void push(const SQLrequest &q)
 103         {
 104                 log(DEBUG, "QueryQueue::push(): Adding %s query to queue: %s", ((q.pri) ? "priority" : "non-priority"), q.query.q.c_str());
 105
 106                 if(q.pri)
 107                         priority.push_back(q);
 108                 else
 109                         normal.push_back(q);
 110         }
 111
 112         void pop()
 113         {
 114                 if((which == PRI) && priority.size())
 115                 {
 116                         priority.pop_front();
 117                 }
 118                 else if((which == NOR) && normal.size())
 119                 {
 120                         normal.pop_front();
 121                 }
 122
 123                 /* Reset this */
 124                 which = NON;
 125
 126                 /* Silently do nothing if there was no element to pop() */
 127         }
 128
 129         SQLrequest& front()
 130         {
 131                 switch(which)
 132                 {
 133                         case PRI:
 134                                 return priority.front();
 135                         case NOR:
 136                                 return normal.front();
 137                         default:
 138                                 if(priority.size())
 139                                 {
 140                                         which = PRI;
 141                                         return priority.front();
 142                                 }
 143
 144                                 if(normal.size())
 145                                 {
 146                                         which = NOR;
 147                                         return normal.front();
 148                                 }
 149
 150                                 /* This will probably result in a segfault,
 151                                  * but the caller should have checked totalsize()
 152                                  * first so..meh - moron :p
 153                                  */
 154
 155                                 return priority.front();
 156                 }
 157         }
 158
 159         std::pair<int, int> size()
 160         {
 161                 return std::make_pair(priority.size(), normal.size());
 162         }
 163
 164         int totalsize()
 165         {
 166                 return priority.size() + normal.size();
 167         }
 168
 169         void PurgeModule(Module* mod)
 170         {
 171                 DoPurgeModule(mod, priority);
 172                 DoPurgeModule(mod, normal);
 173         }
 174
 175 private:
 176         void DoPurgeModule(Module* mod, ReqDeque& q)
 177         {
 178                 for(ReqDeque::iterator iter = q.begin(); iter != q.end(); iter++)
 179                 {
 180                         if(iter->GetSource() == mod)
 181                         {
 182                                 if(iter->id == front().id)
 183                                 {
 184                                         /* It's the currently active query.. :x */
 185                                         iter->SetSource(NULL);
 186                                 }
 187                                 else
 188                                 {
 189                                         /* It hasn't been executed yet..just remove it */
 190                                         iter = q.erase(iter);
 191                                 }
 192                         }
 193                 }
 194         }
 195 };
 196
 197 /* A mutex to wrap around queue accesses */
 198 pthread_mutex_t queue_mutex = PTHREAD_MUTEX_INITIALIZER;
 199
 200 pthread_mutex_t results_mutex = PTHREAD_MUTEX_INITIALIZER;
 201
 202 class MySQLresult : public SQLresult
 203 {
 204         int currentrow;
 205         //std::vector<std::map<std::string,std::string> > results;
 206         std::vector<std::string> colnames;
 207         std::vector<SQLfieldList> fieldlists;
 208         SQLfieldMap* fieldmap;
 209         int rows;
 210         int cols;
 211  public:
 212
 213         MySQLresult(Module* self, Module* to, MYSQL_RES* res, int affected_rows, unsigned int id) : SQLresult(self, to, id), currentrow(0), fieldmap(NULL)
 214         {
 215                 /* A number of affected rows from from mysql_affected_rows.
 216                  */
 217                 log(DEBUG,"Created new MySQLresult of non-error type");
 218                 fieldlists.clear();
 219                 rows = 0;
 220                 if (affected_rows >= 1)
 221                 {
 222                         rows = affected_rows;
 223                         fieldlists.resize(rows);
 224                 }
 225                 unsigned int field_count = 0;
 226                 if (res)
 227                 {
 228                         MYSQL_ROW row;
 229                         int n = 0;
 230                         while ((row = mysql_fetch_row(res)))
 231                         {
 232                                 if (fieldlists.size() < (unsigned int)rows+1)
 233                                 {
 234                                         fieldlists.resize(fieldlists.size()+1);
 235                                 }
 236                                 field_count = 0;
 237                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 238                                 if(mysql_num_fields(res) == 0)
 239                                         break;
 240                                 if (fields && mysql_num_fields(res))
 241                                 {
 242                                         colnames.clear();
 243                                         while (field_count < mysql_num_fields(res))
 244                                         {
 245                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 246                                                 std::string b = (row[field_count] ? row[field_count] : "");
 247                                                 SQLfield sqlf(b, !row[field_count]);
 248                                                 colnames.push_back(a);
 249                                                 fieldlists[n].push_back(sqlf);
 250                                                 log(DEBUG,"Inc field count to %d",field_count+1);
 251                                                 field_count++;
 252                                         }
 253                                         n++;
 254                                 }
 255                                 rows++;
 256                         }
 257                         mysql_free_result(res);
 258                 }
 259                 log(DEBUG, "Created new MySQL result; %d rows, %d columns", rows, colnames.size());
 260         }
 261
 262         MySQLresult(Module* self, Module* to, SQLerror e, unsigned int id) : SQLresult(self, to, id), currentrow(0)
 263         {
 264                 rows = 0;
 265                 error = e;
 266                 log(DEBUG,"Created new MySQLresult of error type");
 267         }
 268
 269         ~MySQLresult()
 270         {
 271         }
 272
 273         virtual int Rows()
 274         {
 275                 return rows;
 276         }
 277
 278         virtual int Cols()
 279         {
 280                 return colnames.size();
 281         }
 282
 283         virtual std::string ColName(int column)
 284         {
 285                 if (column < (int)colnames.size())
 286                 {
 287                         return colnames[column];
 288                 }
 289                 else
 290                 {
 291                         throw SQLbadColName();
 292                 }
 293                 return "";
 294         }
 295
 296         virtual int ColNum(const std::string &column)
 297         {
 298                 for (unsigned int i = 0; i < colnames.size(); i++)
 299                 {
 300                         if (column == colnames[i])
 301                                 return i;
 302                 }
 303                 throw SQLbadColName();
 304                 return 0;
 305         }
 306
 307         virtual SQLfield GetValue(int row, int column)
 308         {
 309                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < Cols()))
 310                 {
 311                         return fieldlists[row][column];
 312                 }
 313
 314                 log(DEBUG,"Danger will robinson, we don't have row %d, column %d!", row, column);
 315                 throw SQLbadColName();
 316
 317                 /* XXX: We never actually get here because of the throw */
 318                 return SQLfield("",true);
 319         }
 320
 321         virtual SQLfieldList& GetRow()
 322         {
 323                 return fieldlists[currentrow];
 324         }
 325
 326         virtual SQLfieldMap& GetRowMap()
 327         {
 328                 fieldmap = new SQLfieldMap();
 329
 330                 for (int i = 0; i < cols; i++)
 331                 {
 332                         fieldmap->insert(std::make_pair(colnames[cols],GetValue(currentrow, i)));
 333                 }
 334                 currentrow++;
 335
 336                 return *fieldmap;
 337         }
 338
 339         virtual SQLfieldList* GetRowPtr()
 340         {
 341                 return &fieldlists[currentrow++];
 342         }
 343
 344         virtual SQLfieldMap* GetRowMapPtr()
 345         {
 346                 fieldmap = new SQLfieldMap();
 347
 348                 for (int i = 0; i < cols; i++)
 349                 {
 350                         fieldmap->insert(std::make_pair(colnames[cols],GetValue(currentrow, i)));
 351                 }
 352                 currentrow++;
 353
 354                 return fieldmap;
 355         }
 356
 357         virtual void Free(SQLfieldMap* fm)
 358         {
 359                 delete fm;
 360         }
 361
 362         virtual void Free(SQLfieldList* fl)
 363         {
 364                 /* XXX: Yes, this is SUPPOSED to do nothing, we
 365                  * dont want to free our fieldlist until we
 366                  * destruct the object. Unlike the pgsql module,
 367                  * we only have the one.
 368                  */
 369         }
 370 };
 371
 372 class SQLConnection;
 373
 374 void NotifyMainThread(SQLConnection* connection_with_new_result);
 375
 376 class SQLConnection : public classbase
 377 {
 378  protected:
 379
 380         MYSQL connection;
 381         MYSQL_RES *res;
 382         MYSQL_ROW row;
 383         std::string host;
 384         std::string user;
 385         std::string pass;
 386         std::string db;
 387         std::map<std::string,std::string> thisrow;
 388         bool Enabled;
 389         std::string id;
 390
 391  public:
 392
 393         QueryQueue queue;
 394         ResultQueue rq;
 395
 396         // This constructor creates an SQLConnection object with the given credentials, and creates the underlying
 397         // MYSQL struct, but does not connect yet.
 398         SQLConnection(std::string thishost, std::string thisuser, std::string thispass, std::string thisdb, const std::string &myid)
 399         {
 400                 this->Enabled = true;
 401                 this->host = thishost;
 402                 this->user = thisuser;
 403                 this->pass = thispass;
 404                 this->db = thisdb;
 405                 this->id = myid;
 406         }
 407
 408         // This method connects to the database using the credentials supplied to the constructor, and returns
 409         // true upon success.
 410         bool Connect()
 411         {
 412                 unsigned int timeout = 1;
 413                 mysql_init(&connection);
 414                 mysql_options(&connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 415                 return mysql_real_connect(&connection, host.c_str(), user.c_str(), pass.c_str(), db.c_str(), 0, NULL, 0);
 416         }
 417
 418         void DoLeadingQuery()
 419         {
 420                 if (!CheckConnection())
 421                         return;
 422
 423                 /* Parse the command string and dispatch it to mysql */
 424                 SQLrequest& req = queue.front();
 425                 log(DEBUG,"DO QUERY: %s",req.query.q.c_str());
 426
 427                 /* Pointer to the buffer we screw around with substitution in */
 428                 char* query;
 429
 430                 /* Pointer to the current end of query, where we append new stuff */
 431                 char* queryend;
 432
 433                 /* Total length of the unescaped parameters */
 434                 unsigned long paramlen;
 435
 436                 /* Total length of query, used for binary-safety in mysql_real_query */
 437                 unsigned long querylength = 0;
 438
 439                 paramlen = 0;
 440
 441                 for(ParamL::iterator i = req.query.p.begin(); i != req.query.p.end(); i++)
 442                 {
 443                         paramlen += i->size();
 444                 }
 445
 446                 /* To avoid a lot of allocations, allocate enough memory for the biggest the escaped query could possibly be.
 447                  * sizeofquery + (totalparamlength*2) + 1
 448                  *
 449                  * The +1 is for null-terminating the string for mysql_real_escape_string
 450                  */
 451
 452                 query = new char[req.query.q.length() + (paramlen*2)];
 453                 queryend = query;
 454
 455                 /* Okay, now we have a buffer large enough we need to start copying the query into it and escaping and substituting
 456                  * the parameters into it...
 457                  */
 458
 459                 for(unsigned long i = 0; i < req.query.q.length(); i++)
 460                 {
 461                         if(req.query.q[i] == '?')
 462                         {
 463                                 /* We found a place to substitute..what fun.
 464                                  * use mysql calls to escape and write the
 465                                  * escaped string onto the end of our query buffer,
 466                                  * then we "just" need to make sure queryend is
 467                                  * pointing at the right place.
 468                                  */
 469                                 if(req.query.p.size())
 470                                 {
 471                                         unsigned long len = mysql_real_escape_string(&connection, queryend, req.query.p.front().c_str(), req.query.p.front().length());
 472
 473                                         queryend += len;
 474                                         req.query.p.pop_front();
 475                                 }
 476                                 else
 477                                 {
 478                                         log(DEBUG, "Found a substitution location but no parameter to substitute :|");
 479                                         break;
 480                                 }
 481                         }
 482                         else
 483                         {
 484                                 *queryend = req.query.q[i];
 485                                 queryend++;
 486                         }
 487                         querylength++;
 488                 }
 489
 490                 *queryend = 0;
 491
 492                 log(DEBUG, "Attempting to dispatch query: %s", query);
 493
 494                 pthread_mutex_lock(&queue_mutex);
 495                 req.query.q = query;
 496                 pthread_mutex_unlock(&queue_mutex);
 497
 498                 log(DEBUG,"REQUEST ID: %d",req.id);
 499
 500                 if (!mysql_real_query(&connection, req.query.q.data(), req.query.q.length()))
 501                 {
 502                         /* Successfull query */
 503                         res = mysql_use_result(&connection);
 504                         unsigned long rows = mysql_affected_rows(&connection);
 505                         MySQLresult* r = new MySQLresult(SQLModule, req.GetSource(), res, rows, req.id);
 506                         r->dbid = this->GetID();
 507                         r->query = req.query.q;
 508                         /* Put this new result onto the results queue.
 509                          * XXX: Remember to mutex the queue!
 510                          */
 511                         pthread_mutex_lock(&results_mutex);
 512                         rq.push_back(r);
 513                         pthread_mutex_unlock(&results_mutex);
 514                 }
 515                 else
 516                 {
 517                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 518                          * possible error numbers and error messages */
 519                         log(DEBUG,"SQL ERROR: %s",mysql_error(&connection));
 520                         SQLerror e(QREPLY_FAIL, ConvToStr(mysql_errno(&connection)) + std::string(": ") + mysql_error(&connection));
 521                         MySQLresult* r = new MySQLresult(SQLModule, req.GetSource(), e, req.id);
 522                         r->dbid = this->GetID();
 523                         r->query = req.query.q;
 524
 525                         pthread_mutex_lock(&results_mutex);
 526                         rq.push_back(r);
 527                         pthread_mutex_unlock(&results_mutex);
 528                 }
 529
 530                 /* Now signal the main thread that we've got a result to process.
 531                  * Pass them this connection id as what to examine
 532                  */
 533
 534                 NotifyMainThread(this);
 535         }
 536
 537         bool ConnectionLost()
 538         {
 539                 if (&connection) {
 540                         return (mysql_ping(&connection) != 0);
 541                 }
 542                 else return false;
 543         }
 544
 545         bool CheckConnection()
 546         {
 547                 if (ConnectionLost()) {
 548                         return Connect();
 549                 }
 550                 else return true;
 551         }
 552
 553         std::string GetError()
 554         {
 555                 return mysql_error(&connection);
 556         }
 557
 558         const std::string& GetID()
 559         {
 560                 return id;
 561         }
 562
 563         std::string GetHost()
 564         {
 565                 return host;
 566         }
 567
 568         void SetEnable(bool Enable)
 569         {
 570                 Enabled = Enable;
 571         }
 572
 573         bool IsEnabled()
 574         {
 575                 return Enabled;
 576         }
 577
 578 };
 579
 580 ConnMap Connections;
 581
 582 void ConnectDatabases(Server* Srv)
 583 {
 584         for (ConnMap::iterator i = Connections.begin(); i != Connections.end(); i++)
 585         {
 586                 i->second->SetEnable(true);
 587                 if (i->second->Connect())
 588                 {
 589                         Srv->Log(DEFAULT,"SQL: Successfully connected database "+i->second->GetHost());
 590                 }
 591                 else
 592                 {
 593                         Srv->Log(DEFAULT,"SQL: Failed to connect database "+i->second->GetHost()+": Error: "+i->second->GetError());
 594                         i->second->SetEnable(false);
 595                 }
 596         }
 597 }
 598
 599
 600 void LoadDatabases(ConfigReader* ThisConf, Server* Srv)
 601 {
 602         Srv->Log(DEFAULT,"SQL: Loading database settings");
 603         Connections.clear();
 604         Srv->Log(DEBUG,"Cleared connections");
 605         for (int j =0; j < ThisConf->Enumerate("database"); j++)
 606         {
 607                 std::string db = ThisConf->ReadValue("database","name",j);
 608                 std::string user = ThisConf->ReadValue("database","username",j);
 609                 std::string pass = ThisConf->ReadValue("database","password",j);
 610                 std::string host = ThisConf->ReadValue("database","hostname",j);
 611                 std::string id = ThisConf->ReadValue("database","id",j);
 612                 Srv->Log(DEBUG,"Read database settings");
 613                 if ((db != "") && (host != "") && (user != "") && (id != "") && (pass != ""))
 614                 {
 615                         SQLConnection* ThisSQL = new SQLConnection(host,user,pass,db,id);
 616                         Srv->Log(DEFAULT,"Loaded database: "+ThisSQL->GetHost());
 617                         Connections[id] = ThisSQL;
 618                         Srv->Log(DEBUG,"Pushed back connection");
 619                 }
 620         }
 621         ConnectDatabases(Srv);
 622 }
 623
 624 void NotifyMainThread(SQLConnection* connection_with_new_result)
 625 {
 626         /* Here we write() to the socket the main thread has open
 627          * and we connect()ed back to before our thread became active.
 628          * The main thread is using a nonblocking socket tied into
 629          * the socket engine, so they wont block and they'll receive
 630          * nearly instant notification. Because we're in a seperate
 631          * thread, we can just use standard connect(), and we can
 632          * block if we like. We just send the connection id of the
 633          * connection back.
 634          */
 635         log(DEBUG,"Notify of result on connection: %s",connection_with_new_result->GetID().c_str());
 636         if (send(QueueFD, connection_with_new_result->GetID().c_str(), connection_with_new_result->GetID().length()+1, 0) < 1) // add one for null terminator
 637         {
 638                 log(DEBUG,"Error writing to QueueFD: %s",strerror(errno));
 639         }
 640         log(DEBUG,"Sent it on its way via fd=%d",QueueFD);
 641 }
 642
 643 void* DispatcherThread(void* arg);
 644
 645 class Notifier : public InspSocket
 646 {
 647         sockaddr_in sock_us;
 648         socklen_t uslen;
 649         Server* Srv;
 650
 651  public:
 652
 653         /* Create a socket on a random port. Let the tcp stack allocate us an available port */
 654         Notifier(Server* S) : InspSocket("127.0.0.1", 0, true, 3000), Srv(S)
 655         {
 656                 uslen = sizeof(sock_us);
 657                 if (getsockname(this->fd,(sockaddr*)&sock_us,&uslen))
 658                 {
 659                         throw ModuleException("Could not create random listening port on localhost");
 660                 }
 661         }
 662
 663         Notifier(int newfd, char* ip, Server* S) : InspSocket(newfd, ip), Srv(S)
 664         {
 665                 log(DEBUG,"Constructor of new socket");
 666         }
 667
 668         /* Using getsockname and ntohs, we can determine which port number we were allocated */
 669         int GetPort()
 670         {
 671                 return ntohs(sock_us.sin_port);
 672         }
 673
 674         virtual int OnIncomingConnection(int newsock, char* ip)
 675         {
 676                 log(DEBUG,"Inbound connection on fd %d!",newsock);
 677                 Notifier* n = new Notifier(newsock, ip, Srv);
 678                 Srv->AddSocket(n);
 679                 return true;
 680         }
 681
 682         virtual bool OnDataReady()
 683         {
 684                 log(DEBUG,"Inbound data!");
 685                 char* data = this->Read();
 686                 ConnMap::iterator iter;
 687
 688                 if (data && *data)
 689                 {
 690                         log(DEBUG,"Looking for connection %s",data);
 691                         /* We expect to be sent a null terminated string */
 692                         if((iter = Connections.find(data)) != Connections.end())
 693                         {
 694                                 log(DEBUG,"Found it!");
 695
 696                                 /* Lock the mutex, send back the data */
 697                                 pthread_mutex_lock(&results_mutex);
 698                                 ResultQueue::iterator n = iter->second->rq.begin();
 699                                 (*n)->Send();
 700                                 iter->second->rq.pop_front();
 701                                 pthread_mutex_unlock(&results_mutex);
 702                                 return true;
 703                         }
 704                 }
 705
 706                 return false;
 707         }
 708 };
 709
 710 class ModuleSQL : public Module
 711 {
 712  public:
 713         Server *Srv;
 714         ConfigReader *Conf;
 715         pthread_t Dispatcher;
 716         int currid;
 717
 718         void Implements(char* List)
 719         {
 720                 List[I_OnRehash] = List[I_OnRequest] = 1;
 721         }
 722
 723         unsigned long NewID()
 724         {
 725                 if (currid+1 == 0)
 726                         currid++;
 727                 return ++currid;
 728         }
 729
 730         char* OnRequest(Request* request)
 731         {
 732                 if(strcmp(SQLREQID, request->GetData()) == 0)
 733                 {
 734                         SQLrequest* req = (SQLrequest*)request;
 735
 736                         /* XXX: Lock */
 737                         pthread_mutex_lock(&queue_mutex);
 738
 739                         ConnMap::iterator iter;
 740
 741                         char* returnval = NULL;
 742
 743                         log(DEBUG, "Got query: '%s' with %d replacement parameters on id '%s'", req->query.q.c_str(), req->query.p.size(), req->dbid.c_str());
 744
 745                         if((iter = Connections.find(req->dbid)) != Connections.end())
 746                         {
 747                                 req->id = NewID();
 748                                 iter->second->queue.push(*req);
 749                                 returnval = SQLSUCCESS;
 750                         }
 751                         else
 752                         {
 753                                 req->error.Id(BAD_DBID);
 754                         }
 755
 756                         pthread_mutex_unlock(&queue_mutex);
 757                         /* XXX: Unlock */
 758
 759                         return returnval;
 760                 }
 761
 762                 log(DEBUG, "Got unsupported API version string: %s", request->GetData());
 763
 764                 return NULL;
 765         }
 766
 767         ModuleSQL(Server* Me)
 768                 : Module::Module(Me)
 769         {
 770                 Srv = Me;
 771                 Conf = new ConfigReader();
 772                 currid = 0;
 773                 SQLModule = this;
 774
 775                 MessagePipe = new Notifier(Srv);
 776                 Srv->AddSocket(MessagePipe);
 777                 log(DEBUG,"Bound notifier to 127.0.0.1:%d",MessagePipe->GetPort());
 778
 779                 pthread_attr_t attribs;
 780                 pthread_attr_init(&attribs);
 781                 pthread_attr_setdetachstate(&attribs, PTHREAD_CREATE_DETACHED);
 782                 if (pthread_create(&this->Dispatcher, &attribs, DispatcherThread, (void *)this) != 0)
 783                 {
 784                         throw ModuleException("m_mysql: Failed to create dispatcher thread: " + std::string(strerror(errno)));
 785                 }
 786                 if (!Srv->PublishFeature("SQL", this))
 787                 {
 788                         /* Tell worker thread to exit NOW */
 789                         giveup = true;
 790                         throw ModuleException("m_mysql: Unable to publish feature 'SQL'");
 791                 }
 792         }
 793
 794         virtual ~ModuleSQL()
 795         {
 796                 DELETE(Conf);
 797         }
 798
 799         virtual void OnRehash(const std::string &parameter)
 800         {
 801                 /* TODO: set rehash bool here, which makes the dispatcher thread rehash at next opportunity */
 802         }
 803
 804         virtual Version GetVersion()
 805         {
 806                 return Version(1,1,0,0,VF_VENDOR|VF_SERVICEPROVIDER);
 807         }
 808
 809 };
 810
 811 void* DispatcherThread(void* arg)
 812 {
 813         log(DEBUG,"Starting Dispatcher thread, mysql version %d",mysql_get_client_version());
 814         ModuleSQL* thismodule = (ModuleSQL*)arg;
 815         LoadDatabases(thismodule->Conf, thismodule->Srv);
 816
 817         /* Connect back to the Notifier */
 818
 819         if ((QueueFD = socket(AF_INET, SOCK_STREAM, 0)) == -1)
 820         {
 821                 /* crap, we're out of sockets... */
 822                 log(DEBUG,"QueueFD cant be created");
 823                 return NULL;
 824         }
 825
 826         log(DEBUG,"Initialize QueueFD to %d",QueueFD);
 827
 828         sockaddr_in addr;
 829         in_addr ia;
 830         inet_aton("127.0.0.1", &ia);
 831         addr.sin_family = AF_INET;
 832         addr.sin_addr = ia;
 833         addr.sin_port = htons(MessagePipe->GetPort());
 834
 835         if (connect(QueueFD, (sockaddr*)&addr,sizeof(addr)) == -1)
 836         {
 837                 /* wtf, we cant connect to it, but we just created it! */
 838                 log(DEBUG,"QueueFD cant connect!");
 839                 return NULL;
 840         }
 841
 842         log(DEBUG,"Connect QUEUE FD");
 843
 844         while (!giveup)
 845         {
 846                 SQLConnection* conn = NULL;
 847                 /* XXX: Lock here for safety */
 848                 pthread_mutex_lock(&queue_mutex);
 849                 for (ConnMap::iterator i = Connections.begin(); i != Connections.end(); i++)
 850                 {
 851                         if (i->second->queue.totalsize())
 852                         {
 853                                 conn = i->second;
 854                                 break;
 855                         }
 856                 }
 857                 pthread_mutex_unlock(&queue_mutex);
 858                 /* XXX: Unlock */
 859
 860                 /* Theres an item! */
 861                 if (conn)
 862                 {
 863                         log(DEBUG,"Process Leading query");
 864                         conn->DoLeadingQuery();
 865
 866                         /* XXX: Lock */
 867                         pthread_mutex_lock(&queue_mutex);
 868                         conn->queue.pop();
 869                         pthread_mutex_unlock(&queue_mutex);
 870                         /* XXX: Unlock */
 871                 }
 872
 873                 usleep(50);
 874         }
 875
 876         return NULL;
 877 }
 878
 879
 880 // stuff down here is the module-factory stuff. For basic modules you can ignore this.
 881
 882 class ModuleSQLFactory : public ModuleFactory
 883 {
 884  public:
 885         ModuleSQLFactory()
 886         {
 887         }
 888
 889         ~ModuleSQLFactory()
 890         {
 891         }
 892
 893         virtual Module * CreateModule(Server* Me)
 894         {
 895                 return new ModuleSQL(Me);
 896         }
 897
 898 };
 899
 900
 901 extern "C" void * init_module( void )
 902 {
 903         return new ModuleSQLFactory;
 904 }
 905