src/modules/extra/m_mysql.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2010 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 "sql.h"
  20
  21 #ifdef WINDOWS
  22 #pragma comment(lib, "mysqlclient.lib")
  23 #endif
  24
  25 /* VERSION 3 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 class SQLConnection;
  67 class MySQLresult;
  68 class DispatcherThread;
  69
  70 struct QueueItem
  71 {
  72         SQLQuery* q;
  73         SQLConnection* c;
  74         QueueItem(SQLQuery* Q, SQLConnection* C) : q(Q), c(C) {}
  75 };
  76
  77 typedef std::map<std::string, SQLConnection*> ConnMap;
  78 typedef std::deque<QueueItem> QueryQueue;
  79 typedef std::deque<MySQLresult*> ResultQueue;
  80
  81 /** MySQL module
  82  *  */
  83 class ModuleSQL : public Module
  84 {
  85  public:
  86         DispatcherThread* Dispatcher;
  87         QueryQueue qq;
  88         ResultQueue rq;
  89         ConnMap connections;
  90
  91         ModuleSQL();
  92         void init();
  93         ~ModuleSQL();
  94         void OnRehash(User* user);
  95         Version GetVersion();
  96 };
  97
  98 class DispatcherThread : public SocketThread
  99 {
 100  private:
 101         ModuleSQL* const Parent;
 102  public:
 103         DispatcherThread(ModuleSQL* CreatorModule) : Parent(CreatorModule) { }
 104         ~DispatcherThread() { }
 105         virtual void Run();
 106         virtual void OnNotify();
 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  public:
 118         SQLQuery* query;
 119         SQLerror err;
 120         int currentrow;
 121         int rows;
 122         std::vector<std::string> colnames;
 123         std::vector<SQLEntries> fieldlists;
 124
 125         MySQLresult(SQLQuery* q, MYSQL_RES* res, int affected_rows) : query(q), err(SQL_NO_ERROR), currentrow(0), rows(0)
 126         {
 127                 if (affected_rows >= 1)
 128                 {
 129                         rows = affected_rows;
 130                         fieldlists.resize(rows);
 131                 }
 132                 unsigned int field_count = 0;
 133                 if (res)
 134                 {
 135                         MYSQL_ROW row;
 136                         int n = 0;
 137                         while ((row = mysql_fetch_row(res)))
 138                         {
 139                                 if (fieldlists.size() < (unsigned int)rows+1)
 140                                 {
 141                                         fieldlists.resize(fieldlists.size()+1);
 142                                 }
 143                                 field_count = 0;
 144                                 MYSQL_FIELD *fields = mysql_fetch_fields(res);
 145                                 if(mysql_num_fields(res) == 0)
 146                                         break;
 147                                 if (fields && mysql_num_fields(res))
 148                                 {
 149                                         colnames.clear();
 150                                         while (field_count < mysql_num_fields(res))
 151                                         {
 152                                                 std::string a = (fields[field_count].name ? fields[field_count].name : "");
 153                                                 if (row[field_count])
 154                                                         fieldlists[n].push_back(SQLEntry(row[field_count]));
 155                                                 else
 156                                                         fieldlists[n].push_back(SQLEntry());
 157                                                 colnames.push_back(a);
 158                                                 field_count++;
 159                                         }
 160                                         n++;
 161                                 }
 162                                 rows++;
 163                         }
 164                         mysql_free_result(res);
 165                         res = NULL;
 166                 }
 167         }
 168
 169         MySQLresult(SQLQuery* q, SQLerror& e) : query(q), err(e)
 170         {
 171
 172         }
 173
 174         ~MySQLresult()
 175         {
 176         }
 177
 178         virtual int Rows()
 179         {
 180                 return rows;
 181         }
 182
 183         virtual void GetCols(std::vector<std::string>& result)
 184         {
 185                 result.assign(colnames.begin(), colnames.end());
 186         }
 187
 188         virtual SQLEntry GetValue(int row, int column)
 189         {
 190                 if ((row >= 0) && (row < rows) && (column >= 0) && (column < (int)fieldlists[row].size()))
 191                 {
 192                         return fieldlists[row][column];
 193                 }
 194                 return SQLEntry();
 195         }
 196
 197         virtual bool GetRow(SQLEntries& result)
 198         {
 199                 if (currentrow < rows)
 200                 {
 201                         result.assign(fieldlists[currentrow].begin(), fieldlists[currentrow].end());
 202                         currentrow++;
 203                         return true;
 204                 }
 205                 else
 206                 {
 207                         result.clear();
 208                         return false;
 209                 }
 210         }
 211 };
 212
 213 /** Represents a connection to a mysql database
 214  */
 215 class SQLConnection : public SQLProvider
 216 {
 217  public:
 218         reference<ConfigTag> config;
 219         MYSQL *connection;
 220         bool active;
 221
 222         // This constructor creates an SQLConnection object with the given credentials, but does not connect yet.
 223         SQLConnection(Module* p, ConfigTag* tag) : SQLProvider(p, "SQL/" + tag->getString("id")),
 224                 config(tag), active(false)
 225         {
 226         }
 227
 228         ~SQLConnection()
 229         {
 230                 Close();
 231         }
 232
 233         // This method connects to the database using the credentials supplied to the constructor, and returns
 234         // true upon success.
 235         bool Connect()
 236         {
 237                 unsigned int timeout = 1;
 238                 connection = mysql_init(connection);
 239                 mysql_options(connection,MYSQL_OPT_CONNECT_TIMEOUT,(char*)&timeout);
 240                 std::string host = config->getString("host");
 241                 std::string user = config->getString("user");
 242                 std::string pass = config->getString("pass");
 243                 std::string dbname = config->getString("name");
 244                 int port = config->getInt("port");
 245                 bool rv = mysql_real_connect(connection, host.c_str(), user.c_str(), pass.c_str(), dbname.c_str(), port, NULL, 0);
 246                 if (!rv)
 247                         return rv;
 248                 std::string initquery;
 249                 if (config->readString("initialquery", initquery))
 250                 {
 251                         mysql_query(connection,initquery.c_str());
 252                 }
 253                 return true;
 254         }
 255
 256         virtual std::string FormatQuery(const std::string& q, const ParamL& p)
 257         {
 258                 std::string res;
 259                 unsigned int param = 0;
 260                 for(std::string::size_type i = 0; i < q.length(); i++)
 261                 {
 262                         if (q[i] != '?')
 263                                 res.push_back(q[i]);
 264                         else
 265                         {
 266                                 // TODO numbered parameter support ('?1')
 267                                 if (param < p.size())
 268                                 {
 269                                         std::string parm = p[param++];
 270                                         char buffer[MAXBUF];
 271                                         mysql_escape_string(buffer, parm.c_str(), parm.length());
 272 //                                      mysql_real_escape_string(connection, queryend, paramscopy[paramnum].c_str(), paramscopy[paramnum].length());
 273                                         res.append(buffer);
 274                                 }
 275                         }
 276                 }
 277                 return res;
 278         }
 279
 280         std::string FormatQuery(const std::string& q, const ParamM& p)
 281         {
 282                 std::string res;
 283                 for(std::string::size_type i = 0; i < q.length(); i++)
 284                 {
 285                         if (q[i] != '$')
 286                                 res.push_back(q[i]);
 287                         else
 288                         {
 289                                 std::string field;
 290                                 i++;
 291                                 while (i < q.length() && isalpha(q[i]))
 292                                         field.push_back(q[i++]);
 293                                 i--;
 294
 295                                 ParamM::const_iterator it = p.find(field);
 296                                 if (it != p.end())
 297                                 {
 298                                         std::string parm = it->second;
 299                                         char buffer[MAXBUF];
 300                                         mysql_escape_string(buffer, parm.c_str(), parm.length());
 301                                         res.append(buffer);
 302                                 }
 303                         }
 304                 }
 305                 return res;
 306         }
 307
 308         ModuleSQL* Parent()
 309         {
 310                 return (ModuleSQL*)(Module*)creator;
 311         }
 312
 313         void DoBlockingQuery(SQLQuery* req)
 314         {
 315                 /* Parse the command string and dispatch it to mysql */
 316                 if (CheckConnection() && !mysql_real_query(connection, req->query.data(), req->query.length()))
 317                 {
 318                         /* Successfull query */
 319                         MYSQL_RES* res = mysql_use_result(connection);
 320                         unsigned long rows = mysql_affected_rows(connection);
 321                         MySQLresult* r = new MySQLresult(req, res, rows);
 322                         Parent()->Dispatcher->LockQueue();
 323                         Parent()->rq.push_back(r);
 324                         Parent()->Dispatcher->NotifyParent();
 325                         Parent()->Dispatcher->UnlockQueue();
 326                 }
 327                 else
 328                 {
 329                         /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
 330                          * possible error numbers and error messages */
 331                         SQLerror e(SQL_QREPLY_FAIL, ConvToStr(mysql_errno(connection)) + std::string(": ") + mysql_error(connection));
 332                         MySQLresult* r = new MySQLresult(req, e);
 333                         Parent()->Dispatcher->LockQueue();
 334                         Parent()->rq.push_back(r);
 335                         Parent()->Dispatcher->NotifyParent();
 336                         Parent()->Dispatcher->UnlockQueue();
 337                 }
 338         }
 339
 340         bool CheckConnection()
 341         {
 342                 if (mysql_ping(connection) != 0)
 343                 {
 344                         return Connect();
 345                 }
 346                 else return true;
 347         }
 348
 349         std::string GetError()
 350         {
 351                 return mysql_error(connection);
 352         }
 353
 354         void Close()
 355         {
 356                 mysql_close(connection);
 357         }
 358
 359         void submit(SQLQuery* q)
 360         {
 361                 Parent()->Dispatcher->LockQueue();
 362                 Parent()->qq.push_back(QueueItem(q, this));
 363                 Parent()->Dispatcher->UnlockQueueWakeup();
 364         }
 365 };
 366
 367 ModuleSQL::ModuleSQL()
 368 {
 369         Dispatcher = NULL;
 370 }
 371
 372 void ModuleSQL::init()
 373 {
 374         Dispatcher = new DispatcherThread(this);
 375         ServerInstance->Threads->Start(Dispatcher);
 376
 377         Implementation eventlist[] = { I_OnRehash };
 378         ServerInstance->Modules->Attach(eventlist, this, 1);
 379 }
 380
 381 ModuleSQL::~ModuleSQL()
 382 {
 383         if (Dispatcher)
 384         {
 385                 Dispatcher->join();
 386                 Dispatcher->OnNotify();
 387                 delete Dispatcher;
 388         }
 389         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 390         {
 391                 delete i->second;
 392         }
 393 }
 394
 395 void ModuleSQL::OnRehash(User* user)
 396 {
 397         Dispatcher->LockQueue();
 398         ConnMap conns;
 399         ConfigTagList tags = ServerInstance->Config->ConfTags("database");
 400         for(ConfigIter i = tags.first; i != tags.second; i++)
 401         {
 402                 if (i->second->getString("module", "mysql") != "mysql")
 403                         continue;
 404                 std::string id = i->second->getString("id");
 405                 ConnMap::iterator curr = connections.find(id);
 406                 if (curr == connections.end())
 407                 {
 408                         SQLConnection* conn = new SQLConnection(this, i->second);
 409                         conns.insert(std::make_pair(id, conn));
 410                         ServerInstance->Modules->AddService(*conn);
 411                 }
 412                 else
 413                 {
 414                         conns.insert(*curr);
 415                         connections.erase(curr);
 416                 }
 417         }
 418         for(ConnMap::iterator i = connections.begin(); i != connections.end(); i++)
 419         {
 420                 if (i->second->active)
 421                 {
 422                         // can't delete it now. Next rehash will try to kill it again
 423                         conns.insert(*i);
 424                 }
 425                 else
 426                 {
 427                         ServerInstance->Modules->DelService(*i->second);
 428                         delete i->second;
 429                 }
 430         }
 431         connections.swap(conns);
 432         Dispatcher->UnlockQueue();
 433 }
 434
 435 Version ModuleSQL::GetVersion()
 436 {
 437         return Version("MySQL support", VF_VENDOR);
 438 }
 439
 440 void DispatcherThread::Run()
 441 {
 442         this->LockQueue();
 443         while (!this->GetExitFlag())
 444         {
 445                 if (!Parent->qq.empty())
 446                 {
 447                         QueueItem i = Parent->qq.front();
 448                         Parent->qq.pop_front();
 449                         i.c->active = true;
 450                         this->UnlockQueue();
 451                         i.c->DoBlockingQuery(i.q);
 452                         this->LockQueue();
 453                         i.c->active = false;
 454                 }
 455                 else
 456                 {
 457                         /* We know the queue is empty, we can safely hang this thread until
 458                          * something happens
 459                          */
 460                         this->WaitForQueue();
 461                 }
 462         }
 463         this->UnlockQueue();
 464 }
 465
 466 void DispatcherThread::OnNotify()
 467 {
 468         // this could unlock during the dispatch, but OnResult isn't expected to take that long
 469         this->LockQueue();
 470         for(ResultQueue::iterator i = Parent->rq.begin(); i != Parent->rq.end(); i++)
 471         {
 472                 MySQLresult* res = *i;
 473                 if (res->err.id == SQL_NO_ERROR)
 474                         res->query->OnResult(*res);
 475                 else
 476                         res->query->OnError(res->err);
 477                 delete res->query;
 478                 delete res;
 479         }
 480         Parent->rq.clear();
 481         this->UnlockQueue();
 482 }
 483
 484 MODULE_INIT(ModuleSQL)