/* $CompileFlags: `mysql_config --include` */
/* $LinkerFlags: `mysql_config --libs_r` `perl ../mysql_rpath.pl` */
+/* THE NONBLOCKING MYSQL API!
+ *
+ * MySQL provides no nonblocking (asyncronous) API of its own, and its developers recommend
+ * that instead, you should thread your program. This is what i've done here to allow for
+ * asyncronous SQL requests via mysql. The way this works is as follows:
+ *
+ * The module spawns a thread via pthreads, and performs its mysql queries in this thread,
+ * using a queue with priorities. There is a mutex on either end which prevents two threads
+ * adjusting the queue at the same time, and crashing the ircd. Every 50 milliseconds, the
+ * worker thread wakes up, and checks if there is a request at the head of its queue.
+ * If there is, it processes this request, blocking the worker thread but leaving the ircd
+ * thread to go about its business as usual. During this period, the ircd thread is able
+ * to insert futher pending requests into the queue.
+ *
+ * Once the processing of a request is complete, it is removed from the incoming queue to
+ * an outgoing queue, and initialized as a 'response'. The worker thread then signals the
+ * ircd thread (via a loopback socket) of the fact a result is available, by sending the
+ * connection ID through the connection.
+ *
+ * The ircd thread then mutexes the queue once more, reads the outbound response off the head
+ * of the queue, and sends it on its way to the original calling module.
+ *
+ * XXX: You might be asking "why doesnt he just send the response from within the worker thread?"
+ * The answer to this is simple. The majority of InspIRCd, and in fact most ircd's are not
+ * threadsafe. This module is designed to be threadsafe and is careful with its use of threads,
+ * however, if we were to call a module's OnRequest even from within a thread which was not the
+ * one the module was originally instantiated upon, there is a chance of all hell breaking loose
+ * if a module is ever put in a re-enterant state (stack corruption could occur, crashes, data
+ * corruption, and worse, so DONT think about it until the day comes when InspIRCd is 100%
+ * gauranteed threadsafe!)
+ *
+ * For a diagram of this system please see http://www.inspircd.org/wiki/Mysql2
+ */
+
class SQLConnection;
+class Notifier;
extern InspIRCd* ServerInstance;
typedef std::map<std::string, SQLConnection*> ConnMap;
bool giveup = false;
+static Module* SQLModule = NULL;
+static Notifier* MessagePipe = NULL;
+int QueueFD = -1;
#if !defined(MYSQL_VERSION_ID) || MYSQL_VERSION_ID<32224
#define mysql_field_count mysql_num_fields
#endif
+typedef std::deque<SQLresult*> ResultQueue;
+
class QueryQueue : public classbase
{
private:
/* A mutex to wrap around queue accesses */
pthread_mutex_t queue_mutex = PTHREAD_MUTEX_INITIALIZER;
+pthread_mutex_t results_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+class MySQLresult : public SQLresult
+{
+ int currentrow;
+ //std::vector<std::map<std::string,std::string> > results;
+ std::vector<std::string> colnames;
+ std::vector<SQLfieldList> fieldlists;
+ SQLfieldMap* fieldmap;
+ int rows;
+ int cols;
+ public:
+
+ MySQLresult(Module* self, Module* to, MYSQL_RES* res, int affected_rows, unsigned int id) : SQLresult(self, to, id), currentrow(0), fieldmap(NULL)
+ {
+ /* A number of affected rows from from mysql_affected_rows.
+ */
+ log(DEBUG,"Created new MySQLresult of non-error type");
+ fieldlists.clear();
+ rows = 0;
+ if (affected_rows >= 1)
+ {
+ rows = affected_rows;
+ fieldlists.resize(rows);
+ }
+ unsigned int field_count;
+ if (res)
+ {
+ MYSQL_ROW row;
+ int n = 0;
+ while ((row = mysql_fetch_row(res)))
+ {
+ if (fieldlists.size() < (unsigned int)rows+1)
+ {
+ fieldlists.resize(fieldlists.size()+1);
+ }
+ field_count = 0;
+ MYSQL_FIELD *fields = mysql_fetch_fields(res);
+ if(mysql_num_fields(res) == 0)
+ break;
+ if (fields && mysql_num_fields(res))
+ {
+ colnames.clear();
+ while (field_count < mysql_num_fields(res))
+ {
+ std::string a = (fields[field_count].name ? fields[field_count].name : "");
+ std::string b = (row[field_count] ? row[field_count] : "");
+ SQLfield sqlf(b, !row[field_count]);
+ colnames.push_back(a);
+ fieldlists[n].push_back(sqlf);
+ field_count++;
+ }
+ n++;
+ }
+ rows++;
+ }
+ cols = mysql_num_fields(res);
+ mysql_free_result(res);
+ }
+ cols = field_count;
+ log(DEBUG, "Created new MySQL result; %d rows, %d columns", rows, cols);
+ }
+
+ MySQLresult(Module* self, Module* to, SQLerror e, unsigned int id) : SQLresult(self, to, id), currentrow(0)
+ {
+ rows = 0;
+ cols = 0;
+ error = e;
+ log(DEBUG,"Created new MySQLresult of error type");
+ }
+
+ ~MySQLresult()
+ {
+ }
+
+ virtual int Rows()
+ {
+ return rows;
+ }
+
+ virtual int Cols()
+ {
+ return cols;
+ }
+
+ virtual std::string ColName(int column)
+ {
+ if (column < (int)colnames.size())
+ {
+ return colnames[column];
+ }
+ else
+ {
+ throw SQLbadColName();
+ }
+ return "";
+ }
+
+ virtual int ColNum(const std::string &column)
+ {
+ for (unsigned int i = 0; i < colnames.size(); i++)
+ {
+ if (column == colnames[i])
+ return i;
+ }
+ throw SQLbadColName();
+ return 0;
+ }
+
+ virtual SQLfield GetValue(int row, int column)
+ {
+ if ((row >= 0) && (row < rows) && (column >= 0) && (column < cols))
+ {
+ return fieldlists[row][column];
+ }
+
+ log(DEBUG,"Danger will robinson, we don't have row %d, column %d!", row, column);
+ throw SQLbadColName();
+
+ /* XXX: We never actually get here because of the throw */
+ return SQLfield("",true);
+ }
+
+ virtual SQLfieldList& GetRow()
+ {
+ return fieldlists[currentrow];
+ }
+
+ virtual SQLfieldMap& GetRowMap()
+ {
+ fieldmap = new SQLfieldMap();
+
+ for (int i = 0; i < cols; i++)
+ {
+ fieldmap->insert(std::make_pair(colnames[cols],GetValue(currentrow, i)));
+ }
+ currentrow++;
+
+ return *fieldmap;
+ }
+
+ virtual SQLfieldList* GetRowPtr()
+ {
+ return &fieldlists[currentrow++];
+ }
+
+ virtual SQLfieldMap* GetRowMapPtr()
+ {
+ fieldmap = new SQLfieldMap();
+
+ for (int i = 0; i < cols; i++)
+ {
+ fieldmap->insert(std::make_pair(colnames[cols],GetValue(currentrow, i)));
+ }
+ currentrow++;
+
+ return fieldmap;
+ }
+
+ virtual void Free(SQLfieldMap* fm)
+ {
+ delete fm;
+ }
+
+ virtual void Free(SQLfieldList* fl)
+ {
+ /* XXX: Yes, this is SUPPOSED to do nothing, we
+ * dont want to free our fieldlist until we
+ * destruct the object. Unlike the pgsql module,
+ * we only have the one.
+ */
+ }
+};
+
+class SQLConnection;
+
+void NotifyMainThread(SQLConnection* connection_with_new_result);
+
class SQLConnection : public classbase
{
protected:
std::string db;
std::map<std::string,std::string> thisrow;
bool Enabled;
- long id;
+ std::string id;
public:
QueryQueue queue;
+ ResultQueue rq;
// This constructor creates an SQLConnection object with the given credentials, and creates the underlying
// MYSQL struct, but does not connect yet.
- SQLConnection(std::string thishost, std::string thisuser, std::string thispass, std::string thisdb, long myid)
+ SQLConnection(std::string thishost, std::string thisuser, std::string thispass, std::string thisdb, const std::string &myid)
{
this->Enabled = true;
this->host = thishost;
void DoLeadingQuery()
{
- SQLrequest& query = queue.front();
- log(DEBUG,"DO QUERY: %s",query.query.q.c_str());
- }
+ if (!CheckConnection())
+ return;
- // This method issues a query that expects multiple rows of results. Use GetRow() and QueryDone() to retrieve
- // multiple rows.
- bool QueryResult(std::string query)
- {
- if (!CheckConnection()) return false;
-
- int r = mysql_query(&connection, query.c_str());
- if (!r)
- {
- res = mysql_use_result(&connection);
- }
- return (!r);
- }
+ /* Parse the command string and dispatch it to mysql */
+ SQLrequest& req = queue.front();
+ log(DEBUG,"DO QUERY: %s",req.query.q.c_str());
- // This method issues a query that just expects a number of 'effected' rows (e.g. UPDATE or DELETE FROM).
- // the number of effected rows is returned in the return value.
- long QueryCount(std::string query)
- {
- /* If the connection is down, we return a negative value - New to 1.1 */
- if (!CheckConnection()) return -1;
+ /* Pointer to the buffer we screw around with substitution in */
+ char* query;
+
+ /* Pointer to the current end of query, where we append new stuff */
+ char* queryend;
- int r = mysql_query(&connection, query.c_str());
- if (!r)
+ /* Total length of the unescaped parameters */
+ unsigned long paramlen;
+
+ /* Total length of query, used for binary-safety in mysql_real_query */
+ unsigned long querylength = 0;
+
+ paramlen = 0;
+
+ for(ParamL::iterator i = req.query.p.begin(); i != req.query.p.end(); i++)
{
- res = mysql_store_result(&connection);
- unsigned long rows = mysql_affected_rows(&connection);
- mysql_free_result(res);
- return rows;
+ paramlen += i->size();
}
- return 0;
- }
- // This method fetches a row, if available from the database. You must issue a query
- // using QueryResult() first! The row's values are returned as a map of std::string
- // where each item is keyed by the column name.
- std::map<std::string,std::string> GetRow()
- {
- thisrow.clear();
- if (res)
+ /* To avoid a lot of allocations, allocate enough memory for the biggest the escaped query could possibly be.
+ * sizeofquery + (totalparamlength*2) + 1
+ *
+ * The +1 is for null-terminating the string for mysql_real_escape_string
+ */
+
+ query = new char[req.query.q.length() + (paramlen*2)];
+ queryend = query;
+
+ /* Okay, now we have a buffer large enough we need to start copying the query into it and escaping and substituting
+ * the parameters into it...
+ */
+
+ for(unsigned long i = 0; i < req.query.q.length(); i++)
{
- row = mysql_fetch_row(res);
- if (row)
+ if(req.query.q[i] == '?')
{
- unsigned int field_count = 0;
- MYSQL_FIELD *fields = mysql_fetch_fields(res);
- if(mysql_field_count(&connection) == 0)
- return thisrow;
- if (fields && mysql_field_count(&connection))
+ /* We found a place to substitute..what fun.
+ * use mysql calls to escape and write the
+ * escaped string onto the end of our query buffer,
+ * then we "just" need to make sure queryend is
+ * pointing at the right place.
+ */
+ if(req.query.p.size())
{
- while (field_count < mysql_field_count(&connection))
- {
- std::string a = (fields[field_count].name ? fields[field_count].name : "");
- std::string b = (row[field_count] ? row[field_count] : "");
- thisrow[a] = b;
- field_count++;
- }
- return thisrow;
+ unsigned long len = mysql_real_escape_string(&connection, queryend, req.query.p.front().c_str(), req.query.p.front().length());
+
+ queryend += len;
+ req.query.p.pop_front();
+ }
+ else
+ {
+ log(DEBUG, "Found a substitution location but no parameter to substitute :|");
+ break;
}
}
+ else
+ {
+ *queryend = req.query.q[i];
+ queryend++;
+ }
+ querylength++;
}
- return thisrow;
- }
- bool QueryDone()
- {
- if (res)
+ *queryend = 0;
+
+ log(DEBUG, "Attempting to dispatch query: %s", query);
+
+ pthread_mutex_lock(&queue_mutex);
+ req.query.q = query;
+ pthread_mutex_unlock(&queue_mutex);
+
+ if (!mysql_real_query(&connection, req.query.q.data(), req.query.q.length()))
{
- mysql_free_result(res);
- res = NULL;
- return true;
+ /* Successfull query */
+ res = mysql_use_result(&connection);
+ unsigned long rows = mysql_affected_rows(&connection);
+ MySQLresult* r = new MySQLresult(SQLModule, req.GetSource(), res, rows, req.id);
+ r->dbid = this->GetID();
+ r->query = req.query.q;
+ /* Put this new result onto the results queue.
+ * XXX: Remember to mutex the queue!
+ */
+ pthread_mutex_lock(&results_mutex);
+ rq.push_back(r);
+ pthread_mutex_unlock(&results_mutex);
}
- else return false;
+ else
+ {
+ /* XXX: See /usr/include/mysql/mysqld_error.h for a list of
+ * possible error numbers and error messages */
+ log(DEBUG,"SQL ERROR: %s",mysql_error(&connection));
+ SQLerror e((SQLerrorNum)mysql_errno(&connection), mysql_error(&connection));
+ MySQLresult* r = new MySQLresult(SQLModule, req.GetSource(), e, req.id);
+ r->dbid = this->GetID();
+ r->query = req.query.q;
+
+ pthread_mutex_lock(&results_mutex);
+ rq.push_back(r);
+ pthread_mutex_unlock(&results_mutex);
+ }
+
+ /* Now signal the main thread that we've got a result to process.
+ * Pass them this connection id as what to examine
+ */
+
+ NotifyMainThread(this);
}
bool ConnectionLost()
return mysql_error(&connection);
}
- long GetID()
+ const std::string& GetID()
{
return id;
}
return host;
}
- void Enable()
- {
- Enabled = true;
- }
-
- void Disable()
+ void SetEnable(bool Enable)
{
- Enabled = false;
+ Enabled = Enable;
}
bool IsEnabled()
{
for (ConnMap::iterator i = Connections.begin(); i != Connections.end(); i++)
{
- i->second->Enable();
+ i->second->SetEnable(true);
if (i->second->Connect())
{
Srv->Log(DEFAULT,"SQL: Successfully connected database "+i->second->GetHost());
else
{
Srv->Log(DEFAULT,"SQL: Failed to connect database "+i->second->GetHost()+": Error: "+i->second->GetError());
- i->second->Disable();
+ i->second->SetEnable(false);
}
}
}
Srv->Log(DEBUG,"Read database settings");
if ((db != "") && (host != "") && (user != "") && (id != "") && (pass != ""))
{
- SQLConnection* ThisSQL = new SQLConnection(host,user,pass,db,atoi(id.c_str()));
+ SQLConnection* ThisSQL = new SQLConnection(host,user,pass,db,id);
Srv->Log(DEFAULT,"Loaded database: "+ThisSQL->GetHost());
Connections[id] = ThisSQL;
Srv->Log(DEBUG,"Pushed back connection");
ConnectDatabases(Srv);
}
+void NotifyMainThread(SQLConnection* connection_with_new_result)
+{
+ /* Here we write() to the socket the main thread has open
+ * and we connect()ed back to before our thread became active.
+ * The main thread is using a nonblocking socket tied into
+ * the socket engine, so they wont block and they'll receive
+ * nearly instant notification. Because we're in a seperate
+ * thread, we can just use standard connect(), and we can
+ * block if we like. We just send the connection id of the
+ * connection back.
+ */
+ log(DEBUG,"Notify of result on connection: %s",connection_with_new_result->GetID().c_str());
+ if (send(QueueFD, connection_with_new_result->GetID().c_str(), connection_with_new_result->GetID().length()+1, 0) < 1) // add one for null terminator
+ {
+ log(DEBUG,"Error writing to QueueFD: %s",strerror(errno));
+ }
+ log(DEBUG,"Sent it on its way via fd=%d",QueueFD);
+}
+
void* DispatcherThread(void* arg);
+class Notifier : public InspSocket
+{
+ sockaddr_in sock_us;
+ socklen_t uslen;
+ Server* Srv;
+
+ public:
+
+ /* Create a socket on a random port. Let the tcp stack allocate us an available port */
+ Notifier(Server* S) : InspSocket("127.0.0.1", 0, true, 3000), Srv(S)
+ {
+ uslen = sizeof(sock_us);
+ if (getsockname(this->fd,(sockaddr*)&sock_us,&uslen))
+ {
+ throw ModuleException("Could not create random listening port on localhost");
+ }
+ }
+
+ Notifier(int newfd, char* ip, Server* S) : InspSocket(newfd, ip), Srv(S)
+ {
+ log(DEBUG,"Constructor of new socket");
+ }
+
+ /* Using getsockname and ntohs, we can determine which port number we were allocated */
+ int GetPort()
+ {
+ return ntohs(sock_us.sin_port);
+ }
+
+ virtual int OnIncomingConnection(int newsock, char* ip)
+ {
+ log(DEBUG,"Inbound connection on fd %d!",newsock);
+ Notifier* n = new Notifier(newsock, ip, Srv);
+ Srv->AddSocket(n);
+ return true;
+ }
+
+ virtual bool OnDataReady()
+ {
+ log(DEBUG,"Inbound data!");
+ char* data = this->Read();
+ ConnMap::iterator iter;
+
+ if (data && *data)
+ {
+ log(DEBUG,"Looking for connection %s",data);
+ /* We expect to be sent a null terminated string */
+ if((iter = Connections.find(data)) != Connections.end())
+ {
+ log(DEBUG,"Found it!");
+
+ /* Lock the mutex, send back the data */
+ pthread_mutex_lock(&results_mutex);
+ ResultQueue::iterator n = iter->second->rq.begin();
+ (*n)->Send();
+ iter->second->rq.pop_front();
+ pthread_mutex_unlock(&results_mutex);
+ return true;
+ }
+ }
+
+ return false;
+ }
+};
+
class ModuleSQL : public Module
{
public:
List[I_OnRehash] = List[I_OnRequest] = 1;
}
- unsigned long NewID()
+ unsigned long NewID()
{
if (currid+1 == 0)
currid++;
Srv = Me;
Conf = new ConfigReader();
currid = 0;
+ SQLModule = this;
+
+ MessagePipe = new Notifier(Srv);
+ Srv->AddSocket(MessagePipe);
+ log(DEBUG,"Bound notifier to 127.0.0.1:%d",MessagePipe->GetPort());
+
pthread_attr_t attribs;
pthread_attr_init(&attribs);
pthread_attr_setdetachstate(&attribs, PTHREAD_CREATE_DETACHED);
void* DispatcherThread(void* arg)
{
+ log(DEBUG,"Starting Dispatcher thread, mysql version %d",mysql_get_client_version());
ModuleSQL* thismodule = (ModuleSQL*)arg;
LoadDatabases(thismodule->Conf, thismodule->Srv);
+ /* Connect back to the Notifier */
+
+ if ((QueueFD = socket(AF_INET, SOCK_STREAM, 0)) == -1)
+ {
+ /* crap, we're out of sockets... */
+ log(DEBUG,"QueueFD cant be created");
+ return NULL;
+ }
+
+ log(DEBUG,"Initialize QueueFD to %d",QueueFD);
+
+ sockaddr_in addr;
+ in_addr ia;
+ inet_aton("127.0.0.1", &ia);
+ addr.sin_family = AF_INET;
+ addr.sin_addr = ia;
+ addr.sin_port = htons(MessagePipe->GetPort());
+
+ if (connect(QueueFD, (sockaddr*)&addr,sizeof(addr)) == -1)
+ {
+ /* wtf, we cant connect to it, but we just created it! */
+ log(DEBUG,"QueueFD cant connect!");
+ return NULL;
+ }
+
+ log(DEBUG,"Connect QUEUE FD");
+
while (!giveup)
{
SQLConnection* conn = NULL;
/* Theres an item! */
if (conn)
{
+ log(DEBUG,"Process Leading query");
conn->DoLeadingQuery();
/* XXX: Lock */