[user/henk/code/inspircd.git] / src / modules / extra / m_pgsql.cpp

/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2007 InspIRCd Development Team
 * See: http://www.inspircd.org/wiki/index.php/Credits
 *
 * This program is free but copyrighted software; see
 *            the file COPYING for details.
 *
 * ---------------------------------------------------
 */

#include <cstdlib>
#include <sstream>
#include <string>
#include <deque>
#include <map>
#include <libpq-fe.h>

#include "users.h"
#include "channels.h"
#include "modules.h"

#include "inspircd.h"
#include "configreader.h"

#include "m_sqlv2.h"

/* $ModDesc: PostgreSQL Service Provider module for all other m_sql* modules, uses v2 of the SQL API */
/* $CompileFlags: -I`pg_config --includedir` `perl extra/pgsql_config.pl` */
/* $LinkerFlags: -L`pg_config --libdir` -lpq */
/* $ModDep: m_sqlv2.h */

/* UGH, UGH, UGH, UGH, UGH, UGH
 * I'm having trouble seeing how I
 * can avoid this. The core-defined
 * constructors for InspSocket just
 * aren't suitable...and if I'm
 * reimplementing them I need this so
 * I can access the socket engine :\
 */

/* Forward declare, so we can have the typedef neatly at the top */
class SQLConn;
/* Also needs forward declaration, as it's used inside SQLconn */
class ModulePgSQL;

typedef std::map<std::string, SQLConn*> ConnMap;

/* CREAD,       Connecting and wants read event
 * CWRITE,      Connecting and wants write event
 * WREAD,       Connected/Working and wants read event
 * WWRITE,      Connected/Working and wants write event
 * RREAD,       Resetting and wants read event
 * RWRITE,      Resetting and wants write event
 */
enum SQLstatus { CREAD, CWRITE, WREAD, WWRITE, RREAD, RWRITE };

/** SQLhost, simple structure to store information about a SQL-connection-to-be
 * We use this struct simply to make it neater passing around host information
 * when we're creating connections and resolving hosts.
 * Rather than giving SQLresolver a parameter for every field here so it can in
 * turn call SQLConn's constructor with them all, both can simply use a SQLhost.
 */
class SQLhost
{
 public:
        std::string     id;     /* Database handle id */
        std::string     host;   /* Database server hostname */
        unsigned int    port;   /* Database server port */
        std::string     name;   /* Database name */
        std::string     user;   /* Database username */
        std::string     pass;   /* Database password */
        bool            ssl;    /* If we should require SSL */
 
        SQLhost()
        {
        }               

        SQLhost(const std::string& i, const std::string& h, unsigned int p, const std::string& n, const std::string& u, const std::string& pa, bool s)
        : id(i), host(h), port(p), name(n), user(u), pass(pa), ssl(s)
        {
        }
};

/** Used to resolve sql server hostnames
 */
class SQLresolver : public Resolver
{
 private:
        SQLhost host;
        ModulePgSQL* mod;
 public:
        SQLresolver(ModulePgSQL* m, InspIRCd* Instance, const SQLhost& hi)
        : Resolver(Instance, hi.host, DNS_QUERY_FORWARD, (Module*)m), host(hi), mod(m)
        {
        }

        virtual void OnLookupComplete(const std::string &result);

        virtual void OnError(ResolverError e, const std::string &errormessage)
        {
                ServerInstance->Log(DEBUG, "DNS lookup failed (%s), dying horribly", errormessage.c_str());
        }

        virtual ~SQLresolver()
        {
        }
};

/** QueryQueue, a queue of queries waiting to be executed.
 * This maintains two queues internally, one for 'priority'
 * queries and one for less important ones. Each queue has
 * new queries appended to it and ones to execute are popped
 * off the front. This keeps them flowing round nicely and no
 * query should ever get 'stuck' for too long. If there are
 * queries in the priority queue they will be executed first,
 * 'unimportant' queries will only be executed when the
 * priority queue is empty.
 *
 * We store lists of SQLrequest's here, by value as we want to avoid storing
 * any data allocated inside the client module (in case that module is unloaded
 * while the query is in progress).
 *
 * Because we want to work on the current SQLrequest in-situ, we need a way
 * of accessing the request we are currently processing, QueryQueue::front(),
 * but that call needs to always return the same request until that request
 * is removed from the queue, this is what the 'which' variable is. New queries are
 * always added to the back of one of the two queues, but if when front()
 * is first called then the priority queue is empty then front() will return
 * a query from the normal queue, but if a query is then added to the priority
 * queue then front() must continue to return the front of the *normal* queue
 * until pop() is called.
 */

class QueryQueue : public classbase
{
private:
        typedef std::deque<SQLrequest> ReqDeque;        

        ReqDeque priority;      /* The priority queue */
        ReqDeque normal;        /* The 'normal' queue */
        enum { PRI, NOR, NON } which;   /* Which queue the currently active element is at the front of */

public:
        QueryQueue()
        : which(NON)
        {
        }
        
        void push(const SQLrequest &q)
        {
                //ServerInstance->Log(DEBUG, "QueryQueue::push(): Adding %s query to queue: %s", ((q.pri) ? "priority" : "non-priority"), q.query.q.c_str());
                
                if(q.pri)
                        priority.push_back(q);
                else
                        normal.push_back(q);
        }
        
        void pop()
        {
                if((which == PRI) && priority.size())
                {
                        priority.pop_front();
                }
                else if((which == NOR) && normal.size())
                {
                        normal.pop_front();
                }
                
                /* Reset this */
                which = NON;
                
                /* Silently do nothing if there was no element to pop() */
        }
        
        SQLrequest& front()
        {
                switch(which)
                {
                        case PRI:
                                return priority.front();
                        case NOR:
                                return normal.front();
                        default:
                                if(priority.size())
                                {
                                        which = PRI;
                                        return priority.front();
                                }
                                
                                if(normal.size())
                                {
                                        which = NOR;
                                        return normal.front();
                                }
                                
                                /* This will probably result in a segfault,
                                 * but the caller should have checked totalsize()
                                 * first so..meh - moron :p
                                 */
                                
                                return priority.front();
                }
        }
        
        std::pair<int, int> size()
        {
                return std::make_pair(priority.size(), normal.size());
        }
        
        int totalsize()
        {
                return priority.size() + normal.size();
        }
        
        void PurgeModule(Module* mod)
        {
                DoPurgeModule(mod, priority);
                DoPurgeModule(mod, normal);
        }
        
private:
        void DoPurgeModule(Module* mod, ReqDeque& q)
        {
                for(ReqDeque::iterator iter = q.begin(); iter != q.end(); iter++)
                {
                        if(iter->GetSource() == mod)
                        {
                                if(iter->id == front().id)
                                {
                                        /* It's the currently active query.. :x */
                                        iter->SetSource(NULL);
                                }
                                else
                                {
                                        /* It hasn't been executed yet..just remove it */
                                        iter = q.erase(iter);
                                }
                        }
                }
        }
};

/** PgSQLresult is a subclass of the mostly-pure-virtual class SQLresult.
 * All SQL providers must create their own subclass and define it's methods using that
 * database library's data retriveal functions. The aim is to avoid a slow and inefficient process
 * of converting all data to a common format before it reaches the result structure. This way
 * data is passes to the module nearly as directly as if it was using the API directly itself.
 */

class PgSQLresult : public SQLresult
{
        PGresult* res;
        int currentrow;
        int rows;
        int cols;
        
        SQLfieldList* fieldlist;
        SQLfieldMap* fieldmap;
public:
        PgSQLresult(Module* self, Module* to, unsigned long id, PGresult* result)
        : SQLresult(self, to, id), res(result), currentrow(0), fieldlist(NULL), fieldmap(NULL)
        {
                rows = PQntuples(res);
                cols = PQnfields(res);
                
                //ServerInstance->Log(DEBUG, "Created new PgSQL result; %d rows, %d columns, %s affected", rows, cols, PQcmdTuples(res));
        }
        
        ~PgSQLresult()
        {
                /* If we allocated these, free them... */
                if(fieldlist)
                        DELETE(fieldlist);
                
                if(fieldmap)
                        DELETE(fieldmap);
                
                PQclear(res);
        }
        
        virtual int Rows()
        {
                if(!cols && !rows)
                {
                        return atoi(PQcmdTuples(res));
                }
                else
                {
                        return rows;
                }
        }
        
        virtual int Cols()
        {
                return PQnfields(res);
        }
        
        virtual std::string ColName(int column)
        {
                char* name = PQfname(res, column);
                
                return (name) ? name : "";
        }
        
        virtual int ColNum(const std::string &column)
        {
                int n = PQfnumber(res, column.c_str());
                
                if(n == -1)
                {
                        throw SQLbadColName();
                }
                else
                {
                        return n;
                }
        }
        
        virtual SQLfield GetValue(int row, int column)
        {
                char* v = PQgetvalue(res, row, column);
                
                if(v)
                {
                        return SQLfield(std::string(v, PQgetlength(res, row, column)), PQgetisnull(res, row, column));
                }
                else
                {
                        //ServerInstance->Log(DEBUG, "PQgetvalue returned a null pointer..nobody wants to tell us what this means");
                        throw SQLbadColName();
                }
        }
        
        virtual SQLfieldList& GetRow()
        {
                /* In an effort to reduce overhead we don't actually allocate the list
                 * until the first time it's needed...so...
                 */
                if(fieldlist)
                {
                        fieldlist->clear();
                }
                else
                {
                        fieldlist = new SQLfieldList;
                }
                
                if(currentrow < PQntuples(res))
                {
                        int cols = PQnfields(res);
                        
                        for(int i = 0; i < cols; i++)
                        {
                                fieldlist->push_back(GetValue(currentrow, i));
                        }
                        
                        currentrow++;
                }
                
                return *fieldlist;
        }
        
        virtual SQLfieldMap& GetRowMap()
        {
                /* In an effort to reduce overhead we don't actually allocate the map
                 * until the first time it's needed...so...
                 */
                if(fieldmap)
                {
                        fieldmap->clear();
                }
                else
                {
                        fieldmap = new SQLfieldMap;
                }
                
                if(currentrow < PQntuples(res))
                {
                        int cols = PQnfields(res);
                        
                        for(int i = 0; i < cols; i++)
                        {
                                fieldmap->insert(std::make_pair(ColName(i), GetValue(currentrow, i)));
                        }
                        
                        currentrow++;
                }
                
                return *fieldmap;
        }
        
        virtual SQLfieldList* GetRowPtr()
        {
                SQLfieldList* fl = new SQLfieldList;
                
                if(currentrow < PQntuples(res))
                {
                        int cols = PQnfields(res);
                        
                        for(int i = 0; i < cols; i++)
                        {
                                fl->push_back(GetValue(currentrow, i));
                        }
                        
                        currentrow++;
                }
                
                return fl;
        }
        
        virtual SQLfieldMap* GetRowMapPtr()
        {
                SQLfieldMap* fm = new SQLfieldMap;
                
                if(currentrow < PQntuples(res))
                {
                        int cols = PQnfields(res);
                        
                        for(int i = 0; i < cols; i++)
                        {
                                fm->insert(std::make_pair(ColName(i), GetValue(currentrow, i)));
                        }
                        
                        currentrow++;
                }
                
                return fm;
        }
        
        virtual void Free(SQLfieldMap* fm)
        {
                DELETE(fm);
        }
        
        virtual void Free(SQLfieldList* fl)
        {
                DELETE(fl);
        }
};

/** SQLConn represents one SQL session.
 * Each session has its own persistent connection to the database.
 * This is a subclass of InspSocket so it can easily recieve read/write events from the core socket
 * engine, unlike the original MySQL module this module does not block. Ever. It gets a mild stabbing
 * if it dares to.
 */

class SQLConn : public InspSocket
{
private:
        ModulePgSQL* us;                /* Pointer to the SQL provider itself */
        std::string     dbhost; /* Database server hostname */
        unsigned int    dbport; /* Database server port */
        std::string     dbname; /* Database name */
        std::string     dbuser; /* Database username */
        std::string     dbpass; /* Database password */
        bool                    ssl;    /* If we should require SSL */
        PGconn*                 sql;    /* PgSQL database connection handle */
        SQLstatus               status; /* PgSQL database connection status */
        bool                    qinprog;/* If there is currently a query in progress */
        QueryQueue              queue;  /* Queue of queries waiting to be executed on this connection */
        time_t                  idle;   /* Time we last heard from the database */

public:

        /* This class should only ever be created inside this module, using this constructor, so we don't have to worry about the default ones */

        SQLConn(InspIRCd* SI, ModulePgSQL* self, const SQLhost& hostinfo);

        ~SQLConn();

        bool DoConnect();

        virtual void Close();
        
        bool DoPoll();
        
        bool DoConnectedPoll();

        bool DoResetPoll();
        
        void ShowStatus();      
        
        virtual bool OnDataReady();

        virtual bool OnWriteReady();
        
        virtual bool OnConnected();
        
        bool DoEvent();
        
        bool Reconnect();
        
        std::string MkInfoStr();
        
        const char* StatusStr();
        
        SQLerror DoQuery(SQLrequest &req);
        
        SQLerror Query(const SQLrequest &req);
        
        void OnUnloadModule(Module* mod);
};

class ModulePgSQL : public Module
{
private:
        
        ConnMap connections;
        unsigned long currid;
        char* sqlsuccess;

public:
        ModulePgSQL(InspIRCd* Me)
        : Module::Module(Me), currid(0)
        {
                ServerInstance->UseInterface("SQLutils");

                sqlsuccess = new char[strlen(SQLSUCCESS)+1];
                
                strlcpy(sqlsuccess, SQLSUCCESS, strlen(SQLSUCCESS)+1);

                if (!ServerInstance->PublishFeature("SQL", this))
                {
                        throw ModuleException("m_pgsql: Unable to publish feature 'SQL'");
                }

                OnRehash("");

                ServerInstance->PublishInterface("SQL", this);
        }

        virtual ~ModulePgSQL()
        {
                DELETE(sqlsuccess);
                ClearConnections();
                ServerInstance->UnpublishInterface("SQL", this);
                ServerInstance->UnpublishFeature("SQL");
                ServerInstance->DoneWithInterface("SQLutils");
        }       


        void Implements(char* List)
        {
                List[I_OnUnloadModule] = List[I_OnRequest] = List[I_OnRehash] = List[I_OnUserRegister] = List[I_OnCheckReady] = List[I_OnUserDisconnect] = 1;
        }

        void ClearConnections()
        {
                ConnMap::iterator iter;
                while ((iter = connections.begin()) != connections.end())
                {
                        connections.erase(iter);
                        DELETE(iter->second);
                }
        }

        virtual void OnRehash(const std::string &parameter)
        {
                ConfigReader conf(ServerInstance);

                ClearConnections();             
                for(int i = 0; i < conf.Enumerate("database"); i++)
                {
                        SQLhost host;                   
                        int ipvalid;
                        insp_inaddr blargle;
                        
                        host.id         = conf.ReadValue("database", "id", i);
                        host.host       = conf.ReadValue("database", "hostname", i);
                        host.port       = conf.ReadInteger("database", "port", i, true);
                        host.name       = conf.ReadValue("database", "name", i);
                        host.user       = conf.ReadValue("database", "username", i);
                        host.pass       = conf.ReadValue("database", "password", i);
                        host.ssl        = conf.ReadFlag("database", "ssl", i);
                        
                        ipvalid = insp_aton(host.host.c_str(), &blargle);
                        
                        if(ipvalid > 0)
                        {
                                /* The conversion succeeded, we were given an IP and we can give it straight to SQLConn */
                                this->AddConn(host);
                        }
                        else if(ipvalid == 0)
                        {
                                /* Conversion failed, assume it's a host */
                                SQLresolver* resolver;
                                
                                try
                                {
                                        resolver = new SQLresolver(this, ServerInstance, host);
                                        
                                        ServerInstance->AddResolver(resolver);
                                }
                                catch(...)
                                {
                                        ServerInstance->Log(DEBUG, "Couldn't make a SQLresolver..this connection is gonna diiiiiie...actually we just won't create it");
                                }
                        }
                        else
                        {
                                /* Invalid address family, die horribly. */
                                ServerInstance->Log(DEBUG, "insp_aton failed returning -1, oh noes.");
                        }
                }       
        }
        
        void AddConn(const SQLhost& hi)
        {
                SQLConn* newconn;
                                
                /* The conversion succeeded, we were given an IP and we can give it straight to SQLConn */
                newconn = new SQLConn(ServerInstance, this, hi);
                                
                connections.insert(std::make_pair(hi.id, newconn));
        }
        
        virtual char* OnRequest(Request* request)
        {
                if(strcmp(SQLREQID, request->GetId()) == 0)
                {
                        SQLrequest* req = (SQLrequest*)request;
                        ConnMap::iterator iter;
                
                        ServerInstance->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());

                        if((iter = connections.find(req->dbid)) != connections.end())
                        {
                                /* Execute query */
                                req->id = NewID();
                                req->error = iter->second->Query(*req);
                                
                                return (req->error.Id() == NO_ERROR) ? sqlsuccess : NULL;
                        }
                        else
                        {
                                req->error.Id(BAD_DBID);
                                return NULL;
                        }
                }

                ServerInstance->Log(DEBUG, "Got unsupported API version string: %s", request->GetId());
                
                return NULL;
        }
        
        virtual void OnUnloadModule(Module* mod, const std::string&     name)
        {
                /* When a module unloads we have to check all the pending queries for all our connections
                 * and set the Module* specifying where the query came from to NULL. If the query has already
                 * been dispatched then when it is processed it will be dropped if the pointer is NULL.
                 *
                 * If the queries we find are not already being executed then we can simply remove them immediately.
                 */
                for(ConnMap::iterator iter = connections.begin(); iter != connections.end(); iter++)
                {
                        iter->second->OnUnloadModule(mod);
                }
        }

        unsigned long NewID()
        {
                if (currid+1 == 0)
                        currid++;
                
                return ++currid;
        }
                
        virtual Version GetVersion()
        {
                return Version(1, 1, 0, 0, VF_VENDOR|VF_SERVICEPROVIDER, API_VERSION);
        }

};

SQLConn::SQLConn(InspIRCd* SI, ModulePgSQL* self, const SQLhost& hi)
: InspSocket::InspSocket(SI), us(self), dbhost(hi.host), dbport(hi.port), dbname(hi.name), dbuser(hi.user), dbpass(hi.pass), ssl(hi.ssl), sql(NULL), status(CWRITE), qinprog(false)
{
        //ServerInstance->Log(DEBUG, "Creating new PgSQL connection to database %s on %s:%u (%s/%s)", dbname.c_str(), dbhost.c_str(), dbport, dbuser.c_str(), dbpass.c_str());

        /* Some of this could be reviewed, unsure if I need to fill 'host' etc...
         * just copied this over from the InspSocket constructor.
         */
        strlcpy(this->host, dbhost.c_str(), MAXBUF);
        strlcpy(this->IP, dbhost.c_str(), MAXBUF);
        this->port = dbport;
        idle = this->Instance->Time();
        
        this->ClosePending = false;
                        
        Instance->Log(DEBUG,"No need to resolve %s", this->host);
        
        if(!this->DoConnect())
        {
                throw ModuleException("Connect failed");
        }
}

SQLConn::~SQLConn()
{
        Close();
}

bool SQLConn::DoConnect()
{
        //ServerInstance->Log(DEBUG, "SQLConn::DoConnect()");
        
        if(!(sql = PQconnectStart(MkInfoStr().c_str())))
        {
                Instance->Log(DEBUG, "Couldn't allocate PGconn structure, aborting: %s", PQerrorMessage(sql));
                Close();
                return false;
        }
        
        if(PQstatus(sql) == CONNECTION_BAD)
        {
                Instance->Log(DEBUG, "PQconnectStart failed: %s", PQerrorMessage(sql));
                Close();
                return false;
        }
        
        ShowStatus();
        
        if(PQsetnonblocking(sql, 1) == -1)
        {
                Instance->Log(DEBUG, "Couldn't set connection nonblocking: %s", PQerrorMessage(sql));
                Close();
                return false;
        }
        
        /* OK, we've initalised the connection, now to get it hooked into the socket engine
         * and then start polling it.
         */
        
        //ServerInstance->Log(DEBUG, "Old DNS socket: %d", this->fd);
        this->fd = PQsocket(sql);
        Instance->Log(DEBUG, "New SQL socket: %d", this->fd);
        
        if(this->fd <= -1)
        {
                Instance->Log(DEBUG, "PQsocket says we have an invalid FD: %d", this->fd);
                Close();
                return false;
        }
        
        this->state = I_CONNECTING;
        if (!this->Instance->SE->AddFd(this))
        {
                Instance->Log(DEBUG, "A PQsocket cant be added to the socket engine!");
                Close();
                return false;
        }
        
        /* Socket all hooked into the engine, now to tell PgSQL to start connecting */
        
        return DoPoll();
}

void SQLConn::Close()
{
        Instance->Log(DEBUG,"SQLConn::Close");

        if (!this->Instance->SE->DelFd(this))
        {
                Instance->Log(DEBUG, "PQsocket cant be removed from the socket engine!");
        }
        this->fd = -1;
        this->state = I_ERROR;
        this->OnError(I_ERR_SOCKET);
        this->ClosePending = true;
        
        if(sql)
        {
                PQfinish(sql);
                sql = NULL;
        }
}

bool SQLConn::DoPoll()
{
        switch(PQconnectPoll(sql))
        {
                case PGRES_POLLING_WRITING:
                        //ServerInstance->Log(DEBUG, "PGconnectPoll: PGRES_POLLING_WRITING");
                        WantWrite();
                        status = CWRITE;
                        return DoPoll();
                case PGRES_POLLING_READING:
                        //ServerInstance->Log(DEBUG, "PGconnectPoll: PGRES_POLLING_READING");
                        status = CREAD;
                        return true;
                case PGRES_POLLING_FAILED:
                        //ServerInstance->Log(DEBUG, "PGconnectPoll: PGRES_POLLING_FAILED: %s", PQerrorMessage(sql));
                        return false;
                case PGRES_POLLING_OK:
                        //ServerInstance->Log(DEBUG, "PGconnectPoll: PGRES_POLLING_OK");
                        status = WWRITE;
                        return DoConnectedPoll();
                default:
                        //ServerInstance->Log(DEBUG, "PGconnectPoll: wtf?");
                        return true;
        }
}

bool SQLConn::DoConnectedPoll()
{
        if(!qinprog && queue.totalsize())
        {
                /* There's no query currently in progress, and there's queries in the queue. */
                SQLrequest& query = queue.front();
                DoQuery(query);
        }
        
        if(PQconsumeInput(sql))
        {
                Instance->Log(DEBUG, "PQconsumeInput succeeded");
                
                /* We just read stuff from the server, that counts as it being alive
                 * so update the idle-since time :p
                 */
                idle = this->Instance->Time();
                        
                if(PQisBusy(sql))
                {
                        //ServerInstance->Log(DEBUG, "Still busy processing command though");
                }
                else if(qinprog)
                {
                        //ServerInstance->Log(DEBUG, "Looks like we have a result to process!");
                        
                        /* Grab the request we're processing */
                        SQLrequest& query = queue.front();
                        
                        Instance->Log(DEBUG, "ID is %lu", query.id);
                        
                        /* Get a pointer to the module we're about to return the result to */
                        Module* to = query.GetSource();
                        
                        /* Fetch the result.. */
                        PGresult* result = PQgetResult(sql);
                        
                        /* PgSQL would allow a query string to be sent which has multiple
                         * queries in it, this isn't portable across database backends and
                         * we don't want modules doing it. But just in case we make sure we
                         * drain any results there are and just use the last one.
                         * If the module devs are behaving there will only be one result.
                         */
                        while (PGresult* temp = PQgetResult(sql))
                        {
                                PQclear(result);
                                result = temp;
                        }
                        
                        if(to)
                        {
                                /* ..and the result */
                                PgSQLresult reply(us, to, query.id, result);

                                /* Fix by brain, make sure the original query gets sent back in the reply */
                                reply.query = query.query.q;
                                
                                Instance->Log(DEBUG, "Got result, status code: %s; error message: %s", PQresStatus(PQresultStatus(result)), PQresultErrorMessage(result));      
                                
                                switch(PQresultStatus(result))
                                {
                                        case PGRES_EMPTY_QUERY:
                                        case PGRES_BAD_RESPONSE:
                                        case PGRES_FATAL_ERROR:
                                                reply.error.Id(QREPLY_FAIL);
                                                reply.error.Str(PQresultErrorMessage(result));
                                        default:;
                                                /* No action, other values are not errors */
                                }
                                
                                reply.Send();
                                
                                /* PgSQLresult's destructor will free the PGresult */
                        }
                        else
                        {
                                /* If the client module is unloaded partway through a query then the provider will set
                                 * the pointer to NULL. We cannot just cancel the query as the result will still come
                                 * through at some point...and it could get messy if we play with invalid pointers...
                                 */
                                Instance->Log(DEBUG, "Looks like we're handling a zombie query from a module which unloaded before it got a result..fun. ID: %lu", query.id);
                                PQclear(result);
                        }
                        
                        qinprog = false;
                        queue.pop();                            
                        DoConnectedPoll();
                }
                else
                {
                        Instance->Log(DEBUG, "Eh!? We just got a read event, and connection isn't busy..but no result :(");
                }
                
                return true;
        }
        else
        {
                /* I think we'll assume this means the server died...it might not,
                 * but I think that any error serious enough we actually get here
                 * deserves to reconnect [/excuse]
                 * Returning true so the core doesn't try and close the connection.
                 */
                Instance->Log(DEBUG, "PQconsumeInput failed: %s", PQerrorMessage(sql));
                Reconnect();
                return true;
        }
}

bool SQLConn::DoResetPoll()
{
        switch(PQresetPoll(sql))
        {
                case PGRES_POLLING_WRITING:
                        //ServerInstance->Log(DEBUG, "PGresetPoll: PGRES_POLLING_WRITING");
                        WantWrite();
                        status = CWRITE;
                        return DoPoll();
                case PGRES_POLLING_READING:
                        //ServerInstance->Log(DEBUG, "PGresetPoll: PGRES_POLLING_READING");
                        status = CREAD;
                        return true;
                case PGRES_POLLING_FAILED:
                        //ServerInstance->Log(DEBUG, "PGresetPoll: PGRES_POLLING_FAILED: %s", PQerrorMessage(sql));
                        return false;
                case PGRES_POLLING_OK:
                        //ServerInstance->Log(DEBUG, "PGresetPoll: PGRES_POLLING_OK");
                        status = WWRITE;
                        return DoConnectedPoll();
                default:
                        //ServerInstance->Log(DEBUG, "PGresetPoll: wtf?");
                        return true;
        }
}

void SQLConn::ShowStatus()
{
        switch(PQstatus(sql))
        {
                case CONNECTION_STARTED:
                        Instance->Log(DEBUG, "PQstatus: CONNECTION_STARTED: Waiting for connection to be made.");
                        break;

                case CONNECTION_MADE:
                        Instance->Log(DEBUG, "PQstatus: CONNECTION_MADE: Connection OK; waiting to send.");
                        break;
                
                case CONNECTION_AWAITING_RESPONSE:
                        Instance->Log(DEBUG, "PQstatus: CONNECTION_AWAITING_RESPONSE: Waiting for a response from the server.");
                        break;
                
                case CONNECTION_AUTH_OK:
                        Instance->Log(DEBUG, "PQstatus: CONNECTION_AUTH_OK: Received authentication; waiting for backend start-up to finish.");
                        break;
                
                case CONNECTION_SSL_STARTUP:
                        Instance->Log(DEBUG, "PQstatus: CONNECTION_SSL_STARTUP: Negotiating SSL encryption.");
                        break;
                
                case CONNECTION_SETENV:
                        Instance->Log(DEBUG, "PQstatus: CONNECTION_SETENV: Negotiating environment-driven parameter settings.");
                        break;
                
                default:
                        Instance->Log(DEBUG, "PQstatus: ???");
        }
}

bool SQLConn::OnDataReady()
{
        /* Always return true here, false would close the socket - we need to do that ourselves with the pgsql API */
        Instance->Log(DEBUG, "OnDataReady(): status = %s", StatusStr());
        
        return DoEvent();
}

bool SQLConn::OnWriteReady()
{
        /* Always return true here, false would close the socket - we need to do that ourselves with the pgsql API */
        Instance->Log(DEBUG, "OnWriteReady(): status = %s", StatusStr());
        
        return DoEvent();
}

bool SQLConn::OnConnected()
{
        Instance->Log(DEBUG, "OnConnected(): status = %s", StatusStr());
        
        return DoEvent();
}

bool SQLConn::Reconnect()
{
        Instance->Log(DEBUG, "Initiating reconnect");
        
        if(PQresetStart(sql))
        {
                /* Successfully initiatied database reconnect,
                 * set flags so PQresetPoll() will be called appropriately
                 */
                status = RWRITE;
                qinprog = false;
                return true;
        }
        else
        {
                Instance->Log(DEBUG, "Failed to initiate reconnect...fun");
                return false;
        }       
}

bool SQLConn::DoEvent()
{
        bool ret;
        
        if((status == CREAD) || (status == CWRITE))
        {
                ret = DoPoll();
        }
        else if((status == RREAD) || (status == RWRITE))
        {
                ret = DoResetPoll();
        }
        else
        {
                ret = DoConnectedPoll();
        }
        
        switch(PQflush(sql))
        {
                case -1:
                        Instance->Log(DEBUG, "Error flushing write queue: %s", PQerrorMessage(sql));
                        break;
                case 0:
                        Instance->Log(DEBUG, "Successfully flushed write queue (or there was nothing to write)");
                        break;
                case 1:
                        Instance->Log(DEBUG, "Not all of the write queue written, triggering write event so we can have another go");
                        WantWrite();
                        break;
        }

        return ret;
}

std::string SQLConn::MkInfoStr()
{                       
        std::ostringstream conninfo("connect_timeout = '2'");
        
        if(dbhost.length())
                conninfo << " hostaddr = '" << dbhost << "'";
        
        if(dbport)
                conninfo << " port = '" << dbport << "'";
        
        if(dbname.length())
                conninfo << " dbname = '" << dbname << "'";
        
        if(dbuser.length())
                conninfo << " user = '" << dbuser << "'";
        
        if(dbpass.length())
                conninfo << " password = '" << dbpass << "'";
        
        if(ssl)
                conninfo << " sslmode = 'require'";
        
        return conninfo.str();
}

const char* SQLConn::StatusStr()
{
        if(status == CREAD) return "CREAD";
        if(status == CWRITE) return "CWRITE";
        if(status == WREAD) return "WREAD";
        if(status == WWRITE) return "WWRITE";
        return "Err...what, erm..BUG!";
}

SQLerror SQLConn::DoQuery(SQLrequest &req)
{
        if((status == WREAD) || (status == WWRITE))
        {
                if(!qinprog)
                {
                        /* Parse the command string and dispatch it */
                        
                        /* 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;
                        /* Total length of the unescaped parameters */
                        unsigned int paramlen;
                        
                        paramlen = 0;
                        
                        for(ParamL::iterator i = req.query.p.begin(); i != req.query.p.end(); i++)
                        {
                                paramlen += i->size();
                        }
                        
                        /* 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 PQsendQuery()
                         */
                        
                        query = new char[req.query.q.length() + (paramlen*2) + 1];
                        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 int i = 0; i < req.query.q.length(); i++)
                        {
                                if(req.query.q[i] == '?')
                                {
                                        /* We found a place to substitute..what fun.
                                         * Use the PgSQL 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())
                                        {
                                                int error = 0;
                                                size_t len = 0;

#ifdef PGSQL_HAS_ESCAPECONN
                                                len = PQescapeStringConn(sql, queryend, req.query.p.front().c_str(), req.query.p.front().length(), &error);
#else
                                                len = PQescapeString         (queryend, req.query.p.front().c_str(), req.query.p.front().length());
#endif
                                                if(error)
                                                {
                                                        Instance->Log(DEBUG, "Apparently PQescapeStringConn() failed somehow...don't know how or what to do...");
                                                }
                                                
                                                Instance->Log(DEBUG, "Appended %d bytes of escaped string onto the query", len);
                                                
                                                /* Incremenet queryend to the end of the newly escaped parameter */
                                                queryend += len;
                                                
                                                /* Remove the parameter we just substituted in */
                                                req.query.p.pop_front();
                                        }
                                        else
                                        {
                                                Instance->Log(DEBUG, "Found a substitution location but no parameter to substitute :|");
                                                break;
                                        }
                                }
                                else
                                {
                                        *queryend = req.query.q[i];
                                        queryend++;
                                }
                        }
                        
                        /* Null-terminate the query */
                        *queryend = 0;
        
                        Instance->Log(DEBUG, "Attempting to dispatch query: %s", query);
                        
                        req.query.q = query;

                        if(PQsendQuery(sql, query))
                        {
                                Instance->Log(DEBUG, "Dispatched query successfully");
                                qinprog = true;
                                delete[] query;
                                return SQLerror();
                        }
                        else
                        {
                                Instance->Log(DEBUG, "Failed to dispatch query: %s", PQerrorMessage(sql));
                                delete[] query;
                                return SQLerror(QSEND_FAIL, PQerrorMessage(sql));
                        }
                }
        }

        Instance->Log(DEBUG, "Can't query until connection is complete");
        return SQLerror(BAD_CONN, "Can't query until connection is complete");
}

SQLerror SQLConn::Query(const SQLrequest &req)
{
        queue.push(req);
        
        if(!qinprog && queue.totalsize())
        {
                /* There's no query currently in progress, and there's queries in the queue. */
                SQLrequest& query = queue.front();
                return DoQuery(query);
        }
        else
        {
                return SQLerror();
        }
}

void SQLConn::OnUnloadModule(Module* mod)
{
        queue.PurgeModule(mod);
}

void SQLresolver::OnLookupComplete(const std::string &result)
{
        host.host = result;
        mod->AddConn(host);
}

class ModulePgSQLFactory : public ModuleFactory
{
 public:
        ModulePgSQLFactory()
        {
        }
        
        ~ModulePgSQLFactory()
        {
        }
        
        virtual Module * CreateModule(InspIRCd* Me)
        {
                return new ModulePgSQL(Me);
        }
};


extern "C" void * init_module( void )
{
        return new ModulePgSQLFactory;
}