db_postgres/dbase.c

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/*
 * $Id: dbase.c 5431 2009-01-07 14:46:10Z henningw $
 *
 * Copyright (C) 2003 August.Net Services, LLC
 * Copyright (C) 2006 Norman Brandinger
 * Copyright (C) 2008 1&1 Internet AG
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version
 *
 * Kamailio is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * History
 * -------
 * 2003-04-06 initial code written (Greg Fausak/Andy Fullford)
 * 2006-07-28 within pg_get_result(): added check to immediatly return of no 
 *            result set was returned added check to only execute 
 *            convert_result() if PGRES_TUPLES_OK added safety check to avoid 
 *            double pg_free_result() (norm)
 * 2006-08-07 Rewrote pg_get_result().
 *            Additional debugging lines have been placed through out the code.
 *            Added Asynchronous Command Processing (PQsendQuery/PQgetResult) 
 *            instead of PQexec. this was done in preparation of adding FETCH 
 *            support.  Note that PQexec returns a result pointer while 
 *            PQsendQuery does not.  The result set pointer is obtained from 
 *            a call (or multiple calls) to PQgetResult.
 *            Removed transaction processing calls (BEGIN/COMMIT/ROLLBACK) as 
 *            they added uneeded overhead.  Klaus' testing showed in excess of 
 *            1ms gain by removing each command.  In addition, Kamailio only 
 *            issues single queries and is not, at this time transaction aware.
 *            The transaction processing routines have been left in place 
 *            should this support be needed in the future.
 *            Updated logic in pg_query / pg_raw_query to accept a (0) result 
 *            set (_r) parameter.  In this case, control is returned
 *            immediately after submitting the query and no call to 
 *            pg_get_results() is performed. This is a requirement for 
 *            FETCH support. (norm)
 * 2006-10-27 Added fetch support (norm)
 *            Removed dependency on aug_* memory routines (norm)
 *            Added connection pooling support (norm)
 *            Standardized API routines to pg_* names (norm)
 * 2006-11-01 Updated pg_insert(), pg_delete(), pg_update() and 
 *            pg_get_result() to handle failed queries.  Detailed warnings 
 *            along with the text of the failed query is now displayed in the 
 *            log. Callers of these routines can now assume that a non-zero 
 *            rc indicates the query failed and that remedial action may need 
 *            to be taken. (norm)
 */

/*! \file
 *  \brief DB_POSTGRES :: Core
 *  \ingroup db_postgres
 *  Module: \ref db_postgres
 */

/*! maximum number of columns */
#define MAXCOLUMNS   512

#include <string.h>
#include <stdio.h>
#include "../../dprint.h"
#include "../../mem/mem.h"
#include "../../db/db.h"
#include "../../db/db_ut.h"
#include "../../db/db_query.h"
#include "dbase.h"
#include "pg_con.h"
#include "val.h"
#include "res.h"

static void db_postgres_free_query(const db_con_t* _con);


/*!
 * \brief Initialize database for future queries
 * \param _url URL of the database that should be opened
 * \return database connection on success, NULL on error
 * \note this function must be called prior to any database functions
 */
db_con_t *db_postgres_init(const str* _url)
{
   return db_do_init(_url, (void*) db_postgres_new_connection);
}


/*!
 * \brief Close database when the database is no longer needed
 * \param _h closed connection, as returned from db_postgres_init
 * \note free all memory and resources
 */
void db_postgres_close(db_con_t* _h)
{
   db_do_close(_h, db_postgres_free_connection);
}


/*!
 * \brief Submit_query, run a query
 * \param _con database connection
 * \param _s query string
 * \return 0 on success, negative on failure
 */
static int db_postgres_submit_query(const db_con_t* _con, const str* _s)
{
   if(! _con || !_s || !_s->s)
   {
      LM_ERR("invalid parameter value\n");
      return(-1);
   }

   /* this bit of nonsense in case our connection get screwed up */
   switch(PQstatus(CON_CONNECTION(_con)))
   {
      case CONNECTION_OK: 
         break;
      case CONNECTION_BAD:
         LM_DBG("connection reset\n");
         PQreset(CON_CONNECTION(_con));
         break;
      case CONNECTION_STARTED:
      case CONNECTION_MADE:
      case CONNECTION_AWAITING_RESPONSE:
      case CONNECTION_AUTH_OK:
      case CONNECTION_SETENV:
      case CONNECTION_SSL_STARTUP:
      case CONNECTION_NEEDED:
      default:
         LM_ERR("%p PQstatus(%s) invalid: %.*s\n", _con,
            PQerrorMessage(CON_CONNECTION(_con)), _s->len, _s->s);
         return -1;
   }

   /* free any previous query that is laying about */
   db_postgres_free_query(_con);

   /* exec the query */
   if (PQsendQuery(CON_CONNECTION(_con), _s->s)) {
      LM_DBG("%p PQsendQuery(%.*s)\n", _con, _s->len, _s->s);
   } else {
      LM_ERR("%p PQsendQuery Error: %s Query: %.*s\n", _con,
      PQerrorMessage(CON_CONNECTION(_con)), _s->len, _s->s);
      return -1;
   }

   return 0;
}


/*!
 * \brief Gets a partial result set, fetch rows from a result
 *
 * Gets a partial result set, fetch a number of rows from a database result.
 * This function initialize the given result structure on the first run, and
 * fetches the nrows number of rows. On subsequenting runs, it uses the
 * existing result and fetches more rows, until it reaches the end of the
 * result set. Because of this the result needs to be null in the first
 * invocation of the function. If the number of wanted rows is zero, the
 * function returns anything with a result of zero.
 * \param _con database connection
 * \param _res result set
 * \param nrows number of fetches rows
 * \return 0 on success, negative on failure
 */
int db_postgres_fetch_result(const db_con_t* _con, db_res_t** _res, const int nrows)
{
   int rows;
   PGresult *res = NULL;
   ExecStatusType pqresult;

   if (!_con || !_res || nrows < 0) {
      LM_ERR("invalid parameter value\n");
      return -1;
   }

   /* exit if the fetch count is zero */
   if (nrows == 0) {
      if (*_res)
         db_free_result(*_res);

      *_res = 0;
      return 0;
   }

   if (*_res == NULL) {
      /* Allocate a new result structure */
      *_res = db_new_result();

      /* Get the result of the previous query */
      while (1) {
         if ((res = PQgetResult(CON_CONNECTION(_con)))) {
            CON_RESULT(_con) = res;
         } else {
            break;
         }
      }
      pqresult = PQresultStatus(CON_RESULT(_con));
      LM_DBG("%p PQresultStatus(%s) PQgetResult(%p)\n", _con,
         PQresStatus(pqresult), CON_RESULT(_con));

      switch(pqresult) {
         case PGRES_COMMAND_OK:
            /* Successful completion of a command returning no data (such as INSERT or UPDATE). */
            return 0;

         case PGRES_TUPLES_OK:
            /* Successful completion of a command returning data (such as a SELECT or SHOW). */
            if (db_postgres_get_columns(_con, *_res) < 0) {
               LM_ERR("failed to get column names\n");
               return -2;
            }
            break;

         case PGRES_FATAL_ERROR:
            LM_ERR("%p - invalid query, execution aborted\n", _con);
            LM_ERR("%p - PQresultStatus(%s)\n", _con, PQresStatus(pqresult));
            LM_ERR("%p: %s\n", _con, PQresultErrorMessage(CON_RESULT(_con)));
            if (*_res)
               db_free_result(*_res);
            *_res = 0;
            return -3;

         case PGRES_EMPTY_QUERY:
         /* notice or warning */
         case PGRES_NONFATAL_ERROR:
         /* status for COPY command, not used */
         case PGRES_COPY_OUT:
         case PGRES_COPY_IN:
         /* unexpected response */
         case PGRES_BAD_RESPONSE:
         default:
            LM_ERR("%p - probable invalid query\n", _con);
            LM_ERR("%p - PQresultStatus(%s)\n", _con, PQresStatus(pqresult));
            LM_ERR("%p: %s\n", _con, PQresultErrorMessage(CON_RESULT(_con)));
            if (*_res)
               db_free_result(*_res);
            *_res = 0;
            return -4;
      }

   } else {
      if(RES_ROWS(*_res) != NULL) {
         db_free_rows(*_res);
      }
      RES_ROWS(*_res) = 0;
      RES_ROW_N(*_res) = 0;
   }

   /* Get the number of rows (tuples) in the query result. */
   RES_NUM_ROWS(*_res) = PQntuples(CON_RESULT(_con));

   /* determine the number of rows remaining to be processed */
   rows = RES_NUM_ROWS(*_res) - RES_LAST_ROW(*_res);

   /* If there aren't any more rows left to process, exit */
   if (rows <= 0)
      return 0;

   /* if the fetch count is less than the remaining rows to process                 */
   /* set the number of rows to process (during this call) equal to the fetch count */
   if (nrows < rows)
      rows = nrows;

   RES_ROW_N(*_res) = rows;

   LM_DBG("converting row %d of %d count %d\n", RES_LAST_ROW(*_res),
         RES_NUM_ROWS(*_res), RES_ROW_N(*_res));

   if (db_postgres_convert_rows(_con, *_res) < 0) {
      LM_ERR("failed to convert rows\n");
      if (*_res)
         db_free_result(*_res);

      *_res = 0;
      return -3;
   }

   /* update the total number of rows processed */
   RES_LAST_ROW(*_res) += rows;
   return 0;
}


/*!
 * \brief Free database and any old query results
 * \param _con database connection
 */
static void db_postgres_free_query(const db_con_t* _con)
{
   if(CON_RESULT(_con))
   {
      LM_DBG("PQclear(%p) result set\n", CON_RESULT(_con));
      PQclear(CON_RESULT(_con));
      CON_RESULT(_con) = 0;
   }
}


/*!
 * \brief Free the query and the result memory in the core
 * \param _con database connection
 * \param _r result set
 * \return 0 on success, -1 on failure
 */
int db_postgres_free_result(db_con_t* _con, db_res_t* _r)
{
     if ((!_con) || (!_r)) {
        LM_ERR("invalid parameter value\n");
        return -1;
     }
     if (db_free_result(_r) < 0) {
        LM_ERR("unable to free result structure\n");
        return -1;
     }
   db_postgres_free_query(_con);
   return 0;
}


/*!
 * \brief Query table for specified rows
 * \param _h structure representing database connection
 * \param _k key names
 * \param _op operators
 * \param _v values of the keys that must match
 * \param _c column names to return
 * \param _n nmber of key=values pairs to compare
 * \param _nc number of columns to return
 * \param _o order by the specified column
 * \param _r result set
 * \return 0 on success, negative on failure
 */
int db_postgres_query(const db_con_t* _h, const db_key_t* _k, const db_op_t* _op,
        const db_val_t* _v, const db_key_t* _c, const int _n, const int _nc,
        const db_key_t _o, db_res_t** _r)
{
   return db_do_query(_h, _k, _op, _v, _c, _n, _nc, _o, _r, db_postgres_val2str,
      db_postgres_submit_query, db_postgres_store_result);
}


/*!
 * Execute a raw SQL query
 * \param _h database connection
 * \param _s raw query string
 * \param _r result set
 * \return 0 on success, negative on failure
 */
int db_postgres_raw_query(const db_con_t* _h, const str* _s, db_res_t** _r)
{
   return db_do_raw_query(_h, _s, _r, db_postgres_submit_query,
      db_postgres_store_result);
}


/*!
 * \brief Retrieve result set
 * \param _con structure representing the database connection
 * \param _r pointer to a structure represending the result set
 * \return 0 If the status of the last command produced a result set and,
 *   If the result set contains data or the convert_result() routine
 *   completed successfully. Negative if the status of the last command was
 * not handled or if the convert_result() returned an error.
 * \note A new result structure is allocated on every call to this routine.
 * If this routine returns 0, it is the callers responsbility to free the
 * result structure. If this routine returns < 0, then the result structure
 * is freed before returning to the caller.
 */
int db_postgres_store_result(const db_con_t* _con, db_res_t** _r)
{
   PGresult *res = NULL;
   ExecStatusType pqresult;
   int rc = 0;

   *_r = db_new_result();
   if (*_r==NULL) {
      LM_ERR("failed to init new result\n");
      rc = -1;
      goto done;
   }

   while (1) {
      if ((res = PQgetResult(CON_CONNECTION(_con)))) {
         CON_RESULT(_con) = res;
      } else {
         break;
      }
   }

   pqresult = PQresultStatus(CON_RESULT(_con));
   
   LM_DBG("%p PQresultStatus(%s) PQgetResult(%p)\n", _con,
      PQresStatus(pqresult), CON_RESULT(_con));

   switch(pqresult) {
      case PGRES_COMMAND_OK:
      /* Successful completion of a command returning no data
       * (such as INSERT or UPDATE). */
      rc = 0;
      break;

      case PGRES_TUPLES_OK:
         /* Successful completion of a command returning data
          * (such as a SELECT or SHOW). */
         if (db_postgres_convert_result(_con, *_r) < 0) {
            LM_ERR("error while converting result\n");
            LM_DBG("freeing result set at %p\n", _r);
            pkg_free(*_r);
            *_r = 0;
            rc = -4;
            break;
         }
         rc =  0;
         break;
      /* query failed */
      case PGRES_FATAL_ERROR:
         LM_ERR("invalid query, execution aborted\n");
         LM_ERR("driver error: %s, %s\n", PQresStatus(pqresult), PQresultErrorMessage(CON_RESULT(_con)));
         db_free_result(*_r);
         *_r = 0;
         rc = -3;
         break;

      case PGRES_EMPTY_QUERY:
      /* notice or warning */
      case PGRES_NONFATAL_ERROR:
      /* status for COPY command, not used */
      case PGRES_COPY_OUT:
      case PGRES_COPY_IN:
      /* unexpected response */
      case PGRES_BAD_RESPONSE:
      default:
         LM_ERR("probable invalid query, execution aborted\n");
         LM_ERR("driver message: %s, %s\n", PQresStatus(pqresult), PQresultErrorMessage(CON_RESULT(_con)));
         db_free_result(*_r);
         *_r = 0;
         rc = -4;
         break;
   }

done:
   db_postgres_free_query(_con);
   return (rc);
}


/*!
 * \brief Insert a row into specified table
 * \param _h structure representing database connection
 * \param _k key names
 * \param _v values of the keys
 * \param _n number of key=value pairs
 * \return 0 on success, negative on failure
 */
int db_postgres_insert(const db_con_t* _h, const db_key_t* _k, const db_val_t* _v,
      const int _n)
{
   db_res_t* _r = NULL;

   int tmp = db_do_insert(_h, _k, _v, _n, db_postgres_val2str, db_postgres_submit_query);
   // finish the async query, otherwise the next query will not complete
   if (db_postgres_store_result(_h, &_r) != 0)
      LM_WARN("unexpected result returned");
   
   if (_r)
      db_free_result(_r);

   return tmp;
}


/*!
 * \brief Delete a row from the specified table
 * \param _h structure representing database connection
 * \param _k key names
 * \param _o operators
 * \param _v values of the keys that must match
 * \param _n number of key=value pairs
 * \return 0 on success, negative on failure
 */
int db_postgres_delete(const db_con_t* _h, const db_key_t* _k, const db_op_t* _o,
      const db_val_t* _v, const int _n)
{
   db_res_t* _r = NULL;
   int tmp = db_do_delete(_h, _k, _o, _v, _n, db_postgres_val2str,
      db_postgres_submit_query);

   if (db_postgres_store_result(_h, &_r) != 0)
      LM_WARN("unexpected result returned");
   
   if (_r)
      db_free_result(_r);

   return tmp;
}


/*!
 * Update some rows in the specified table
 * \param _h structure representing database connection
 * \param _k key names
 * \param _o operators
 * \param _v values of the keys that must match
 * \param _uk updated columns
 * \param _uv updated values of the columns
 * \param _n number of key=value pairs
 * \param _un number of columns to update
 * \return 0 on success, negative on failure
 */
int db_postgres_update(const db_con_t* _h, const db_key_t* _k, const db_op_t* _o,
      const db_val_t* _v, const db_key_t* _uk, const db_val_t* _uv, const int _n,
      const int _un)
{
   db_res_t* _r = NULL;
   int tmp = db_do_update(_h, _k, _o, _v, _uk, _uv, _n, _un, db_postgres_val2str,
      db_postgres_submit_query);

   if (db_postgres_store_result(_h, &_r) != 0)
      LM_WARN("unexpected result returned");
   
   if (_r)
      db_free_result(_r);

   return tmp;
}


/*!
 * Store name of table that will be used by subsequent database functions
 * \param _con database connection
 * \param _t table name
 * \return 0 on success, negative on error
 */
int db_postgres_use_table(db_con_t* _con, const str* _t)
{
   return db_use_table(_con, _t);
}