db_mysql/res.c

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/* 
 * $Id: res.c 5362 2008-12-15 16:33:22Z henningw $ 
 *
 * MySQL module result related functions
 *
 * Copyright (C) 2001-2003 FhG Fokus
 * Copyright (C) 2007-2008 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
 */


/*! \file
 *  \brief DB_MYSQL :: Result related functions
 *  \ingroup db_mysql
 *  Module: \ref db_mysql
 */


#include <string.h>
#include <mysql/mysql.h>
#include "../../db/db_res.h"
#include "../../mem/mem.h"
#include "../../dprint.h"
#include "row.h"
#include "my_con.h"
#include "res.h"


/*!
 * \brief Get and convert columns from a result
 *
 * Get and convert columns from a result, fills the result structure
 * with data from the database.
 * \param _h database connection
 * \param _r database result set
 * \return 0 on success, negative on failure
 */
int db_mysql_get_columns(const db_con_t* _h, db_res_t* _r)
{
   int col;
   MYSQL_FIELD* fields;

   if ((!_h) || (!_r)) {
      LM_ERR("invalid parameter\n");
      return -1;
   }

   RES_COL_N(_r) = mysql_field_count(CON_CONNECTION(_h));
   if (!RES_COL_N(_r)) {
      LM_ERR("no columns returned from the query\n");
      return -2;
   } else {
      LM_DBG("%d columns returned from the query\n", RES_COL_N(_r));
   }
   
   if (db_allocate_columns(_r, RES_COL_N(_r)) != 0) {
      LM_ERR("could not allocate columns\n");
      return -3;
   }

   fields = mysql_fetch_fields(CON_RESULT(_h));
   for(col = 0; col < RES_COL_N(_r); col++) {
      RES_NAMES(_r)[col] = (str*)pkg_malloc(sizeof(str));
      if (! RES_NAMES(_r)[col]) {
         LM_ERR("no private memory left\n");
         db_free_columns(_r);
         return -4;
      }
      LM_DBG("allocate %lu bytes for RES_NAMES[%d] at %p\n",
            (unsigned long)sizeof(str), col, RES_NAMES(_r)[col]);

      /* The pointer that is here returned is part of the result structure. */
      RES_NAMES(_r)[col]->s = fields[col].name;
      RES_NAMES(_r)[col]->len = strlen(fields[col].name);

      LM_DBG("RES_NAMES(%p)[%d]=[%.*s]\n", RES_NAMES(_r)[col], col,
            RES_NAMES(_r)[col]->len, RES_NAMES(_r)[col]->s);

      switch(fields[col].type) {
         case MYSQL_TYPE_TINY:
         case MYSQL_TYPE_SHORT:
         case MYSQL_TYPE_LONG:
         case MYSQL_TYPE_INT24:
         case MYSQL_TYPE_TIMESTAMP:
            LM_DBG("use DB_INT result type\n");
            RES_TYPES(_r)[col] = DB_INT;
            break;

         case MYSQL_TYPE_LONGLONG:
            LM_DBG("use DB_BIGINT result type\n");
            RES_TYPES(_r)[col] = DB_BIGINT;
            break;

         case MYSQL_TYPE_FLOAT:
         case MYSQL_TYPE_DOUBLE:
            LM_DBG("use DB_DOUBLE result type\n");
            RES_TYPES(_r)[col] = DB_DOUBLE;
            break;

         case MYSQL_TYPE_DATETIME:
            LM_DBG("use DB_DATETIME result type\n");
            RES_TYPES(_r)[col] = DB_DATETIME;
            break;

         case MYSQL_TYPE_BLOB:
            LM_DBG("use DB_BLOB result type\n");
            RES_TYPES(_r)[col] = DB_BLOB;
            break;

         case FIELD_TYPE_SET:
            LM_DBG("use DB_BITMAP result type\n");
            RES_TYPES(_r)[col] = DB_BITMAP;
            break;

         case MYSQL_TYPE_DECIMAL:
         #if MYSQL_VERSION_ID > 49999
         case MYSQL_TYPE_NEWDECIMAL:
         #endif
         case MYSQL_TYPE_STRING:
         case MYSQL_TYPE_VAR_STRING:
            LM_DBG("use DB_STRING result type\n");
            RES_TYPES(_r)[col] = DB_STRING;
            break;

         default:
            LM_WARN("unhandled data type column (%.*s) type id (%d), "
                  "use DB_STRING as default\n", RES_NAMES(_r)[col]->len,
                  RES_NAMES(_r)[col]->s, fields[col].type);
            RES_TYPES(_r)[col] = DB_STRING;
            break;
      }
   }
   return 0;
}


/*!
 * \brief Convert rows from mysql to db API representation
 * \param _h database connection
 * \param _r database result set
 * \return 0 on success, negative on failure
 */
static inline int db_mysql_convert_rows(const db_con_t* _h, db_res_t* _r)
{
   int row;

   if ((!_h) || (!_r)) {
      LM_ERR("invalid parameter\n");
      return -1;
   }

   RES_ROW_N(_r) = mysql_num_rows(CON_RESULT(_h));
   if (!RES_ROW_N(_r)) {
      LM_DBG("no rows returned from the query\n");
      RES_ROWS(_r) = 0;
      return 0;
   }

   if (db_allocate_rows(_r) < 0) {
      LM_ERR("could not allocate rows");
      return -2;
   }

   for(row = 0; row < RES_ROW_N(_r); row++) {
      CON_ROW(_h) = mysql_fetch_row(CON_RESULT(_h));
      if (!CON_ROW(_h)) {
         LM_ERR("driver error: %s\n", mysql_error(CON_CONNECTION(_h)));
         RES_ROW_N(_r) = row;
         db_free_rows(_r);
         return -3;
      }
      if (db_mysql_convert_row(_h, _r, &(RES_ROWS(_r)[row])) < 0) {
         LM_ERR("error while converting row #%d\n", row);
         RES_ROW_N(_r) = row;
         db_free_rows(_r);
         return -4;
      }
   }
   return 0;
}


/*!
 * \brief Fill the result structure with data from database
 * \param _h database connection
 * \param _r database result
 * \return 0 on success, negative on failure
 */
int db_mysql_convert_result(const db_con_t* _h, db_res_t* _r)
{
   if ((!_h) || (!_r)) {
      LM_ERR("invalid parameter\n");
      return -1;
   }

   if (db_mysql_get_columns(_h, _r) < 0) {
      LM_ERR("error while getting column names\n");
      return -2;
   }

   if (db_mysql_convert_rows(_h, _r) < 0) {
      LM_ERR("error while converting rows\n");
      db_free_columns(_r);
      return -3;
   }
   return 0;
}