db_postgres/km_res.c

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/*
 * $Id$
 *
 * 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)
 *
 * 2006-07-26 added BPCHAROID as a valid type for DB1_STRING conversions
 *            this removes the "unknown type 1042" log messages (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)
 */

#include <stdlib.h>
#include <string.h>
#include "../../lib/srdb1/db_id.h"
#include "../../lib/srdb1/db_res.h"
#include "../../lib/srdb1/db_con.h"
#include "../../dprint.h"
#include "../../mem/mem.h"
#include "km_res.h"
#include "km_val.h"
#include "km_pg_con.h"
#include "km_pg_type.h"


int db_postgres_convert_result(const db1_con_t* _h, db1_res_t* _r)
{
        if (!_h || !_r)  {
                LM_ERR("invalid parameter value\n");
                return -1;
        }

        if (db_postgres_get_columns(_h, _r) < 0) {
                LM_ERR("failed to get column names\n");
                return -2;
        }

        if (db_postgres_convert_rows(_h, _r) < 0) {
                LM_ERR("failed to convert rows\n");
                db_free_columns(_r);
                return -3;
        }
        return 0;
}


int db_postgres_get_columns(const db1_con_t* _h, db1_res_t* _r)
{
        int col, datatype;

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

        /* Get the number of rows (tuples) in the query result. */
        RES_ROW_N(_r) = PQntuples(CON_RESULT(_h));

        /* Get the number of columns (fields) in each row of the query result. */
        RES_COL_N(_r) = PQnfields(CON_RESULT(_h));

        if (!RES_COL_N(_r)) {
                LM_DBG("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;
        }

        /* For each column both the name and the OID number of the data type are saved. */
        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 %d bytes for RES_NAMES[%d] at %p\n", (unsigned int) sizeof(str), col,
                                RES_NAMES(_r)[col]);

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

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

                /* get the datatype of the column */
                switch(datatype = PQftype(CON_RESULT(_h),col))
                {
                        case INT2OID:
                        case INT4OID:
                                LM_DBG("use DB1_INT result type\n");
                                RES_TYPES(_r)[col] = DB1_INT;
                        break;

                        case INT8OID:
                                LM_DBG("use DB1_BIGINT result type\n");
                                RES_TYPES(_r)[col] = DB1_BIGINT;

                        case FLOAT4OID:
                        case FLOAT8OID:
                        case NUMERICOID:
                                LM_DBG("use DB1_DOUBLE result type\n");
                                RES_TYPES(_r)[col] = DB1_DOUBLE;
                        break;

                        case DATEOID:
                        case TIMESTAMPOID:
                        case TIMESTAMPTZOID:
                                LM_DBG("use DB1_DATETIME result type\n");
                                RES_TYPES(_r)[col] = DB1_DATETIME;
                        break;

                        case BOOLOID:
                        case CHAROID:
                        case VARCHAROID:
                        case BPCHAROID:
                                LM_DBG("use DB1_STRING result type\n");
                                RES_TYPES(_r)[col] = DB1_STRING;
                        break;

                        case TEXTOID:
                        case BYTEAOID:
                                LM_DBG("use DB1_BLOB result type\n");
                                RES_TYPES(_r)[col] = DB1_BLOB;
                        break;

                        case BITOID:
                        case VARBITOID:
                                LM_DBG("use DB1_BITMAP result type\n");
                                RES_TYPES(_r)[col] = DB1_BITMAP;
                        break;
                                
                        default:
                                LM_WARN("unhandled data type column (%.*s) type id (%d), "
                                                "use DB1_STRING as default\n", RES_NAMES(_r)[col]->len,
                                                RES_NAMES(_r)[col]->s, datatype);
                                RES_TYPES(_r)[col] = DB1_STRING;
                        break;
                }
        }
        return 0;
}


int db_postgres_convert_rows(const db1_con_t* _h, db1_res_t* _r)
{
        char **row_buf, *s;
        int row, col, len;

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

        if (!RES_ROW_N(_r)) {
                LM_DBG("no rows returned from the query\n");
                RES_ROWS(_r) = 0;
                return 0;
        }
        /*Allocate an array of pointers per column to holds the string representation */
        len = sizeof(char *) * RES_COL_N(_r);
        row_buf = (char**)pkg_malloc(len);
        if (!row_buf) {
                LM_ERR("no private memory left\n");
                return -1;
        }
        LM_DBG("allocate for %d columns %d bytes in row buffer at %p\n", RES_COL_N(_r), len, row_buf);

        if (db_allocate_rows(_r) < 0) {
                LM_ERR("could not allocate rows\n");
                LM_DBG("freeing row buffer at %p\n", row_buf);
                pkg_free(row_buf);
                return -2;
        }

        for(row = RES_LAST_ROW(_r); row < (RES_LAST_ROW(_r) + RES_ROW_N(_r)); row++) {
                /* reset row buf content */
                memset(row_buf, 0, len);
                for(col = 0; col < RES_COL_N(_r); col++) {
                        /*
                         * The row data pointer returned by PQgetvalue points to storage
                         * that is part of the PGresult structure. One should not modify
                         * the data it points to, and one must explicitly copy the data
                         * into other storage if it is to be used past the lifetime of
                         * the PGresult structure itself.
                         */
                        s = PQgetvalue(CON_RESULT(_h), row, col);
                        LM_DBG("PQgetvalue(%p,%d,%d)=[%s]\n", _h, row, col, s);
                        /*
                         * A empty string can be a NULL value, or just an empty string.
                         * This differs from the mysql behaviour, that further processing
                         * steps expect. So we need to simulate this here unfortunally.
                         */
                        if (PQgetisnull(CON_RESULT(_h), row, col) == 0) {
                                row_buf[col] = s;
                                LM_DBG("[%d][%d] Column[%.*s]=[%s]\n",
                                        row, col, RES_NAMES(_r)[col]->len, RES_NAMES(_r)[col]->s, row_buf[col]);
                        }
                }

                /* ASSERT: row_buf contains an entire row in strings */
                if(db_postgres_convert_row(_h, _r, &(RES_ROWS(_r)[row - RES_LAST_ROW(_r)]), row_buf)<0){
                        LM_ERR("failed to convert row #%d\n",  row);
                        RES_ROW_N(_r) = row - RES_LAST_ROW(_r);
                        LM_DBG("freeing row buffer at %p\n", row_buf);
                        pkg_free(row_buf);
                        db_free_rows(_r);
                        return -4;
                }
        }

        LM_DBG("freeing row buffer at %p\n", row_buf);
        pkg_free(row_buf);
        row_buf = NULL;
        return 0;
}


int db_postgres_convert_row(const db1_con_t* _h, db1_res_t* _r, db_row_t* _row,
                char **row_buf)
{
        int col, col_len;

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

        if (db_allocate_row(_r, _row) != 0) {
                LM_ERR("could not allocate row\n");
                return -2;
        }

        /* For each column in the row */
        for(col = 0; col < ROW_N(_row); col++) {
                /* because it can contain NULL */
                if (!row_buf[col]) {
                        col_len = 0;
                } else {
                        col_len = strlen(row_buf[col]);
                }
                /* Convert the string representation into the value representation */
                if (db_postgres_str2val(RES_TYPES(_r)[col], &(ROW_VALUES(_row)[col]),
                row_buf[col], col_len) < 0) {
                        LM_ERR("failed to convert value\n");
                        LM_DBG("free row at %p\n", _row);
                        db_free_row(_row);
                        return -3;
                }
        }
        return 0;
}