Exemple #1
0
/*!
 * \brief Gets a partial result set, fetch rows from a result
 *
 * Gets a partial result set, fetch a number of rows from a databae 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 _h structure representing the database connection
 * \param _r pointer to a structure representing the result
 * \param nrows number of fetched rows
 * \return return zero on success, negative value on failure
 */
int db_unixodbc_fetch_result(const db1_con_t* _h, db1_res_t** _r, const int nrows)
{
	int row_n = 0, i = 0, ret = 0, len;
	SQLSMALLINT columns;
	list* rows = NULL;
	list* rowstart = NULL;
	strn* temp_row = NULL;

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

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

	/* On the first fetch for a query, allocate structures and get columns */
	if(*_r == NULL) {
		/* Allocate a new result structure */
		*_r = db_new_result();
		LM_DBG("just allocated a new db result structure");

		if (*_r == NULL) {
			LM_ERR("no memory left\n");
			return -2;
		}

		/* Get columns names and count */
		if (db_unixodbc_get_columns(_h, *_r) < 0) {
			LM_ERR("getting column names failed\n");
			db_free_columns(*_r);
			return -2;
		}

	/* On subsequent fetch attempts, reuse already allocated structures */
	} else {
		LM_DBG("db result structure already exist, reusing\n");
		/* free old rows */
		if(RES_ROWS(*_r) != NULL)
			db_free_rows(*_r);
		RES_ROWS(*_r) = 0;
		RES_ROW_N(*_r) = 0;
	}

	SQLNumResultCols(CON_RESULT(_h), (SQLSMALLINT *)&columns);

	/* Now fetch nrows at most */
	len = sizeof(db_row_t) * nrows;
	RES_ROWS(*_r) = (struct db_row*)pkg_malloc(len);
	if (!RES_ROWS(*_r)) {
		LM_ERR("no memory left\n");
		return -5;
	}
	LM_DBG("allocated %d bytes for RES_ROWS at %p\n", len, RES_ROWS(*_r));

	LM_DBG("Now fetching %i rows at most\n", nrows);
	while(SQL_SUCCEEDED(ret = SQLFetch(CON_RESULT(_h)))) {
		/* Allocate a temporary row */
		temp_row = db_unixodbc_new_cellrow(columns);
		if (!temp_row) {
			LM_ERR("no private memory left\n");
			pkg_free(RES_ROWS(*_r));
			pkg_free(*_r);
			*_r = 0;
			return -1;
		}

		LM_DBG("fetching %d columns for row %d...\n",columns, row_n);
		for(i=0; i < columns; i++) {
			LM_DBG("fetching column %d\n",i);
			if (!db_unixodbc_load_cell(_h, i+1, temp_row + i, RES_TYPES(*_r)[i])) {
			    pkg_free(RES_ROWS(*_r));
			    db_unixodbc_free_cellrow(columns, temp_row);
			    pkg_free(*_r);
			    *_r = 0;
			    return -5;
			}
		}

		LM_DBG("got temp_row at %p\n", temp_row);

		if (db_unixodbc_list_insert(&rowstart, &rows, columns, temp_row) < 0) {
			LM_ERR("SQL result row insert failed\n");
			pkg_free(RES_ROWS(*_r));
			db_unixodbc_free_cellrow(columns, temp_row);
			pkg_free(*_r);
			*_r = 0;
			return -5;
		}

		/* Free temporary row data */
		LM_DBG("freeing temp_row at %p\n", temp_row);
		db_unixodbc_free_cellrow(columns, temp_row);
		temp_row = NULL;

		row_n++;
		if (row_n == nrows) {
			break;
		}
	}

	CON_ROW(_h) = NULL;

	RES_ROW_N(*_r) = row_n;
	if (!row_n) {
		LM_DBG("no more rows to process for db fetch");
		pkg_free(RES_ROWS(*_r));
		RES_ROWS(*_r) = 0;
		return 0;
	}

	/* Convert rows to internal format */
	memset(RES_ROWS(*_r), 0, len);
	i = 0;
	rows = rowstart;
	while(rows)
	{
		LM_DBG("converting row #%d\n", i);
		CON_ROW(_h) = rows->data;
		if (!CON_ROW(_h))
		{
			LM_ERR("string null\n");
			RES_ROW_N(*_r) = row_n;
			db_free_rows(*_r);
			return -3;
		}
		if (db_unixodbc_convert_row(_h, *_r, &(RES_ROWS(*_r)[i]), rows->lengths) < 0) {
			LM_ERR("converting fetched row #%d failed\n", i);
			RES_ROW_N(*_r) = i;
			db_free_rows(*_r);
			return -4;
		}
		i++;
		rows = rows->next;
	}
	db_unixodbc_list_destroy(rowstart);

	/* update the total number of rows processed */
	RES_LAST_ROW(*_r) += row_n;
	LM_DBG("fetch from db processed %d rows so far\n", RES_LAST_ROW(*_r));

	return 0;
}
Exemple #2
0
/*
 * Convert rows from UNIXODBC to db API representation
 */
static inline int db_unixodbc_convert_rows(const db1_con_t* _h, db1_res_t* _r)
{
	int i = 0, ret = 0;
	SQLSMALLINT columns;
	list* rows = NULL;
	list* rowstart = NULL;
	strn* temp_row = NULL;

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

	SQLNumResultCols(CON_RESULT(_h), (SQLSMALLINT *)&columns);
	temp_row = (strn*)pkg_malloc( columns*sizeof(strn) );
	if(!temp_row) {
		LM_ERR("no private memory left\n");
		return -1;
	}

	while(SQL_SUCCEEDED(ret = SQLFetch(CON_RESULT(_h))))
	{
		for(i=0; i < columns; i++)
		{
			SQLLEN indicator;
			ret = SQLGetData(CON_RESULT(_h), i+1, SQL_C_CHAR,
				temp_row[i].s, STRN_LEN, &indicator);
			if (SQL_SUCCEEDED(ret)) {
				if (indicator == SQL_NULL_DATA)
					strcpy(temp_row[i].s, "NULL");
			}
			else {
				LM_ERR("SQLGetData failed\n");
			}
		}

		if (db_unixodbc_list_insert(&rowstart, &rows, columns, temp_row) < 0) {
			LM_ERR("insert failed\n");
			pkg_free(temp_row);
			temp_row= NULL;
			return -5;
		}
		RES_ROW_N(_r)++;
	}
	/* free temporary row data */
	pkg_free(temp_row);
	CON_ROW(_h) = NULL;

	if (!RES_ROW_N(_r)) {
		RES_ROWS(_r) = 0;
		return 0;
	}

	if (db_allocate_rows(_r) != 0) {
		LM_ERR("could not allocate rows");
		db_unixodbc_list_destroy(rowstart);
		return -2;
	}

	i = 0;
	rows = rowstart;
	while(rows)
	{
		CON_ROW(_h) = rows->data;
		if (!CON_ROW(_h))
		{
			LM_ERR("string null\n");
			RES_ROW_N(_r) = i;
			db_free_rows(_r);
			db_unixodbc_list_destroy(rowstart);
			return -3;
		}
		if (db_unixodbc_convert_row(_h, _r, &(RES_ROWS(_r)[i]), rows->lengths) < 0) {
			LM_ERR("converting row failed #%d\n", i);
			RES_ROW_N(_r) = i;
			db_free_rows(_r);
			db_unixodbc_list_destroy(rowstart);
			return -4;
		}
		i++;
		rows = rows->next;
	}
	db_unixodbc_list_destroy(rowstart);
	return 0;
}