static PGresult *c_psql_exec_query_params (c_psql_database_t *db,
udb_query_t *q, c_psql_user_data_t *data)
{
char *params[db->max_params_num];
char interval[64];
int i;
if ((data == NULL) || (data->params_num == 0))
return (c_psql_exec_query_noparams (db, q));
assert (db->max_params_num >= data->params_num);
for (i = 0; i < data->params_num; ++i) {
switch (data->params[i]) {
case C_PSQL_PARAM_HOST:
params[i] = C_PSQL_IS_UNIX_DOMAIN_SOCKET (db->host)
? "localhost" : db->host;
break;
case C_PSQL_PARAM_DB:
params[i] = db->database;
break;
case C_PSQL_PARAM_USER:
params[i] = db->user;
break;
case C_PSQL_PARAM_INTERVAL:
ssnprintf (interval, sizeof (interval), "%.3f",
(db->interval > 0)
? CDTIME_T_TO_DOUBLE (db->interval)
: plugin_get_interval ());
params[i] = interval;
break;
case C_PSQL_PARAM_INSTANCE:
params[i] = db->instance;
break;
default:
assert (0);
}
}
return PQexecParams (db->conn, udb_query_get_statement (q),
data->params_num, NULL,
(const char *const *) params,
NULL, NULL, /* return text data */ 0);
} /* c_psql_exec_query_params */
static int c_psql_exec_query (c_psql_database_t *db, udb_query_t *q,
udb_query_preparation_area_t *prep_area)
{
PGresult *res;
c_psql_user_data_t *data;
const char *host;
char **column_names;
char **column_values;
int column_num;
int rows_num;
int status;
int row, col;
/* The user data may hold parameter information, but may be NULL. */
data = udb_query_get_user_data (q);
/* Versions up to `3' don't know how to handle parameters. */
if (3 <= db->proto_version)
res = c_psql_exec_query_params (db, q, data);
else if ((NULL == data) || (0 == data->params_num))
res = c_psql_exec_query_noparams (db, q);
else {
log_err ("Connection to database \"%s\" (%s) does not support "
"parameters (protocol version %d) - "
"cannot execute query \"%s\".",
db->database, db->instance, db->proto_version,
udb_query_get_name (q));
return -1;
}
column_names = NULL;
column_values = NULL;
#define BAIL_OUT(status) \
sfree (column_names); \
sfree (column_values); \
PQclear (res); \
return status
if (PGRES_TUPLES_OK != PQresultStatus (res)) {
log_err ("Failed to execute SQL query: %s",
PQerrorMessage (db->conn));
log_info ("SQL query was: %s",
udb_query_get_statement (q));
BAIL_OUT (-1);
}
rows_num = PQntuples (res);
if (1 > rows_num) {
BAIL_OUT (0);
}
column_num = PQnfields (res);
column_names = (char **) calloc (column_num, sizeof (char *));
if (NULL == column_names) {
log_err ("calloc failed.");
BAIL_OUT (-1);
}
column_values = (char **) calloc (column_num, sizeof (char *));
if (NULL == column_values) {
log_err ("calloc failed.");
BAIL_OUT (-1);
}
for (col = 0; col < column_num; ++col) {
/* Pointers returned by `PQfname' are freed by `PQclear' via
* `BAIL_OUT'. */
column_names[col] = PQfname (res, col);
if (NULL == column_names[col]) {
log_err ("Failed to resolve name of column %i.", col);
BAIL_OUT (-1);
}
}
if (C_PSQL_IS_UNIX_DOMAIN_SOCKET (db->host)
|| (0 == strcmp (db->host, "localhost")))
host = hostname_g;
else
host = db->host;
status = udb_query_prepare_result (q, prep_area, host, "postgresql",
db->instance, column_names, (size_t) column_num, db->interval);
if (0 != status) {
log_err ("udb_query_prepare_result failed with status %i.",
status);
BAIL_OUT (-1);
}
for (row = 0; row < rows_num; ++row) {
for (col = 0; col < column_num; ++col) {
/* Pointers returned by `PQgetvalue' are freed by `PQclear' via
* `BAIL_OUT'. */
column_values[col] = PQgetvalue (res, row, col);
if (NULL == column_values[col]) {
log_err ("Failed to get value at (row = %i, col = %i).",
row, col);
break;
}
}
/* check for an error */
if (col < column_num)
continue;
status = udb_query_handle_result (q, prep_area, column_values);
if (status != 0) {
log_err ("udb_query_handle_result failed with status %i.",
status);
}
} /* for (row = 0; row < rows_num; ++row) */
udb_query_finish_result (q, prep_area);
BAIL_OUT (0);
#undef BAIL_OUT
} /* c_psql_exec_query */
