/**
* Ends a transaction and rollsback the changes (SQL ROLLBACK)
* \param _h database handle
* \return 1 if there was something to rollback, 0 if not, negative on failure
*/
int db_postgres_abort_transaction(db1_con_t* _h)
{
db1_res_t *res = NULL;
str query_str = str_init("ROLLBACK");
if (!_h) {
LM_ERR("invalid parameter value\n");
return -1;
}
if (CON_TRANSACTION(_h) == 0) {
LM_DBG("nothing to rollback\n");
return 0;
}
/* Whether the rollback succeeds or not we need to _end_ the
transaction now or all future starts will fail */
CON_TRANSACTION(_h) = 0;
if (db_postgres_raw_query(_h, &query_str, &res) < 0)
{
LM_ERR("executing raw_query\n");
return -1;
}
if (res) db_postgres_free_result(_h, res);
return 1;
}
/**
* Starts a single transaction that will consist of one or more queries (SQL BEGIN)
* \param _h database handle
* \return 0 on success, negative on failure
*/
int db_postgres_start_transaction(db1_con_t* _h)
{
db1_res_t *res = NULL;
str query_str = str_init("BEGIN");
if (!_h) {
LM_ERR("invalid parameter value\n");
return -1;
}
if (CON_TRANSACTION(_h) == 1) {
LM_ERR("transaction already started\n");
return -1;
}
if (db_postgres_raw_query(_h, &query_str, &res) < 0)
{
LM_ERR("executing raw_query\n");
return -1;
}
if (res) db_postgres_free_result(_h, res);
CON_TRANSACTION(_h) = 1;
return 0;
}
/**
* Ends a transaction and commits the changes (SQL COMMIT)
* \param _h database handle
* \return 0 on success, negative on failure
*/
int db_postgres_end_transaction(db1_con_t* _h)
{
db1_res_t *res = NULL;
str query_str = str_init("COMMIT");
if (!_h) {
LM_ERR("invalid parameter value\n");
return -1;
}
if (CON_TRANSACTION(_h) == 0) {
LM_ERR("transaction not in progress\n");
return -1;
}
if (db_postgres_raw_query(_h, &query_str, &res) < 0)
{
LM_ERR("executing raw_query\n");
return -1;
}
if (res) db_postgres_free_result(_h, res);
/* Only _end_ the transaction after the raw_query. That way, if the
raw_query fails, and the calling module does an abort_transaction()
to clean-up, a ROLLBACK will be sent to the DB. */
CON_TRANSACTION(_h) = 0;
return 0;
}
/**
* Starts a single transaction that will consist of one or more queries (SQL BEGIN)
* \param _h database handle
* \return 0 on success, negative on failure
*/
int db_postgres_start_transaction(db1_con_t* _h, db_locking_t _l)
{
db1_res_t *res = NULL;
str begin_str = str_init("BEGIN");
str lock_start_str = str_init("LOCK TABLE ");
str lock_write_end_str = str_init(" IN EXCLUSIVE MODE");
str lock_full_end_str = str_init(" IN ACCESS EXCLUSIVE MODE");
str *lock_end_str = &lock_write_end_str;
str lock_str = {0, 0};
if (!_h) {
LM_ERR("invalid parameter value\n");
return -1;
}
if (CON_TRANSACTION(_h) == 1) {
LM_ERR("transaction already started\n");
return -1;
}
if (db_postgres_raw_query(_h, &begin_str, &res) < 0)
{
LM_ERR("executing raw_query\n");
return -1;
}
if (res) db_postgres_free_result(_h, res);
CON_TRANSACTION(_h) = 1;
switch(_l)
{
case DB_LOCKING_NONE:
break;
case DB_LOCKING_FULL:
lock_end_str = &lock_full_end_str;
/* Fall-thru */
case DB_LOCKING_WRITE:
if ((lock_str.s = pkg_malloc((lock_start_str.len + CON_TABLE(_h)->len + lock_end_str->len) * sizeof(char))) == NULL)
{
LM_ERR("allocating pkg memory\n");
goto error;
}
memcpy(lock_str.s, lock_start_str.s, lock_start_str.len);
lock_str.len += lock_start_str.len;
memcpy(lock_str.s + lock_str.len, CON_TABLE(_h)->s, CON_TABLE(_h)->len);
lock_str.len += CON_TABLE(_h)->len;
memcpy(lock_str.s + lock_str.len, lock_end_str->s, lock_end_str->len);
lock_str.len += lock_end_str->len;
if (db_postgres_raw_query(_h, &lock_str, &res) < 0)
{
LM_ERR("executing raw_query\n");
goto error;
}
if (res) db_postgres_free_result(_h, res);
if (lock_str.s) pkg_free(lock_str.s);
break;
default:
LM_WARN("unrecognised lock type\n");
goto error;
}
return 0;
error:
if (lock_str.s) pkg_free(lock_str.s);
db_postgres_abort_transaction(_h);
return -1;
}