diff options
Diffstat (limited to 'src/backenddb/plugin_merchantdb_postgres.c')
| -rw-r--r-- | src/backenddb/plugin_merchantdb_postgres.c | 210 |
1 files changed, 182 insertions, 28 deletions
diff --git a/src/backenddb/plugin_merchantdb_postgres.c b/src/backenddb/plugin_merchantdb_postgres.c index a86bf549..61f9e6d1 100644 --- a/src/backenddb/plugin_merchantdb_postgres.c +++ b/src/backenddb/plugin_merchantdb_postgres.c @@ -44,6 +44,16 @@ struct PostgresClosure }; /** + * Error code returned by Postgres for deadlock. + */ +#define PQ_DIAG_SQLSTATE_DEADLOCK "40P01" + +/** + * Error code returned by Postgres on serialization failure. + */ +#define PQ_DIAG_SQLSTATE_SERIALIZATION_FAILURE "40001" + +/** * Extract error code. * * @param res postgres result object with error details @@ -51,6 +61,21 @@ struct PostgresClosure #define EXTRACT_DB_ERROR(res) \ PQresultErrorField(res, PG_DIAG_SQLSTATE) +/** + * Log a query error. + * + * @param result PQ result object of the query that failed + * @param conn SQL connection that was used + */ +#define QUERY_ERR(result,conn) \ + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, \ + "Query failed at %s:%u: %s/%s/%s/%s/%s\n", \ + __FILE__, __LINE__, \ + PQresultErrorField (result, PG_DIAG_MESSAGE_PRIMARY), \ + PQresultErrorField (result, PG_DIAG_MESSAGE_DETAIL), \ + PQresultErrorMessage (result), \ + PQresStatus (PQresultStatus (result)), \ + PQerrorMessage (conn)); /** * Log error from PostGres. @@ -101,6 +126,142 @@ postgres_drop_tables (void *cls) es); } +/** + * Start a transaction. + * + * @param cls the `struct PostgresClosure` with the plugin-specific state + * @return #GNUNET_OK on success + */ +static int +postgres_start (void *cls) +{ + struct PostgresClosure *pg = cls; + PGresult *result; + ExecStatusType ex; + + result = PQexec (pg->conn, + "START TRANSACTION ISOLATION LEVEL SERIALIZABLE"); + if (PGRES_COMMAND_OK != + (ex = PQresultStatus (result))) + { + TALER_LOG_ERROR ("Failed to start transaction (%s): %s\n", + PQresStatus (ex), + PQerrorMessage (pg->conn)); + GNUNET_break (0); + PQclear (result); + return GNUNET_SYSERR; + } + PQclear (result); + return GNUNET_OK; + + /** + * NOTE: this function equals 99% the one from the exchange codebase. + * The difference is that here we don't use the session->state field ( + * see original code: exchange/src/exchangedb/plugin_exchangedb_postgres.c). + * Good/bad? + */ +} + +/** + * Roll back the current transaction of a database connection. + * + * @param cls the `struct PostgresClosure` with the plugin-specific state + * @return #GNUNET_OK on success + */ +static void +postgres_rollback (void *cls) +{ + struct PostgresClosure *pg = cls; + PGresult *result; + + result = PQexec (pg->conn, + "ROLLBACK"); + GNUNET_break (PGRES_COMMAND_OK == + PQresultStatus (result)); + PQclear (result); +} + +/** + * Check the @a result's error code to see what happened. + * Also logs errors. + * + * @param pg `struct PostgresClosure` + * @param result result to check + * @return #GNUNET_OK if the request/transaction succeeded + * #GNUNET_NO if it failed but could succeed if retried + * #GNUNET_SYSERR on hard errors + */ +static int +evaluate_pq_result (struct PostgresClosure *pg, + PGresult *result) +{ + if (PGRES_COMMAND_OK != + PQresultStatus (result)) + { + const char *sqlstate; + + sqlstate = PQresultErrorField (result, + PG_DIAG_SQLSTATE); + if (NULL == sqlstate) + { + /* very unexpected... */ + GNUNET_break (0); + return GNUNET_SYSERR; + } + if ( (0 == strcmp (sqlstate, + PQ_DIAG_SQLSTATE_DEADLOCK)) || + (0 == strcmp (sqlstate, + PQ_DIAG_SQLSTATE_SERIALIZATION_FAILURE)) ) + { + /* These two can be retried and have a fair chance of working + the next time */ + QUERY_ERR (result, pg->conn); + return GNUNET_NO; + } + BREAK_DB_ERR(result); + return GNUNET_SYSERR; + } + return GNUNET_OK; + + /** + * NOTE: this function equals 99% the one from the exchange codebase. + * The difference is that here we don't use the session->state field ( + * see original code: exchange/src/exchangedb/plugin_exchangedb_postgres.c). + * Good/bad? + */ +} + +/** + * Commit the current transaction of a database connection. + * + * @param cls the `struct PostgresClosure` with the plugin-specific state + * @return #GNUNET_SYSERR on hard error, + * #GNUNET_NO if commit failed but retry may work, + * #GNUNET_OK on success + */ +static int +postgres_commit (void *cls) +{ + struct PostgresClosure *pg = cls; + PGresult *result; + int ret; + + result = PQexec (pg->conn, + "COMMIT"); + ret = evaluate_pq_result (pg, + result); + GNUNET_break (GNUNET_SYSERR != ret); + PQclear (result); + return ret; + + /** + * NOTE: this function equals 99% the one from the exchange codebase. + * The difference is that here we don't use the session->state field ( + * see original code: exchange/src/exchangedb/plugin_exchangedb_postgres.c). + * Good/bad? + */ +} + /** * Initialize merchant tables @@ -185,21 +346,6 @@ postgres_initialize (void *cls) GNUNET_PQ_EXECUTE_STATEMENT_END }; struct GNUNET_PQ_PreparedStatement ps[] = { - GNUNET_PQ_make_prepare ("get_refund_information", - "SELECT" - " merchant_deposits.coin_pub" - ",merchant_deposits.amount_with_fee_val" - ",merchant_deposits.amount_with_fee_frac" - ",merchant_deposits.amount_with_fee_curr" - ",merchant_refunds.refund_amount_val" - ",merchant_refunds.refund_amount_frac" - ",merchant_refunds.refund_amount_curr" - " FROM merchant_deposits" - " LEFT OUTER JOIN merchant_refunds USING (coin_pub)" - " WHERE merchant_deposits.coin_pub=$1" - /*FIXME, GROUP BY better than ORDER BY?*/ - " ORDER BY merchant_deposits.coin_pub", - 1), GNUNET_PQ_make_prepare ("insert_transaction", "INSERT INTO merchant_transactions" "(h_contract_terms" @@ -1612,6 +1758,7 @@ postgres_get_refunds_from_contract_terms_hash (void *cls, * * @param cls closure * @param h_contract_terms + * @param merchant_pub merchant's instance public key * @param refund maximum refund to return to the customer for this contract * @param reason 0-terminated UTF-8 string giving the reason why the customer * got a refund (free form, business-specific) @@ -1623,6 +1770,7 @@ postgres_get_refunds_from_contract_terms_hash (void *cls, int postgres_increase_refund_for_contract (void *cls, const struct GNUNET_HashCode *h_contract_terms, + const struct TALER_MerchantPublicKeyP *merchant_pub, const struct TALER_Amount *refund, const char *reason) { @@ -1633,11 +1781,13 @@ postgres_increase_refund_for_contract (void *cls, struct GNUNET_PQ_QueryParam params[] = { GNUNET_PQ_query_param_auto_from_type (h_contract_terms), + GNUNET_PQ_query_param_auto_from_type (merchant_pub), GNUNET_PQ_query_param_end }; + /*FIXME: begin transaction*/ result = GNUNET_PQ_exec_prepared (pg->conn, - "get_refund_information", + "find_deposits", params); if (PGRES_TUPLES_OK != PQresultStatus (result)) @@ -1647,26 +1797,27 @@ postgres_increase_refund_for_contract (void *cls, return GNUNET_SYSERR; } - /*FIXME, logic incomplete*/ + if (0 == PQntuples (result)) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "Unknown contract: %s (merchant_pub: %s), no refund possible\n", + GNUNET_h2s (h_contract_terms), + TALER_B2S (merchant_pub)); + return GNUNET_SYSERR; + } + + /*FIXME, logic incomplete!!*/ - GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, - "increase DB routine\n"); for (i=0;i<PQntuples (result);i++) { - GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, - "increase DB routine loop (%d)\n", - i); struct TALER_CoinSpendPublicKeyP coin_pub; struct TALER_Amount amount_with_fee; - struct TALER_Amount refund_amount_awarded; struct GNUNET_PQ_ResultSpec rs[] = { - GNUNET_PQ_result_spec_auto_from_type ("merchant_deposits.coin_pub", + GNUNET_PQ_result_spec_auto_from_type ("coin_pub", &coin_pub), - TALER_PQ_result_spec_amount ("merchant_deposits.amount_with_fee", + TALER_PQ_result_spec_amount ("amount_with_fee", &amount_with_fee), - TALER_PQ_result_spec_amount ("merchant_refunds.refund_amount", - &refund_amount_awarded), GNUNET_PQ_result_spec_end }; @@ -1679,7 +1830,10 @@ postgres_increase_refund_for_contract (void *cls, PQclear (result); return GNUNET_SYSERR; } - + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Found: coin_pub '%s' amount_with_fee '%s'.\n", + TALER_B2S (&coin_pub), + TALER_amount_to_string (&amount_with_fee)); } return GNUNET_OK; |