diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/exchangedb/plugin_exchangedb_postgres.c | 128 |
1 files changed, 79 insertions, 49 deletions
diff --git a/src/exchangedb/plugin_exchangedb_postgres.c b/src/exchangedb/plugin_exchangedb_postgres.c index 6536bdc3..d06fc6a1 100644 --- a/src/exchangedb/plugin_exchangedb_postgres.c +++ b/src/exchangedb/plugin_exchangedb_postgres.c @@ -436,7 +436,8 @@ postgres_get_session (void *cls) ",expiration_date" ",gc_date" ") VALUES " - "($1, $2, $3, $4, $5, $6);", + "($1, $2, $3, $4, $5, $6)" + " ON CONFLICT DO NOTHING;", 6), /* Used in #postgres_insert_reserve_closed() */ GNUNET_PQ_make_prepare ("reserves_close_insert", @@ -3442,36 +3443,25 @@ postgres_reserves_in_insert (void *cls, uint64_t wire_ref) { struct PostgresClosure *pg = cls; - enum GNUNET_DB_QueryStatus reserve_exists; - enum GNUNET_DB_QueryStatus qs; + enum GNUNET_DB_QueryStatus qs1; struct TALER_EXCHANGEDB_Reserve reserve; struct GNUNET_TIME_Absolute expiry; reserve.pub = *reserve_pub; - reserve_exists = postgres_reserves_get (cls, - session, - &reserve); - if (0 > reserve_exists) - { - GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == reserve_exists); - return reserve_exists; - } + expiry = GNUNET_TIME_absolute_add (execution_time, + pg->idle_reserve_expiration_time); + (void) GNUNET_TIME_round_abs (&expiry); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Creating reserve %s with expiration in %s\n", TALER_B2S (reserve_pub), GNUNET_STRINGS_relative_time_to_string ( pg->idle_reserve_expiration_time, GNUNET_NO)); - expiry = GNUNET_TIME_absolute_add (execution_time, - pg->idle_reserve_expiration_time); - (void) GNUNET_TIME_round_abs (&expiry); - if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == reserve_exists) + /* Optimistically assume this is a new reserve, create balance for the first + time; we do this before adding the actual transaction to "reserves_in", + as for a new reserve it can't be a duplicate 'add' operation, and as + the 'add' operation may need the reserve entry as a foreign key. */ { - /* New reserve, create balance for the first time; we do this - before adding the actual transaction to "reserves_in", as - for a new reserve it can't be a duplicate 'add' operation, - and as the 'add' operation may need the reserve entry - as a foreign key. */ struct GNUNET_PQ_QueryParam params[] = { GNUNET_PQ_query_param_auto_from_type (reserve_pub), GNUNET_PQ_query_param_string (sender_account_details), @@ -3483,24 +3473,16 @@ postgres_reserves_in_insert (void *cls, GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Reserve does not exist; creating a new one\n"); - qs = GNUNET_PQ_eval_prepared_non_select (session->conn, - "reserve_create", - params); - if (0 > qs) - { - GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR != qs); - return qs; - } - if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs) - { - /* Maybe DB did not detect serializiability error already, - but clearly there must be one. Still odd. */ - GNUNET_break (0); - return GNUNET_DB_STATUS_SOFT_ERROR; - } + /* Note: query uses 'on conflict do nothing' */ + qs1 = GNUNET_PQ_eval_prepared_non_select (session->conn, + "reserve_create", + params); + if (qs1 < 0) + return qs1; } + /* Create new incoming transaction, "ON CONFLICT DO NOTHING" - is used to guard against duplicates. */ + is again used to guard against duplicates. */ { struct GNUNET_PQ_QueryParam params[] = { GNUNET_PQ_query_param_auto_from_type (&reserve.pub), @@ -3511,26 +3493,59 @@ postgres_reserves_in_insert (void *cls, TALER_PQ_query_param_absolute_time (&execution_time), GNUNET_PQ_query_param_end }; + enum GNUNET_DB_QueryStatus qs2; - qs = GNUNET_PQ_eval_prepared_non_select (session->conn, - "reserves_in_add_transaction", - params); - if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT != qs) + qs2 = GNUNET_PQ_eval_prepared_non_select (session->conn, + "reserves_in_add_transaction", + params); + if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT != qs2) { - GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR != qs); - return qs; + GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR != qs2); + return qs2; + } + if (0 >= qs2) + { + /* Transaction was already known or error. We are finished. */ + return qs2; + } + } + if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == qs1) + return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT; /* new reserve, we are finished */ + + /* we were wrong with our optimistic assumption: + reserve does exist, need to do an update instead */ + { + enum GNUNET_DB_QueryStatus reserve_exists; + + reserve_exists = postgres_reserves_get (cls, + session, + &reserve); + switch (reserve_exists) + { + case GNUNET_DB_STATUS_HARD_ERROR: + GNUNET_break (0); + return reserve_exists; + case GNUNET_DB_STATUS_SOFT_ERROR: + return reserve_exists; + case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS: + /* First we got a conflict, but then we cannot select? Very strange. */ + GNUNET_break (0); + return GNUNET_DB_STATUS_SOFT_ERROR; + case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT: + /* continued below */ + break; } } - if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == reserve_exists) { + struct TALER_EXCHANGEDB_Reserve updated_reserve; + enum GNUNET_DB_QueryStatus qs3; + /* If the reserve already existed, we need to still update the balance; we do this after checking for duplication, as otherwise we might have to actually pay the cost to roll this back for duplicate transactions; like this, we should virtually never actually have to rollback anything. */ - struct TALER_EXCHANGEDB_Reserve updated_reserve; - updated_reserve.pub = reserve.pub; if (0 > TALER_amount_add (&updated_reserve.balance, @@ -3548,11 +3563,26 @@ postgres_reserves_in_insert (void *cls, updated_reserve.gc = GNUNET_TIME_absolute_max (updated_reserve.expiry, reserve.gc); (void) GNUNET_TIME_round_abs (&updated_reserve.gc); - return reserves_update (cls, - session, - &updated_reserve); + qs3 = reserves_update (cls, + session, + &updated_reserve); + switch (qs3) + { + case GNUNET_DB_STATUS_HARD_ERROR: + GNUNET_break (0); + return qs3; + case GNUNET_DB_STATUS_SOFT_ERROR: + return qs3; + case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS: + /* How can the UPDATE not work here? Very strange. */ + GNUNET_break (0); + return GNUNET_DB_STATUS_HARD_ERROR; + case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT: + /* continued below */ + break; + } + return qs3; } - return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT; } |