/* This file is part of GNUnet Copyright (C) 2017 GNUnet e.V. GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, If not, see */ /** * @file pq/pq_eval.c * @brief functions to execute SQL statements with arguments and/or results (PostGres) * @author Christian Grothoff */ #include "platform.h" #include "gnunet_util_lib.h" #include "gnunet_pq_lib.h" /** * Error code returned by Postgres for deadlock. */ #define PQ_DIAG_SQLSTATE_DEADLOCK "40P01" /** * Error code returned by Postgres for uniqueness violation. */ #define PQ_DIAG_SQLSTATE_UNIQUE_VIOLATION "23505" /** * Error code returned by Postgres on serialization failure. */ #define PQ_DIAG_SQLSTATE_SERIALIZATION_FAILURE "40001" /** * Check the @a result's error code to see what happened. * Also logs errors. * * @param connection connection to execute the statement in * @param statement_name name of the statement that created @a result * @param result result to check * @return status code from the result, mapping PQ status * codes to `enum GNUNET_PQ_QueryStatus`. Never * returns positive values as this function does * not look at the result set. * @deprecated (low level, let's see if we can do with just the high-level functions) */ enum GNUNET_PQ_QueryStatus GNUNET_PQ_eval_result (PGconn *connection, const char *statement_name, PGresult *result) { ExecStatusType est; est = PQresultStatus (result); if ( (PGRES_COMMAND_OK != est) && (PGRES_TUPLES_OK != est) ) { const char *sqlstate; sqlstate = PQresultErrorField (result, PG_DIAG_SQLSTATE); if (NULL == sqlstate) { /* very unexpected... */ GNUNET_break (0); return GNUNET_PQ_STATUS_HARD_ERROR; } 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 */ GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "pq", "Query `%s' failed with result: %s/%s/%s/%s/%s\n", statement_name, PQresultErrorField (result, PG_DIAG_MESSAGE_PRIMARY), PQresultErrorField (result, PG_DIAG_MESSAGE_DETAIL), PQresultErrorMessage (result), PQresStatus (PQresultStatus (result)), PQerrorMessage (connection)); return GNUNET_PQ_STATUS_SOFT_ERROR; } GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "pq", "Query `%s' failed with result: %s/%s/%s/%s/%s\n", statement_name, PQresultErrorField (result, PG_DIAG_MESSAGE_PRIMARY), PQresultErrorField (result, PG_DIAG_MESSAGE_DETAIL), PQresultErrorMessage (result), PQresStatus (PQresultStatus (result)), PQerrorMessage (connection)); return GNUNET_PQ_STATUS_HARD_ERROR; } return GNUNET_PQ_STATUS_SUCCESS_NO_RESULTS; } /** * Execute a named prepared @a statement that is NOT a SELECT * statement in @a connnection using the given @a params. Returns the * resulting session state. * * @param connection connection to execute the statement in * @param statement_name name of the statement * @param params parameters to give to the statement (#GNUNET_PQ_query_param_end-terminated) * @return status code from the result, mapping PQ status * codes to `enum GNUNET_PQ_QueryStatus`. If the * statement was a DELETE or UPDATE statement, the * number of affected rows is returned. */ enum GNUNET_PQ_QueryStatus GNUNET_PQ_eval_prepared_non_select (PGconn *connection, const char *statement_name, const struct GNUNET_PQ_QueryParam *params) { PGresult *result; enum GNUNET_PQ_QueryStatus qs; result = GNUNET_PQ_exec_prepared (connection, statement_name, params); qs = GNUNET_PQ_eval_result (connection, statement_name, result); if (GNUNET_PQ_STATUS_SUCCESS_NO_RESULTS == qs) { const char *tuples; /* What an awful API, this function really does return a string */ tuples = PQcmdTuples (result); if (NULL != tuples) qs = strtol (tuples, NULL, 10); } PQclear (result); return qs; } /** * Execute a named prepared @a statement that is a SELECT statement * which may return multiple results in @a connection using the given * @a params. Call @a rh with the results. Returns the query * status including the number of results given to @a rh (possibly zero). * @a rh will not have been called if the return value is negative. * * @param connection connection to execute the statement in * @param statement_name name of the statement * @param params parameters to give to the statement (#GNUNET_PQ_query_param_end-terminated) * @param rh function to call with the result set, NULL to ignore * @param rh_cls closure to pass to @a rh * @return status code from the result, mapping PQ status * codes to `enum GNUNET_PQ_QueryStatus`. */ enum GNUNET_PQ_QueryStatus GNUNET_PQ_eval_prepared_multi_select (PGconn *connection, const char *statement_name, const struct GNUNET_PQ_QueryParam *params, GNUNET_PQ_PostgresResultHandler rh, void *rh_cls) { PGresult *result; enum GNUNET_PQ_QueryStatus qs; unsigned int ret; result = GNUNET_PQ_exec_prepared (connection, statement_name, params); qs = GNUNET_PQ_eval_result (connection, statement_name, result); if (qs < 0) { PQclear (result); return qs; } ret = PQntuples (result); if (NULL != rh) rh (rh_cls, result, ret); PQclear (result); return ret; } /** * Execute a named prepared @a statement that is a SELECT statement * which must return a single result in @a connection using the given * @a params. Stores the result (if any) in @a rs, which the caller * must then clean up using #GNUNET_PQ_cleanup_result() if the return * value was #GNUNET_PQ_STATUS_SUCCESS_ONE_RESULT. Returns the * resulting session status. * * @param connection connection to execute the statement in * @param statement_name name of the statement * @param params parameters to give to the statement (#GNUNET_PQ_query_param_end-terminated) * @param[in,out] rs result specification to use for storing the result of the query * @return status code from the result, mapping PQ status * codes to `enum GNUNET_PQ_QueryStatus`. */ enum GNUNET_PQ_QueryStatus GNUNET_PQ_eval_prepared_singleton_select (PGconn *connection, const char *statement_name, const struct GNUNET_PQ_QueryParam *params, struct GNUNET_PQ_ResultSpec *rs) { PGresult *result; enum GNUNET_PQ_QueryStatus qs; result = GNUNET_PQ_exec_prepared (connection, statement_name, params); qs = GNUNET_PQ_eval_result (connection, statement_name, result); if (qs < 0) { PQclear (result); return qs; } if (0 == PQntuples (result)) { PQclear (result); return GNUNET_PQ_STATUS_SUCCESS_NO_RESULTS; } if (1 != PQntuples (result)) { /* more than one result, but there must be at most one */ GNUNET_break (0); PQclear (result); return GNUNET_PQ_STATUS_HARD_ERROR; } if (GNUNET_OK != GNUNET_PQ_extract_result (result, rs, 0)) { PQclear (result); return GNUNET_PQ_STATUS_HARD_ERROR; } PQclear (result); return GNUNET_PQ_STATUS_SUCCESS_ONE_RESULT; } /* end of pq/pq_eval.c */