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Diffstat (limited to 'src/backenddb/pg_lookup_products.c')
-rw-r--r-- | src/backenddb/pg_lookup_products.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/backenddb/pg_lookup_products.c b/src/backenddb/pg_lookup_products.c new file mode 100644 index 00000000..fa2887a8 --- /dev/null +++ b/src/backenddb/pg_lookup_products.c @@ -0,0 +1,155 @@ +/* + This file is part of TALER + Copyright (C) 2022 Taler Systems SA + + TALER 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. + + TALER 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 + TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/> + */ +/** + * @file backenddb/pg_lookup_products.c + * @brief Implementation of the lookup_products function for Postgres + * @author Iván Ávalos + */ +#include "platform.h" +#include <taler/taler_error_codes.h> +#include <taler/taler_dbevents.h> +#include <taler/taler_pq_lib.h> +#include "pg_lookup_products.h" +#include "pg_helper.h" + +/** + * Context used for TMH_PG_lookup_products(). + */ +struct LookupProductsContext +{ + /** + * Function to call with the results. + */ + TALER_MERCHANTDB_ProductsCallback cb; + + /** + * Closure for @a cb. + */ + void *cb_cls; + + /** + * Did database result extraction fail? + */ + bool extract_failed; +}; + + +/** + * Function to be called with the results of a SELECT statement + * that has returned @a num_results results about products. + * + * @param[in,out] cls of type `struct LookupProductsContext *` + * @param result the postgres result + * @param num_results the number of results in @a result + */ +static void +lookup_products_cb (void *cls, + PGresult *result, + unsigned int num_results) +{ + struct LookupProductsContext *plc = cls; + + for (unsigned int i = 0; i < num_results; i++) + { + char *product_id; + uint64_t product_serial; + struct GNUNET_PQ_ResultSpec rs[] = { + GNUNET_PQ_result_spec_string ("product_id", + &product_id), + GNUNET_PQ_result_spec_uint64 ("product_serial", + &product_serial), + GNUNET_PQ_result_spec_end + }; + + if (GNUNET_OK != + GNUNET_PQ_extract_result (result, + rs, + i)) + { + GNUNET_break (0); + plc->extract_failed = true; + return; + } + plc->cb (plc->cb_cls, + product_serial, + product_id); + GNUNET_PQ_cleanup_result (rs); + } +} + + +enum GNUNET_DB_QueryStatus +TMH_PG_lookup_products (void *cls, + const char *instance_id, + uint64_t offset, + int64_t limit, + TALER_MERCHANTDB_ProductsCallback cb, + void *cb_cls) +{ + struct PostgresClosure *pg = cls; + uint64_t plimit = (uint64_t) ((limit < 0) ? -limit : limit); + struct LookupProductsContext plc = { + .cb = cb, + .cb_cls = cb_cls, + /* Can be overwritten by the lookup_products_cb */ + .extract_failed = false, + }; + struct GNUNET_PQ_QueryParam params[] = { + GNUNET_PQ_query_param_string (instance_id), + GNUNET_PQ_query_param_uint64 (&offset), + GNUNET_PQ_query_param_uint64 (&plimit), + GNUNET_PQ_query_param_end + }; + enum GNUNET_DB_QueryStatus qs; + + check_connection (pg); + PREPARE (pg, + "lookup_products_asc", + "SELECT" + " product_id" + " ,product_serial" + " FROM merchant_inventory" + " JOIN merchant_instances" + " USING (merchant_serial)" + " WHERE merchant_instances.merchant_id=$1" + " AND product_serial > $2" + " ORDER BY product_serial ASC" + " LIMIT $3"); + PREPARE (pg, + "lookup_products_desc", + "SELECT" + " product_id" + " ,product_serial" + " FROM merchant_inventory" + " JOIN merchant_instances" + " USING (merchant_serial)" + " WHERE merchant_instances.merchant_id=$1" + " AND product_serial < $2" + " ORDER BY product_serial DESC" + " LIMIT $3"); + qs = GNUNET_PQ_eval_prepared_multi_select ( + pg->conn, + (limit > 0) + ? "lookup_products_asc" + : "lookup_products_desc", + params, + &lookup_products_cb, + &plc); + /* If there was an error inside lookup_products_cb, return a hard error. */ + if (plc.extract_failed) + return GNUNET_DB_STATUS_HARD_ERROR; + return qs; +} |