From eae1896a4bfc02b5d7586f81bbedfea69b29acc8 Mon Sep 17 00:00:00 2001 From: Christian Grothoff Date: Fri, 27 Mar 2015 19:58:40 +0100 Subject: major rename-fest for more constent symbol names --- src/include/taler_pq_lib.h | 188 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 188 insertions(+) create mode 100644 src/include/taler_pq_lib.h (limited to 'src/include/taler_pq_lib.h') diff --git a/src/include/taler_pq_lib.h b/src/include/taler_pq_lib.h new file mode 100644 index 000000000..3cfd27f91 --- /dev/null +++ b/src/include/taler_pq_lib.h @@ -0,0 +1,188 @@ +/* + This file is part of TALER + Copyright (C) 2014 Christian Grothoff (and other contributing authors) + + 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, If not, see +*/ +/** + * @file pq/taler_pq_lib.h + * @brief helper functions for DB interactions + * @author Sree Harsha Totakura + * @author Florian Dold + * @author Christian Grothoff + */ +#ifndef TALER_PQ_LIB_H_ +#define TALER_PQ_LIB_H_ + +#include +#include "taler_util.h" + +/** + * Description of a DB query parameter. + */ +struct TALER_PQ_QueryParam +{ + /** + * Data or NULL + */ + const void *data; + + /** + * Size of @e data + */ + size_t size; + + /** + * Non-null if this is not the last parameter. + * This allows for null as sentinal value. + */ + int more; +}; + +/** + * End of query parameter specification. + */ +#define TALER_PQ_QUERY_PARAM_END { NULL, 0, 0 } + +/** + * Generate fixed-size query parameter with size given explicitly. + * + * @param x pointer to the query parameter to pass + * @param s number of bytes of @a x to use for the query + */ +#define TALER_PQ_QUERY_PARAM_PTR_SIZED(x, s) { (x), (s), 1 } + +/** + * Generate fixed-size query parameter with size determined + * by variable type. + * + * @param x pointer to the query parameter to pass. + */ +#define TALER_PQ_QUERY_PARAM_PTR(x) TALER_PQ_QUERY_PARAM_PTR_SIZED(x, sizeof (*(x))) + + +/** + * Description of a DB result cell. + */ +struct TALER_PQ_ResultSpec +{ + /** + * Destination for the data. + */ + void *dst; + + /** + * Allowed size for the data, 0 for variable-size + * (in this case, the type of @e dst is a `void **` + * and we need to allocate a buffer of the right size). + */ + size_t dst_size; + + /** + * Field name of the desired result. + */ + char *fname; + + /** + * Actual size of the result. + */ + size_t *result_size; + +}; + + +/** + * End of result parameter specification. + */ +#define TALER_PQ_RESULT_SPEC_END { NULL, 0, NULL, NULL } + +/** + * We expect a fixed-size result, with size given explicitly + * + * @param name name of the field in the table + * @param dst point to where to store the result + * @param s number of bytes we should use in @a dst + */ +#define TALER_PQ_RESULT_SPEC_SIZED(name, dst, s) { (void *) (dst), (s), (name), NULL } + +/** + * We expect a fixed-size result, with size determined by the type of `* dst` + * + * @param name name of the field in the table + * @param dst point to where to store the result, type fits expected result size + */ +#define TALER_PQ_RESULT_SPEC(name, dst) TALER_PQ_RESULT_SPEC_SIZED(name, dst, sizeof (*(dst))) + +/** + * Variable-size result expected. + * + * @param name name of the field in the table + * @param dst where to store the result (of type void **), to be allocated + * @param sptr pointer to a `size_t` for where to store the size of @a dst + */ +#define TALER_PQ_RESULT_SPEC_VAR(name, dst, sptr) { (void *) (dst), 0, (name), sptr } + + +/** + * Execute a prepared statement. + */ +PGresult * +TALER_PQ_exec_prepared (PGconn *db_conn, + const char *name, + const struct TALER_PQ_QueryParam *params); + + +/** + * Extract results from a query result according to the given specification. + * If colums are NULL, the destination is not modified, and GNUNET_NO + * is returned. + * + * @return + * #GNUNET_YES if all results could be extracted + * #GNUNET_NO if at least one result was NULL + * #GNUNET_SYSERR if a result was invalid (non-existing field) + */ +int +TALER_PQ_extract_result (PGresult *result, + struct TALER_PQ_ResultSpec *rs, + int row); + + +int +TALER_PQ_field_isnull (PGresult *result, + int row, + const char *fname); + + +int +TALER_PQ_extract_amount_nbo (PGresult *result, + int row, + const char *val_name, + const char *frac_name, + const char *curr_name, + struct TALER_AmountNBO *r_amount_nbo); + + +int +TALER_PQ_extract_amount (PGresult *result, + int row, + const char *val_name, + const char *frac_name, + const char *curr_name, + struct TALER_Amount *r_amount); + + + + +#endif /* TALER_PQ_LIB_H_ */ + +/* end of db/taler_pq_lib.h */ -- cgit v1.2.3