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-rw-r--r--src/util/db.c196
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diff --git a/src/util/db.c b/src/util/db.c
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+++ b/src/util/db.c
@@ -0,0 +1,196 @@
+/*
+ This file is part of TALER
+ (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 <http://www.gnu.org/licenses/>
+*/
+
+
+/**
+ * @file util/db.c
+ * @brief helper functions for DB interactions
+ * @author Sree Harsha Totakura <sreeharsha@totakura.in>
+ * @author Florian Dold
+ */
+
+#include "platform.h"
+#include <gnunet/gnunet_util_lib.h>
+#include "taler_db_lib.h"
+
+
+/**
+ * Execute a prepared statement.
+ */
+PGresult *
+TALER_DB_exec_prepared (PGconn *db_conn,
+ const char *name,
+ const struct TALER_DB_QueryParam *params)
+{
+ unsigned len;
+ unsigned i;
+
+ /* count the number of parameters */
+
+ {
+ const struct TALER_DB_QueryParam *x;
+ for (len = 0, x = params;
+ x->more;
+ len +=1, x += 1);
+ }
+
+ /* new scope to allow stack allocation without alloca */
+
+ {
+ void *param_values[len];
+ int param_lengths[len];
+ int param_formats[len];
+
+ for (i = 0; i < len; i += 1)
+ {
+ param_values[i] = (void *) params[i].data;
+ param_lengths[i] = params[i].size;
+ param_formats[i] = 1;
+ }
+ return PQexecPrepared (db_conn, name, len,
+ (const char **) param_values, param_lengths, param_formats, 1);
+ }
+}
+
+
+/**
+ * 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_DB_extract_result (PGresult *result,
+ struct TALER_DB_ResultSpec *rs,
+ int row)
+{
+ int had_null = GNUNET_NO;
+
+ for (; NULL != rs->fname; rs += 1)
+ {
+ int fnum;
+ fnum = PQfnumber (result, rs->fname);
+ if (fnum < 0)
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "field '%s' does not exist in result\n", rs->fname);
+ return GNUNET_SYSERR;
+ }
+
+ /* if a field is null, continue but
+ * remember that we now return a different result */
+
+ if (PQgetisnull (result, row, fnum))
+ {
+ had_null = GNUNET_YES;
+ continue;
+ }
+ const char *res;
+ if (rs->dst_size != PQgetlength (result, row, fnum))
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "field '%s' has wrong size (got %u, expected %u)\n",
+ rs->fname, (int) PQgetlength (result, row, fnum), (int) rs->dst_size);
+ return GNUNET_SYSERR;
+ }
+ res = PQgetvalue (result, row, fnum);
+ GNUNET_assert (NULL != res);
+ memcpy (rs->dst, res, rs->dst_size);
+ }
+ if (GNUNET_YES == had_null)
+ return GNUNET_NO;
+ return GNUNET_YES;
+}
+
+
+int
+TALER_DB_field_isnull (PGresult *result,
+ int row,
+ const char *fname)
+{
+ int fnum;
+ fnum = PQfnumber (result, fname);
+ GNUNET_assert (fnum >= 0);
+ if (PQgetisnull (result, row, fnum))
+ return GNUNET_YES;
+ return GNUNET_NO;
+}
+
+
+int
+TALER_DB_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 val_num;
+ int frac_num;
+ int curr_num;
+ int len;
+
+ GNUNET_assert (NULL != strstr (val_name, "_val"));
+ GNUNET_assert (NULL != strstr (frac_name, "_frac"));
+ GNUNET_assert (NULL != strstr (curr_name, "_curr"));
+
+ val_num = PQfnumber (result, val_name);
+ GNUNET_assert (val_num >= 0);
+ frac_num = PQfnumber (result, frac_name);
+ GNUNET_assert (frac_num >= 0);
+ curr_num = PQfnumber (result, curr_name);
+ GNUNET_assert (curr_num >= 0);
+
+ r_amount_nbo->value = *(uint32_t *) PQgetvalue (result, row, val_num);
+ r_amount_nbo->fraction = *(uint32_t *) PQgetvalue (result, row, frac_num);
+ memset (r_amount_nbo->currency, 0, TALER_CURRENCY_LEN);
+ // FIXME: overflow?
+ len = PQgetlength (result, row, curr_num);
+ len = GNUNET_MIN (TALER_CURRENCY_LEN, len);
+ memcpy (r_amount_nbo->currency, PQgetvalue (result, row, curr_num), len);
+ r_amount_nbo->currency[TALER_CURRENCY_LEN - 1] = '\0';
+
+ return GNUNET_OK;
+}
+
+
+int
+TALER_DB_extract_amount (PGresult *result,
+ int row,
+ const char *val_name,
+ const char *frac_name,
+ const char *curr_name,
+ struct TALER_Amount *r_amount)
+{
+ struct TALER_AmountNBO amount_nbo;
+
+ (void)
+ TALER_DB_extract_amount_nbo (result,
+ row,
+ val_name,
+ frac_name,
+ curr_name,
+ &amount_nbo);
+ r_amount->value = ntohl (amount_nbo.value);
+ r_amount->fraction = ntohl (amount_nbo.fraction);
+ (void) strncpy (r_amount->currency, amount_nbo.currency, TALER_CURRENCY_LEN);
+
+ return GNUNET_OK;
+}
+
+/* end of util/db.c */