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authorChristian Grothoff <christian@grothoff.org>2015-01-28 20:53:21 +0100
committerChristian Grothoff <christian@grothoff.org>2015-01-28 20:53:21 +0100
commit9c3c6295a85a03fdad9a77799e85289ce65a109b (patch)
tree4325f5a0d8f26f32effd9b2bf4c900a83a038d8a /src/pq
parentc4b63c13029b9d731b826ffab4a9d59005b0c6a5 (diff)
even cleaner separation of PostGres-specific logic, and nicer libtalerutil headers
Diffstat (limited to 'src/pq')
-rw-r--r--src/pq/Makefile.am2
-rw-r--r--src/pq/db_pq.c2
-rw-r--r--src/pq/db_pq.h186
3 files changed, 188 insertions, 2 deletions
diff --git a/src/pq/Makefile.am b/src/pq/Makefile.am
index cd7a5c93f..532d2909b 100644
--- a/src/pq/Makefile.am
+++ b/src/pq/Makefile.am
@@ -4,7 +4,7 @@ lib_LTLIBRARIES = \
libtalerpq.la
libtalerpq_la_SOURCES = \
- db_pq.c
+ db_pq.c db_pq.h
libtalerpq_la_LIBADD = \
-lgnunetutil \
diff --git a/src/pq/db_pq.c b/src/pq/db_pq.c
index 2864f3475..069827579 100644
--- a/src/pq/db_pq.c
+++ b/src/pq/db_pq.c
@@ -22,7 +22,7 @@
*/
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
-#include "taler_db_lib.h"
+#include "db_pq.h"
/**
diff --git a/src/pq/db_pq.h b/src/pq/db_pq.h
new file mode 100644
index 000000000..6e2b2b2c0
--- /dev/null
+++ b/src/pq/db_pq.h
@@ -0,0 +1,186 @@
+/*
+ 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 include/taler_db_lib.h
+ * @brief helper functions for DB interactions
+ * @author Sree Harsha Totakura <sreeharsha@totakura.in>
+ * @author Florian Dold
+ * @author Christian Grothoff
+ */
+
+#ifndef TALER_DB_LIB_H_
+#define TALER_DB_LIB_H_
+
+#include <libpq-fe.h>
+#include "taler_util.h"
+
+/**
+ * Description of a DB query parameter.
+ */
+struct TALER_DB_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_DB_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_DB_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_DB_QUERY_PARAM_PTR(x) TALER_DB_QUERY_PARAM_PTR_SIZED(x, sizeof (*(x)))
+
+
+/**
+ * Description of a DB result cell.
+ */
+struct TALER_DB_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_DB_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_DB_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_DB_RESULT_SPEC(name, dst) TALER_DB_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_DB_RESULT_SPEC_VAR(name, dst, sptr) { (void *) (dst), 0, (name), sptr }
+
+
+/**
+ * Execute a prepared statement.
+ */
+PGresult *
+TALER_DB_exec_prepared (PGconn *db_conn,
+ const char *name,
+ const struct TALER_DB_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_DB_extract_result (PGresult *result,
+ struct TALER_DB_ResultSpec *rs,
+ int row);
+
+
+int
+TALER_DB_field_isnull (PGresult *result,
+ int row,
+ const char *fname);
+
+
+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
+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);
+
+#endif /* TALER_DB_LIB_H_ */
+
+/* end of include/taler_db_lib.h */