move to new libgnunetpq library, simplifying libtalerpq

1 files changed, 358 insertions, 0 deletions

diff --git a/src/pq/pq_result_helper.c b/src/pq/pq_result_helper.c
new file mode 100644
index 000000000..c8b3b01fc
--- /dev/null
+++ b/src/pq/pq_result_helper.c
@@ -0,0 +1,358 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014, 2015, 2016 GNUnet e.V.
+
+  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 pq/pq_result_helper.c
+ * @brief functions to initialize parameter arrays
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet/gnunet_util_lib.h>
+#include "taler_pq_lib.h"
+
+
+/**
+ * Extract a currency amount from a query result according to the
+ * given specification.
+ *
+ * @param result the result to extract the amount from
+ * @param row which row of the result to extract the amount from (needed as results can have multiple rows)
+ * @param val_name name of the column with the amount's "value", must include the substring "_val".
+ * @param frac_name name of the column with the amount's "fractional" value, must include the substring "_frac".
+ * @param curr_name name of the column with the amount's currency name, must include the substring "_curr".
+ * @param[out] r_amount_nbo where to store the amount, in network byte order
+ * @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)
+ */
+static int
+extract_amount_nbo_helper (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;
+
+  /* These checks are simply to check that clients obey by our naming
+     conventions, and not for any functional reason */
+  GNUNET_assert (NULL !=
+                 strstr (val_name,
+                         "_val"));
+  GNUNET_assert (NULL !=
+                 strstr (frac_name,
+                         "_frac"));
+  GNUNET_assert (NULL !=
+                 strstr (curr_name,
+                         "_curr"));
+  /* Set return value to invalid in case we don't finish */
+  memset (r_amount_nbo,
+          0,
+          sizeof (struct TALER_AmountNBO));
+  val_num = PQfnumber (result,
+                       val_name);
+  frac_num = PQfnumber (result,
+                        frac_name);
+  curr_num = PQfnumber (result,
+                        curr_name);
+  if ( (val_num < 0) ||
+       (frac_num < 0) ||
+       (curr_num < 0) )
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  if ( (PQgetisnull (result,
+                     row,
+                     val_num)) ||
+       (PQgetisnull (result,
+                     row,
+                     frac_num)) ||
+       (PQgetisnull (result,
+                     row,
+                     curr_num)) )
+  {
+    GNUNET_break (0);
+    return GNUNET_NO;
+  }
+  /* Note that Postgres stores value in NBO internally,
+     so no conversion needed in this case */
+  r_amount_nbo->value = *(uint64_t *) PQgetvalue (result,
+                                                  row,
+                                                  val_num);
+  r_amount_nbo->fraction = *(uint32_t *) PQgetvalue (result,
+                                                     row,
+                                                     frac_num);
+  len = GNUNET_MIN (TALER_CURRENCY_LEN - 1,
+                    PQgetlength (result,
+                                 row,
+                                 curr_num));
+  memcpy (r_amount_nbo->currency,
+          PQgetvalue (result,
+                      row,
+                      curr_num),
+          len);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Extract data from a Postgres database @a result at row @a row.
+ *
+ * @param cls closure
+ * @param result where to extract data from
+ * @param int row to extract data from
+ * @param fname name (or prefix) of the fields to extract from
+ * @param[in,out] dst_size where to store size of result, may be NULL
+ * @param[out] dst where to store the result
+ * @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)
+ */ 
+static int
+extract_amount_nbo (void *cls,
+		    PGresult *result,
+		    int row,
+		    const char *fname,
+		    size_t *dst_size,
+		    void *dst)
+{
+  char *val_name;
+  char *frac_name;
+  char *curr_name;
+  int ret;
+  
+  GNUNET_asprintf (&val_name,
+		   "%s_val",
+		   fname);
+  GNUNET_asprintf (&frac_name,
+		   "%s_frac",
+		   fname);
+  GNUNET_asprintf (&curr_name,
+		   "%s_curr",
+		   fname);
+  ret = extract_amount_nbo_helper (result,
+				   row,
+				   val_name,
+				   frac_name,
+				   curr_name,
+				   dst);
+  GNUNET_free (val_name);
+  GNUNET_free (frac_name);
+  GNUNET_free (curr_name);
+  return ret;
+}
+
+
+/**
+ * Currency amount expected.
+ *
+ * @param name name of the field in the table
+ * @param[out] amount where to store the result
+ * @return array entry for the result specification to use
+ */
+struct GNUNET_PQ_ResultSpec
+TALER_PQ_result_spec_amount_nbo (const char *name,
+				 struct TALER_AmountNBO *amount)
+{
+  struct GNUNET_PQ_ResultSpec res =
+    { &extract_amount_nbo, NULL, NULL,
+      (void *) amount, sizeof (*amount), 
+      name, NULL };
+  return res;
+}
+
+
+/**
+ * Extract data from a Postgres database @a result at row @a row.
+ *
+ * @param cls closure
+ * @param result where to extract data from
+ * @param int row to extract data from
+ * @param fname name (or prefix) of the fields to extract from
+ * @param[in,out] dst_size where to store size of result, may be NULL
+ * @param[out] dst where to store the result
+ * @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)
+ */ 
+static int
+extract_amount (void *cls,
+		PGresult *result,
+		int row,
+		const char *fname,
+		size_t *dst_size,
+		void *dst)
+{
+  struct TALER_Amount *r_amount = dst;
+  char *val_name;
+  char *frac_name;
+  char *curr_name;
+  struct TALER_AmountNBO amount_nbo;
+  int ret;
+  
+  GNUNET_asprintf (&val_name,
+		   "%s_val",
+		   fname);
+  GNUNET_asprintf (&frac_name,
+		   "%s_frac",
+		   fname);
+  GNUNET_asprintf (&curr_name,
+		   "%s_curr",
+		   fname);
+  ret = extract_amount_nbo_helper (result,
+				   row,
+				   val_name,
+				   frac_name,
+				   curr_name,
+				   &amount_nbo);
+  TALER_amount_ntoh (r_amount,
+                     &amount_nbo);
+  GNUNET_free (val_name);
+  GNUNET_free (frac_name);
+  GNUNET_free (curr_name);
+  return ret;
+}
+
+
+/**
+ * Currency amount expected.
+ *
+ * @param name name of the field in the table
+ * @param[out] amount where to store the result
+ * @return array entry for the result specification to use
+ */
+struct GNUNET_PQ_ResultSpec
+TALER_PQ_result_spec_amount (const char *name,
+			     struct TALER_Amount *amount)
+{
+  struct GNUNET_PQ_ResultSpec res =
+    { &extract_amount, NULL, NULL,
+      (void *) amount, sizeof (*amount),
+      name, NULL };
+  return res;
+}
+
+
+/**
+ * Extract data from a Postgres database @a result at row @a row.
+ *
+ * @param cls closure
+ * @param result where to extract data from
+ * @param int row to extract data from
+ * @param fname name (or prefix) of the fields to extract from
+ * @param[in,out] dst_size where to store size of result, may be NULL
+ * @param[out] dst where to store the result
+ * @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)
+ */ 
+static int
+extract_json (void *cls,
+	      PGresult *result,
+	      int row,
+	      const char *fname,
+	      size_t *dst_size,
+	      void *dst)
+{
+  json_t **j_dst = dst;
+  const char *res;
+  int fnum;
+  json_error_t json_error;
+  size_t slen;
+  
+  fnum = PQfnumber (result,
+		    fname);
+  if (fnum < 0)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+		"Field `%s' does not exist in result\n",
+		fname);
+    return GNUNET_SYSERR;
+  }
+  if (PQgetisnull (result,
+		   row,
+		   fnum))
+    return GNUNET_NO;
+  slen = PQgetlength (result,
+		      row,
+		      fnum);
+  res = (const char *) PQgetvalue (result,
+				   row,
+				   fnum);
+  *j_dst = json_loadb (res,
+		       slen,
+		       JSON_REJECT_DUPLICATES,
+		       &json_error);
+  if (NULL == *j_dst)
+  {
+    TALER_json_warn (json_error);
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+		"Failed to parse JSON result for field `%s'\n",
+		fname);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function called to clean up memory allocated
+ * by a #GNUNET_PQ_ResultConverter.
+ *
+ * @param cls closure
+ * @param rd result data to clean up
+ */
+static void
+clean_json (void *cls,
+	    void *rd)
+{
+  json_t **dst = rd;
+
+  if (NULL != *dst)
+  {
+    json_decref (*dst);
+    *dst = NULL;
+  }
+}
+
+
+/**
+ * json_t expected.
+ *
+ * @param name name of the field in the table
+ * @param[out] jp where to store the result
+ * @return array entry for the result specification to use
+ */
+struct GNUNET_PQ_ResultSpec
+TALER_PQ_result_spec_json (const char *name,
+                           json_t **jp)
+{
+  struct GNUNET_PQ_ResultSpec res =
+    { &extract_json, &clean_json, NULL,
+      (void *) jp, 0, 
+      name, NULL };
+  return res;
+}
+
+/* end of pq_result_helper.c */