first refactoring of JSON logic to address #4150 and #4237

1 files changed, 146 insertions, 0 deletions

diff --git a/src/json/json_helper.c b/src/json/json_helper.c
new file mode 100644
index 000000000..b61fe21a6
--- /dev/null
+++ b/src/json/json_helper.c
@@ -0,0 +1,146 @@
+/*
+  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 json/json_helper.c
+ * @brief helper functions to generate specifications to parse
+ *        Taler-specific JSON objects with libgnunetjson
+ * @author Sree Harsha Totakura <sreeharsha@totakura.in>
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet/gnunet_util_lib.h>
+#include "taler_util.h"
+#include "taler_json_lib.h"
+
+
+/**
+ * Convert a TALER amount to a JSON object.
+ *
+ * @param amount the amount
+ * @return a json object describing the amount
+ */
+json_t *
+TALER_JSON_from_amount (const struct TALER_Amount *amount)
+{
+  json_t *j;
+
+  if ( (amount->value != (uint64_t) ((json_int_t) amount->value)) ||
+       (0 > ((json_int_t) amount->value)) )
+  {
+    /* Theoretically, json_int_t can be a 32-bit "long", or we might
+       have a 64-bit value which converted to a 63-bit signed long
+       long causes problems here.  So we check.  Note that depending
+       on the platform, the compiler may be able to statically tell
+       that at least the first check is always false. */
+    GNUNET_break (0);
+    return NULL;
+  }
+  j = json_pack ("{s:s, s:I, s:I}",
+                 "currency", amount->currency,
+                 "value", (json_int_t) amount->value,
+                 "fraction", (json_int_t) amount->fraction);
+  GNUNET_assert (NULL != j);
+  return j;
+}
+
+
+/**
+ * Parse given JSON object to Amount
+ *
+ * @param cls closure, NULL
+ * @param root the json object representing data
+ * @param[out] spec where to write the data
+ * @return #GNUNET_OK upon successful parsing; #GNUNET_SYSERR upon error
+ */
+static int
+parse_amount (void *cls,
+              json_t *root,
+              struct GNUNET_JSON_Specification *spec)
+{
+  struct TALER_Amount *r_amount = spec->ptr;
+  json_int_t value;
+  json_int_t fraction;
+  const char *currency;
+
+  memset (r_amount,
+          0,
+          sizeof (struct TALER_Amount));
+  if (0 != json_unpack (root,
+                        "{s:I, s:I, s:s}",
+                        "value", &value,
+                        "fraction", &fraction,
+                        "currency", &currency))
+  {
+    char *json_enc;
+
+    if (NULL == (json_enc = json_dumps (root,
+                                        JSON_COMPACT | JSON_ENCODE_ANY)))
+    {
+      GNUNET_break (0);
+      return GNUNET_SYSERR;
+    }
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                "Malformed JSON amount: %s\n",
+                json_enc);
+    free (json_enc);
+    return GNUNET_SYSERR;
+  }
+  if ( (value < 0) ||
+       (fraction < 0) ||
+       (value > UINT64_MAX) ||
+       (fraction > UINT32_MAX) )
+  {
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
+  }
+  if (strlen (currency) >= TALER_CURRENCY_LEN)
+  {
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
+  }
+  r_amount->value = (uint64_t) value;
+  r_amount->fraction = (uint32_t) fraction;
+  strcpy (r_amount->currency, currency);
+  (void) TALER_amount_normalize (r_amount);
+  return GNUNET_OK;
+}
+
+
+
+/**
+ * Provide specification to parse given JSON object to an amount.
+ *
+ * @param name name of the amount field in the JSON
+ * @param[out] r_amount where the amount has to be written
+ */
+struct GNUNET_JSON_Specification
+TALER_JSON_spec_amount (const char *name,
+                        struct TALER_Amount *r_amount)
+{
+  struct GNUNET_JSON_Specification ret = {
+    .parser = &parse_amount,
+    .cleaner = NULL,
+    .cls = NULL,
+    .field = name,
+    .ptr = r_amount,
+    .ptr_size = 0,
+    .size_ptr = NULL
+  };
+  return ret;
+}
+
+
+/* end of json/json_helper.c */