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Diffstat (limited to 'src/util/json.c')
| -rw-r--r-- | src/util/json.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/util/json.c b/src/util/json.c new file mode 100644 index 000000000..269e6cf26 --- /dev/null +++ b/src/util/json.c @@ -0,0 +1,194 @@ +/* + 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/json.c + * @brief helper functions for JSON processing using libjansson + * @author Sree Harsha Totakura <sreeharsha@totakura.in> + */ + +#include "platform.h" +#include <gnunet/gnunet_util_lib.h> +#include "taler_util.h" +#include "taler_json_lib.h" + +/** + * Shorthand for exit jumps. + */ +#define EXITIF(cond) \ + do { \ + if (cond) { GNUNET_break (0); goto EXITIF_exit; } \ + } while (0) + +/** + * Print JSON parsing related error information + */ +#define WARN_JSON(error) \ + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, \ + "JSON parsing failed at %s:%u: %s (%s)", \ + __FILE__, __LINE__, error.text, error.source) + +/** + * Shorthand for JSON parsing related exit jumps. + */ +#define UNPACK_EXITIF(cond) \ + do { \ + if (cond) { WARN_JSON(error); goto EXITIF_exit; } \ + } while (0) + +/** + * 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 (struct TALER_Amount amount) +{ + json_t *j; + 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; +} + + +/** + * Convert absolute timestamp to a json string. + * + * @param the time stamp + * @return a json string with the timestamp in @a stamp + */ +json_t * +TALER_JSON_from_abs (struct GNUNET_TIME_Absolute stamp) +{ + json_t *j; + char *mystr; + int ret; + ret = GNUNET_asprintf (&mystr, "%llu", + (long long) (stamp.abs_value_us / (1000 * 1000))); + GNUNET_assert (ret > 0); + j = json_string (mystr); + GNUNET_free (mystr); + return j; +} + + + +/** + * Convert binary data to a JSON string + * with the base32crockford encoding. + * + * @param data binary data + * @param size size of @a data in bytes + * @return json string that encodes @a data + */ +json_t * +TALER_JSON_from_data (const void *data, size_t size) +{ + char *buf; + json_t *json; + buf = TALER_data_to_string_alloc (data, size); + json = json_string (buf); + GNUNET_free (buf); + return json; +} + + +/** + * Parse given JSON object to Amount + * + * @param json the json object representing Amount + * @param r_amount where the amount has to be written + * @return GNUNET_OK upon successful parsing; GNUNET_SYSERR upon error + */ +int +TALER_JSON_to_amount (json_t *json, + struct TALER_Amount *r_amount) +{ + char *currency; + json_int_t value; + json_int_t fraction; + json_error_t error; + + UNPACK_EXITIF (0 != json_unpack_ex (json, &error, JSON_STRICT, + "{s:s, s:I, s:I}", + "curreny", ¤cy, + "value", &value, + "fraction", &fraction)); + EXITIF (3 < strlen (currency)); + r_amount->value = (uint32_t) value; + r_amount->fraction = (uint32_t) fraction; + return GNUNET_OK; + + EXITIF_exit: + return GNUNET_SYSERR; +} + + +/** + * Parse given JSON object to Amount + * + * @param json the json object representing Amount + * @param r_amount where the amount has to be written + * @return GNUNET_OK upon successful parsing; GNUNET_SYSERR upon error + */ +int +TALER_JSON_to_abs (json_t *json, + struct GNUNET_TIME_Absolute *abs) +{ + const char *str; + unsigned long long abs_value_s; + + GNUNET_assert (NULL != abs); + EXITIF (NULL == (str = json_string_value (json))); + EXITIF (1 > sscanf (str, "%llu", &abs_value_s)); + abs->abs_value_us = abs_value_s * 1000 * 1000; + return GNUNET_OK; + + EXITIF_exit: + return GNUNET_SYSERR; +} + +/** + * Parse given JSON object to data + * + * @param json the json object representing data + * @param out the pointer to hold the parsed data. + * @param out_size the size of r_data. + * @return GNUNET_OK upon successful parsing; GNUNET_SYSERR upon error + */ +int +TALER_JSON_to_data (json_t *json, + void *out, + size_t out_size) +{ + const char *enc; + unsigned int len; + + EXITIF (NULL == (enc = json_string_value (json))); + len = strlen (enc); + EXITIF ((((len * 5) / 8) + ((((len * 5) % 8) == 0) ? 0 : 1)) == out_size); + EXITIF (GNUNET_OK != GNUNET_STRINGS_string_to_data (enc, len, out, out_size)); + return GNUNET_OK; + EXITIF_exit: + return GNUNET_SYSERR; +} + +/* End of util/json.c */ |