762 lines
19 KiB
C
762 lines
19 KiB
C
/*
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This file is part of TALER
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Copyright (C) 2014-2021 Taler Systems SA
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TALER is free software; you can redistribute it and/or modify it under the
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terms of the GNU General Public License as published by the Free Software
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Foundation; either version 3, or (at your option) any later version.
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TALER is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
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A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along with
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TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
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*/
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/**
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* @file util/amount.c
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* @brief Common utility functions to deal with units of currency
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* @author Sree Harsha Totakura <sreeharsha@totakura.in>
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* @author Florian Dold
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* @author Benedikt Mueller
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* @author Christian Grothoff
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*/
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#include "platform.h"
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#include "taler_util.h"
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/**
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* Set @a a to "invalid".
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*
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* @param[out] a amount to set to invalid
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*/
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static void
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invalidate (struct TALER_Amount *a)
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{
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memset (a,
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0,
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sizeof (struct TALER_Amount));
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}
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enum GNUNET_GenericReturnValue
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TALER_string_to_amount (const char *str,
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struct TALER_Amount *amount)
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{
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int n;
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uint32_t b;
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const char *colon;
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const char *value;
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/* skip leading whitespace */
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while (isspace ( (unsigned char) str[0]))
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str++;
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if ('\0' == str[0])
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{
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GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
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"Null before currency\n");
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invalidate (amount);
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return GNUNET_SYSERR;
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}
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/* parse currency */
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colon = strchr (str, (int) ':');
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if ( (NULL == colon) ||
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((colon - str) >= TALER_CURRENCY_LEN) )
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{
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GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
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"Invalid currency specified before colon: `%s'\n",
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str);
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invalidate (amount);
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return GNUNET_SYSERR;
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}
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GNUNET_assert (TALER_CURRENCY_LEN > (colon - str));
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memcpy (amount->currency,
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str,
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colon - str);
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/* 0-terminate *and* normalize buffer by setting everything to '\0' */
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memset (&amount->currency [colon - str],
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0,
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TALER_CURRENCY_LEN - (colon - str));
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/* skip colon */
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value = colon + 1;
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if ('\0' == value[0])
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{
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GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
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"Actual value missing in amount `%s'\n",
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str);
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invalidate (amount);
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return GNUNET_SYSERR;
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}
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amount->value = 0;
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amount->fraction = 0;
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/* parse value */
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while ('.' != *value)
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{
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if ('\0' == *value)
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{
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/* we are done */
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return GNUNET_OK;
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}
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if ( (*value < '0') ||
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(*value > '9') )
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{
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GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
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"Invalid character `%c' in amount `%s'\n",
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(int) *value,
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str);
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invalidate (amount);
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return GNUNET_SYSERR;
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}
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n = *value - '0';
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if ( (amount->value * 10 < amount->value) ||
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(amount->value * 10 + n < amount->value) ||
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(amount->value > TALER_AMOUNT_MAX_VALUE) ||
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(amount->value * 10 + n > TALER_AMOUNT_MAX_VALUE) )
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{
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GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
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"Value specified in amount `%s' is too large\n",
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str);
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invalidate (amount);
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return GNUNET_SYSERR;
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}
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amount->value = (amount->value * 10) + n;
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value++;
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}
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/* skip the dot */
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value++;
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/* parse fraction */
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if ('\0' == *value)
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{
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GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
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"Amount `%s' ends abruptly after `.'\n",
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str);
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invalidate (amount);
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return GNUNET_SYSERR;
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}
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b = TALER_AMOUNT_FRAC_BASE / 10;
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while ('\0' != *value)
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{
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if (0 == b)
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{
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GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
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"Fractional value too small (only %u digits supported) in amount `%s'\n",
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(unsigned int) TALER_AMOUNT_FRAC_LEN,
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str);
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invalidate (amount);
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return GNUNET_SYSERR;
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}
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if ( (*value < '0') ||
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(*value > '9') )
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{
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GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
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"Error after dot\n");
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invalidate (amount);
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return GNUNET_SYSERR;
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}
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n = *value - '0';
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amount->fraction += n * b;
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b /= 10;
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value++;
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}
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return GNUNET_OK;
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}
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enum GNUNET_GenericReturnValue
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TALER_string_to_amount_nbo (const char *str,
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struct TALER_AmountNBO *amount_nbo)
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{
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struct TALER_Amount amount;
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if (GNUNET_OK !=
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TALER_string_to_amount (str,
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&amount))
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return GNUNET_SYSERR;
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TALER_amount_hton (amount_nbo,
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&amount);
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return GNUNET_OK;
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}
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void
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TALER_amount_hton (struct TALER_AmountNBO *res,
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const struct TALER_Amount *d)
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{
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GNUNET_assert (GNUNET_YES ==
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TALER_amount_is_valid (d));
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res->value = GNUNET_htonll (d->value);
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res->fraction = htonl (d->fraction);
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memcpy (res->currency,
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d->currency,
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TALER_CURRENCY_LEN);
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}
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void
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TALER_amount_ntoh (struct TALER_Amount *res,
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const struct TALER_AmountNBO *dn)
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{
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res->value = GNUNET_ntohll (dn->value);
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res->fraction = ntohl (dn->fraction);
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memcpy (res->currency,
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dn->currency,
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TALER_CURRENCY_LEN);
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GNUNET_assert (GNUNET_YES ==
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TALER_amount_is_valid (res));
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}
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enum GNUNET_GenericReturnValue
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TALER_amount_set_zero (const char *cur,
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struct TALER_Amount *amount)
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{
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size_t slen;
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slen = strlen (cur);
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if (slen >= TALER_CURRENCY_LEN)
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return GNUNET_SYSERR;
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memset (amount,
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0,
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sizeof (struct TALER_Amount));
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memcpy (amount->currency,
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cur,
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slen);
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return GNUNET_OK;
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}
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enum GNUNET_GenericReturnValue
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TALER_amount_is_valid (const struct TALER_Amount *amount)
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{
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if (amount->value > TALER_AMOUNT_MAX_VALUE)
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return GNUNET_SYSERR;
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return ('\0' != amount->currency[0]) ? GNUNET_OK : GNUNET_NO;
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}
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bool
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TALER_amount_is_zero (const struct TALER_Amount *amount)
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{
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if (GNUNET_OK !=
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TALER_amount_is_valid (amount))
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return false;
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return
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(0 == amount->value) &&
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(0 == amount->fraction);
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}
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enum GNUNET_GenericReturnValue
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TALER_amount_is_currency (const struct TALER_Amount *amount,
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const char *currency)
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{
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if (GNUNET_OK !=
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TALER_amount_is_valid (amount))
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return GNUNET_SYSERR;
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return (0 == strcasecmp (currency,
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amount->currency))
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? GNUNET_OK
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: GNUNET_NO;
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}
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/**
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* Test if @a a is valid, NBO variant.
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*
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* @param a amount to test
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* @return #GNUNET_YES if valid,
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* #GNUNET_NO if invalid
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*/
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static enum GNUNET_GenericReturnValue
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test_valid_nbo (const struct TALER_AmountNBO *a)
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{
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return ('\0' != a->currency[0]) ? GNUNET_YES : GNUNET_NO;
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}
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enum GNUNET_GenericReturnValue
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TALER_amount_cmp_currency (const struct TALER_Amount *a1,
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const struct TALER_Amount *a2)
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{
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if ( (GNUNET_NO == TALER_amount_is_valid (a1)) ||
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(GNUNET_NO == TALER_amount_is_valid (a2)) )
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return GNUNET_SYSERR;
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if (0 == strcasecmp (a1->currency,
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a2->currency))
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return GNUNET_YES;
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return GNUNET_NO;
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}
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enum GNUNET_GenericReturnValue
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TALER_amount_cmp_currency_nbo (const struct TALER_AmountNBO *a1,
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const struct TALER_AmountNBO *a2)
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{
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if ( (GNUNET_NO == test_valid_nbo (a1)) ||
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(GNUNET_NO == test_valid_nbo (a2)) )
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return GNUNET_SYSERR;
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if (0 == strcasecmp (a1->currency,
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a2->currency))
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return GNUNET_YES;
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return GNUNET_NO;
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}
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int
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TALER_amount_cmp (const struct TALER_Amount *a1,
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const struct TALER_Amount *a2)
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{
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struct TALER_Amount n1;
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struct TALER_Amount n2;
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GNUNET_assert (GNUNET_YES ==
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TALER_amount_cmp_currency (a1,
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a2));
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n1 = *a1;
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n2 = *a2;
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GNUNET_assert (GNUNET_SYSERR !=
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TALER_amount_normalize (&n1));
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GNUNET_assert (GNUNET_SYSERR !=
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TALER_amount_normalize (&n2));
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if (n1.value == n2.value)
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{
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if (n1.fraction < n2.fraction)
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return -1;
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if (n1.fraction > n2.fraction)
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return 1;
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return 0;
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}
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if (n1.value < n2.value)
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return -1;
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return 1;
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}
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int
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TALER_amount_cmp_nbo (const struct TALER_AmountNBO *a1,
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const struct TALER_AmountNBO *a2)
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{
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struct TALER_Amount h1;
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struct TALER_Amount h2;
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TALER_amount_ntoh (&h1,
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a1);
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TALER_amount_ntoh (&h2,
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a2);
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return TALER_amount_cmp (&h1,
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&h2);
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}
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enum TALER_AmountArithmeticResult
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TALER_amount_subtract (struct TALER_Amount *diff,
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const struct TALER_Amount *a1,
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const struct TALER_Amount *a2)
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{
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struct TALER_Amount n1;
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struct TALER_Amount n2;
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if (GNUNET_YES !=
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TALER_amount_cmp_currency (a1,
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a2))
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{
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invalidate (diff);
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return TALER_AAR_INVALID_CURRENCIES_INCOMPATIBLE;
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}
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/* make local copies to avoid aliasing problems between
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diff and a1/a2 */
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n1 = *a1;
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n2 = *a2;
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if ( (GNUNET_SYSERR == TALER_amount_normalize (&n1)) ||
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(GNUNET_SYSERR == TALER_amount_normalize (&n2)) )
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{
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invalidate (diff);
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return TALER_AAR_INVALID_NORMALIZATION_FAILED;
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}
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if (n1.fraction < n2.fraction)
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{
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if (0 == n1.value)
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{
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invalidate (diff);
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return TALER_AAR_INVALID_NEGATIVE_RESULT;
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}
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n1.fraction += TALER_AMOUNT_FRAC_BASE;
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n1.value--;
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}
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if (n1.value < n2.value)
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{
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invalidate (diff);
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return TALER_AAR_INVALID_NEGATIVE_RESULT;
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}
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GNUNET_assert (GNUNET_OK ==
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TALER_amount_set_zero (n1.currency,
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diff));
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GNUNET_assert (n1.fraction >= n2.fraction);
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diff->fraction = n1.fraction - n2.fraction;
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GNUNET_assert (n1.value >= n2.value);
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diff->value = n1.value - n2.value;
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if ( (0 == diff->fraction) &&
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(0 == diff->value) )
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return TALER_AAR_RESULT_ZERO;
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return TALER_AAR_RESULT_POSITIVE;
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}
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enum TALER_AmountArithmeticResult
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TALER_amount_add (struct TALER_Amount *sum,
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const struct TALER_Amount *a1,
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const struct TALER_Amount *a2)
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{
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struct TALER_Amount n1;
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struct TALER_Amount n2;
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struct TALER_Amount res;
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if (GNUNET_YES !=
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TALER_amount_cmp_currency (a1,
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a2))
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{
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invalidate (sum);
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return TALER_AAR_INVALID_CURRENCIES_INCOMPATIBLE;
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}
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/* make local copies to avoid aliasing problems between
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diff and a1/a2 */
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n1 = *a1;
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n2 = *a2;
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if ( (GNUNET_SYSERR ==
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TALER_amount_normalize (&n1)) ||
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(GNUNET_SYSERR ==
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TALER_amount_normalize (&n2)) )
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{
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invalidate (sum);
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return TALER_AAR_INVALID_NORMALIZATION_FAILED;
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}
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GNUNET_assert (GNUNET_OK ==
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TALER_amount_set_zero (a1->currency,
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&res));
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res.value = n1.value + n2.value;
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if (res.value < n1.value)
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{
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/* integer overflow */
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invalidate (sum);
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return TALER_AAR_INVALID_RESULT_OVERFLOW;
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}
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if (res.value > TALER_AMOUNT_MAX_VALUE)
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{
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/* too large to be legal */
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invalidate (sum);
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return TALER_AAR_INVALID_RESULT_OVERFLOW;
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}
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res.fraction = n1.fraction + n2.fraction;
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if (GNUNET_SYSERR ==
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TALER_amount_normalize (&res))
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{
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/* integer overflow via carry from fraction */
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invalidate (sum);
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return TALER_AAR_INVALID_RESULT_OVERFLOW;
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}
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*sum = res;
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if ( (0 == sum->fraction) &&
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(0 == sum->value) )
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return TALER_AAR_RESULT_ZERO;
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return TALER_AAR_RESULT_POSITIVE;
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}
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enum GNUNET_GenericReturnValue
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TALER_amount_normalize (struct TALER_Amount *amount)
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{
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uint32_t overflow;
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if (GNUNET_YES != TALER_amount_is_valid (amount))
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return GNUNET_SYSERR;
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if (amount->fraction < TALER_AMOUNT_FRAC_BASE)
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return GNUNET_NO;
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overflow = amount->fraction / TALER_AMOUNT_FRAC_BASE;
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amount->fraction %= TALER_AMOUNT_FRAC_BASE;
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amount->value += overflow;
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if ( (amount->value < overflow) ||
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(amount->value > TALER_AMOUNT_MAX_VALUE) )
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{
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invalidate (amount);
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return GNUNET_SYSERR;
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}
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return GNUNET_OK;
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}
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/**
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* Convert the fraction of @a amount to a string in decimals.
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*
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* @param amount value to convert
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* @param[out] tail where to write the result
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*/
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static void
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amount_to_tail (const struct TALER_Amount *amount,
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char tail[TALER_AMOUNT_FRAC_LEN + 1])
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{
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uint32_t n = amount->fraction;
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unsigned int i;
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for (i = 0; (i < TALER_AMOUNT_FRAC_LEN) && (0 != n); i++)
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{
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tail[i] = '0' + (n / (TALER_AMOUNT_FRAC_BASE / 10));
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n = (n * 10) % (TALER_AMOUNT_FRAC_BASE);
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}
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tail[i] = '\0';
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}
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char *
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TALER_amount_to_string (const struct TALER_Amount *amount)
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{
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char *result;
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struct TALER_Amount norm;
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if (GNUNET_YES != TALER_amount_is_valid (amount))
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return NULL;
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norm = *amount;
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GNUNET_break (GNUNET_SYSERR !=
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TALER_amount_normalize (&norm));
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if (0 != norm.fraction)
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{
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char tail[TALER_AMOUNT_FRAC_LEN + 1];
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amount_to_tail (&norm,
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tail);
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GNUNET_asprintf (&result,
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"%s:%llu.%s",
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norm.currency,
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(unsigned long long) norm.value,
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tail);
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}
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else
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{
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GNUNET_asprintf (&result,
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|
"%s:%llu",
|
|
norm.currency,
|
|
(unsigned long long) norm.value);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
|
|
const char *
|
|
TALER_amount2s (const struct TALER_Amount *amount)
|
|
{
|
|
/* 24 is sufficient for a uint64_t value in decimal; 3 is for ":.\0" */
|
|
static TALER_THREAD_LOCAL char result[TALER_AMOUNT_FRAC_LEN
|
|
+ TALER_CURRENCY_LEN + 3 + 24];
|
|
struct TALER_Amount norm;
|
|
|
|
if (GNUNET_YES != TALER_amount_is_valid (amount))
|
|
return NULL;
|
|
norm = *amount;
|
|
GNUNET_break (GNUNET_SYSERR !=
|
|
TALER_amount_normalize (&norm));
|
|
if (0 != norm.fraction)
|
|
{
|
|
char tail[TALER_AMOUNT_FRAC_LEN + 1];
|
|
|
|
amount_to_tail (&norm,
|
|
tail);
|
|
GNUNET_snprintf (result,
|
|
sizeof (result),
|
|
"%s:%llu.%s",
|
|
norm.currency,
|
|
(unsigned long long) norm.value,
|
|
tail);
|
|
}
|
|
else
|
|
{
|
|
GNUNET_snprintf (result,
|
|
sizeof (result),
|
|
"%s:%llu",
|
|
norm.currency,
|
|
(unsigned long long) norm.value);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
|
|
void
|
|
TALER_amount_divide (struct TALER_Amount *result,
|
|
const struct TALER_Amount *dividend,
|
|
uint32_t divisor)
|
|
{
|
|
uint64_t modr;
|
|
|
|
GNUNET_assert (0 != divisor); /* division by zero is discouraged */
|
|
*result = *dividend;
|
|
/* in case @a dividend was not yet normalized */
|
|
GNUNET_assert (GNUNET_SYSERR !=
|
|
TALER_amount_normalize (result));
|
|
if (1 == divisor)
|
|
return;
|
|
modr = result->value % divisor;
|
|
result->value /= divisor;
|
|
/* modr fits into 32 bits, so we can safely multiply by (<32-bit) base and add fraction! */
|
|
modr = (modr * TALER_AMOUNT_FRAC_BASE) + result->fraction;
|
|
result->fraction = (uint32_t) (modr / divisor);
|
|
/* 'fraction' could now be larger than #TALER_AMOUNT_FRAC_BASE, so we must normalize */
|
|
GNUNET_assert (GNUNET_SYSERR !=
|
|
TALER_amount_normalize (result));
|
|
}
|
|
|
|
|
|
int
|
|
TALER_amount_divide2 (const struct TALER_Amount *dividend,
|
|
const struct TALER_Amount *divisor)
|
|
{
|
|
double approx;
|
|
double d;
|
|
double r;
|
|
int ret;
|
|
struct TALER_Amount tmp;
|
|
struct TALER_Amount nxt;
|
|
|
|
if (GNUNET_YES !=
|
|
TALER_amount_cmp_currency (dividend,
|
|
divisor))
|
|
{
|
|
GNUNET_break (0);
|
|
return -1;
|
|
}
|
|
if ( (0 == divisor->fraction) &&
|
|
(0 == divisor->value) )
|
|
return INT_MAX;
|
|
/* first, get rounded approximation */
|
|
d = ((double) dividend->value) * ((double) TALER_AMOUNT_FRAC_BASE)
|
|
+ ( (double) dividend->fraction);
|
|
r = ((double) divisor->value) * ((double) TALER_AMOUNT_FRAC_BASE)
|
|
+ ( (double) divisor->fraction);
|
|
approx = d / r;
|
|
if (approx > ((double) INT_MAX))
|
|
return INT_MAX; /* 'infinity' */
|
|
/* round down */
|
|
if (approx < 2)
|
|
ret = 0;
|
|
else
|
|
ret = (int) approx - 2;
|
|
/* Now do *exact* calculation, using well rounded-down factor as starting
|
|
point to avoid having to do too many steps. */
|
|
GNUNET_assert (0 <=
|
|
TALER_amount_multiply (&tmp,
|
|
divisor,
|
|
ret));
|
|
/* in practice, this loop will only run for one or two iterations */
|
|
while (1)
|
|
{
|
|
GNUNET_assert (0 <=
|
|
TALER_amount_add (&nxt,
|
|
&tmp,
|
|
divisor));
|
|
if (1 ==
|
|
TALER_amount_cmp (&nxt,
|
|
dividend))
|
|
break; /* nxt > dividend */
|
|
ret++;
|
|
tmp = nxt;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
|
|
enum TALER_AmountArithmeticResult
|
|
TALER_amount_multiply (struct TALER_Amount *result,
|
|
const struct TALER_Amount *amount,
|
|
uint32_t factor)
|
|
{
|
|
struct TALER_Amount in = *amount;
|
|
|
|
if (GNUNET_SYSERR ==
|
|
TALER_amount_normalize (&in))
|
|
return TALER_AAR_INVALID_NORMALIZATION_FAILED;
|
|
memcpy (result->currency,
|
|
amount->currency,
|
|
TALER_CURRENCY_LEN);
|
|
if ( (0 == factor) ||
|
|
( (0 == in.value) &&
|
|
(0 == in.fraction) ) )
|
|
{
|
|
result->value = 0;
|
|
result->fraction = 0;
|
|
return TALER_AAR_RESULT_ZERO;
|
|
}
|
|
result->value = in.value * ((uint64_t) factor);
|
|
if (in.value != result->value / factor)
|
|
return TALER_AAR_INVALID_RESULT_OVERFLOW;
|
|
{
|
|
/* This multiplication cannot overflow since both inputs are 32-bit values */
|
|
uint64_t tmp = ((uint64_t) factor) * ((uint64_t) in.fraction);
|
|
uint64_t res;
|
|
|
|
res = tmp / TALER_AMOUNT_FRAC_BASE;
|
|
/* check for overflow */
|
|
if (result->value + res < result->value)
|
|
return TALER_AAR_INVALID_RESULT_OVERFLOW;
|
|
result->value += res;
|
|
result->fraction = tmp % TALER_AMOUNT_FRAC_BASE;
|
|
}
|
|
if (result->value > TALER_AMOUNT_MAX_VALUE)
|
|
return TALER_AAR_INVALID_RESULT_OVERFLOW;
|
|
/* This check should be redundant... */
|
|
GNUNET_assert (GNUNET_SYSERR !=
|
|
TALER_amount_normalize (result));
|
|
return TALER_AAR_RESULT_POSITIVE;
|
|
}
|
|
|
|
|
|
enum GNUNET_GenericReturnValue
|
|
TALER_amount_round_down (struct TALER_Amount *amount,
|
|
const struct TALER_Amount *round_unit)
|
|
{
|
|
if (GNUNET_OK !=
|
|
TALER_amount_cmp_currency (amount,
|
|
round_unit))
|
|
{
|
|
GNUNET_break (0);
|
|
return GNUNET_SYSERR;
|
|
}
|
|
if ( (0 != round_unit->fraction) &&
|
|
(0 != round_unit->value) )
|
|
{
|
|
GNUNET_break (0);
|
|
return GNUNET_SYSERR;
|
|
}
|
|
if ( (0 == round_unit->fraction) &&
|
|
(0 == round_unit->value) )
|
|
return GNUNET_NO; /* no rounding requested */
|
|
if (0 != round_unit->fraction)
|
|
{
|
|
uint32_t delta;
|
|
|
|
delta = amount->fraction % round_unit->fraction;
|
|
if (0 == delta)
|
|
return GNUNET_NO;
|
|
amount->fraction -= delta;
|
|
}
|
|
if (0 != round_unit->value)
|
|
{
|
|
uint64_t delta;
|
|
|
|
delta = amount->value % round_unit->value;
|
|
if (0 == delta)
|
|
return GNUNET_NO;
|
|
amount->value -= delta;
|
|
amount->fraction = 0;
|
|
}
|
|
return GNUNET_OK;
|
|
}
|
|
|
|
|
|
/* end of amount.c */
|