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/*
This file is part of TALER
Copyright (C) 2014, 2015 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_amount_lib.h
* @brief amount-representation utility functions
* @author Sree Harsha Totakura <sreeharsha@totakura.in>
*/
#ifndef TALER_AMOUNT_LIB_H
#define TALER_AMOUNT_LIB_H
/**
* Number of characters (plus 1 for 0-termination) we use to
* represent currency names (i.e. EUR, USD, etc.). We use
* 8 for alignment (!).
*/
#define TALER_CURRENCY_LEN 4
GNUNET_NETWORK_STRUCT_BEGIN
/**
* Amount, encoded for network transmission.
*/
struct TALER_AmountNBO
{
/**
* Value in the main currency, in NBO.
*/
uint32_t value;
/**
* Additinal fractional value, in NBO.
*/
uint32_t fraction;
/**
* Type of the currency being represented.
*/
char currency[TALER_CURRENCY_LEN];
};
GNUNET_NETWORK_STRUCT_END
/**
* Representation of monetary value in a given currency.
*/
struct TALER_Amount
{
/**
* Value (numerator of fraction)
*/
uint32_t value;
/**
* Fraction (denominator of fraction)
*/
uint32_t fraction;
/**
* Currency string, left adjusted and padded with zeros.
*/
char currency[TALER_CURRENCY_LEN];
};
/**
* Parse denomination description, in the format "T : V : F".
*
* @param str denomination description
* @param denom denomination to write the result to
* @return #GNUNET_OK if the string is a valid denomination specification,
* #GNUNET_SYSERR if it is invalid.
*/
int
TALER_string_to_amount (const char *str,
struct TALER_Amount *denom);
/**
* Convert amount from host to network representation.
*
* @param d amount in host representation
* @return amount in network representation
*/
struct TALER_AmountNBO
TALER_amount_hton (const struct TALER_Amount d);
/**
* Convert amount from network to host representation.
*
* @param d amount in network representation
* @return amount in host representation
*/
struct TALER_Amount
TALER_amount_ntoh (const struct TALER_AmountNBO dn);
/**
* Compare the value/fraction of two amounts. Does not compare the currency,
* i.e. comparing amounts with the same value and fraction but different
* currency would return 0.
*
* @param a1 first amount
* @param a2 second amount
* @return result of the comparison
*/
int
TALER_amount_cmp (struct TALER_Amount a1,
struct TALER_Amount a2);
/**
* Perform saturating subtraction of amounts.
*
* @param a1 amount to subtract from
* @param a2 amount to subtract
* @return (a1-a2) or 0 if a2>=a1
*/
struct TALER_Amount
TALER_amount_subtract (struct TALER_Amount a1,
struct TALER_Amount a2);
/**
* Perform saturating addition of amounts
*
* @param a1 first amount to add
* @param a2 second amount to add
* @return sum of a1 and a2
*/
struct TALER_Amount
TALER_amount_add (struct TALER_Amount a1,
struct TALER_Amount a2);
/**
* Normalize the given amount.
*
* @param amout amount to normalize
* @return normalized amount
*/
struct TALER_Amount
TALER_amount_normalize (struct TALER_Amount amount);
/**
* Convert amount to string.
*
* @param amount amount to convert to string
* @return freshly allocated string representation
*/
char *
TALER_amount_to_string (struct TALER_Amount amount);
#endif
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