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diff --git a/src/backend/taler_amount_lib.h b/src/backend/taler_amount_lib.h
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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
+
+#ifdef __cplusplus
+extern "C"
+{
+#if 0                           /* keep Emacsens' auto-indent happy */
+}
+#endif
+#endif
+
+#include <gnunet/platform.h>
+
+
+/**
+ * @brief Number of characters (plus 1 for 0-termination) we use to
+ * represent currency names (i.e. EUR, USD, etc.).  We use 8+4 for
+ * alignment in the `struct TALER_Amount`.  The amount is typically an
+ * ISO 4217 currency code when an alpha-numeric 3-digit code is used.
+ * For regional currencies, the first character should be a "*" followed
+ * by a region-specific name (i.e. "*BRETAGNEFR").
+ */
+#define TALER_CURRENCY_LEN 12
+
+/**
+ * Taler currency length as a string.
+ */
+#define TALER_CURRENCY_LEN_STR "12"
+
+/**
+ * @brief The "fraction" value in a `struct TALER_Amount` represents which
+ * fraction of the "main" value?
+ *
+ * Note that we need sub-cent precision here as transaction fees might
+ * be that low, and as we want to support microdonations.
+ */
+#define TALER_AMOUNT_FRAC_BASE 1000000
+
+/**
+ * @brief How many digits behind the comma are required to represent the
+ * fractional value in human readable decimal format?  Must match
+ * lg(#TALER_AMOUNT_FRAC_BASE).
+ */
+#define TALER_AMOUNT_FRAC_LEN 6
+
+
+GNUNET_NETWORK_STRUCT_BEGIN
+
+
+/**
+ * @brief Amount, encoded for network transmission.
+ */
+struct TALER_AmountNBO
+{
+  /**
+   * Value in the main currency, in NBO.
+   */
+  uint64_t value GNUNET_PACKED;
+
+  /**
+   * Additinal fractional value, in NBO.
+   */
+  uint32_t fraction GNUNET_PACKED;
+
+  /**
+   * Type of the currency being represented.
+   */
+  char currency[TALER_CURRENCY_LEN];
+};
+
+GNUNET_NETWORK_STRUCT_END
+
+
+/**
+ * @brief Representation of monetary value in a given currency.
+ */
+struct TALER_Amount
+{
+  /**
+   * Value (numerator of fraction)
+   */
+  uint64_t value;
+
+  /**
+   * Fraction (denominator of fraction)
+   */
+  uint32_t fraction;
+
+  /**
+   * Currency string, left adjusted and padded with zeros.  All zeros
+   * for "invalid" values.
+   */
+  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);
+
+
+/**
+ * Get the value of "zero" in a particular currency.
+ *
+ * @param cur currency description
+ * @param denom denomination to write the result to
+ * @return #GNUNET_OK if @a cur is a valid currency specification,
+ *         #GNUNET_SYSERR if it is invalid.
+ */
+int
+TALER_amount_get_zero (const char *cur,
+                       struct TALER_Amount *denom);
+
+
+/**
+ * Convert amount from host to network representation.
+ *
+ * @param res where to store amount in network representation
+ * @param d amount in host representation
+ */
+void
+TALER_amount_hton (struct TALER_AmountNBO *res,
+                   const struct TALER_Amount *d);
+
+
+/**
+ * Convert amount from network to host representation.
+ *
+ * @param res where to store amount in host representation
+ * @param dn amount in network representation
+ */
+void
+TALER_amount_ntoh (struct TALER_Amount *res,
+                   const struct TALER_AmountNBO *dn);
+
+
+/**
+ * Compare the value/fraction of two amounts.  Does not compare the currency.
+ * Comparing amounts of different currencies will cause the program to abort().
+ * If unsure, check with #TALER_amount_cmp_currency() first to be sure that
+ * the currencies of the two amounts are identical.
+ *
+ * @param a1 first amount
+ * @param a2 second amount
+ * @return result of the comparison
+ *         -1 if `a1 < a2`
+ *          1 if `a1 > a2`
+ *          0 if `a1 == a2`.
+ */
+int
+TALER_amount_cmp (const struct TALER_Amount *a1,
+                  const struct TALER_Amount *a2);
+
+
+/**
+ * Test if @a a1 and @a a2 are the same currency.
+ *
+ * @param a1 amount to test
+ * @param a2 amount to test
+ * @return #GNUNET_YES if @a a1 and @a a2 are the same currency
+ *         #GNUNET_NO if the currencies are different
+ *         #GNUNET_SYSERR if either amount is invalid
+ */
+int
+TALER_amount_cmp_currency (const struct TALER_Amount *a1,
+                           const struct TALER_Amount *a2);
+
+
+/**
+ * Test if @a a1 and @a a2 are the same currency, NBO variant.
+ *
+ * @param a1 amount to test
+ * @param a2 amount to test
+ * @return #GNUNET_YES if @a a1 and @a a2 are the same currency
+ *         #GNUNET_NO if the currencies are different
+ *         #GNUNET_SYSERR if either amount is invalid
+ */
+int
+TALER_amount_cmp_currency_nbo (const struct TALER_AmountNBO *a1,
+                               const struct TALER_AmountNBO *a2);
+
+
+/**
+ * Perform saturating subtraction of amounts.
+ *
+ * @param diff where to store (@a a1 - @a a2), or invalid if @a a2 > @a a1
+ * @param a1 amount to subtract from
+ * @param a2 amount to subtract
+ * @return #GNUNET_OK if the subtraction worked,
+ *         #GNUNET_NO if @a a1 = @a a2
+ *         #GNUNET_SYSERR if @a a2 > @a a1 or currencies are incompatible;
+ *                        @a diff is set to invalid
+ */
+int
+TALER_amount_subtract (struct TALER_Amount *diff,
+                       const struct TALER_Amount *a1,
+                       const struct TALER_Amount *a2);
+
+
+/**
+ * Perform addition of amounts.
+ *
+ * @param sum where to store @a a1 + @a a2, set to "invalid" on overflow
+ * @param a1 first amount to add
+ * @param a2 second amount to add
+ * @return #GNUNET_OK if the addition worked,
+ *         #GNUNET_SYSERR on overflow
+ */
+int
+TALER_amount_add (struct TALER_Amount *sum,
+                  const struct TALER_Amount *a1,
+                  const struct TALER_Amount *a2);
+
+
+/**
+ * Normalize the given amount.
+ *
+ * @param amount amount to normalize
+ * @return #GNUNET_OK if normalization worked
+ *         #GNUNET_NO if value was already normalized
+ *         #GNUNET_SYSERR if value was invalid or could not be normalized
+ */
+int
+TALER_amount_normalize (struct TALER_Amount *amount);
+
+
+/**
+ * Convert amount to string.
+ *
+ * @param amount amount to convert to string
+ * @return freshly allocated string representation,
+ *         NULL if the @a amount was invalid
+ */
+char *
+TALER_amount_to_string (const struct TALER_Amount *amount);
+
+#if 0                           /* keep Emacsens' auto-indent happy */
+{
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif