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Diffstat (limited to 'src/include/taler_amount_lib.h')
-rw-r--r-- | src/include/taler_amount_lib.h | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/src/include/taler_amount_lib.h b/src/include/taler_amount_lib.h new file mode 100644 index 000000000..50b34ff15 --- /dev/null +++ b/src/include/taler_amount_lib.h | |||
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1 | /* | ||
2 | This file is part of TALER | ||
3 | (C) 2014, 2015 Christian Grothoff (and other contributing authors) | ||
4 | |||
5 | TALER is free software; you can redistribute it and/or modify it under the | ||
6 | terms of the GNU General Public License as published by the Free Software | ||
7 | Foundation; either version 3, or (at your option) any later version. | ||
8 | |||
9 | TALER is distributed in the hope that it will be useful, but WITHOUT ANY | ||
10 | WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR | ||
11 | A PARTICULAR PURPOSE. See the GNU General Public License for more details. | ||
12 | |||
13 | You should have received a copy of the GNU General Public License along with | ||
14 | TALER; see the file COPYING. If not, If not, see <http://www.gnu.org/licenses/> | ||
15 | */ | ||
16 | /** | ||
17 | * @file include/taler_amount_lib.h | ||
18 | * @brief amount-representation utility functions | ||
19 | * @author Sree Harsha Totakura <sreeharsha@totakura.in> | ||
20 | */ | ||
21 | #ifndef TALER_AMOUNT_LIB_H | ||
22 | #define TALER_AMOUNT_LIB_H | ||
23 | |||
24 | |||
25 | /** | ||
26 | * Number of characters (plus 1 for 0-termination) we use to | ||
27 | * represent currency names (i.e. EUR, USD, etc.). We use | ||
28 | * 8 for alignment (!). | ||
29 | */ | ||
30 | #define TALER_CURRENCY_LEN 8 | ||
31 | |||
32 | |||
33 | GNUNET_NETWORK_STRUCT_BEGIN | ||
34 | |||
35 | |||
36 | /** | ||
37 | * Amount, encoded for network transmission. | ||
38 | */ | ||
39 | struct TALER_AmountNBO | ||
40 | { | ||
41 | /** | ||
42 | * Value in the main currency, in NBO. | ||
43 | */ | ||
44 | uint32_t value; | ||
45 | |||
46 | /** | ||
47 | * Additinal fractional value, in NBO. | ||
48 | */ | ||
49 | uint32_t fraction; | ||
50 | |||
51 | /** | ||
52 | * Type of the currency being represented. | ||
53 | */ | ||
54 | char currency[TALER_CURRENCY_LEN]; | ||
55 | }; | ||
56 | |||
57 | GNUNET_NETWORK_STRUCT_END | ||
58 | |||
59 | |||
60 | /** | ||
61 | * Representation of monetary value in a given currency. | ||
62 | */ | ||
63 | struct TALER_Amount | ||
64 | { | ||
65 | /** | ||
66 | * Value (numerator of fraction) | ||
67 | */ | ||
68 | uint32_t value; | ||
69 | |||
70 | /** | ||
71 | * Fraction (denominator of fraction) | ||
72 | */ | ||
73 | uint32_t fraction; | ||
74 | |||
75 | /** | ||
76 | * Currency string, left adjusted and padded with zeros. | ||
77 | */ | ||
78 | char currency[TALER_CURRENCY_LEN]; | ||
79 | }; | ||
80 | |||
81 | |||
82 | /** | ||
83 | * Parse denomination description, in the format "T : V : F". | ||
84 | * | ||
85 | * @param str denomination description | ||
86 | * @param denom denomination to write the result to | ||
87 | * @return #GNUNET_OK if the string is a valid denomination specification, | ||
88 | * #GNUNET_SYSERR if it is invalid. | ||
89 | */ | ||
90 | int | ||
91 | TALER_string_to_amount (const char *str, | ||
92 | struct TALER_Amount *denom); | ||
93 | |||
94 | |||
95 | /** | ||
96 | * Convert amount from host to network representation. | ||
97 | * | ||
98 | * @param d amount in host representation | ||
99 | * @return amount in network representation | ||
100 | */ | ||
101 | struct TALER_AmountNBO | ||
102 | TALER_amount_hton (struct TALER_Amount d); | ||
103 | |||
104 | |||
105 | /** | ||
106 | * Convert amount from network to host representation. | ||
107 | * | ||
108 | * @param d amount in network representation | ||
109 | * @return amount in host representation | ||
110 | */ | ||
111 | struct TALER_Amount | ||
112 | TALER_amount_ntoh (struct TALER_AmountNBO dn); | ||
113 | |||
114 | |||
115 | /** | ||
116 | * Compare the value/fraction of two amounts. Does not compare the currency, | ||
117 | * i.e. comparing amounts with the same value and fraction but different | ||
118 | * currency would return 0. | ||
119 | * | ||
120 | * @param a1 first amount | ||
121 | * @param a2 second amount | ||
122 | * @return result of the comparison | ||
123 | */ | ||
124 | int | ||
125 | TALER_amount_cmp (struct TALER_Amount a1, | ||
126 | struct TALER_Amount a2); | ||
127 | |||
128 | |||
129 | /** | ||
130 | * Perform saturating subtraction of amounts. | ||
131 | * | ||
132 | * @param a1 amount to subtract from | ||
133 | * @param a2 amount to subtract | ||
134 | * @return (a1-a2) or 0 if a2>=a1 | ||
135 | */ | ||
136 | struct TALER_Amount | ||
137 | TALER_amount_subtract (struct TALER_Amount a1, | ||
138 | struct TALER_Amount a2); | ||
139 | |||
140 | |||
141 | /** | ||
142 | * Perform saturating addition of amounts | ||
143 | * | ||
144 | * @param a1 first amount to add | ||
145 | * @param a2 second amount to add | ||
146 | * @return sum of a1 and a2 | ||
147 | */ | ||
148 | struct TALER_Amount | ||
149 | TALER_amount_add (struct TALER_Amount a1, | ||
150 | struct TALER_Amount a2); | ||
151 | |||
152 | |||
153 | /** | ||
154 | * Normalize the given amount. | ||
155 | * | ||
156 | * @param amout amount to normalize | ||
157 | * @return normalized amount | ||
158 | */ | ||
159 | struct TALER_Amount | ||
160 | TALER_amount_normalize (struct TALER_Amount amount); | ||
161 | |||
162 | |||
163 | /** | ||
164 | * Convert amount to string. | ||
165 | * | ||
166 | * @param amount amount to convert to string | ||
167 | * @return freshly allocated string representation | ||
168 | */ | ||
169 | char * | ||
170 | TALER_amount_to_string (struct TALER_Amount amount); | ||
171 | |||
172 | |||
173 | #endif | ||