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Diffstat (limited to 'src/util/amount.c')
-rw-r--r-- | src/util/amount.c | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/src/util/amount.c b/src/util/amount.c new file mode 100644 index 000000000..8bd899bf5 --- /dev/null +++ b/src/util/amount.c | |||
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1 | /* | ||
2 | This file is part of TALER | ||
3 | (C) 2014 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 | /** | ||
18 | * @file amount.c | ||
19 | * @brief Common utility functions to deal with units of currency | ||
20 | * @author Sree Harsha Totakura <sreeharsha@totakura.in> | ||
21 | * @author Florian Dold | ||
22 | * @author Benedikt Mueller | ||
23 | */ | ||
24 | #include "platform.h" | ||
25 | #include "taler_util.h" | ||
26 | #include <gnunet/gnunet_common.h> | ||
27 | #include <gnunet/gnunet_util_lib.h> | ||
28 | #include <gcrypt.h> | ||
29 | |||
30 | #define AMOUNT_FRAC_BASE 1000000 | ||
31 | |||
32 | #define AMOUNT_FRAC_LEN 6 | ||
33 | |||
34 | |||
35 | /** | ||
36 | * Parse money amount description, in the format "A:B.C". | ||
37 | * | ||
38 | * @param str amount description | ||
39 | * @param denom amount to write the result to | ||
40 | * @return #GNUNET_OK if the string is a valid amount specification, | ||
41 | * #GNUNET_SYSERR if it is invalid. | ||
42 | */ | ||
43 | int | ||
44 | TALER_string_to_amount (const char *str, | ||
45 | struct TALER_Amount *denom) | ||
46 | { | ||
47 | unsigned int i; // pos in str | ||
48 | int n; // number tmp | ||
49 | unsigned int c; // currency pos | ||
50 | uint32_t b; // base for suffix | ||
51 | |||
52 | memset (denom, 0, sizeof (struct TALER_Amount)); | ||
53 | |||
54 | i = n = c = 0; | ||
55 | |||
56 | while (isspace(str[i])) | ||
57 | i++; | ||
58 | |||
59 | if (0 == str[i]) | ||
60 | { | ||
61 | printf("null before currency\n"); | ||
62 | return GNUNET_SYSERR; | ||
63 | } | ||
64 | |||
65 | while (str[i] != ':') | ||
66 | { | ||
67 | if (0 == str[i]) | ||
68 | { | ||
69 | printf("null before colon"); | ||
70 | return GNUNET_SYSERR; | ||
71 | } | ||
72 | if (c > 3) | ||
73 | { | ||
74 | printf("currency too long\n"); | ||
75 | return GNUNET_SYSERR; | ||
76 | } | ||
77 | denom->currency[c] = str[i]; | ||
78 | c++; | ||
79 | i++; | ||
80 | } | ||
81 | |||
82 | // skip colon | ||
83 | i++; | ||
84 | |||
85 | if (0 == str[i]) | ||
86 | { | ||
87 | printf("null before value\n"); | ||
88 | return GNUNET_SYSERR; | ||
89 | } | ||
90 | |||
91 | while (str[i] != '.') | ||
92 | { | ||
93 | if (0 == str[i]) | ||
94 | { | ||
95 | return GNUNET_OK; | ||
96 | } | ||
97 | n = str[i] - '0'; | ||
98 | if (n < 0 || n > 9) | ||
99 | { | ||
100 | printf("invalid character '%c' before comma at %u\n", (char) n, i); | ||
101 | return GNUNET_SYSERR; | ||
102 | } | ||
103 | denom->value = (denom->value * 10) + n; | ||
104 | i++; | ||
105 | } | ||
106 | |||
107 | // skip the dot | ||
108 | i++; | ||
109 | |||
110 | if (0 == str[i]) | ||
111 | { | ||
112 | printf("null after dot"); | ||
113 | return GNUNET_SYSERR; | ||
114 | } | ||
115 | |||
116 | b = 100000; | ||
117 | |||
118 | while (0 != str[i]) | ||
119 | { | ||
120 | n = str[i] - '0'; | ||
121 | if (b == 0 || n < 0 || n > 9) | ||
122 | { | ||
123 | printf("error after comma"); | ||
124 | return GNUNET_SYSERR; | ||
125 | } | ||
126 | denom->fraction += n * b; | ||
127 | b /= 10; | ||
128 | i++; | ||
129 | } | ||
130 | |||
131 | return GNUNET_OK; | ||
132 | } | ||
133 | |||
134 | |||
135 | /** | ||
136 | * FIXME | ||
137 | */ | ||
138 | struct TALER_AmountNBO | ||
139 | TALER_amount_hton (struct TALER_Amount d) | ||
140 | { | ||
141 | struct TALER_AmountNBO dn; | ||
142 | dn.value = htonl (d.value); | ||
143 | dn.fraction = htonl (d.fraction); | ||
144 | memcpy (dn.currency, d.currency, TALER_CURRENCY_LEN); | ||
145 | |||
146 | return dn; | ||
147 | } | ||
148 | |||
149 | |||
150 | /** | ||
151 | * FIXME | ||
152 | */ | ||
153 | struct TALER_Amount | ||
154 | TALER_amount_ntoh (struct TALER_AmountNBO dn) | ||
155 | { | ||
156 | struct TALER_Amount d; | ||
157 | d.value = ntohl (dn.value); | ||
158 | d.fraction = ntohl (dn.fraction); | ||
159 | memcpy (d.currency, dn.currency, sizeof(dn.currency)); | ||
160 | |||
161 | return d; | ||
162 | } | ||
163 | |||
164 | |||
165 | /** | ||
166 | * Compare the value/fraction of two amounts. Does not compare the currency, | ||
167 | * i.e. comparing amounts with the same value and fraction but different | ||
168 | * currency would return 0. | ||
169 | * | ||
170 | * @param a1 first amount | ||
171 | * @param a2 second amount | ||
172 | * @return result of the comparison | ||
173 | */ | ||
174 | int | ||
175 | TALER_amount_cmp (struct TALER_Amount a1, struct TALER_Amount a2) | ||
176 | { | ||
177 | a1 = TALER_amount_normalize (a1); | ||
178 | a2 = TALER_amount_normalize (a2); | ||
179 | if (a1.value == a2.value) | ||
180 | { | ||
181 | if (a1.fraction < a2.fraction) | ||
182 | return -1; | ||
183 | if (a1.fraction > a2.fraction) | ||
184 | return 1; | ||
185 | return 0; | ||
186 | } | ||
187 | if (a1.value < a2.value) | ||
188 | return -1; | ||
189 | return 1; | ||
190 | } | ||
191 | |||
192 | |||
193 | /** | ||
194 | * Perform saturating subtraction of amounts. | ||
195 | * | ||
196 | * @param a1 amount to subtract from | ||
197 | * @param a2 amount to subtract | ||
198 | * @return (a1-a2) or 0 if a2>=a1 | ||
199 | */ | ||
200 | struct TALER_Amount | ||
201 | TALER_amount_subtract (struct TALER_Amount a1, struct TALER_Amount a2) | ||
202 | { | ||
203 | a1 = TALER_amount_normalize (a1); | ||
204 | a2 = TALER_amount_normalize (a2); | ||
205 | |||
206 | if (a1.value < a2.value) | ||
207 | { | ||
208 | a1.value = 0; | ||
209 | a1.fraction = 0; | ||
210 | return a1; | ||
211 | } | ||
212 | |||
213 | if (a1.fraction < a2.fraction) | ||
214 | { | ||
215 | if (0 == a1.value) | ||
216 | { | ||
217 | a1.fraction = 0; | ||
218 | return a1; | ||
219 | } | ||
220 | a1.fraction += AMOUNT_FRAC_BASE; | ||
221 | a1.value -= 1; | ||
222 | } | ||
223 | |||
224 | a1.fraction -= a2.fraction; | ||
225 | a1.value -= a2.value; | ||
226 | |||
227 | return a1; | ||
228 | } | ||
229 | |||
230 | |||
231 | /** | ||
232 | * Perform saturating addition of amounts. | ||
233 | * | ||
234 | * @param a1 first amount to add | ||
235 | * @param a2 second amount to add | ||
236 | * @return sum of a1 and a2 | ||
237 | */ | ||
238 | struct TALER_Amount | ||
239 | TALER_amount_add (struct TALER_Amount a1, struct TALER_Amount a2) | ||
240 | { | ||
241 | a1 = TALER_amount_normalize (a1); | ||
242 | a2 = TALER_amount_normalize (a2); | ||
243 | |||
244 | a1.value += a2.value; | ||
245 | a1.fraction += a2.fraction; | ||
246 | |||
247 | if (0 == a1.currency[0]) | ||
248 | { | ||
249 | memcpy (a2.currency, a1.currency, TALER_CURRENCY_LEN); | ||
250 | } | ||
251 | |||
252 | if (0 == a2.currency[0]) | ||
253 | { | ||
254 | memcpy (a1.currency, a2.currency, TALER_CURRENCY_LEN); | ||
255 | } | ||
256 | |||
257 | if (0 != a1.currency[0] && 0 != memcmp (a1.currency, a2.currency, TALER_CURRENCY_LEN)) | ||
258 | { | ||
259 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "adding mismatching currencies\n"); | ||
260 | } | ||
261 | |||
262 | if (a1.value < a2.value) | ||
263 | { | ||
264 | a1.value = UINT32_MAX; | ||
265 | a2.value = UINT32_MAX; | ||
266 | return a1; | ||
267 | } | ||
268 | |||
269 | return TALER_amount_normalize (a1); | ||
270 | } | ||
271 | |||
272 | |||
273 | /** | ||
274 | * Normalize the given amount. | ||
275 | * | ||
276 | * @param amout amount to normalize | ||
277 | * @return normalized amount | ||
278 | */ | ||
279 | struct TALER_Amount | ||
280 | TALER_amount_normalize (struct TALER_Amount amount) | ||
281 | { | ||
282 | while (amount.value != UINT32_MAX && amount.fraction >= AMOUNT_FRAC_BASE) | ||
283 | { | ||
284 | amount.fraction -= AMOUNT_FRAC_BASE; | ||
285 | amount.value += 1; | ||
286 | } | ||
287 | return amount; | ||
288 | } | ||
289 | |||
290 | |||
291 | /** | ||
292 | * Convert amount to string. | ||
293 | * | ||
294 | * @param amount amount to convert to string | ||
295 | * @return freshly allocated string representation | ||
296 | */ | ||
297 | char * | ||
298 | TALER_amount_to_string (struct TALER_Amount amount) | ||
299 | { | ||
300 | char tail[AMOUNT_FRAC_LEN + 1] = { 0 }; | ||
301 | char curr[TALER_CURRENCY_LEN + 1] = { 0 }; | ||
302 | char *result = NULL; | ||
303 | int len; | ||
304 | |||
305 | memcpy (curr, amount.currency, TALER_CURRENCY_LEN); | ||
306 | |||
307 | amount = TALER_amount_normalize (amount); | ||
308 | if (0 != amount.fraction) | ||
309 | { | ||
310 | unsigned int i; | ||
311 | uint32_t n = amount.fraction; | ||
312 | for (i = 0; (i < AMOUNT_FRAC_LEN) && (n != 0); i++) | ||
313 | { | ||
314 | tail[i] = '0' + (n / (AMOUNT_FRAC_BASE / 10)); | ||
315 | n = (n * 10) % (AMOUNT_FRAC_BASE); | ||
316 | } | ||
317 | tail[i] = 0; | ||
318 | len = GNUNET_asprintf (&result, "%s:%lu.%s", curr, (unsigned long) amount.value, tail); | ||
319 | } | ||
320 | else | ||
321 | { | ||
322 | len = GNUNET_asprintf (&result, "%s:%lu", curr, (unsigned long) amount.value); | ||
323 | } | ||
324 | GNUNET_assert (len > 0); | ||
325 | return result; | ||
326 | } | ||
327 | |||
328 | |||
329 | /* end of amount.c */ | ||