d3409d5e |
1 | /* -*-c-*- |
2 | * |
a69a3efd |
3 | * $Id$ |
d3409d5e |
4 | * |
5 | * Textual representation of multiprecision numbers |
6 | * |
7 | * (c) 1999 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
d3409d5e |
30 | /*----- Header files ------------------------------------------------------*/ |
31 | |
32 | #include <ctype.h> |
2b26f2d7 |
33 | #include <limits.h> |
d3409d5e |
34 | #include <stdio.h> |
35 | |
d3409d5e |
36 | #include "mp.h" |
37 | #include "mptext.h" |
e360a4f2 |
38 | #include "paranoia.h" |
d3409d5e |
39 | |
2b26f2d7 |
40 | /*----- Magical numbers ---------------------------------------------------*/ |
41 | |
42 | /* --- Maximum recursion depth --- * |
43 | * |
44 | * This is the number of bits in a @size_t@ object. Why? |
45 | * |
eaa515d8 |
46 | * To see this, let %$b = \textit{MPW\_MAX} + 1$% and let %$Z$% be the |
dd9199f0 |
47 | * largest @size_t@ value. Then the largest possible @mp@ is %$M - 1$% where |
48 | * %$M = b^Z$%. Let %$r$% be a radix to read or write. Since the recursion |
49 | * squares the radix at each step, the highest number reached by the |
50 | * recursion is %$d$%, where: |
2b26f2d7 |
51 | * |
dd9199f0 |
52 | * %$r^{2^d} = b^Z$%. |
2b26f2d7 |
53 | * |
54 | * Solving gives that %$d = \lg \log_r b^Z$%. If %$r = 2$%, this is maximum, |
55 | * so choosing %$d = \lg \lg b^Z = \lg (Z \lg b) = \lg Z + \lg \lg b$%. |
56 | * |
57 | * Expressing %$\lg Z$% as @CHAR_BIT * sizeof(size_t)@ yields an |
58 | * overestimate, since a @size_t@ representation may contain `holes'. |
59 | * Choosing to represent %$\lg \lg b$% by 10 is almost certainly sufficient |
60 | * for `some time to come'. |
61 | */ |
62 | |
63 | #define DEPTH (CHAR_BIT * sizeof(size_t) + 10) |
64 | |
d3409d5e |
65 | /*----- Main code ---------------------------------------------------------*/ |
66 | |
67 | /* --- @mp_read@ --- * |
68 | * |
69 | * Arguments: @mp *m@ = destination multiprecision number |
70 | * @int radix@ = base to assume for data (or zero to guess) |
71 | * @const mptext_ops *ops@ = pointer to operations block |
72 | * @void *p@ = data for the operations block |
73 | * |
74 | * Returns: The integer read, or zero if it didn't work. |
75 | * |
76 | * Use: Reads an integer from some source. If the @radix@ is |
77 | * specified, the number is assumed to be given in that radix, |
78 | * with the letters `a' (either upper- or lower-case) upwards |
79 | * standing for digits greater than 9. Otherwise, base 10 is |
80 | * assumed unless the number starts with `0' (octal), `0x' (hex) |
81 | * or `nnn_' (base `nnn'). An arbitrary amount of whitespace |
82 | * before the number is ignored. |
83 | */ |
84 | |
2b26f2d7 |
85 | /* --- About the algorithm --- * |
86 | * |
87 | * The algorithm here is rather aggressive. I maintain an array of |
88 | * successive squarings of the radix, and a stack of partial results, each |
89 | * with a counter attached indicating which radix square to multiply by. |
90 | * Once the item at the top of the stack reaches the same counter level as |
91 | * the next item down, they are combined together and the result is given a |
92 | * counter level one higher than either of the results. |
93 | * |
94 | * Gluing the results together at the end is slightly tricky. Pay attention |
95 | * to the code. |
96 | * |
97 | * This is more complicated because of the need to handle the slightly |
98 | * bizarre syntax. |
99 | */ |
100 | |
d3409d5e |
101 | mp *mp_read(mp *m, int radix, const mptext_ops *ops, void *p) |
102 | { |
2b26f2d7 |
103 | int ch; /* Current char being considered */ |
104 | unsigned f = 0; /* Flags about the current number */ |
105 | int r; /* Radix to switch over to */ |
106 | mpw rd; /* Radix as an @mp@ digit */ |
107 | mp rr; /* The @mp@ for the radix */ |
108 | unsigned nf = m ? m->f & MP_BURN : 0; /* New @mp@ flags */ |
109 | |
110 | /* --- Stacks --- */ |
111 | |
112 | mp *pow[DEPTH]; /* List of powers */ |
113 | unsigned pows; /* Next index to fill */ |
114 | struct { unsigned i; mp *m; } s[DEPTH]; /* Main stack */ |
115 | unsigned sp; /* Current stack pointer */ |
116 | |
117 | /* --- Flags --- */ |
d3409d5e |
118 | |
3bc9cb53 |
119 | #define f_neg 1u |
120 | #define f_ok 2u |
a951033d |
121 | #define f_start 4u |
d3409d5e |
122 | |
2b26f2d7 |
123 | /* --- Initialize the stacks --- */ |
124 | |
125 | mp_build(&rr, &rd, &rd + 1); |
126 | pow[0] = &rr; |
127 | pows = 1; |
128 | |
129 | sp = 0; |
130 | |
d3409d5e |
131 | /* --- Initialize the destination number --- */ |
132 | |
2b26f2d7 |
133 | if (m) |
134 | MP_DROP(m); |
d3409d5e |
135 | |
136 | /* --- Read an initial character --- */ |
137 | |
138 | ch = ops->get(p); |
139 | while (isspace(ch)) |
140 | ch = ops->get(p); |
141 | |
142 | /* --- Handle an initial sign --- */ |
143 | |
9d3838a0 |
144 | if (radix >= 0 && (ch == '-' || ch == '+')) { |
145 | if (ch == '-') |
146 | f |= f_neg; |
147 | do ch = ops->get(p); while isspace(ch); |
d3409d5e |
148 | } |
149 | |
150 | /* --- If the radix is zero, look for leading zeros --- */ |
151 | |
2b26f2d7 |
152 | if (radix > 0) { |
631673a1 |
153 | assert(((void)"ascii radix must be <= 62", radix <= 62)); |
2b26f2d7 |
154 | rd = radix; |
155 | r = -1; |
156 | } else if (radix < 0) { |
157 | rd = -radix; |
25b5e686 |
158 | assert(((void)"binary radix must fit in a byte", rd <= UCHAR_MAX)); |
d3409d5e |
159 | r = -1; |
2b26f2d7 |
160 | } else if (ch != '0') { |
161 | rd = 10; |
d3409d5e |
162 | r = 0; |
163 | } else { |
164 | ch = ops->get(p); |
3db58009 |
165 | switch (ch) { |
166 | case 'x': |
167 | rd = 16; |
168 | goto prefix; |
169 | case 'o': |
170 | rd = 8; |
171 | goto prefix; |
172 | case 'b': |
173 | rd = 2; |
174 | goto prefix; |
175 | prefix: |
176 | ch = ops->get(p); |
177 | break; |
178 | default: |
179 | rd = 8; |
180 | f |= f_ok; |
d3409d5e |
181 | } |
182 | r = -1; |
183 | } |
184 | |
a951033d |
185 | /* --- Use fast algorithm for binary radix --- * |
186 | * |
187 | * This is the restart point after having parsed a radix number from the |
188 | * input. We check whether the radix is binary, and if so use a fast |
189 | * algorithm which just stacks the bits up in the right order. |
190 | */ |
191 | |
192 | restart: |
193 | switch (rd) { |
194 | unsigned bit; |
195 | |
196 | case 2: bit = 1; goto bin; |
197 | case 4: bit = 2; goto bin; |
198 | case 8: bit = 3; goto bin; |
199 | case 16: bit = 4; goto bin; |
200 | case 32: bit = 5; goto bin; |
201 | case 64: bit = 6; goto bin; |
202 | case 128: bit = 7; goto bin; |
203 | default: |
204 | break; |
205 | |
206 | /* --- The fast binary algorithm --- * |
207 | * |
208 | * We stack bits up starting at the top end of a word. When one word is |
209 | * full, we write it to the integer, and start another with the left-over |
210 | * bits. When the array in the integer is full, we resize using low-level |
211 | * calls and copy the current data to the top end. Finally, we do a single |
212 | * bit-shift when we know where the end of the number is. |
213 | */ |
214 | |
215 | bin: { |
216 | mpw a = 0; |
217 | unsigned b = MPW_BITS; |
218 | size_t len, n; |
219 | mpw *v; |
220 | |
221 | m = mp_dest(MP_NEW, 1, nf); |
222 | len = n = m->sz; |
223 | n = len; |
224 | v = m->v + n; |
225 | for (;; ch = ops->get(p)) { |
226 | unsigned x; |
227 | |
228 | if (ch < 0) |
229 | break; |
230 | |
231 | /* --- Check that the character is a digit and in range --- */ |
232 | |
233 | if (radix < 0) |
234 | x = ch % rd; |
235 | else { |
236 | if (!isalnum(ch)) |
237 | break; |
238 | if (ch >= '0' && ch <= '9') |
239 | x = ch - '0'; |
240 | else { |
631673a1 |
241 | if (rd <= 36) |
242 | ch = tolower(ch); |
a951033d |
243 | if (ch >= 'a' && ch <= 'z') /* ASCII dependent! */ |
244 | x = ch - 'a' + 10; |
631673a1 |
245 | else if (ch >= 'A' && ch <= 'Z') |
246 | x = ch - 'A' + 36; |
a951033d |
247 | else |
248 | break; |
249 | } |
250 | } |
251 | if (x >= rd) |
252 | break; |
253 | |
254 | /* --- Feed the digit into the accumulator --- */ |
255 | |
256 | f |= f_ok; |
257 | if (!x && !(f & f_start)) |
258 | continue; |
259 | f |= f_start; |
260 | if (b > bit) { |
261 | b -= bit; |
262 | a |= MPW(x) << b; |
263 | } else { |
264 | a |= MPW(x) >> (bit - b); |
265 | b += MPW_BITS - bit; |
266 | *--v = MPW(a); |
267 | n--; |
268 | if (!n) { |
269 | n = len; |
270 | len <<= 1; |
271 | v = mpalloc(m->a, len); |
272 | memcpy(v + n, m->v, MPWS(n)); |
273 | mpfree(m->a, m->v); |
274 | m->v = v; |
275 | v = m->v + n; |
276 | } |
277 | a = (b < MPW_BITS) ? MPW(x) << b : 0; |
278 | } |
279 | } |
280 | |
281 | /* --- Finish up --- */ |
282 | |
283 | if (!(f & f_ok)) { |
284 | mp_drop(m); |
285 | m = 0; |
286 | } else { |
287 | *--v = MPW(a); |
288 | n--; |
289 | m->sz = len; |
290 | m->vl = m->v + len; |
291 | m->f &= ~MP_UNDEF; |
292 | m = mp_lsr(m, m, (unsigned long)n * MPW_BITS + b); |
293 | } |
50bea2af |
294 | ops->unget(ch, p); |
a951033d |
295 | goto done; |
296 | }} |
297 | |
d3409d5e |
298 | /* --- Time to start --- */ |
299 | |
300 | for (;; ch = ops->get(p)) { |
a951033d |
301 | unsigned x; |
d3409d5e |
302 | |
7d45ed6c |
303 | if (ch < 0) |
304 | break; |
305 | |
d3409d5e |
306 | /* --- An underscore indicates a numbered base --- */ |
307 | |
6ea6fe51 |
308 | if (ch == '_' && r > 0 && r <= 62) { |
2b26f2d7 |
309 | unsigned i; |
310 | |
311 | /* --- Clear out the stacks --- */ |
312 | |
313 | for (i = 1; i < pows; i++) |
314 | MP_DROP(pow[i]); |
315 | pows = 1; |
316 | for (i = 0; i < sp; i++) |
317 | MP_DROP(s[i].m); |
318 | sp = 0; |
319 | |
320 | /* --- Restart the search --- */ |
321 | |
322 | rd = r; |
d3409d5e |
323 | r = -1; |
324 | f &= ~f_ok; |
a951033d |
325 | ch = ops->get(p); |
326 | goto restart; |
d3409d5e |
327 | } |
328 | |
329 | /* --- Check that the character is a digit and in range --- */ |
330 | |
2b26f2d7 |
331 | if (radix < 0) |
9d3838a0 |
332 | x = ch % rd; |
d3409d5e |
333 | else { |
2b26f2d7 |
334 | if (!isalnum(ch)) |
d3409d5e |
335 | break; |
2b26f2d7 |
336 | if (ch >= '0' && ch <= '9') |
337 | x = ch - '0'; |
338 | else { |
631673a1 |
339 | if (rd <= 36) |
340 | ch = tolower(ch); |
2b26f2d7 |
341 | if (ch >= 'a' && ch <= 'z') /* ASCII dependent! */ |
342 | x = ch - 'a' + 10; |
631673a1 |
343 | else if (ch >= 'A' && ch <= 'Z') |
344 | x = ch - 'A' + 36; |
2b26f2d7 |
345 | else |
346 | break; |
347 | } |
d3409d5e |
348 | } |
349 | |
350 | /* --- Sort out what to do with the character --- */ |
351 | |
352 | if (x >= 10 && r >= 0) |
353 | r = -1; |
2b26f2d7 |
354 | if (x >= rd) |
d3409d5e |
355 | break; |
356 | |
357 | if (r >= 0) |
358 | r = r * 10 + x; |
359 | |
360 | /* --- Stick the character on the end of my integer --- */ |
361 | |
2b26f2d7 |
362 | assert(((void)"Number is too unimaginably huge", sp < DEPTH)); |
363 | s[sp].m = m = mp_new(1, nf); |
364 | m->v[0] = x; |
365 | s[sp].i = 0; |
366 | |
367 | /* --- Now grind through the stack --- */ |
368 | |
369 | while (sp > 0 && s[sp - 1].i == s[sp].i) { |
370 | |
371 | /* --- Combine the top two items --- */ |
372 | |
373 | sp--; |
374 | m = s[sp].m; |
375 | m = mp_mul(m, m, pow[s[sp].i]); |
376 | m = mp_add(m, m, s[sp + 1].m); |
377 | s[sp].m = m; |
378 | MP_DROP(s[sp + 1].m); |
379 | s[sp].i++; |
380 | |
381 | /* --- Make a new radix power if necessary --- */ |
382 | |
383 | if (s[sp].i >= pows) { |
384 | assert(((void)"Number is too unimaginably huge", pows < DEPTH)); |
385 | pow[pows] = mp_sqr(MP_NEW, pow[pows - 1]); |
386 | pows++; |
387 | } |
388 | } |
d3409d5e |
389 | f |= f_ok; |
2b26f2d7 |
390 | sp++; |
d3409d5e |
391 | } |
392 | |
393 | ops->unget(ch, p); |
394 | |
2b26f2d7 |
395 | /* --- If we're done, compute the rest of the number --- */ |
396 | |
397 | if (f & f_ok) { |
398 | if (!sp) |
399 | return (MP_ZERO); |
400 | else { |
401 | mp *z = MP_ONE; |
402 | sp--; |
403 | |
404 | while (sp > 0) { |
405 | |
406 | /* --- Combine the top two items --- */ |
407 | |
408 | sp--; |
409 | m = s[sp].m; |
410 | z = mp_mul(z, z, pow[s[sp + 1].i]); |
411 | m = mp_mul(m, m, z); |
412 | m = mp_add(m, m, s[sp + 1].m); |
413 | s[sp].m = m; |
414 | MP_DROP(s[sp + 1].m); |
415 | |
416 | /* --- Make a new radix power if necessary --- */ |
417 | |
418 | if (s[sp].i >= pows) { |
419 | assert(((void)"Number is too unimaginably huge", pows < DEPTH)); |
420 | pow[pows] = mp_sqr(MP_NEW, pow[pows - 1]); |
421 | pows++; |
422 | } |
423 | } |
424 | MP_DROP(z); |
425 | m = s[0].m; |
426 | } |
427 | } else { |
428 | unsigned i; |
429 | for (i = 0; i < sp; i++) |
430 | MP_DROP(s[i].m); |
431 | } |
432 | |
433 | /* --- Clear the radix power list --- */ |
434 | |
435 | { |
436 | unsigned i; |
437 | for (i = 1; i < pows; i++) |
438 | MP_DROP(pow[i]); |
439 | } |
440 | |
d3409d5e |
441 | /* --- Bail out if the number was bad --- */ |
442 | |
a951033d |
443 | done: |
2b26f2d7 |
444 | if (!(f & f_ok)) |
d3409d5e |
445 | return (0); |
d3409d5e |
446 | |
447 | /* --- Set the sign and return --- */ |
448 | |
d3409d5e |
449 | if (f & f_neg) |
450 | m->f |= MP_NEG; |
9bca44cb |
451 | MP_SHRINK(m); |
d3409d5e |
452 | return (m); |
3bc9cb53 |
453 | |
a951033d |
454 | #undef f_start |
3bc9cb53 |
455 | #undef f_neg |
456 | #undef f_ok |
d3409d5e |
457 | } |
458 | |
459 | /* --- @mp_write@ --- * |
460 | * |
461 | * Arguments: @mp *m@ = pointer to a multi-precision integer |
462 | * @int radix@ = radix to use when writing the number out |
463 | * @const mptext_ops *ops@ = pointer to an operations block |
464 | * @void *p@ = data for the operations block |
465 | * |
466 | * Returns: Zero if it worked, nonzero otherwise. |
467 | * |
468 | * Use: Writes a large integer in textual form. |
469 | */ |
470 | |
e360a4f2 |
471 | /* --- Simple case --- * |
472 | * |
3bc9cb53 |
473 | * Use a fixed-sized buffer and single-precision arithmetic to pick off |
474 | * low-order digits. Put each digit in a buffer, working backwards from the |
475 | * end. If the buffer becomes full, recurse to get another one. Ensure that |
476 | * there are at least @z@ digits by writing leading zeroes if there aren't |
477 | * enough real digits. |
e360a4f2 |
478 | */ |
479 | |
3bc9cb53 |
480 | static int simple(mpw n, int radix, unsigned z, |
e360a4f2 |
481 | const mptext_ops *ops, void *p) |
482 | { |
483 | int rc = 0; |
484 | char buf[64]; |
485 | unsigned i = sizeof(buf); |
2b26f2d7 |
486 | int rd = radix > 0 ? radix : -radix; |
e360a4f2 |
487 | |
488 | do { |
489 | int ch; |
490 | mpw x; |
491 | |
3bc9cb53 |
492 | x = n % rd; |
493 | n /= rd; |
2b26f2d7 |
494 | if (radix < 0) |
495 | ch = x; |
3bc9cb53 |
496 | else if (x < 10) |
497 | ch = '0' + x; |
631673a1 |
498 | else if (x < 36) /* Ascii specific */ |
3bc9cb53 |
499 | ch = 'a' + x - 10; |
631673a1 |
500 | else |
501 | ch = 'A' + x - 36; |
e360a4f2 |
502 | buf[--i] = ch; |
503 | if (z) |
504 | z--; |
3bc9cb53 |
505 | } while (i && n); |
e360a4f2 |
506 | |
3bc9cb53 |
507 | if (n) |
508 | rc = simple(n, radix, z, ops, p); |
e360a4f2 |
509 | else { |
a951033d |
510 | char zbuf[32]; |
511 | memset(zbuf, (radix < 0) ? 0 : '0', sizeof(zbuf)); |
512 | while (!rc && z >= sizeof(zbuf)) { |
513 | rc = ops->put(zbuf, sizeof(zbuf), p); |
514 | z -= sizeof(zbuf); |
e360a4f2 |
515 | } |
516 | if (!rc && z) |
a951033d |
517 | rc = ops->put(zbuf, z, p); |
e360a4f2 |
518 | } |
519 | if (!rc) |
3bc9cb53 |
520 | rc = ops->put(buf + i, sizeof(buf) - i, p); |
521 | BURN(buf); |
e360a4f2 |
522 | return (rc); |
523 | } |
524 | |
525 | /* --- Complicated case --- * |
526 | * |
527 | * If the number is small, fall back to the simple case above. Otherwise |
528 | * divide and take remainder by current large power of the radix, and emit |
529 | * each separately. Don't emit a zero quotient. Be very careful about |
530 | * leading zeroes on the remainder part, because they're deeply significant. |
531 | */ |
532 | |
533 | static int complicated(mp *m, int radix, mp **pr, unsigned i, unsigned z, |
534 | const mptext_ops *ops, void *p) |
535 | { |
536 | int rc = 0; |
537 | mp *q = MP_NEW; |
538 | unsigned d = 1 << i; |
539 | |
3bc9cb53 |
540 | if (MP_LEN(m) < 2) |
541 | return (simple(MP_LEN(m) ? m->v[0] : 0, radix, z, ops, p)); |
e360a4f2 |
542 | |
3bc9cb53 |
543 | assert(i); |
e360a4f2 |
544 | mp_div(&q, &m, m, pr[i]); |
a69a3efd |
545 | if (MP_ZEROP(q)) |
e360a4f2 |
546 | d = z; |
547 | else { |
548 | if (z > d) |
549 | z -= d; |
550 | else |
551 | z = 0; |
552 | rc = complicated(q, radix, pr, i - 1, z, ops, p); |
553 | } |
554 | if (!rc) |
555 | rc = complicated(m, radix, pr, i - 1, d, ops, p); |
556 | mp_drop(q); |
557 | return (rc); |
558 | } |
559 | |
a951033d |
560 | /* --- Binary case --- * |
561 | * |
562 | * Special case for binary output. Goes much faster. |
563 | */ |
564 | |
565 | static int binary(mp *m, int bit, int radix, const mptext_ops *ops, void *p) |
566 | { |
567 | mpw *v; |
568 | mpw a; |
569 | int rc = 0; |
570 | unsigned b; |
571 | unsigned mask; |
572 | unsigned long n; |
573 | unsigned f = 0; |
574 | char buf[8], *q; |
575 | unsigned x; |
576 | int ch; |
577 | |
578 | #define f_out 1u |
579 | |
580 | /* --- Work out where to start --- */ |
581 | |
582 | n = mp_bits(m); |
afd054c1 |
583 | if (n % bit) |
584 | n += bit - (n % bit); |
a951033d |
585 | b = n % MPW_BITS; |
586 | n /= MPW_BITS; |
afd054c1 |
587 | |
588 | if (n >= MP_LEN(m)) { |
a951033d |
589 | n--; |
590 | b += MPW_BITS; |
591 | } |
592 | |
593 | v = m->v + n; |
594 | a = *v; |
595 | mask = (1 << bit) - 1; |
596 | q = buf; |
597 | |
598 | /* --- Main code --- */ |
599 | |
600 | for (;;) { |
601 | if (b > bit) { |
602 | b -= bit; |
603 | x = a >> b; |
604 | } else { |
605 | x = a << (bit - b); |
606 | b += MPW_BITS - bit; |
607 | if (v == m->v) |
608 | break; |
609 | a = *--v; |
610 | if (b < MPW_BITS) |
611 | x |= a >> b; |
612 | } |
613 | x &= mask; |
614 | if (!x && !(f & f_out)) |
615 | continue; |
616 | |
617 | if (radix < 0) |
618 | ch = x; |
619 | else if (x < 10) |
620 | ch = '0' + x; |
631673a1 |
621 | else if (x < 36) |
622 | ch = 'a' + x - 10; /* Ascii specific */ |
a951033d |
623 | else |
631673a1 |
624 | ch = 'A' + x - 36; |
a951033d |
625 | *q++ = ch; |
626 | if (q >= buf + sizeof(buf)) { |
627 | if ((rc = ops->put(buf, sizeof(buf), p)) != 0) |
628 | goto done; |
629 | q = buf; |
630 | } |
631 | f |= f_out; |
632 | } |
633 | |
634 | x &= mask; |
635 | if (radix < 0) |
636 | ch = x; |
637 | else if (x < 10) |
638 | ch = '0' + x; |
631673a1 |
639 | else if (x < 36) |
640 | ch = 'a' + x - 10; /* Ascii specific */ |
a951033d |
641 | else |
631673a1 |
642 | ch = 'A' + x - 36; |
a951033d |
643 | *q++ = ch; |
644 | rc = ops->put(buf, q - buf, p); |
645 | |
646 | done: |
647 | mp_drop(m); |
648 | return (rc); |
649 | |
650 | #undef f_out |
651 | } |
652 | |
e360a4f2 |
653 | /* --- Main driver code --- */ |
654 | |
d3409d5e |
655 | int mp_write(mp *m, int radix, const mptext_ops *ops, void *p) |
656 | { |
e360a4f2 |
657 | int rc; |
d3409d5e |
658 | |
afd054c1 |
659 | if (MP_EQ(m, MP_ZERO)) |
660 | return (ops->put("0", 1, p)); |
661 | |
d3409d5e |
662 | /* --- Set various things up --- */ |
663 | |
664 | m = MP_COPY(m); |
e360a4f2 |
665 | MP_SPLIT(m); |
d3409d5e |
666 | |
2b26f2d7 |
667 | /* --- Check the radix for sensibleness --- */ |
668 | |
669 | if (radix > 0) |
631673a1 |
670 | assert(((void)"ascii radix must be <= 62", radix <= 62)); |
2b26f2d7 |
671 | else if (radix < 0) |
25b5e686 |
672 | assert(((void)"binary radix must fit in a byte", -radix <= UCHAR_MAX)); |
2b26f2d7 |
673 | else |
674 | assert(((void)"radix can't be zero in mp_write", 0)); |
675 | |
d3409d5e |
676 | /* --- If the number is negative, sort that out --- */ |
677 | |
a69a3efd |
678 | if (MP_NEGP(m)) { |
d3409d5e |
679 | if (ops->put("-", 1, p)) |
680 | return (EOF); |
2b26f2d7 |
681 | m->f &= ~MP_NEG; |
d3409d5e |
682 | } |
683 | |
a951033d |
684 | /* --- Handle binary radix --- */ |
685 | |
686 | switch (radix) { |
687 | case 2: case -2: return (binary(m, 1, radix, ops, p)); |
688 | case 4: case -4: return (binary(m, 2, radix, ops, p)); |
689 | case 8: case -8: return (binary(m, 3, radix, ops, p)); |
690 | case 16: case -16: return (binary(m, 4, radix, ops, p)); |
691 | case 32: case -32: return (binary(m, 5, radix, ops, p)); |
692 | case -64: return (binary(m, 6, radix, ops, p)); |
693 | case -128: return (binary(m, 7, radix, ops, p)); |
694 | } |
695 | |
e360a4f2 |
696 | /* --- If the number is small, do it the easy way --- */ |
697 | |
3bc9cb53 |
698 | if (MP_LEN(m) < 2) |
699 | rc = simple(MP_LEN(m) ? m->v[0] : 0, radix, 0, ops, p); |
e360a4f2 |
700 | |
701 | /* --- Use a clever algorithm --- * |
702 | * |
703 | * Square the radix repeatedly, remembering old results, until I get |
704 | * something more than half the size of the number @m@. Use this to divide |
705 | * the number: the quotient and remainder will be approximately the same |
706 | * size, and I'll have split them on a digit boundary, so I can just emit |
707 | * the quotient and remainder recursively, in order. |
e360a4f2 |
708 | */ |
709 | |
710 | else { |
2b26f2d7 |
711 | mp *pr[DEPTH]; |
3bc9cb53 |
712 | size_t target = (MP_LEN(m) + 1) / 2; |
e360a4f2 |
713 | unsigned i = 0; |
2b26f2d7 |
714 | mp *z = mp_new(1, 0); |
e360a4f2 |
715 | |
716 | /* --- Set up the exponent table --- */ |
717 | |
2b26f2d7 |
718 | z->v[0] = (radix > 0 ? radix : -radix); |
e360a4f2 |
719 | z->f = 0; |
720 | for (;;) { |
2b26f2d7 |
721 | assert(((void)"Number is too unimaginably huge", i < DEPTH)); |
e360a4f2 |
722 | pr[i++] = z; |
723 | if (MP_LEN(z) > target) |
724 | break; |
725 | z = mp_sqr(MP_NEW, z); |
726 | } |
d3409d5e |
727 | |
e360a4f2 |
728 | /* --- Write out the answer --- */ |
d3409d5e |
729 | |
e360a4f2 |
730 | rc = complicated(m, radix, pr, i - 1, 0, ops, p); |
d3409d5e |
731 | |
e360a4f2 |
732 | /* --- Tidy away the array --- */ |
d3409d5e |
733 | |
e360a4f2 |
734 | while (i > 0) |
735 | mp_drop(pr[--i]); |
d3409d5e |
736 | } |
e360a4f2 |
737 | |
738 | /* --- Tidying up code --- */ |
739 | |
740 | MP_DROP(m); |
741 | return (rc); |
d3409d5e |
742 | } |
743 | |
744 | /*----- Test rig ----------------------------------------------------------*/ |
745 | |
746 | #ifdef TEST_RIG |
747 | |
748 | #include <mLib/testrig.h> |
749 | |
750 | static int verify(dstr *v) |
751 | { |
752 | int ok = 1; |
753 | int ib = *(int *)v[0].buf, ob = *(int *)v[2].buf; |
754 | dstr d = DSTR_INIT; |
50bea2af |
755 | size_t off = 0; |
756 | mp *m = mp_readdstr(MP_NEW, &v[1], &off, ib); |
d3409d5e |
757 | if (m) { |
758 | if (!ob) { |
759 | fprintf(stderr, "*** unexpected successful parse\n" |
a951033d |
760 | "*** input [%2i] = ", ib); |
2b26f2d7 |
761 | if (ib < 0) |
762 | type_hex.dump(&v[1], stderr); |
763 | else |
764 | fputs(v[1].buf, stderr); |
d3409d5e |
765 | mp_writedstr(m, &d, 10); |
2b26f2d7 |
766 | fprintf(stderr, "\n*** (value = %s)\n", d.buf); |
d3409d5e |
767 | ok = 0; |
768 | } else { |
769 | mp_writedstr(m, &d, ob); |
770 | if (d.len != v[3].len || memcmp(d.buf, v[3].buf, d.len) != 0) { |
771 | fprintf(stderr, "*** failed read or write\n" |
a951033d |
772 | "*** input [%2i] = ", ib); |
2b26f2d7 |
773 | if (ib < 0) |
774 | type_hex.dump(&v[1], stderr); |
775 | else |
776 | fputs(v[1].buf, stderr); |
a951033d |
777 | fprintf(stderr, "\n*** output [%2i] = ", ob); |
2b26f2d7 |
778 | if (ob < 0) |
779 | type_hex.dump(&d, stderr); |
780 | else |
781 | fputs(d.buf, stderr); |
a951033d |
782 | fprintf(stderr, "\n*** expected [%2i] = ", ob); |
2b26f2d7 |
783 | if (ob < 0) |
784 | type_hex.dump(&v[3], stderr); |
785 | else |
786 | fputs(v[3].buf, stderr); |
787 | fputc('\n', stderr); |
d3409d5e |
788 | ok = 0; |
789 | } |
790 | } |
791 | mp_drop(m); |
792 | } else { |
793 | if (ob) { |
794 | fprintf(stderr, "*** unexpected parse failure\n" |
50bea2af |
795 | "*** input [%2i] = ", ib); |
2b26f2d7 |
796 | if (ib < 0) |
797 | type_hex.dump(&v[1], stderr); |
798 | else |
799 | fputs(v[1].buf, stderr); |
50bea2af |
800 | fprintf(stderr, "\n*** expected [%2i] = ", ob); |
2b26f2d7 |
801 | if (ob < 0) |
802 | type_hex.dump(&v[3], stderr); |
803 | else |
804 | fputs(v[3].buf, stderr); |
805 | fputc('\n', stderr); |
d3409d5e |
806 | ok = 0; |
807 | } |
808 | } |
809 | |
50bea2af |
810 | if (v[1].len - off != v[4].len || |
811 | memcmp(v[1].buf + off, v[4].buf, v[4].len) != 0) { |
812 | fprintf(stderr, "*** leftovers incorrect\n" |
813 | "*** input [%2i] = ", ib); |
814 | if (ib < 0) |
815 | type_hex.dump(&v[1], stderr); |
816 | else |
817 | fputs(v[1].buf, stderr); |
818 | fprintf(stderr, "\n*** expected `%s'\n" |
819 | "*** found `%s'\n", |
820 | v[4].buf, v[1].buf + off); |
821 | ok = 0; |
822 | } |
823 | |
d3409d5e |
824 | dstr_destroy(&d); |
9c3df6c0 |
825 | assert(mparena_count(MPARENA_GLOBAL) == 0); |
d3409d5e |
826 | return (ok); |
827 | } |
828 | |
829 | static test_chunk tests[] = { |
2b26f2d7 |
830 | { "mptext-ascii", verify, |
50bea2af |
831 | { &type_int, &type_string, &type_int, &type_string, &type_string, 0 } }, |
2b26f2d7 |
832 | { "mptext-bin-in", verify, |
50bea2af |
833 | { &type_int, &type_hex, &type_int, &type_string, &type_string, 0 } }, |
2b26f2d7 |
834 | { "mptext-bin-out", verify, |
50bea2af |
835 | { &type_int, &type_string, &type_int, &type_hex, &type_string, 0 } }, |
d3409d5e |
836 | { 0, 0, { 0 } } |
837 | }; |
838 | |
839 | int main(int argc, char *argv[]) |
840 | { |
841 | sub_init(); |
842 | test_run(argc, argv, tests, SRCDIR "/tests/mptext"); |
843 | return (0); |
844 | } |
845 | |
846 | #endif |
847 | |
848 | /*----- That's all, folks -------------------------------------------------*/ |