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3443546f LT |
1 | /* |
2 | * LibXDiff by Davide Libenzi ( File Differential Library ) | |
3 | * Copyright (C) 2003 Davide Libenzi | |
4 | * | |
5 | * This library is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU Lesser General Public | |
7 | * License as published by the Free Software Foundation; either | |
8 | * version 2.1 of the License, or (at your option) any later version. | |
9 | * | |
10 | * This library is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * Lesser General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU Lesser General Public | |
16 | * License along with this library; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | * | |
19 | * Davide Libenzi <davidel@xmailserver.org> | |
20 | * | |
21 | */ | |
22 | ||
23 | #include "xinclude.h" | |
24 | ||
25 | ||
3443546f | 26 | #define XDL_KPDIS_RUN 4 |
ca557aff | 27 | #define XDL_MAX_EQLIMIT 1024 |
9b28d554 | 28 | #define XDL_SIMSCAN_WINDOW 100 |
3443546f LT |
29 | |
30 | ||
31 | typedef struct s_xdlclass { | |
32 | struct s_xdlclass *next; | |
33 | unsigned long ha; | |
34 | char const *line; | |
35 | long size; | |
36 | long idx; | |
37 | } xdlclass_t; | |
38 | ||
39 | typedef struct s_xdlclassifier { | |
40 | unsigned int hbits; | |
41 | long hsize; | |
42 | xdlclass_t **rchash; | |
43 | chastore_t ncha; | |
44 | long count; | |
0d21efa5 | 45 | long flags; |
3443546f LT |
46 | } xdlclassifier_t; |
47 | ||
48 | ||
49 | ||
50 | ||
0d21efa5 | 51 | static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags); |
3443546f LT |
52 | static void xdl_free_classifier(xdlclassifier_t *cf); |
53 | static int xdl_classify_record(xdlclassifier_t *cf, xrecord_t **rhash, unsigned int hbits, | |
54 | xrecord_t *rec); | |
55 | static int xdl_prepare_ctx(mmfile_t *mf, long narec, xpparam_t const *xpp, | |
56 | xdlclassifier_t *cf, xdfile_t *xdf); | |
57 | static void xdl_free_ctx(xdfile_t *xdf); | |
58 | static int xdl_clean_mmatch(char const *dis, long i, long s, long e); | |
59 | static int xdl_cleanup_records(xdfile_t *xdf1, xdfile_t *xdf2); | |
60 | static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2); | |
61 | static int xdl_optimize_ctxs(xdfile_t *xdf1, xdfile_t *xdf2); | |
62 | ||
63 | ||
64 | ||
65 | ||
0d21efa5 | 66 | static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags) { |
3443546f LT |
67 | long i; |
68 | ||
0d21efa5 JS |
69 | cf->flags = flags; |
70 | ||
3443546f LT |
71 | cf->hbits = xdl_hashbits((unsigned int) size); |
72 | cf->hsize = 1 << cf->hbits; | |
73 | ||
74 | if (xdl_cha_init(&cf->ncha, sizeof(xdlclass_t), size / 4 + 1) < 0) { | |
75 | ||
76 | return -1; | |
77 | } | |
78 | if (!(cf->rchash = (xdlclass_t **) xdl_malloc(cf->hsize * sizeof(xdlclass_t *)))) { | |
79 | ||
80 | xdl_cha_free(&cf->ncha); | |
81 | return -1; | |
82 | } | |
83 | for (i = 0; i < cf->hsize; i++) | |
84 | cf->rchash[i] = NULL; | |
85 | ||
86 | cf->count = 0; | |
87 | ||
88 | return 0; | |
89 | } | |
90 | ||
91 | ||
92 | static void xdl_free_classifier(xdlclassifier_t *cf) { | |
93 | ||
94 | xdl_free(cf->rchash); | |
95 | xdl_cha_free(&cf->ncha); | |
96 | } | |
97 | ||
98 | ||
99 | static int xdl_classify_record(xdlclassifier_t *cf, xrecord_t **rhash, unsigned int hbits, | |
100 | xrecord_t *rec) { | |
101 | long hi; | |
102 | char const *line; | |
103 | xdlclass_t *rcrec; | |
104 | ||
105 | line = rec->ptr; | |
106 | hi = (long) XDL_HASHLONG(rec->ha, cf->hbits); | |
107 | for (rcrec = cf->rchash[hi]; rcrec; rcrec = rcrec->next) | |
0d21efa5 JS |
108 | if (rcrec->ha == rec->ha && |
109 | xdl_recmatch(rcrec->line, rcrec->size, | |
110 | rec->ptr, rec->size, cf->flags)) | |
3443546f LT |
111 | break; |
112 | ||
113 | if (!rcrec) { | |
114 | if (!(rcrec = xdl_cha_alloc(&cf->ncha))) { | |
115 | ||
116 | return -1; | |
117 | } | |
118 | rcrec->idx = cf->count++; | |
119 | rcrec->line = line; | |
120 | rcrec->size = rec->size; | |
121 | rcrec->ha = rec->ha; | |
122 | rcrec->next = cf->rchash[hi]; | |
123 | cf->rchash[hi] = rcrec; | |
124 | } | |
125 | ||
126 | rec->ha = (unsigned long) rcrec->idx; | |
127 | ||
128 | hi = (long) XDL_HASHLONG(rec->ha, hbits); | |
129 | rec->next = rhash[hi]; | |
130 | rhash[hi] = rec; | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
135 | ||
136 | static int xdl_prepare_ctx(mmfile_t *mf, long narec, xpparam_t const *xpp, | |
137 | xdlclassifier_t *cf, xdfile_t *xdf) { | |
138 | unsigned int hbits; | |
139 | long i, nrec, hsize, bsize; | |
140 | unsigned long hav; | |
141 | char const *blk, *cur, *top, *prev; | |
142 | xrecord_t *crec; | |
143 | xrecord_t **recs, **rrecs; | |
144 | xrecord_t **rhash; | |
145 | unsigned long *ha; | |
146 | char *rchg; | |
147 | long *rindex; | |
148 | ||
149 | if (xdl_cha_init(&xdf->rcha, sizeof(xrecord_t), narec / 4 + 1) < 0) { | |
150 | ||
151 | return -1; | |
152 | } | |
153 | if (!(recs = (xrecord_t **) xdl_malloc(narec * sizeof(xrecord_t *)))) { | |
154 | ||
155 | xdl_cha_free(&xdf->rcha); | |
156 | return -1; | |
157 | } | |
158 | ||
159 | hbits = xdl_hashbits((unsigned int) narec); | |
160 | hsize = 1 << hbits; | |
161 | if (!(rhash = (xrecord_t **) xdl_malloc(hsize * sizeof(xrecord_t *)))) { | |
162 | ||
163 | xdl_free(recs); | |
164 | xdl_cha_free(&xdf->rcha); | |
165 | return -1; | |
166 | } | |
167 | for (i = 0; i < hsize; i++) | |
168 | rhash[i] = NULL; | |
169 | ||
170 | nrec = 0; | |
171 | if ((cur = blk = xdl_mmfile_first(mf, &bsize)) != NULL) { | |
172 | for (top = blk + bsize;;) { | |
173 | if (cur >= top) { | |
174 | if (!(cur = blk = xdl_mmfile_next(mf, &bsize))) | |
175 | break; | |
176 | top = blk + bsize; | |
177 | } | |
178 | prev = cur; | |
0d21efa5 | 179 | hav = xdl_hash_record(&cur, top, xpp->flags); |
3443546f LT |
180 | if (nrec >= narec) { |
181 | narec *= 2; | |
182 | if (!(rrecs = (xrecord_t **) xdl_realloc(recs, narec * sizeof(xrecord_t *)))) { | |
183 | ||
184 | xdl_free(rhash); | |
185 | xdl_free(recs); | |
186 | xdl_cha_free(&xdf->rcha); | |
187 | return -1; | |
188 | } | |
189 | recs = rrecs; | |
190 | } | |
191 | if (!(crec = xdl_cha_alloc(&xdf->rcha))) { | |
192 | ||
193 | xdl_free(rhash); | |
194 | xdl_free(recs); | |
195 | xdl_cha_free(&xdf->rcha); | |
196 | return -1; | |
197 | } | |
198 | crec->ptr = prev; | |
199 | crec->size = (long) (cur - prev); | |
200 | crec->ha = hav; | |
201 | recs[nrec++] = crec; | |
202 | ||
203 | if (xdl_classify_record(cf, rhash, hbits, crec) < 0) { | |
204 | ||
205 | xdl_free(rhash); | |
206 | xdl_free(recs); | |
207 | xdl_cha_free(&xdf->rcha); | |
208 | return -1; | |
209 | } | |
210 | } | |
211 | } | |
212 | ||
213 | if (!(rchg = (char *) xdl_malloc((nrec + 2) * sizeof(char)))) { | |
214 | ||
215 | xdl_free(rhash); | |
216 | xdl_free(recs); | |
217 | xdl_cha_free(&xdf->rcha); | |
218 | return -1; | |
219 | } | |
220 | memset(rchg, 0, (nrec + 2) * sizeof(char)); | |
221 | ||
222 | if (!(rindex = (long *) xdl_malloc((nrec + 1) * sizeof(long)))) { | |
223 | ||
224 | xdl_free(rchg); | |
225 | xdl_free(rhash); | |
226 | xdl_free(recs); | |
227 | xdl_cha_free(&xdf->rcha); | |
228 | return -1; | |
229 | } | |
230 | if (!(ha = (unsigned long *) xdl_malloc((nrec + 1) * sizeof(unsigned long)))) { | |
231 | ||
232 | xdl_free(rindex); | |
233 | xdl_free(rchg); | |
234 | xdl_free(rhash); | |
235 | xdl_free(recs); | |
236 | xdl_cha_free(&xdf->rcha); | |
237 | return -1; | |
238 | } | |
239 | ||
240 | xdf->nrec = nrec; | |
241 | xdf->recs = recs; | |
242 | xdf->hbits = hbits; | |
243 | xdf->rhash = rhash; | |
244 | xdf->rchg = rchg + 1; | |
245 | xdf->rindex = rindex; | |
246 | xdf->nreff = 0; | |
247 | xdf->ha = ha; | |
248 | xdf->dstart = 0; | |
249 | xdf->dend = nrec - 1; | |
250 | ||
251 | return 0; | |
252 | } | |
253 | ||
254 | ||
255 | static void xdl_free_ctx(xdfile_t *xdf) { | |
256 | ||
257 | xdl_free(xdf->rhash); | |
258 | xdl_free(xdf->rindex); | |
259 | xdl_free(xdf->rchg - 1); | |
260 | xdl_free(xdf->ha); | |
261 | xdl_free(xdf->recs); | |
262 | xdl_cha_free(&xdf->rcha); | |
263 | } | |
264 | ||
265 | ||
266 | int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, | |
267 | xdfenv_t *xe) { | |
268 | long enl1, enl2; | |
269 | xdlclassifier_t cf; | |
270 | ||
271 | enl1 = xdl_guess_lines(mf1) + 1; | |
272 | enl2 = xdl_guess_lines(mf2) + 1; | |
273 | ||
0d21efa5 | 274 | if (xdl_init_classifier(&cf, enl1 + enl2 + 1, xpp->flags) < 0) { |
3443546f LT |
275 | |
276 | return -1; | |
277 | } | |
278 | ||
279 | if (xdl_prepare_ctx(mf1, enl1, xpp, &cf, &xe->xdf1) < 0) { | |
280 | ||
281 | xdl_free_classifier(&cf); | |
282 | return -1; | |
283 | } | |
284 | if (xdl_prepare_ctx(mf2, enl2, xpp, &cf, &xe->xdf2) < 0) { | |
285 | ||
286 | xdl_free_ctx(&xe->xdf1); | |
287 | xdl_free_classifier(&cf); | |
288 | return -1; | |
289 | } | |
290 | ||
291 | xdl_free_classifier(&cf); | |
292 | ||
92b7de93 JS |
293 | if (!(xpp->flags & XDF_PATIENCE_DIFF) && |
294 | xdl_optimize_ctxs(&xe->xdf1, &xe->xdf2) < 0) { | |
3443546f LT |
295 | |
296 | xdl_free_ctx(&xe->xdf2); | |
297 | xdl_free_ctx(&xe->xdf1); | |
298 | return -1; | |
299 | } | |
300 | ||
301 | return 0; | |
302 | } | |
303 | ||
304 | ||
305 | void xdl_free_env(xdfenv_t *xe) { | |
306 | ||
307 | xdl_free_ctx(&xe->xdf2); | |
308 | xdl_free_ctx(&xe->xdf1); | |
309 | } | |
310 | ||
311 | ||
312 | static int xdl_clean_mmatch(char const *dis, long i, long s, long e) { | |
ca557aff DL |
313 | long r, rdis0, rpdis0, rdis1, rpdis1; |
314 | ||
9b28d554 DL |
315 | /* |
316 | * Limits the window the is examined during the similar-lines | |
317 | * scan. The loops below stops when dis[i - r] == 1 (line that | |
318 | * has no match), but there are corner cases where the loop | |
319 | * proceed all the way to the extremities by causing huge | |
320 | * performance penalties in case of big files. | |
321 | */ | |
322 | if (i - s > XDL_SIMSCAN_WINDOW) | |
323 | s = i - XDL_SIMSCAN_WINDOW; | |
324 | if (e - i > XDL_SIMSCAN_WINDOW) | |
325 | e = i + XDL_SIMSCAN_WINDOW; | |
326 | ||
ca557aff DL |
327 | /* |
328 | * Scans the lines before 'i' to find a run of lines that either | |
329 | * have no match (dis[j] == 0) or have multiple matches (dis[j] > 1). | |
330 | * Note that we always call this function with dis[i] > 1, so the | |
331 | * current line (i) is already a multimatch line. | |
332 | */ | |
333 | for (r = 1, rdis0 = 0, rpdis0 = 1; (i - r) >= s; r++) { | |
3443546f | 334 | if (!dis[i - r]) |
ca557aff | 335 | rdis0++; |
3443546f | 336 | else if (dis[i - r] == 2) |
ca557aff | 337 | rpdis0++; |
3443546f LT |
338 | else |
339 | break; | |
340 | } | |
ca557aff DL |
341 | /* |
342 | * If the run before the line 'i' found only multimatch lines, we | |
343 | * return 0 and hence we don't make the current line (i) discarded. | |
344 | * We want to discard multimatch lines only when they appear in the | |
345 | * middle of runs with nomatch lines (dis[j] == 0). | |
346 | */ | |
347 | if (rdis0 == 0) | |
348 | return 0; | |
349 | for (r = 1, rdis1 = 0, rpdis1 = 1; (i + r) <= e; r++) { | |
3443546f | 350 | if (!dis[i + r]) |
ca557aff | 351 | rdis1++; |
3443546f | 352 | else if (dis[i + r] == 2) |
ca557aff | 353 | rpdis1++; |
3443546f LT |
354 | else |
355 | break; | |
356 | } | |
ca557aff DL |
357 | /* |
358 | * If the run after the line 'i' found only multimatch lines, we | |
359 | * return 0 and hence we don't make the current line (i) discarded. | |
360 | */ | |
361 | if (rdis1 == 0) | |
362 | return 0; | |
363 | rdis1 += rdis0; | |
364 | rpdis1 += rpdis0; | |
365 | ||
366 | return rpdis1 * XDL_KPDIS_RUN < (rpdis1 + rdis1); | |
3443546f LT |
367 | } |
368 | ||
369 | ||
370 | /* | |
371 | * Try to reduce the problem complexity, discard records that have no | |
372 | * matches on the other file. Also, lines that have multiple matches | |
373 | * might be potentially discarded if they happear in a run of discardable. | |
374 | */ | |
375 | static int xdl_cleanup_records(xdfile_t *xdf1, xdfile_t *xdf2) { | |
ca557aff | 376 | long i, nm, rhi, nreff, mlim; |
3443546f LT |
377 | unsigned long hav; |
378 | xrecord_t **recs; | |
379 | xrecord_t *rec; | |
380 | char *dis, *dis1, *dis2; | |
381 | ||
ca557aff | 382 | if (!(dis = (char *) xdl_malloc(xdf1->nrec + xdf2->nrec + 2))) { |
3443546f LT |
383 | |
384 | return -1; | |
385 | } | |
ca557aff | 386 | memset(dis, 0, xdf1->nrec + xdf2->nrec + 2); |
3443546f LT |
387 | dis1 = dis; |
388 | dis2 = dis1 + xdf1->nrec + 1; | |
389 | ||
ca557aff DL |
390 | if ((mlim = xdl_bogosqrt(xdf1->nrec)) > XDL_MAX_EQLIMIT) |
391 | mlim = XDL_MAX_EQLIMIT; | |
3443546f LT |
392 | for (i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; i <= xdf1->dend; i++, recs++) { |
393 | hav = (*recs)->ha; | |
394 | rhi = (long) XDL_HASHLONG(hav, xdf2->hbits); | |
ca557aff DL |
395 | for (nm = 0, rec = xdf2->rhash[rhi]; rec; rec = rec->next) |
396 | if (rec->ha == hav && ++nm == mlim) | |
3443546f | 397 | break; |
ca557aff | 398 | dis1[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1; |
3443546f LT |
399 | } |
400 | ||
ca557aff DL |
401 | if ((mlim = xdl_bogosqrt(xdf2->nrec)) > XDL_MAX_EQLIMIT) |
402 | mlim = XDL_MAX_EQLIMIT; | |
3443546f LT |
403 | for (i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; i <= xdf2->dend; i++, recs++) { |
404 | hav = (*recs)->ha; | |
405 | rhi = (long) XDL_HASHLONG(hav, xdf1->hbits); | |
ca557aff DL |
406 | for (nm = 0, rec = xdf1->rhash[rhi]; rec; rec = rec->next) |
407 | if (rec->ha == hav && ++nm == mlim) | |
3443546f | 408 | break; |
ca557aff | 409 | dis2[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1; |
3443546f LT |
410 | } |
411 | ||
412 | for (nreff = 0, i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; | |
413 | i <= xdf1->dend; i++, recs++) { | |
414 | if (dis1[i] == 1 || | |
415 | (dis1[i] == 2 && !xdl_clean_mmatch(dis1, i, xdf1->dstart, xdf1->dend))) { | |
416 | xdf1->rindex[nreff] = i; | |
417 | xdf1->ha[nreff] = (*recs)->ha; | |
418 | nreff++; | |
419 | } else | |
420 | xdf1->rchg[i] = 1; | |
421 | } | |
422 | xdf1->nreff = nreff; | |
423 | ||
424 | for (nreff = 0, i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; | |
425 | i <= xdf2->dend; i++, recs++) { | |
426 | if (dis2[i] == 1 || | |
427 | (dis2[i] == 2 && !xdl_clean_mmatch(dis2, i, xdf2->dstart, xdf2->dend))) { | |
428 | xdf2->rindex[nreff] = i; | |
429 | xdf2->ha[nreff] = (*recs)->ha; | |
430 | nreff++; | |
431 | } else | |
432 | xdf2->rchg[i] = 1; | |
433 | } | |
434 | xdf2->nreff = nreff; | |
435 | ||
436 | xdl_free(dis); | |
437 | ||
438 | return 0; | |
439 | } | |
440 | ||
441 | ||
442 | /* | |
443 | * Early trim initial and terminal matching records. | |
444 | */ | |
445 | static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2) { | |
446 | long i, lim; | |
447 | xrecord_t **recs1, **recs2; | |
448 | ||
449 | recs1 = xdf1->recs; | |
450 | recs2 = xdf2->recs; | |
451 | for (i = 0, lim = XDL_MIN(xdf1->nrec, xdf2->nrec); i < lim; | |
452 | i++, recs1++, recs2++) | |
453 | if ((*recs1)->ha != (*recs2)->ha) | |
454 | break; | |
455 | ||
456 | xdf1->dstart = xdf2->dstart = i; | |
457 | ||
458 | recs1 = xdf1->recs + xdf1->nrec - 1; | |
459 | recs2 = xdf2->recs + xdf2->nrec - 1; | |
460 | for (lim -= i, i = 0; i < lim; i++, recs1--, recs2--) | |
461 | if ((*recs1)->ha != (*recs2)->ha) | |
462 | break; | |
463 | ||
464 | xdf1->dend = xdf1->nrec - i - 1; | |
465 | xdf2->dend = xdf2->nrec - i - 1; | |
466 | ||
467 | return 0; | |
468 | } | |
469 | ||
470 | ||
471 | static int xdl_optimize_ctxs(xdfile_t *xdf1, xdfile_t *xdf2) { | |
472 | ||
473 | if (xdl_trim_ends(xdf1, xdf2) < 0 || | |
474 | xdl_cleanup_records(xdf1, xdf2) < 0) { | |
475 | ||
476 | return -1; | |
477 | } | |
478 | ||
479 | return 0; | |
480 | } |