]>
Commit | Line | Data |
---|---|---|
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 |
86abba80 TRC |
29 | #define XDL_GUESS_NLINES1 256 |
30 | #define XDL_GUESS_NLINES2 20 | |
3443546f LT |
31 | |
32 | ||
33 | typedef struct s_xdlclass { | |
34 | struct s_xdlclass *next; | |
35 | unsigned long ha; | |
36 | char const *line; | |
37 | long size; | |
38 | long idx; | |
39 | } xdlclass_t; | |
40 | ||
41 | typedef struct s_xdlclassifier { | |
42 | unsigned int hbits; | |
43 | long hsize; | |
44 | xdlclass_t **rchash; | |
45 | chastore_t ncha; | |
46 | long count; | |
0d21efa5 | 47 | long flags; |
3443546f LT |
48 | } xdlclassifier_t; |
49 | ||
50 | ||
51 | ||
52 | ||
0d21efa5 | 53 | static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags); |
3443546f LT |
54 | static void xdl_free_classifier(xdlclassifier_t *cf); |
55 | static int xdl_classify_record(xdlclassifier_t *cf, xrecord_t **rhash, unsigned int hbits, | |
56 | xrecord_t *rec); | |
57 | static int xdl_prepare_ctx(mmfile_t *mf, long narec, xpparam_t const *xpp, | |
58 | xdlclassifier_t *cf, xdfile_t *xdf); | |
59 | static void xdl_free_ctx(xdfile_t *xdf); | |
60 | static int xdl_clean_mmatch(char const *dis, long i, long s, long e); | |
61 | static int xdl_cleanup_records(xdfile_t *xdf1, xdfile_t *xdf2); | |
62 | static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2); | |
63 | static int xdl_optimize_ctxs(xdfile_t *xdf1, xdfile_t *xdf2); | |
64 | ||
65 | ||
66 | ||
67 | ||
0d21efa5 | 68 | static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags) { |
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 | } | |
452f4fa5 | 83 | memset(cf->rchash, 0, cf->hsize * sizeof(xdlclass_t *)); |
3443546f LT |
84 | |
85 | cf->count = 0; | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
90 | ||
91 | static void xdl_free_classifier(xdlclassifier_t *cf) { | |
92 | ||
93 | xdl_free(cf->rchash); | |
94 | xdl_cha_free(&cf->ncha); | |
95 | } | |
96 | ||
97 | ||
98 | static int xdl_classify_record(xdlclassifier_t *cf, xrecord_t **rhash, unsigned int hbits, | |
99 | xrecord_t *rec) { | |
100 | long hi; | |
101 | char const *line; | |
102 | xdlclass_t *rcrec; | |
103 | ||
104 | line = rec->ptr; | |
105 | hi = (long) XDL_HASHLONG(rec->ha, cf->hbits); | |
106 | for (rcrec = cf->rchash[hi]; rcrec; rcrec = rcrec->next) | |
0d21efa5 JS |
107 | if (rcrec->ha == rec->ha && |
108 | xdl_recmatch(rcrec->line, rcrec->size, | |
109 | rec->ptr, rec->size, cf->flags)) | |
3443546f LT |
110 | break; |
111 | ||
112 | if (!rcrec) { | |
113 | if (!(rcrec = xdl_cha_alloc(&cf->ncha))) { | |
114 | ||
115 | return -1; | |
116 | } | |
117 | rcrec->idx = cf->count++; | |
118 | rcrec->line = line; | |
119 | rcrec->size = rec->size; | |
120 | rcrec->ha = rec->ha; | |
121 | rcrec->next = cf->rchash[hi]; | |
122 | cf->rchash[hi] = rcrec; | |
123 | } | |
124 | ||
125 | rec->ha = (unsigned long) rcrec->idx; | |
126 | ||
127 | hi = (long) XDL_HASHLONG(rec->ha, hbits); | |
128 | rec->next = rhash[hi]; | |
129 | rhash[hi] = rec; | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | ||
135 | static int xdl_prepare_ctx(mmfile_t *mf, long narec, xpparam_t const *xpp, | |
136 | xdlclassifier_t *cf, xdfile_t *xdf) { | |
137 | unsigned int hbits; | |
452f4fa5 | 138 | long nrec, hsize, bsize; |
3443546f LT |
139 | unsigned long hav; |
140 | char const *blk, *cur, *top, *prev; | |
141 | xrecord_t *crec; | |
142 | xrecord_t **recs, **rrecs; | |
143 | xrecord_t **rhash; | |
144 | unsigned long *ha; | |
145 | char *rchg; | |
146 | long *rindex; | |
147 | ||
159607a8 TRC |
148 | ha = NULL; |
149 | rindex = NULL; | |
150 | rchg = NULL; | |
151 | rhash = NULL; | |
152 | recs = NULL; | |
3443546f | 153 | |
159607a8 TRC |
154 | if (xdl_cha_init(&xdf->rcha, sizeof(xrecord_t), narec / 4 + 1) < 0) |
155 | goto abort; | |
156 | if (!(recs = (xrecord_t **) xdl_malloc(narec * sizeof(xrecord_t *)))) | |
157 | goto abort; | |
3443546f | 158 | |
9f37c275 TRC |
159 | if (xpp->flags & XDF_HISTOGRAM_DIFF) |
160 | hbits = hsize = 0; | |
161 | else { | |
162 | hbits = xdl_hashbits((unsigned int) narec); | |
163 | hsize = 1 << hbits; | |
164 | if (!(rhash = (xrecord_t **) xdl_malloc(hsize * sizeof(xrecord_t *)))) | |
165 | goto abort; | |
166 | memset(rhash, 0, hsize * sizeof(xrecord_t *)); | |
167 | } | |
3443546f LT |
168 | |
169 | nrec = 0; | |
170 | if ((cur = blk = xdl_mmfile_first(mf, &bsize)) != NULL) { | |
739864b1 | 171 | for (top = blk + bsize; cur < top; ) { |
3443546f | 172 | prev = cur; |
0d21efa5 | 173 | hav = xdl_hash_record(&cur, top, xpp->flags); |
3443546f LT |
174 | if (nrec >= narec) { |
175 | narec *= 2; | |
159607a8 TRC |
176 | if (!(rrecs = (xrecord_t **) xdl_realloc(recs, narec * sizeof(xrecord_t *)))) |
177 | goto abort; | |
3443546f LT |
178 | recs = rrecs; |
179 | } | |
159607a8 TRC |
180 | if (!(crec = xdl_cha_alloc(&xdf->rcha))) |
181 | goto abort; | |
3443546f LT |
182 | crec->ptr = prev; |
183 | crec->size = (long) (cur - prev); | |
184 | crec->ha = hav; | |
185 | recs[nrec++] = crec; | |
186 | ||
9f37c275 TRC |
187 | if (!(xpp->flags & XDF_HISTOGRAM_DIFF) && |
188 | xdl_classify_record(cf, rhash, hbits, crec) < 0) | |
159607a8 | 189 | goto abort; |
3443546f LT |
190 | } |
191 | } | |
192 | ||
159607a8 TRC |
193 | if (!(rchg = (char *) xdl_malloc((nrec + 2) * sizeof(char)))) |
194 | goto abort; | |
3443546f LT |
195 | memset(rchg, 0, (nrec + 2) * sizeof(char)); |
196 | ||
159607a8 TRC |
197 | if (!(rindex = (long *) xdl_malloc((nrec + 1) * sizeof(long)))) |
198 | goto abort; | |
199 | if (!(ha = (unsigned long *) xdl_malloc((nrec + 1) * sizeof(unsigned long)))) | |
200 | goto abort; | |
3443546f LT |
201 | |
202 | xdf->nrec = nrec; | |
203 | xdf->recs = recs; | |
204 | xdf->hbits = hbits; | |
205 | xdf->rhash = rhash; | |
206 | xdf->rchg = rchg + 1; | |
207 | xdf->rindex = rindex; | |
208 | xdf->nreff = 0; | |
209 | xdf->ha = ha; | |
210 | xdf->dstart = 0; | |
211 | xdf->dend = nrec - 1; | |
212 | ||
213 | return 0; | |
159607a8 TRC |
214 | |
215 | abort: | |
216 | xdl_free(ha); | |
217 | xdl_free(rindex); | |
218 | xdl_free(rchg); | |
219 | xdl_free(rhash); | |
220 | xdl_free(recs); | |
221 | xdl_cha_free(&xdf->rcha); | |
222 | return -1; | |
3443546f LT |
223 | } |
224 | ||
225 | ||
226 | static void xdl_free_ctx(xdfile_t *xdf) { | |
227 | ||
228 | xdl_free(xdf->rhash); | |
229 | xdl_free(xdf->rindex); | |
230 | xdl_free(xdf->rchg - 1); | |
231 | xdl_free(xdf->ha); | |
232 | xdl_free(xdf->recs); | |
233 | xdl_cha_free(&xdf->rcha); | |
234 | } | |
235 | ||
236 | ||
237 | int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, | |
238 | xdfenv_t *xe) { | |
86abba80 | 239 | long enl1, enl2, sample; |
3443546f LT |
240 | xdlclassifier_t cf; |
241 | ||
86abba80 TRC |
242 | /* |
243 | * For histogram diff, we can afford a smaller sample size and | |
244 | * thus a poorer estimate of the number of lines, as the hash | |
245 | * table (rhash) won't be filled up/grown. The number of lines | |
246 | * (nrecs) will be updated correctly anyway by | |
247 | * xdl_prepare_ctx(). | |
248 | */ | |
249 | sample = xpp->flags & XDF_HISTOGRAM_DIFF ? XDL_GUESS_NLINES2 : XDL_GUESS_NLINES1; | |
250 | ||
251 | enl1 = xdl_guess_lines(mf1, sample) + 1; | |
252 | enl2 = xdl_guess_lines(mf2, sample) + 1; | |
3443546f | 253 | |
9f37c275 TRC |
254 | if (!(xpp->flags & XDF_HISTOGRAM_DIFF) && |
255 | xdl_init_classifier(&cf, enl1 + enl2 + 1, xpp->flags) < 0) { | |
3443546f LT |
256 | |
257 | return -1; | |
258 | } | |
259 | ||
260 | if (xdl_prepare_ctx(mf1, enl1, xpp, &cf, &xe->xdf1) < 0) { | |
261 | ||
262 | xdl_free_classifier(&cf); | |
263 | return -1; | |
264 | } | |
265 | if (xdl_prepare_ctx(mf2, enl2, xpp, &cf, &xe->xdf2) < 0) { | |
266 | ||
267 | xdl_free_ctx(&xe->xdf1); | |
268 | xdl_free_classifier(&cf); | |
269 | return -1; | |
270 | } | |
271 | ||
9f37c275 TRC |
272 | if (!(xpp->flags & XDF_HISTOGRAM_DIFF)) |
273 | xdl_free_classifier(&cf); | |
3443546f | 274 | |
92b7de93 | 275 | if (!(xpp->flags & XDF_PATIENCE_DIFF) && |
9f37c275 | 276 | !(xpp->flags & XDF_HISTOGRAM_DIFF) && |
92b7de93 | 277 | xdl_optimize_ctxs(&xe->xdf1, &xe->xdf2) < 0) { |
3443546f LT |
278 | |
279 | xdl_free_ctx(&xe->xdf2); | |
280 | xdl_free_ctx(&xe->xdf1); | |
281 | return -1; | |
282 | } | |
283 | ||
284 | return 0; | |
285 | } | |
286 | ||
287 | ||
288 | void xdl_free_env(xdfenv_t *xe) { | |
289 | ||
290 | xdl_free_ctx(&xe->xdf2); | |
291 | xdl_free_ctx(&xe->xdf1); | |
292 | } | |
293 | ||
294 | ||
295 | static int xdl_clean_mmatch(char const *dis, long i, long s, long e) { | |
ca557aff DL |
296 | long r, rdis0, rpdis0, rdis1, rpdis1; |
297 | ||
9b28d554 DL |
298 | /* |
299 | * Limits the window the is examined during the similar-lines | |
300 | * scan. The loops below stops when dis[i - r] == 1 (line that | |
301 | * has no match), but there are corner cases where the loop | |
302 | * proceed all the way to the extremities by causing huge | |
303 | * performance penalties in case of big files. | |
304 | */ | |
305 | if (i - s > XDL_SIMSCAN_WINDOW) | |
306 | s = i - XDL_SIMSCAN_WINDOW; | |
307 | if (e - i > XDL_SIMSCAN_WINDOW) | |
308 | e = i + XDL_SIMSCAN_WINDOW; | |
309 | ||
ca557aff DL |
310 | /* |
311 | * Scans the lines before 'i' to find a run of lines that either | |
312 | * have no match (dis[j] == 0) or have multiple matches (dis[j] > 1). | |
313 | * Note that we always call this function with dis[i] > 1, so the | |
314 | * current line (i) is already a multimatch line. | |
315 | */ | |
316 | for (r = 1, rdis0 = 0, rpdis0 = 1; (i - r) >= s; r++) { | |
3443546f | 317 | if (!dis[i - r]) |
ca557aff | 318 | rdis0++; |
3443546f | 319 | else if (dis[i - r] == 2) |
ca557aff | 320 | rpdis0++; |
3443546f LT |
321 | else |
322 | break; | |
323 | } | |
ca557aff DL |
324 | /* |
325 | * If the run before the line 'i' found only multimatch lines, we | |
326 | * return 0 and hence we don't make the current line (i) discarded. | |
327 | * We want to discard multimatch lines only when they appear in the | |
328 | * middle of runs with nomatch lines (dis[j] == 0). | |
329 | */ | |
330 | if (rdis0 == 0) | |
331 | return 0; | |
332 | for (r = 1, rdis1 = 0, rpdis1 = 1; (i + r) <= e; r++) { | |
3443546f | 333 | if (!dis[i + r]) |
ca557aff | 334 | rdis1++; |
3443546f | 335 | else if (dis[i + r] == 2) |
ca557aff | 336 | rpdis1++; |
3443546f LT |
337 | else |
338 | break; | |
339 | } | |
ca557aff DL |
340 | /* |
341 | * If the run after the line 'i' found only multimatch lines, we | |
342 | * return 0 and hence we don't make the current line (i) discarded. | |
343 | */ | |
344 | if (rdis1 == 0) | |
345 | return 0; | |
346 | rdis1 += rdis0; | |
347 | rpdis1 += rpdis0; | |
348 | ||
349 | return rpdis1 * XDL_KPDIS_RUN < (rpdis1 + rdis1); | |
3443546f LT |
350 | } |
351 | ||
352 | ||
353 | /* | |
354 | * Try to reduce the problem complexity, discard records that have no | |
355 | * matches on the other file. Also, lines that have multiple matches | |
356 | * might be potentially discarded if they happear in a run of discardable. | |
357 | */ | |
358 | static int xdl_cleanup_records(xdfile_t *xdf1, xdfile_t *xdf2) { | |
ca557aff | 359 | long i, nm, rhi, nreff, mlim; |
3443546f LT |
360 | unsigned long hav; |
361 | xrecord_t **recs; | |
362 | xrecord_t *rec; | |
363 | char *dis, *dis1, *dis2; | |
364 | ||
ca557aff | 365 | if (!(dis = (char *) xdl_malloc(xdf1->nrec + xdf2->nrec + 2))) { |
3443546f LT |
366 | |
367 | return -1; | |
368 | } | |
ca557aff | 369 | memset(dis, 0, xdf1->nrec + xdf2->nrec + 2); |
3443546f LT |
370 | dis1 = dis; |
371 | dis2 = dis1 + xdf1->nrec + 1; | |
372 | ||
ca557aff DL |
373 | if ((mlim = xdl_bogosqrt(xdf1->nrec)) > XDL_MAX_EQLIMIT) |
374 | mlim = XDL_MAX_EQLIMIT; | |
3443546f LT |
375 | for (i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; i <= xdf1->dend; i++, recs++) { |
376 | hav = (*recs)->ha; | |
377 | rhi = (long) XDL_HASHLONG(hav, xdf2->hbits); | |
ca557aff DL |
378 | for (nm = 0, rec = xdf2->rhash[rhi]; rec; rec = rec->next) |
379 | if (rec->ha == hav && ++nm == mlim) | |
3443546f | 380 | break; |
ca557aff | 381 | dis1[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1; |
3443546f LT |
382 | } |
383 | ||
ca557aff DL |
384 | if ((mlim = xdl_bogosqrt(xdf2->nrec)) > XDL_MAX_EQLIMIT) |
385 | mlim = XDL_MAX_EQLIMIT; | |
3443546f LT |
386 | for (i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; i <= xdf2->dend; i++, recs++) { |
387 | hav = (*recs)->ha; | |
388 | rhi = (long) XDL_HASHLONG(hav, xdf1->hbits); | |
ca557aff DL |
389 | for (nm = 0, rec = xdf1->rhash[rhi]; rec; rec = rec->next) |
390 | if (rec->ha == hav && ++nm == mlim) | |
3443546f | 391 | break; |
ca557aff | 392 | dis2[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1; |
3443546f LT |
393 | } |
394 | ||
395 | for (nreff = 0, i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; | |
396 | i <= xdf1->dend; i++, recs++) { | |
397 | if (dis1[i] == 1 || | |
398 | (dis1[i] == 2 && !xdl_clean_mmatch(dis1, i, xdf1->dstart, xdf1->dend))) { | |
399 | xdf1->rindex[nreff] = i; | |
400 | xdf1->ha[nreff] = (*recs)->ha; | |
401 | nreff++; | |
402 | } else | |
403 | xdf1->rchg[i] = 1; | |
404 | } | |
405 | xdf1->nreff = nreff; | |
406 | ||
407 | for (nreff = 0, i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; | |
408 | i <= xdf2->dend; i++, recs++) { | |
409 | if (dis2[i] == 1 || | |
410 | (dis2[i] == 2 && !xdl_clean_mmatch(dis2, i, xdf2->dstart, xdf2->dend))) { | |
411 | xdf2->rindex[nreff] = i; | |
412 | xdf2->ha[nreff] = (*recs)->ha; | |
413 | nreff++; | |
414 | } else | |
415 | xdf2->rchg[i] = 1; | |
416 | } | |
417 | xdf2->nreff = nreff; | |
418 | ||
419 | xdl_free(dis); | |
420 | ||
421 | return 0; | |
422 | } | |
423 | ||
424 | ||
425 | /* | |
426 | * Early trim initial and terminal matching records. | |
427 | */ | |
428 | static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2) { | |
429 | long i, lim; | |
430 | xrecord_t **recs1, **recs2; | |
431 | ||
432 | recs1 = xdf1->recs; | |
433 | recs2 = xdf2->recs; | |
434 | for (i = 0, lim = XDL_MIN(xdf1->nrec, xdf2->nrec); i < lim; | |
435 | i++, recs1++, recs2++) | |
436 | if ((*recs1)->ha != (*recs2)->ha) | |
437 | break; | |
438 | ||
439 | xdf1->dstart = xdf2->dstart = i; | |
440 | ||
441 | recs1 = xdf1->recs + xdf1->nrec - 1; | |
442 | recs2 = xdf2->recs + xdf2->nrec - 1; | |
443 | for (lim -= i, i = 0; i < lim; i++, recs1--, recs2--) | |
444 | if ((*recs1)->ha != (*recs2)->ha) | |
445 | break; | |
446 | ||
447 | xdf1->dend = xdf1->nrec - i - 1; | |
448 | xdf2->dend = xdf2->nrec - i - 1; | |
449 | ||
450 | return 0; | |
451 | } | |
452 | ||
453 | ||
454 | static int xdl_optimize_ctxs(xdfile_t *xdf1, xdfile_t *xdf2) { | |
455 | ||
456 | if (xdl_trim_ends(xdf1, xdf2) < 0 || | |
457 | xdl_cleanup_records(xdf1, xdf2) < 0) { | |
458 | ||
459 | return -1; | |
460 | } | |
461 | ||
462 | return 0; | |
463 | } |