| /* |
| * LibXDiff by Davide Libenzi ( File Differential Library ) |
| * Copyright (C) 2003 Davide Libenzi |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| * |
| * Davide Libenzi <davidel@xmailserver.org> |
| * |
| */ |
| |
| #include "xinclude.h" |
| |
| |
| #define XDL_KPDIS_RUN 4 |
| #define XDL_MAX_EQLIMIT 1024 |
| #define XDL_SIMSCAN_WINDOW 100 |
| |
| |
| typedef struct s_xdlclass { |
| struct s_xdlclass *next; |
| unsigned long ha; |
| char const *line; |
| long size; |
| long idx; |
| } xdlclass_t; |
| |
| typedef struct s_xdlclassifier { |
| unsigned int hbits; |
| long hsize; |
| xdlclass_t **rchash; |
| chastore_t ncha; |
| long count; |
| long flags; |
| } xdlclassifier_t; |
| |
| |
| |
| |
| static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags); |
| static void xdl_free_classifier(xdlclassifier_t *cf); |
| static int xdl_classify_record(xdlclassifier_t *cf, xrecord_t **rhash, unsigned int hbits, |
| xrecord_t *rec); |
| static int xdl_prepare_ctx(mmfile_t *mf, long narec, xpparam_t const *xpp, |
| xdlclassifier_t *cf, xdfile_t *xdf); |
| static void xdl_free_ctx(xdfile_t *xdf); |
| static int xdl_clean_mmatch(char const *dis, long i, long s, long e); |
| static int xdl_cleanup_records(xdfile_t *xdf1, xdfile_t *xdf2); |
| static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2); |
| static int xdl_optimize_ctxs(xdfile_t *xdf1, xdfile_t *xdf2); |
| |
| |
| |
| |
| static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags) { |
| long i; |
| |
| cf->flags = flags; |
| |
| cf->hbits = xdl_hashbits((unsigned int) size); |
| cf->hsize = 1 << cf->hbits; |
| |
| if (xdl_cha_init(&cf->ncha, sizeof(xdlclass_t), size / 4 + 1) < 0) { |
| |
| return -1; |
| } |
| if (!(cf->rchash = (xdlclass_t **) xdl_malloc(cf->hsize * sizeof(xdlclass_t *)))) { |
| |
| xdl_cha_free(&cf->ncha); |
| return -1; |
| } |
| for (i = 0; i < cf->hsize; i++) |
| cf->rchash[i] = NULL; |
| |
| cf->count = 0; |
| |
| return 0; |
| } |
| |
| |
| static void xdl_free_classifier(xdlclassifier_t *cf) { |
| |
| xdl_free(cf->rchash); |
| xdl_cha_free(&cf->ncha); |
| } |
| |
| |
| static int xdl_classify_record(xdlclassifier_t *cf, xrecord_t **rhash, unsigned int hbits, |
| xrecord_t *rec) { |
| long hi; |
| char const *line; |
| xdlclass_t *rcrec; |
| |
| line = rec->ptr; |
| hi = (long) XDL_HASHLONG(rec->ha, cf->hbits); |
| for (rcrec = cf->rchash[hi]; rcrec; rcrec = rcrec->next) |
| if (rcrec->ha == rec->ha && |
| xdl_recmatch(rcrec->line, rcrec->size, |
| rec->ptr, rec->size, cf->flags)) |
| break; |
| |
| if (!rcrec) { |
| if (!(rcrec = xdl_cha_alloc(&cf->ncha))) { |
| |
| return -1; |
| } |
| rcrec->idx = cf->count++; |
| rcrec->line = line; |
| rcrec->size = rec->size; |
| rcrec->ha = rec->ha; |
| rcrec->next = cf->rchash[hi]; |
| cf->rchash[hi] = rcrec; |
| } |
| |
| rec->ha = (unsigned long) rcrec->idx; |
| |
| hi = (long) XDL_HASHLONG(rec->ha, hbits); |
| rec->next = rhash[hi]; |
| rhash[hi] = rec; |
| |
| return 0; |
| } |
| |
| |
| static int xdl_prepare_ctx(mmfile_t *mf, long narec, xpparam_t const *xpp, |
| xdlclassifier_t *cf, xdfile_t *xdf) { |
| unsigned int hbits; |
| long i, nrec, hsize, bsize; |
| unsigned long hav; |
| char const *blk, *cur, *top, *prev; |
| xrecord_t *crec; |
| xrecord_t **recs, **rrecs; |
| xrecord_t **rhash; |
| unsigned long *ha; |
| char *rchg; |
| long *rindex; |
| |
| if (xdl_cha_init(&xdf->rcha, sizeof(xrecord_t), narec / 4 + 1) < 0) { |
| |
| return -1; |
| } |
| if (!(recs = (xrecord_t **) xdl_malloc(narec * sizeof(xrecord_t *)))) { |
| |
| xdl_cha_free(&xdf->rcha); |
| return -1; |
| } |
| |
| hbits = xdl_hashbits((unsigned int) narec); |
| hsize = 1 << hbits; |
| if (!(rhash = (xrecord_t **) xdl_malloc(hsize * sizeof(xrecord_t *)))) { |
| |
| xdl_free(recs); |
| xdl_cha_free(&xdf->rcha); |
| return -1; |
| } |
| for (i = 0; i < hsize; i++) |
| rhash[i] = NULL; |
| |
| nrec = 0; |
| if ((cur = blk = xdl_mmfile_first(mf, &bsize)) != NULL) { |
| for (top = blk + bsize;;) { |
| if (cur >= top) { |
| if (!(cur = blk = xdl_mmfile_next(mf, &bsize))) |
| break; |
| top = blk + bsize; |
| } |
| prev = cur; |
| hav = xdl_hash_record(&cur, top, xpp->flags); |
| if (nrec >= narec) { |
| narec *= 2; |
| if (!(rrecs = (xrecord_t **) xdl_realloc(recs, narec * sizeof(xrecord_t *)))) { |
| |
| xdl_free(rhash); |
| xdl_free(recs); |
| xdl_cha_free(&xdf->rcha); |
| return -1; |
| } |
| recs = rrecs; |
| } |
| if (!(crec = xdl_cha_alloc(&xdf->rcha))) { |
| |
| xdl_free(rhash); |
| xdl_free(recs); |
| xdl_cha_free(&xdf->rcha); |
| return -1; |
| } |
| crec->ptr = prev; |
| crec->size = (long) (cur - prev); |
| crec->ha = hav; |
| recs[nrec++] = crec; |
| |
| if (xdl_classify_record(cf, rhash, hbits, crec) < 0) { |
| |
| xdl_free(rhash); |
| xdl_free(recs); |
| xdl_cha_free(&xdf->rcha); |
| return -1; |
| } |
| } |
| } |
| |
| if (!(rchg = (char *) xdl_malloc((nrec + 2) * sizeof(char)))) { |
| |
| xdl_free(rhash); |
| xdl_free(recs); |
| xdl_cha_free(&xdf->rcha); |
| return -1; |
| } |
| memset(rchg, 0, (nrec + 2) * sizeof(char)); |
| |
| if (!(rindex = (long *) xdl_malloc((nrec + 1) * sizeof(long)))) { |
| |
| xdl_free(rchg); |
| xdl_free(rhash); |
| xdl_free(recs); |
| xdl_cha_free(&xdf->rcha); |
| return -1; |
| } |
| if (!(ha = (unsigned long *) xdl_malloc((nrec + 1) * sizeof(unsigned long)))) { |
| |
| xdl_free(rindex); |
| xdl_free(rchg); |
| xdl_free(rhash); |
| xdl_free(recs); |
| xdl_cha_free(&xdf->rcha); |
| return -1; |
| } |
| |
| xdf->nrec = nrec; |
| xdf->recs = recs; |
| xdf->hbits = hbits; |
| xdf->rhash = rhash; |
| xdf->rchg = rchg + 1; |
| xdf->rindex = rindex; |
| xdf->nreff = 0; |
| xdf->ha = ha; |
| xdf->dstart = 0; |
| xdf->dend = nrec - 1; |
| |
| return 0; |
| } |
| |
| |
| static void xdl_free_ctx(xdfile_t *xdf) { |
| |
| xdl_free(xdf->rhash); |
| xdl_free(xdf->rindex); |
| xdl_free(xdf->rchg - 1); |
| xdl_free(xdf->ha); |
| xdl_free(xdf->recs); |
| xdl_cha_free(&xdf->rcha); |
| } |
| |
| |
| int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, |
| xdfenv_t *xe) { |
| long enl1, enl2; |
| xdlclassifier_t cf; |
| |
| enl1 = xdl_guess_lines(mf1) + 1; |
| enl2 = xdl_guess_lines(mf2) + 1; |
| |
| if (xdl_init_classifier(&cf, enl1 + enl2 + 1, xpp->flags) < 0) { |
| |
| return -1; |
| } |
| |
| if (xdl_prepare_ctx(mf1, enl1, xpp, &cf, &xe->xdf1) < 0) { |
| |
| xdl_free_classifier(&cf); |
| return -1; |
| } |
| if (xdl_prepare_ctx(mf2, enl2, xpp, &cf, &xe->xdf2) < 0) { |
| |
| xdl_free_ctx(&xe->xdf1); |
| xdl_free_classifier(&cf); |
| return -1; |
| } |
| |
| xdl_free_classifier(&cf); |
| |
| if (!(xpp->flags & XDF_PATIENCE_DIFF) && |
| xdl_optimize_ctxs(&xe->xdf1, &xe->xdf2) < 0) { |
| |
| xdl_free_ctx(&xe->xdf2); |
| xdl_free_ctx(&xe->xdf1); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| |
| void xdl_free_env(xdfenv_t *xe) { |
| |
| xdl_free_ctx(&xe->xdf2); |
| xdl_free_ctx(&xe->xdf1); |
| } |
| |
| |
| static int xdl_clean_mmatch(char const *dis, long i, long s, long e) { |
| long r, rdis0, rpdis0, rdis1, rpdis1; |
| |
| /* |
| * Limits the window the is examined during the similar-lines |
| * scan. The loops below stops when dis[i - r] == 1 (line that |
| * has no match), but there are corner cases where the loop |
| * proceed all the way to the extremities by causing huge |
| * performance penalties in case of big files. |
| */ |
| if (i - s > XDL_SIMSCAN_WINDOW) |
| s = i - XDL_SIMSCAN_WINDOW; |
| if (e - i > XDL_SIMSCAN_WINDOW) |
| e = i + XDL_SIMSCAN_WINDOW; |
| |
| /* |
| * Scans the lines before 'i' to find a run of lines that either |
| * have no match (dis[j] == 0) or have multiple matches (dis[j] > 1). |
| * Note that we always call this function with dis[i] > 1, so the |
| * current line (i) is already a multimatch line. |
| */ |
| for (r = 1, rdis0 = 0, rpdis0 = 1; (i - r) >= s; r++) { |
| if (!dis[i - r]) |
| rdis0++; |
| else if (dis[i - r] == 2) |
| rpdis0++; |
| else |
| break; |
| } |
| /* |
| * If the run before the line 'i' found only multimatch lines, we |
| * return 0 and hence we don't make the current line (i) discarded. |
| * We want to discard multimatch lines only when they appear in the |
| * middle of runs with nomatch lines (dis[j] == 0). |
| */ |
| if (rdis0 == 0) |
| return 0; |
| for (r = 1, rdis1 = 0, rpdis1 = 1; (i + r) <= e; r++) { |
| if (!dis[i + r]) |
| rdis1++; |
| else if (dis[i + r] == 2) |
| rpdis1++; |
| else |
| break; |
| } |
| /* |
| * If the run after the line 'i' found only multimatch lines, we |
| * return 0 and hence we don't make the current line (i) discarded. |
| */ |
| if (rdis1 == 0) |
| return 0; |
| rdis1 += rdis0; |
| rpdis1 += rpdis0; |
| |
| return rpdis1 * XDL_KPDIS_RUN < (rpdis1 + rdis1); |
| } |
| |
| |
| /* |
| * Try to reduce the problem complexity, discard records that have no |
| * matches on the other file. Also, lines that have multiple matches |
| * might be potentially discarded if they happear in a run of discardable. |
| */ |
| static int xdl_cleanup_records(xdfile_t *xdf1, xdfile_t *xdf2) { |
| long i, nm, rhi, nreff, mlim; |
| unsigned long hav; |
| xrecord_t **recs; |
| xrecord_t *rec; |
| char *dis, *dis1, *dis2; |
| |
| if (!(dis = (char *) xdl_malloc(xdf1->nrec + xdf2->nrec + 2))) { |
| |
| return -1; |
| } |
| memset(dis, 0, xdf1->nrec + xdf2->nrec + 2); |
| dis1 = dis; |
| dis2 = dis1 + xdf1->nrec + 1; |
| |
| if ((mlim = xdl_bogosqrt(xdf1->nrec)) > XDL_MAX_EQLIMIT) |
| mlim = XDL_MAX_EQLIMIT; |
| for (i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; i <= xdf1->dend; i++, recs++) { |
| hav = (*recs)->ha; |
| rhi = (long) XDL_HASHLONG(hav, xdf2->hbits); |
| for (nm = 0, rec = xdf2->rhash[rhi]; rec; rec = rec->next) |
| if (rec->ha == hav && ++nm == mlim) |
| break; |
| dis1[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1; |
| } |
| |
| if ((mlim = xdl_bogosqrt(xdf2->nrec)) > XDL_MAX_EQLIMIT) |
| mlim = XDL_MAX_EQLIMIT; |
| for (i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; i <= xdf2->dend; i++, recs++) { |
| hav = (*recs)->ha; |
| rhi = (long) XDL_HASHLONG(hav, xdf1->hbits); |
| for (nm = 0, rec = xdf1->rhash[rhi]; rec; rec = rec->next) |
| if (rec->ha == hav && ++nm == mlim) |
| break; |
| dis2[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1; |
| } |
| |
| for (nreff = 0, i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; |
| i <= xdf1->dend; i++, recs++) { |
| if (dis1[i] == 1 || |
| (dis1[i] == 2 && !xdl_clean_mmatch(dis1, i, xdf1->dstart, xdf1->dend))) { |
| xdf1->rindex[nreff] = i; |
| xdf1->ha[nreff] = (*recs)->ha; |
| nreff++; |
| } else |
| xdf1->rchg[i] = 1; |
| } |
| xdf1->nreff = nreff; |
| |
| for (nreff = 0, i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; |
| i <= xdf2->dend; i++, recs++) { |
| if (dis2[i] == 1 || |
| (dis2[i] == 2 && !xdl_clean_mmatch(dis2, i, xdf2->dstart, xdf2->dend))) { |
| xdf2->rindex[nreff] = i; |
| xdf2->ha[nreff] = (*recs)->ha; |
| nreff++; |
| } else |
| xdf2->rchg[i] = 1; |
| } |
| xdf2->nreff = nreff; |
| |
| xdl_free(dis); |
| |
| return 0; |
| } |
| |
| |
| /* |
| * Early trim initial and terminal matching records. |
| */ |
| static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2) { |
| long i, lim; |
| xrecord_t **recs1, **recs2; |
| |
| recs1 = xdf1->recs; |
| recs2 = xdf2->recs; |
| for (i = 0, lim = XDL_MIN(xdf1->nrec, xdf2->nrec); i < lim; |
| i++, recs1++, recs2++) |
| if ((*recs1)->ha != (*recs2)->ha) |
| break; |
| |
| xdf1->dstart = xdf2->dstart = i; |
| |
| recs1 = xdf1->recs + xdf1->nrec - 1; |
| recs2 = xdf2->recs + xdf2->nrec - 1; |
| for (lim -= i, i = 0; i < lim; i++, recs1--, recs2--) |
| if ((*recs1)->ha != (*recs2)->ha) |
| break; |
| |
| xdf1->dend = xdf1->nrec - i - 1; |
| xdf2->dend = xdf2->nrec - i - 1; |
| |
| return 0; |
| } |
| |
| |
| static int xdl_optimize_ctxs(xdfile_t *xdf1, xdfile_t *xdf2) { |
| |
| if (xdl_trim_ends(xdf1, xdf2) < 0 || |
| xdl_cleanup_records(xdf1, xdf2) < 0) { |
| |
| return -1; |
| } |
| |
| return 0; |
| } |
