diff options
Diffstat (limited to 'third_party/git/xdiff/xprepare.c')
| -rw-r--r-- | third_party/git/xdiff/xprepare.c | 483 |
1 files changed, 0 insertions, 483 deletions
diff --git a/third_party/git/xdiff/xprepare.c b/third_party/git/xdiff/xprepare.c deleted file mode 100644 index abeb8fb84e6d..000000000000 --- a/third_party/git/xdiff/xprepare.c +++ /dev/null @@ -1,483 +0,0 @@ -/* - * 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, see - * <http://www.gnu.org/licenses/>. - * - * Davide Libenzi <davidel@xmailserver.org> - * - */ - -#include "xinclude.h" - - -#define XDL_KPDIS_RUN 4 -#define XDL_MAX_EQLIMIT 1024 -#define XDL_SIMSCAN_WINDOW 100 -#define XDL_GUESS_NLINES1 256 -#define XDL_GUESS_NLINES2 20 - - -typedef struct s_xdlclass { - struct s_xdlclass *next; - unsigned long ha; - char const *line; - long size; - long idx; - long len1, len2; -} xdlclass_t; - -typedef struct s_xdlclassifier { - unsigned int hbits; - long hsize; - xdlclass_t **rchash; - chastore_t ncha; - xdlclass_t **rcrecs; - long alloc; - 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(unsigned int pass, xdlclassifier_t *cf, xrecord_t **rhash, - unsigned int hbits, xrecord_t *rec); -static int xdl_prepare_ctx(unsigned int pass, 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(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2); -static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2); -static int xdl_optimize_ctxs(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2); - - - - -static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags) { - 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; - } - memset(cf->rchash, 0, cf->hsize * sizeof(xdlclass_t *)); - - cf->alloc = size; - if (!(cf->rcrecs = (xdlclass_t **) xdl_malloc(cf->alloc * sizeof(xdlclass_t *)))) { - - xdl_free(cf->rchash); - xdl_cha_free(&cf->ncha); - return -1; - } - - cf->count = 0; - - return 0; -} - - -static void xdl_free_classifier(xdlclassifier_t *cf) { - - xdl_free(cf->rcrecs); - xdl_free(cf->rchash); - xdl_cha_free(&cf->ncha); -} - - -static int xdl_classify_record(unsigned int pass, xdlclassifier_t *cf, xrecord_t **rhash, - unsigned int hbits, xrecord_t *rec) { - long hi; - char const *line; - xdlclass_t *rcrec; - xdlclass_t **rcrecs; - - 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++; - if (cf->count > cf->alloc) { - cf->alloc *= 2; - if (!(rcrecs = (xdlclass_t **) xdl_realloc(cf->rcrecs, cf->alloc * sizeof(xdlclass_t *)))) { - - return -1; - } - cf->rcrecs = rcrecs; - } - cf->rcrecs[rcrec->idx] = rcrec; - rcrec->line = line; - rcrec->size = rec->size; - rcrec->ha = rec->ha; - rcrec->len1 = rcrec->len2 = 0; - rcrec->next = cf->rchash[hi]; - cf->rchash[hi] = rcrec; - } - - (pass == 1) ? rcrec->len1++ : rcrec->len2++; - - 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(unsigned int pass, mmfile_t *mf, long narec, xpparam_t const *xpp, - xdlclassifier_t *cf, xdfile_t *xdf) { - unsigned int hbits; - long 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; - - ha = NULL; - rindex = NULL; - rchg = NULL; - rhash = NULL; - recs = NULL; - - if (xdl_cha_init(&xdf->rcha, sizeof(xrecord_t), narec / 4 + 1) < 0) - goto abort; - if (!(recs = (xrecord_t **) xdl_malloc(narec * sizeof(xrecord_t *)))) - goto abort; - - if (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF) - hbits = hsize = 0; - else { - hbits = xdl_hashbits((unsigned int) narec); - hsize = 1 << hbits; - if (!(rhash = (xrecord_t **) xdl_malloc(hsize * sizeof(xrecord_t *)))) - goto abort; - memset(rhash, 0, hsize * sizeof(xrecord_t *)); - } - - nrec = 0; - if ((cur = blk = xdl_mmfile_first(mf, &bsize)) != NULL) { - for (top = blk + bsize; cur < top; ) { - 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 *)))) - goto abort; - recs = rrecs; - } - if (!(crec = xdl_cha_alloc(&xdf->rcha))) - goto abort; - crec->ptr = prev; - crec->size = (long) (cur - prev); - crec->ha = hav; - recs[nrec++] = crec; - - if ((XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) && - xdl_classify_record(pass, cf, rhash, hbits, crec) < 0) - goto abort; - } - } - - if (!(rchg = (char *) xdl_malloc((nrec + 2) * sizeof(char)))) - goto abort; - memset(rchg, 0, (nrec + 2) * sizeof(char)); - - if (!(rindex = (long *) xdl_malloc((nrec + 1) * sizeof(long)))) - goto abort; - if (!(ha = (unsigned long *) xdl_malloc((nrec + 1) * sizeof(unsigned long)))) - goto abort; - - 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; - -abort: - xdl_free(ha); - xdl_free(rindex); - xdl_free(rchg); - xdl_free(rhash); - xdl_free(recs); - xdl_cha_free(&xdf->rcha); - return -1; -} - - -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, sample; - xdlclassifier_t cf; - - memset(&cf, 0, sizeof(cf)); - - /* - * For histogram diff, we can afford a smaller sample size and - * thus a poorer estimate of the number of lines, as the hash - * table (rhash) won't be filled up/grown. The number of lines - * (nrecs) will be updated correctly anyway by - * xdl_prepare_ctx(). - */ - sample = (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF - ? XDL_GUESS_NLINES2 : XDL_GUESS_NLINES1); - - enl1 = xdl_guess_lines(mf1, sample) + 1; - enl2 = xdl_guess_lines(mf2, sample) + 1; - - if (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF && - xdl_init_classifier(&cf, enl1 + enl2 + 1, xpp->flags) < 0) - return -1; - - if (xdl_prepare_ctx(1, mf1, enl1, xpp, &cf, &xe->xdf1) < 0) { - - xdl_free_classifier(&cf); - return -1; - } - if (xdl_prepare_ctx(2, mf2, enl2, xpp, &cf, &xe->xdf2) < 0) { - - xdl_free_ctx(&xe->xdf1); - xdl_free_classifier(&cf); - return -1; - } - - if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) && - (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) && - xdl_optimize_ctxs(&cf, &xe->xdf1, &xe->xdf2) < 0) { - - xdl_free_ctx(&xe->xdf2); - xdl_free_ctx(&xe->xdf1); - xdl_free_classifier(&cf); - return -1; - } - - if (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) - xdl_free_classifier(&cf); - - 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(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) { - long i, nm, nreff, mlim; - xrecord_t **recs; - xdlclass_t *rcrec; - 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++) { - rcrec = cf->rcrecs[(*recs)->ha]; - nm = rcrec ? rcrec->len2 : 0; - 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++) { - rcrec = cf->rcrecs[(*recs)->ha]; - nm = rcrec ? rcrec->len1 : 0; - 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(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) { - - if (xdl_trim_ends(xdf1, xdf2) < 0 || - xdl_cleanup_records(cf, xdf1, xdf2) < 0) { - - return -1; - } - - return 0; -} |