From 1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Sat, 11 Jan 2020 23:36:56 +0000 Subject: Squashed 'third_party/git/' content from commit cb71568594 git-subtree-dir: third_party/git git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7 --- xdiff/xemit.c | 312 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 312 insertions(+) create mode 100644 xdiff/xemit.c (limited to 'xdiff/xemit.c') diff --git a/xdiff/xemit.c b/xdiff/xemit.c new file mode 100644 index 000000000000..30713ae9a98e --- /dev/null +++ b/xdiff/xemit.c @@ -0,0 +1,312 @@ +/* + * 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 + * . + * + * Davide Libenzi + * + */ + +#include "xinclude.h" + +static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) { + + *rec = xdf->recs[ri]->ptr; + + return xdf->recs[ri]->size; +} + + +static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) { + long size, psize = strlen(pre); + char const *rec; + + size = xdl_get_rec(xdf, ri, &rec); + if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) { + + return -1; + } + + return 0; +} + + +/* + * Starting at the passed change atom, find the latest change atom to be included + * inside the differential hunk according to the specified configuration. + * Also advance xscr if the first changes must be discarded. + */ +xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg) +{ + xdchange_t *xch, *xchp, *lxch; + long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen; + long max_ignorable = xecfg->ctxlen; + unsigned long ignored = 0; /* number of ignored blank lines */ + + /* remove ignorable changes that are too far before other changes */ + for (xchp = *xscr; xchp && xchp->ignore; xchp = xchp->next) { + xch = xchp->next; + + if (xch == NULL || + xch->i1 - (xchp->i1 + xchp->chg1) >= max_ignorable) + *xscr = xch; + } + + if (*xscr == NULL) + return NULL; + + lxch = *xscr; + + for (xchp = *xscr, xch = xchp->next; xch; xchp = xch, xch = xch->next) { + long distance = xch->i1 - (xchp->i1 + xchp->chg1); + if (distance > max_common) + break; + + if (distance < max_ignorable && (!xch->ignore || lxch == xchp)) { + lxch = xch; + ignored = 0; + } else if (distance < max_ignorable && xch->ignore) { + ignored += xch->chg2; + } else if (lxch != xchp && + xch->i1 + ignored - (lxch->i1 + lxch->chg1) > max_common) { + break; + } else if (!xch->ignore) { + lxch = xch; + ignored = 0; + } else { + ignored += xch->chg2; + } + } + + return lxch; +} + + +static long def_ff(const char *rec, long len, char *buf, long sz, void *priv) +{ + if (len > 0 && + (isalpha((unsigned char)*rec) || /* identifier? */ + *rec == '_' || /* also identifier? */ + *rec == '$')) { /* identifiers from VMS and other esoterico */ + if (len > sz) + len = sz; + while (0 < len && isspace((unsigned char)rec[len - 1])) + len--; + memcpy(buf, rec, len); + return len; + } + return -1; +} + +static long match_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri, + char *buf, long sz) +{ + const char *rec; + long len = xdl_get_rec(xdf, ri, &rec); + if (!xecfg->find_func) + return def_ff(rec, len, buf, sz, xecfg->find_func_priv); + return xecfg->find_func(rec, len, buf, sz, xecfg->find_func_priv); +} + +static int is_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri) +{ + char dummy[1]; + return match_func_rec(xdf, xecfg, ri, dummy, sizeof(dummy)) >= 0; +} + +struct func_line { + long len; + char buf[80]; +}; + +static long get_func_line(xdfenv_t *xe, xdemitconf_t const *xecfg, + struct func_line *func_line, long start, long limit) +{ + long l, size, step = (start > limit) ? -1 : 1; + char *buf, dummy[1]; + + buf = func_line ? func_line->buf : dummy; + size = func_line ? sizeof(func_line->buf) : sizeof(dummy); + + for (l = start; l != limit && 0 <= l && l < xe->xdf1.nrec; l += step) { + long len = match_func_rec(&xe->xdf1, xecfg, l, buf, size); + if (len >= 0) { + if (func_line) + func_line->len = len; + return l; + } + } + return -1; +} + +static int is_empty_rec(xdfile_t *xdf, long ri) +{ + const char *rec; + long len = xdl_get_rec(xdf, ri, &rec); + + while (len > 0 && XDL_ISSPACE(*rec)) { + rec++; + len--; + } + return !len; +} + +int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb, + xdemitconf_t const *xecfg) { + long s1, s2, e1, e2, lctx; + xdchange_t *xch, *xche; + long funclineprev = -1; + struct func_line func_line = { 0 }; + + for (xch = xscr; xch; xch = xche->next) { + xche = xdl_get_hunk(&xch, xecfg); + if (!xch) + break; + + s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0); + s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0); + + if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) { + long fs1, i1 = xch->i1; + + /* Appended chunk? */ + if (i1 >= xe->xdf1.nrec) { + long i2 = xch->i2; + + /* + * We don't need additional context if + * a whole function was added. + */ + while (i2 < xe->xdf2.nrec) { + if (is_func_rec(&xe->xdf2, xecfg, i2)) + goto post_context_calculation; + i2++; + } + + /* + * Otherwise get more context from the + * pre-image. + */ + i1 = xe->xdf1.nrec - 1; + } + + fs1 = get_func_line(xe, xecfg, NULL, i1, -1); + while (fs1 > 0 && !is_empty_rec(&xe->xdf1, fs1 - 1) && + !is_func_rec(&xe->xdf1, xecfg, fs1 - 1)) + fs1--; + if (fs1 < 0) + fs1 = 0; + if (fs1 < s1) { + s2 = XDL_MAX(s2 - (s1 - fs1), 0); + s1 = fs1; + } + } + + post_context_calculation: + lctx = xecfg->ctxlen; + lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1)); + lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2)); + + e1 = xche->i1 + xche->chg1 + lctx; + e2 = xche->i2 + xche->chg2 + lctx; + + if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) { + long fe1 = get_func_line(xe, xecfg, NULL, + xche->i1 + xche->chg1, + xe->xdf1.nrec); + while (fe1 > 0 && is_empty_rec(&xe->xdf1, fe1 - 1)) + fe1--; + if (fe1 < 0) + fe1 = xe->xdf1.nrec; + if (fe1 > e1) { + e2 = XDL_MIN(e2 + (fe1 - e1), xe->xdf2.nrec); + e1 = fe1; + } + + /* + * Overlap with next change? Then include it + * in the current hunk and start over to find + * its new end. + */ + if (xche->next) { + long l = XDL_MIN(xche->next->i1, + xe->xdf1.nrec - 1); + if (l - xecfg->ctxlen <= e1 || + get_func_line(xe, xecfg, NULL, l, e1) < 0) { + xche = xche->next; + goto post_context_calculation; + } + } + } + + /* + * Emit current hunk header. + */ + + if (xecfg->flags & XDL_EMIT_FUNCNAMES) { + get_func_line(xe, xecfg, &func_line, + s1 - 1, funclineprev); + funclineprev = s1 - 1; + } + if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2, + func_line.buf, func_line.len, ecb) < 0) + return -1; + + /* + * Emit pre-context. + */ + for (; s2 < xch->i2; s2++) + if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0) + return -1; + + for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) { + /* + * Merge previous with current change atom. + */ + for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++) + if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0) + return -1; + + /* + * Removes lines from the first file. + */ + for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++) + if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0) + return -1; + + /* + * Adds lines from the second file. + */ + for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++) + if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0) + return -1; + + if (xch == xche) + break; + s1 = xch->i1 + xch->chg1; + s2 = xch->i2 + xch->chg2; + } + + /* + * Emit post-context. + */ + for (s2 = xche->i2 + xche->chg2; s2 < e2; s2++) + if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0) + return -1; + } + + return 0; +} -- cgit 1.4.1