| /* |
| * 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" |
| |
| 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) |
| 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) { |
| xdchange_t *xchp = xch; |
| xche = xdl_get_hunk(&xch, xecfg); |
| if (!xch) |
| break; |
| |
| pre_context_calculation: |
| 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; |
| |
| /* |
| * Did we extend context upwards into an |
| * ignored change? |
| */ |
| while (xchp != xch && |
| xchp->i1 + xchp->chg1 <= s1 && |
| xchp->i2 + xchp->chg2 <= s2) |
| xchp = xchp->next; |
| |
| /* If so, show it after all. */ |
| if (xchp != xch) { |
| xch = xchp; |
| goto pre_context_calculation; |
| } |
| } |
| } |
| |
| 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 (!(xecfg->flags & XDL_EMIT_NO_HUNK_HDR) && |
| 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; |
| } |