/* * 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" static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec); static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb); 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 int xdl_emit_common(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb, xdemitconf_t const *xecfg) { xdfile_t *xdf = &xe->xdf2; const char *rchg = xdf->rchg; long ix; for (ix = 0; ix < xdf->nrec; ix++) { if (rchg[ix]) continue; if (xdl_emit_record(xdf, ix, "", ecb)) return -1; } return 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) { find_func_t ff = xecfg->find_func ? xecfg->find_func : def_ff; 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) { const char *rec; long reclen = xdl_get_rec(&xe->xdf1, l, &rec); long len = ff(rec, reclen, buf, size, xecfg->find_func_priv); if (len >= 0) { if (func_line) func_line->len = len; return l; } } return -1; } 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 }; if (xecfg->flags & XDL_EMIT_COMMON) return xdl_emit_common(xe, xscr, ecb, xecfg); 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 = get_func_line(xe, xecfg, NULL, xch->i1, -1); if (fs1 < 0) fs1 = 0; if (fs1 < s1) { s2 -= s1 - fs1; s1 = fs1; } } again: 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); if (fe1 < 0) fe1 = xe->xdf1.nrec; if (fe1 > e1) { e2 += fe1 - e1; 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 = xche->next->i1; if (l <= e1 || get_func_line(xe, xecfg, NULL, l, e1) < 0) { xche = xche->next; goto again; } } } /* * 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; }