Andrew's git - gitweb.git/blob

   1/*
   2 *  LibXDiff by Davide Libenzi ( File Differential Library )
   3 *  Copyright (C) 2003  Davide Libenzi
   4 *
   5 *  This library is free software; you can redistribute it and/or
   6 *  modify it under the terms of the GNU Lesser General Public
   7 *  License as published by the Free Software Foundation; either
   8 *  version 2.1 of the License, or (at your option) any later version.
   9 *
  10 *  This library is distributed in the hope that it will be useful,
  11 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 *  Lesser General Public License for more details.
  14 *
  15 *  You should have received a copy of the GNU Lesser General Public
  16 *  License along with this library; if not, write to the Free Software
  17 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 *
  19 *  Davide Libenzi <davidel@xmailserver.org>
  20 *
  21 */
  22
  23#include "xinclude.h"
  24
  25
  26
  27
  28static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec);
  29static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb);
  30static xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg);
  31
  32
  33
  34
  35static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
  36
  37        *rec = xdf->recs[ri]->ptr;
  38
  39        return xdf->recs[ri]->size;
  40}
  41
  42
  43static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) {
  44        long size, psize = strlen(pre);
  45        char const *rec;
  46
  47        size = xdl_get_rec(xdf, ri, &rec);
  48        if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {
  49
  50                return -1;
  51        }
  52
  53        return 0;
  54}
  55
  56
  57/*
  58 * Starting at the passed change atom, find the latest change atom to be included
  59 * inside the differential hunk according to the specified configuration.
  60 */
  61static xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg) {
  62        xdchange_t *xch, *xchp;
  63
  64        for (xchp = xscr, xch = xscr->next; xch; xchp = xch, xch = xch->next)
  65                if (xch->i1 - (xchp->i1 + xchp->chg1) > 2 * xecfg->ctxlen)
  66                        break;
  67
  68        return xchp;
  69}
  70
  71
  72int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
  73                  xdemitconf_t const *xecfg) {
  74        long s1, s2, e1, e2, lctx;
  75        xdchange_t *xch, *xche;
  76
  77        for (xch = xche = xscr; xch; xch = xche->next) {
  78                xche = xdl_get_hunk(xch, xecfg);
  79
  80                s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
  81                s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
  82
  83                lctx = xecfg->ctxlen;
  84                lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
  85                lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
  86
  87                e1 = xche->i1 + xche->chg1 + lctx;
  88                e2 = xche->i2 + xche->chg2 + lctx;
  89
  90                /*
  91                 * Emit current hunk header.
  92                 */
  93                if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2, ecb) < 0)
  94                        return -1;
  95
  96                /*
  97                 * Emit pre-context.
  98                 */
  99                for (; s1 < xch->i1; s1++)
 100                        if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
 101                                return -1;
 102
 103                for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
 104                        /*
 105                         * Merge previous with current change atom.
 106                         */
 107                        for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
 108                                if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
 109                                        return -1;
 110
 111                        /*
 112                         * Removes lines from the first file.
 113                         */
 114                        for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
 115                                if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
 116                                        return -1;
 117
 118                        /*
 119                         * Adds lines from the second file.
 120                         */
 121                        for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
 122                                if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
 123                                        return -1;
 124
 125                        if (xch == xche)
 126                                break;
 127                        s1 = xch->i1 + xch->chg1;
 128                        s2 = xch->i2 + xch->chg2;
 129                }
 130
 131                /*
 132                 * Emit post-context.
 133                 */
 134                for (s1 = xche->i1 + xche->chg1; s1 < e1; s1++)
 135                        if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
 136                                return -1;
 137        }
 138
 139        return 0;
 140}
 141