xdiff/xemit.c

   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
  28 static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec);
  29 static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb);
  30
  31
  32
  33
  34 static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
  35
  36         *rec = xdf->recs[ri]->ptr;
  37
  38         return xdf->recs[ri]->size;
  39 }
  40
  41
  42 static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) {
  43         long size, psize = strlen(pre);
  44         char const *rec;
  45
  46         size = xdl_get_rec(xdf, ri, &rec);
  47         if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {
  48
  49                 return -1;
  50         }
  51
  52         return 0;
  53 }
  54
  55
  56 /*
  57  * Starting at the passed change atom, find the latest change atom to be included
  58  * inside the differential hunk according to the specified configuration.
  59  */
  60 xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg) {
  61         xdchange_t *xch, *xchp;
  62         long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen;
  63
  64         for (xchp = xscr, xch = xscr->next; xch; xchp = xch, xch = xch->next)
  65                 if (xch->i1 - (xchp->i1 + xchp->chg1) > max_common)
  66                         break;
  67
  68         return xchp;
  69 }
  70
  71
  72 static long def_ff(const char *rec, long len, char *buf, long sz, void *priv)
  73 {
  74         if (len > 0 &&
  75                         (isalpha((unsigned char)*rec) || /* identifier? */
  76                          *rec == '_' || /* also identifier? */
  77                          *rec == '$')) { /* identifiers from VMS and other esoterico */
  78                 if (len > sz)
  79                         len = sz;
  80                 while (0 < len && isspace((unsigned char)rec[len - 1]))
  81                         len--;
  82                 memcpy(buf, rec, len);
  83                 return len;
  84         }
  85         return -1;
  86 }
  87
  88 static int xdl_emit_common(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
  89                            xdemitconf_t const *xecfg) {
  90         xdfile_t *xdf = &xe->xdf1;
  91         const char *rchg = xdf->rchg;
  92         long ix;
  93
  94         for (ix = 0; ix < xdf->nrec; ix++) {
  95                 if (rchg[ix])
  96                         continue;
  97                 if (xdl_emit_record(xdf, ix, "", ecb))
  98                         return -1;
  99         }
 100         return 0;
 101 }
 102
 103 int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 104                   xdemitconf_t const *xecfg) {
 105         long s1, s2, e1, e2, lctx;
 106         xdchange_t *xch, *xche;
 107         char funcbuf[80];
 108         long funclen = 0;
 109         long funclineprev = -1;
 110         find_func_t ff = xecfg->find_func ?  xecfg->find_func : def_ff;
 111
 112         if (xecfg->flags & XDL_EMIT_COMMON)
 113                 return xdl_emit_common(xe, xscr, ecb, xecfg);
 114
 115         for (xch = xscr; xch; xch = xche->next) {
 116                 xche = xdl_get_hunk(xch, xecfg);
 117
 118                 s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
 119                 s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
 120
 121                 lctx = xecfg->ctxlen;
 122                 lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
 123                 lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
 124
 125                 e1 = xche->i1 + xche->chg1 + lctx;
 126                 e2 = xche->i2 + xche->chg2 + lctx;
 127
 128                 /*
 129                  * Emit current hunk header.
 130                  */
 131
 132                 if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
 133                         long l;
 134                         for (l = s1 - 1; l >= 0 && l > funclineprev; l--) {
 135                                 const char *rec;
 136                                 long reclen = xdl_get_rec(&xe->xdf1, l, &rec);
 137                                 long newfunclen = ff(rec, reclen, funcbuf,
 138                                                      sizeof(funcbuf),
 139                                                      xecfg->find_func_priv);
 140                                 if (newfunclen >= 0) {
 141                                         funclen = newfunclen;
 142                                         break;
 143                                 }
 144                         }
 145                         funclineprev = s1 - 1;
 146                 }
 147                 if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
 148                                       funcbuf, funclen, ecb) < 0)
 149                         return -1;
 150
 151                 /*
 152                  * Emit pre-context.
 153                  */
 154                 for (; s1 < xch->i1; s1++)
 155                         if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
 156                                 return -1;
 157
 158                 for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
 159                         /*
 160                          * Merge previous with current change atom.
 161                          */
 162                         for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
 163                                 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
 164                                         return -1;
 165
 166                         /*
 167                          * Removes lines from the first file.
 168                          */
 169                         for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
 170                                 if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
 171                                         return -1;
 172
 173                         /*
 174                          * Adds lines from the second file.
 175                          */
 176                         for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
 177                                 if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
 178                                         return -1;
 179
 180                         if (xch == xche)
 181                                 break;
 182                         s1 = xch->i1 + xch->chg1;
 183                         s2 = xch->i2 + xch->chg2;
 184                 }
 185
 186                 /*
 187                  * Emit post-context.
 188                  */
 189                 for (s1 = xche->i1 + xche->chg1; s1 < e1; s1++)
 190                         if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
 191                                 return -1;
 192         }
 193
 194         return 0;
 195 }