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);
  30
  31
  32
  33
  34static 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
  42static 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 */
  60xdchange_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
  72static 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
  88static int xdl_emit_common(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
  89                           xdemitconf_t const *xecfg) {
  90        xdfile_t *xdf = &xe->xdf2;
  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
 103struct func_line {
 104        long len;
 105        char buf[80];
 106};
 107
 108static long get_func_line(xdfenv_t *xe, xdemitconf_t const *xecfg,
 109                          struct func_line *func_line, long start, long limit)
 110{
 111        find_func_t ff = xecfg->find_func ? xecfg->find_func : def_ff;
 112        long l, size, step = (start > limit) ? -1 : 1;
 113        char *buf, dummy[1];
 114
 115        buf = func_line ? func_line->buf : dummy;
 116        size = func_line ? sizeof(func_line->buf) : sizeof(dummy);
 117
 118        for (l = start; l != limit && 0 <= l && l < xe->xdf1.nrec; l += step) {
 119                const char *rec;
 120                long reclen = xdl_get_rec(&xe->xdf1, l, &rec);
 121                long len = ff(rec, reclen, buf, size, xecfg->find_func_priv);
 122                if (len >= 0) {
 123                        if (func_line)
 124                                func_line->len = len;
 125                        return l;
 126                }
 127        }
 128        return -1;
 129}
 130
 131int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 132                  xdemitconf_t const *xecfg) {
 133        long s1, s2, e1, e2, lctx;
 134        xdchange_t *xch, *xche;
 135        long funclineprev = -1;
 136        struct func_line func_line = { 0 };
 137
 138        if (xecfg->flags & XDL_EMIT_COMMON)
 139                return xdl_emit_common(xe, xscr, ecb, xecfg);
 140
 141        for (xch = xscr; xch; xch = xche->next) {
 142                xche = xdl_get_hunk(xch, xecfg);
 143
 144                s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
 145                s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
 146
 147                if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
 148                        long fs1 = get_func_line(xe, xecfg, NULL, xch->i1, -1);
 149                        if (fs1 < 0)
 150                                fs1 = 0;
 151                        if (fs1 < s1) {
 152                                s2 -= s1 - fs1;
 153                                s1 = fs1;
 154                        }
 155                }
 156
 157 again:
 158                lctx = xecfg->ctxlen;
 159                lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
 160                lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
 161
 162                e1 = xche->i1 + xche->chg1 + lctx;
 163                e2 = xche->i2 + xche->chg2 + lctx;
 164
 165                if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
 166                        long fe1 = get_func_line(xe, xecfg, NULL,
 167                                                 xche->i1 + xche->chg1,
 168                                                 xe->xdf1.nrec);
 169                        if (fe1 < 0)
 170                                fe1 = xe->xdf1.nrec;
 171                        if (fe1 > e1) {
 172                                e2 += fe1 - e1;
 173                                e1 = fe1;
 174                        }
 175
 176                        /*
 177                         * Overlap with next change?  Then include it
 178                         * in the current hunk and start over to find
 179                         * its new end.
 180                         */
 181                        if (xche->next) {
 182                                long l = xche->next->i1;
 183                                if (l <= e1 ||
 184                                    get_func_line(xe, xecfg, NULL, l, e1) < 0) {
 185                                        xche = xche->next;
 186                                        goto again;
 187                                }
 188                        }
 189                }
 190
 191                /*
 192                 * Emit current hunk header.
 193                 */
 194
 195                if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
 196                        get_func_line(xe, xecfg, &func_line,
 197                                      s1 - 1, funclineprev);
 198                        funclineprev = s1 - 1;
 199                }
 200                if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
 201                                      func_line.buf, func_line.len, ecb) < 0)
 202                        return -1;
 203
 204                /*
 205                 * Emit pre-context.
 206                 */
 207                for (; s2 < xch->i2; s2++)
 208                        if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
 209                                return -1;
 210
 211                for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
 212                        /*
 213                         * Merge previous with current change atom.
 214                         */
 215                        for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
 216                                if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
 217                                        return -1;
 218
 219                        /*
 220                         * Removes lines from the first file.
 221                         */
 222                        for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
 223                                if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
 224                                        return -1;
 225
 226                        /*
 227                         * Adds lines from the second file.
 228                         */
 229                        for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
 230                                if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
 231                                        return -1;
 232
 233                        if (xch == xche)
 234                                break;
 235                        s1 = xch->i1 + xch->chg1;
 236                        s2 = xch->i2 + xch->chg2;
 237                }
 238
 239                /*
 240                 * Emit post-context.
 241                 */
 242                for (s2 = xche->i2 + xche->chg2; s2 < e2; s2++)
 243                        if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
 244                                return -1;
 245        }
 246
 247        return 0;
 248}