Merge branch 'hv/config-from-blob' into maint
[git/raj.git] / xdiff / xemit.c
blob4d8645867e7d0103d49882877a7e4a8abacd24ea
1 /*
2 * LibXDiff by Davide Libenzi ( File Differential Library )
3 * Copyright (C) 2003 Davide Libenzi
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.
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.
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
19 * Davide Libenzi <davidel@xmailserver.org>
23 #include "xinclude.h"
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);
34 static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
36 *rec = xdf->recs[ri]->ptr;
38 return xdf->recs[ri]->size;
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;
46 size = xdl_get_rec(xdf, ri, &rec);
47 if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {
49 return -1;
52 return 0;
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 * Also advance xscr if the first changes must be discarded.
61 xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg)
63 xdchange_t *xch, *xchp, *lxch;
64 long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen;
65 long max_ignorable = xecfg->ctxlen;
66 unsigned long ignored = 0; /* number of ignored blank lines */
68 /* remove ignorable changes that are too far before other changes */
69 for (xchp = *xscr; xchp && xchp->ignore; xchp = xchp->next) {
70 xch = xchp->next;
72 if (xch == NULL ||
73 xch->i1 - (xchp->i1 + xchp->chg1) >= max_ignorable)
74 *xscr = xch;
77 if (*xscr == NULL)
78 return NULL;
80 lxch = *xscr;
82 for (xchp = *xscr, xch = xchp->next; xch; xchp = xch, xch = xch->next) {
83 long distance = xch->i1 - (xchp->i1 + xchp->chg1);
84 if (distance > max_common)
85 break;
87 if (distance < max_ignorable && (!xch->ignore || lxch == xchp)) {
88 lxch = xch;
89 ignored = 0;
90 } else if (distance < max_ignorable && xch->ignore) {
91 ignored += xch->chg2;
92 } else if (lxch != xchp &&
93 xch->i1 + ignored - (lxch->i1 + lxch->chg1) > max_common) {
94 break;
95 } else if (!xch->ignore) {
96 lxch = xch;
97 ignored = 0;
98 } else {
99 ignored += xch->chg2;
103 return lxch;
107 static long def_ff(const char *rec, long len, char *buf, long sz, void *priv)
109 if (len > 0 &&
110 (isalpha((unsigned char)*rec) || /* identifier? */
111 *rec == '_' || /* also identifier? */
112 *rec == '$')) { /* identifiers from VMS and other esoterico */
113 if (len > sz)
114 len = sz;
115 while (0 < len && isspace((unsigned char)rec[len - 1]))
116 len--;
117 memcpy(buf, rec, len);
118 return len;
120 return -1;
123 static int xdl_emit_common(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
124 xdemitconf_t const *xecfg) {
125 xdfile_t *xdf = &xe->xdf2;
126 const char *rchg = xdf->rchg;
127 long ix;
129 for (ix = 0; ix < xdf->nrec; ix++) {
130 if (rchg[ix])
131 continue;
132 if (xdl_emit_record(xdf, ix, "", ecb))
133 return -1;
135 return 0;
138 struct func_line {
139 long len;
140 char buf[80];
143 static long get_func_line(xdfenv_t *xe, xdemitconf_t const *xecfg,
144 struct func_line *func_line, long start, long limit)
146 find_func_t ff = xecfg->find_func ? xecfg->find_func : def_ff;
147 long l, size, step = (start > limit) ? -1 : 1;
148 char *buf, dummy[1];
150 buf = func_line ? func_line->buf : dummy;
151 size = func_line ? sizeof(func_line->buf) : sizeof(dummy);
153 for (l = start; l != limit && 0 <= l && l < xe->xdf1.nrec; l += step) {
154 const char *rec;
155 long reclen = xdl_get_rec(&xe->xdf1, l, &rec);
156 long len = ff(rec, reclen, buf, size, xecfg->find_func_priv);
157 if (len >= 0) {
158 if (func_line)
159 func_line->len = len;
160 return l;
163 return -1;
166 int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
167 xdemitconf_t const *xecfg) {
168 long s1, s2, e1, e2, lctx;
169 xdchange_t *xch, *xche;
170 long funclineprev = -1;
171 struct func_line func_line = { 0 };
173 if (xecfg->flags & XDL_EMIT_COMMON)
174 return xdl_emit_common(xe, xscr, ecb, xecfg);
176 for (xch = xscr; xch; xch = xche->next) {
177 xche = xdl_get_hunk(&xch, xecfg);
178 if (!xch)
179 break;
181 s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
182 s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
184 if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
185 long fs1 = get_func_line(xe, xecfg, NULL, xch->i1, -1);
186 if (fs1 < 0)
187 fs1 = 0;
188 if (fs1 < s1) {
189 s2 -= s1 - fs1;
190 s1 = fs1;
194 again:
195 lctx = xecfg->ctxlen;
196 lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
197 lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
199 e1 = xche->i1 + xche->chg1 + lctx;
200 e2 = xche->i2 + xche->chg2 + lctx;
202 if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
203 long fe1 = get_func_line(xe, xecfg, NULL,
204 xche->i1 + xche->chg1,
205 xe->xdf1.nrec);
206 if (fe1 < 0)
207 fe1 = xe->xdf1.nrec;
208 if (fe1 > e1) {
209 e2 += fe1 - e1;
210 e1 = fe1;
214 * Overlap with next change? Then include it
215 * in the current hunk and start over to find
216 * its new end.
218 if (xche->next) {
219 long l = xche->next->i1;
220 if (l <= e1 ||
221 get_func_line(xe, xecfg, NULL, l, e1) < 0) {
222 xche = xche->next;
223 goto again;
229 * Emit current hunk header.
232 if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
233 get_func_line(xe, xecfg, &func_line,
234 s1 - 1, funclineprev);
235 funclineprev = s1 - 1;
237 if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
238 func_line.buf, func_line.len, ecb) < 0)
239 return -1;
242 * Emit pre-context.
244 for (; s2 < xch->i2; s2++)
245 if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
246 return -1;
248 for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
250 * Merge previous with current change atom.
252 for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
253 if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
254 return -1;
257 * Removes lines from the first file.
259 for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
260 if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
261 return -1;
264 * Adds lines from the second file.
266 for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
267 if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
268 return -1;
270 if (xch == xche)
271 break;
272 s1 = xch->i1 + xch->chg1;
273 s2 = xch->i2 + xch->chg2;
277 * Emit post-context.
279 for (s2 = xche->i2 + xche->chg2; s2 < e2; s2++)
280 if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
281 return -1;
284 return 0;