d3d9c845c6420e4881636d779c7029f900a0b067
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 */
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);
30 static xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg);
35 static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
37 *rec = xdf->recs[ri]->ptr;
39 return xdf->recs[ri]->size;
40 }
43 static 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;
47 size = xdl_get_rec(xdf, ri, &rec);
48 if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {
50 return -1;
51 }
53 return 0;
54 }
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 */
61 static xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg) {
62 xdchange_t *xch, *xchp;
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;
68 return xchp;
69 }
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 }
88 static void xdl_find_func(xdfile_t *xf, long i, char *buf, long sz, long *ll,
89 find_func_t ff, void *ff_priv) {
91 /*
92 * Be quite stupid about this for now. Find a line in the old file
93 * before the start of the hunk (and context) which starts with a
94 * plausible character.
95 */
97 const char *rec;
98 long len;
100 while (i-- > 0) {
101 len = xdl_get_rec(xf, i, &rec);
102 if ((*ll = ff(rec, len, buf, sz, ff_priv)) >= 0)
103 return;
104 }
105 *ll = 0;
106 }
109 static int xdl_emit_common(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
110 xdemitconf_t const *xecfg) {
111 xdfile_t *xdf = &xe->xdf1;
112 const char *rchg = xdf->rchg;
113 long ix;
115 for (ix = 0; ix < xdf->nrec; ix++) {
116 if (rchg[ix])
117 continue;
118 if (xdl_emit_record(xdf, ix, "", ecb))
119 return -1;
120 }
121 return 0;
122 }
124 int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
125 xdemitconf_t const *xecfg) {
126 long s1, s2, e1, e2, lctx;
127 xdchange_t *xch, *xche;
128 char funcbuf[80];
129 long funclen = 0;
130 find_func_t ff = xecfg->find_func ? xecfg->find_func : def_ff;
132 if (xecfg->flags & XDL_EMIT_COMMON)
133 return xdl_emit_common(xe, xscr, ecb, xecfg);
135 for (xch = xche = xscr; xch; xch = xche->next) {
136 xche = xdl_get_hunk(xch, xecfg);
138 s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
139 s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
141 lctx = xecfg->ctxlen;
142 lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
143 lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
145 e1 = xche->i1 + xche->chg1 + lctx;
146 e2 = xche->i2 + xche->chg2 + lctx;
148 /*
149 * Emit current hunk header.
150 */
152 if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
153 xdl_find_func(&xe->xdf1, s1, funcbuf,
154 sizeof(funcbuf), &funclen,
155 ff, xecfg->find_func_priv);
156 }
157 if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
158 funcbuf, funclen, ecb) < 0)
159 return -1;
161 /*
162 * Emit pre-context.
163 */
164 for (; s1 < xch->i1; s1++)
165 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
166 return -1;
168 for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
169 /*
170 * Merge previous with current change atom.
171 */
172 for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
173 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
174 return -1;
176 /*
177 * Removes lines from the first file.
178 */
179 for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
180 if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
181 return -1;
183 /*
184 * Adds lines from the second file.
185 */
186 for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
187 if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
188 return -1;
190 if (xch == xche)
191 break;
192 s1 = xch->i1 + xch->chg1;
193 s2 = xch->i2 + xch->chg2;
194 }
196 /*
197 * Emit post-context.
198 */
199 for (s1 = xche->i1 + xche->chg1; s1 < e1; s1++)
200 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
201 return -1;
202 }
204 return 0;
205 }