277e2eec5b4cced5882f37ac42af7f22efe92902
[git/git.git] / 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 }