Future-proof source for changes in xdemitconf_t
[git/git.git] / xdiff / xemit.c
CommitLineData
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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);
30static xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg);
31
32
33
34
35static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
36
37 *rec = xdf->recs[ri]->ptr;
38
39 return xdf->recs[ri]->size;
40}
41
42
43static 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;
46
47 size = xdl_get_rec(xdf, ri, &rec);
48 if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {
49
50 return -1;
51 }
52
53 return 0;
54}
55
56
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 */
61static xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg) {
62 xdchange_t *xch, *xchp;
63
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;
67
68 return xchp;
69}
70
71
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72static void xdl_find_func(xdfile_t *xf, long i, char *buf, long sz, long *ll) {
73
74 /*
75 * Be quite stupid about this for now. Find a line in the old file
76 * before the start of the hunk (and context) which starts with a
77 * plausible character.
78 */
79
80 const char *rec;
81 long len;
82
83 *ll = 0;
84 while (i-- > 0) {
85 len = xdl_get_rec(xf, i, &rec);
86 if (len > 0 &&
87 (isalpha((unsigned char)*rec) || /* identifier? */
88 *rec == '_' || /* also identifier? */
70da769a 89 *rec == '$')) { /* mysterious GNU diff's invention */
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90 if (len > sz)
91 len = sz;
67aef034 92 while (0 < len && isspace((unsigned char)rec[len - 1]))
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93 len--;
94 memcpy(buf, rec, len);
95 *ll = len;
96 return;
97 }
98 }
99}
100
101
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102static int xdl_emit_common(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
103 xdemitconf_t const *xecfg) {
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104 xdfile_t *xdf = &xe->xdf1;
105 const char *rchg = xdf->rchg;
106 long ix;
107
108 for (ix = 0; ix < xdf->nrec; ix++) {
109 if (rchg[ix])
110 continue;
111 if (xdl_emit_record(xdf, ix, "", ecb))
112 return -1;
113 }
114 return 0;
115}
116
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117int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
118 xdemitconf_t const *xecfg) {
119 long s1, s2, e1, e2, lctx;
120 xdchange_t *xch, *xche;
f73da29f 121 char funcbuf[80];
acb72577 122 long funclen = 0;
3443546f 123
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124 if (xecfg->flags & XDL_EMIT_COMMON)
125 return xdl_emit_common(xe, xscr, ecb, xecfg);
126
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127 for (xch = xche = xscr; xch; xch = xche->next) {
128 xche = xdl_get_hunk(xch, xecfg);
129
130 s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
131 s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
132
133 lctx = xecfg->ctxlen;
134 lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
135 lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
136
137 e1 = xche->i1 + xche->chg1 + lctx;
138 e2 = xche->i2 + xche->chg2 + lctx;
139
140 /*
141 * Emit current hunk header.
142 */
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143
144 if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
145 xdl_find_func(&xe->xdf1, s1, funcbuf,
146 sizeof(funcbuf), &funclen);
147 }
148 if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
149 funcbuf, funclen, ecb) < 0)
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150 return -1;
151
152 /*
153 * Emit pre-context.
154 */
155 for (; s1 < xch->i1; s1++)
156 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
157 return -1;
158
159 for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
160 /*
161 * Merge previous with current change atom.
162 */
163 for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
164 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
165 return -1;
166
167 /*
168 * Removes lines from the first file.
169 */
170 for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
171 if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
172 return -1;
173
174 /*
175 * Adds lines from the second file.
176 */
177 for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
178 if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
179 return -1;
180
181 if (xch == xche)
182 break;
183 s1 = xch->i1 + xch->chg1;
184 s2 = xch->i2 + xch->chg2;
185 }
186
187 /*
188 * Emit post-context.
189 */
190 for (s1 = xche->i1 + xche->chg1; s1 < e1; s1++)
191 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
192 return -1;
193 }
194
195 return 0;
196}