checkout -m: fix read-tree invocation
[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? */
89 *rec == '(' || /* lisp defun? */
90 *rec == '#')) { /* #define? */
91 if (len > sz)
92 len = sz;
93 if (len && rec[len - 1] == '\n')
94 len--;
95 memcpy(buf, rec, len);
96 *ll = len;
97 return;
98 }
99 }
100}
101
102
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103int 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;
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107 char funcbuf[40];
108 long funclen = 0;
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109
110 for (xch = xche = xscr; xch; xch = xche->next) {
111 xche = xdl_get_hunk(xch, xecfg);
112
113 s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
114 s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
115
116 lctx = xecfg->ctxlen;
117 lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
118 lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
119
120 e1 = xche->i1 + xche->chg1 + lctx;
121 e2 = xche->i2 + xche->chg2 + lctx;
122
123 /*
124 * Emit current hunk header.
125 */
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126
127 if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
128 xdl_find_func(&xe->xdf1, s1, funcbuf,
129 sizeof(funcbuf), &funclen);
130 }
131 if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
132 funcbuf, funclen, ecb) < 0)
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133 return -1;
134
135 /*
136 * Emit pre-context.
137 */
138 for (; s1 < xch->i1; s1++)
139 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
140 return -1;
141
142 for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
143 /*
144 * Merge previous with current change atom.
145 */
146 for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
147 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
148 return -1;
149
150 /*
151 * Removes lines from the first file.
152 */
153 for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
154 if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
155 return -1;
156
157 /*
158 * Adds lines from the second file.
159 */
160 for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
161 if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
162 return -1;
163
164 if (xch == xche)
165 break;
166 s1 = xch->i1 + xch->chg1;
167 s2 = xch->i2 + xch->chg2;
168 }
169
170 /*
171 * Emit post-context.
172 */
173 for (s1 = xche->i1 + xche->chg1; s1 < e1; s1++)
174 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
175 return -1;
176 }
177
178 return 0;
179}
180