summaryrefslogtreecommitdiff
path: root/xdiff/xemit.c
blob: ad5bfb191003f14cd71b2ec7f39fd72ac86eda9b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/*
 *  LibXDiff by Davide Libenzi ( File Differential Library )
 *  Copyright (C) 2003	Davide Libenzi
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  Davide Libenzi <davidel@xmailserver.org>
 *
 */

#include "xinclude.h"




static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec);
static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb);
static xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg);




static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {

	*rec = xdf->recs[ri]->ptr;

	return xdf->recs[ri]->size;
}


static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) {
	long size, psize = strlen(pre);
	char const *rec;

	size = xdl_get_rec(xdf, ri, &rec);
	if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {

		return -1;
	}

	return 0;
}


/*
 * Starting at the passed change atom, find the latest change atom to be included
 * inside the differential hunk according to the specified configuration.
 */
static xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg) {
	xdchange_t *xch, *xchp;

	for (xchp = xscr, xch = xscr->next; xch; xchp = xch, xch = xch->next)
		if (xch->i1 - (xchp->i1 + xchp->chg1) > 2 * xecfg->ctxlen)
			break;

	return xchp;
}


static void xdl_find_func(xdfile_t *xf, long i, char *buf, long sz, long *ll) {

	/*
	 * Be quite stupid about this for now.  Find a line in the old file
	 * before the start of the hunk (and context) which starts with a
	 * plausible character.
	 */

	const char *rec;
	long len;

	*ll = 0;
	while (i-- > 0) {
		len = xdl_get_rec(xf, i, &rec);
		if (len > 0 &&
		    (isalpha((unsigned char)*rec) || /* identifier? */
		     *rec == '_' ||	/* also identifier? */
		     *rec == '(' ||	/* lisp defun? */
		     *rec == '#')) {	/* #define? */
			if (len > sz)
				len = sz;
			if (len && rec[len - 1] == '\n')
				len--;
			memcpy(buf, rec, len);
			*ll = len;
			return;
		}
	}
}


int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
		  xdemitconf_t const *xecfg) {
	long s1, s2, e1, e2, lctx;
	xdchange_t *xch, *xche;
	char funcbuf[40];
	long funclen = 0;

	for (xch = xche = xscr; xch; xch = xche->next) {
		xche = xdl_get_hunk(xch, xecfg);

		s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
		s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);

		lctx = xecfg->ctxlen;
		lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
		lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));

		e1 = xche->i1 + xche->chg1 + lctx;
		e2 = xche->i2 + xche->chg2 + lctx;

		/*
		 * Emit current hunk header.
		 */

		if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
			xdl_find_func(&xe->xdf1, s1, funcbuf,
				      sizeof(funcbuf), &funclen);
		}
		if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
				      funcbuf, funclen, ecb) < 0)
			return -1;

		/*
		 * Emit pre-context.
		 */
		for (; s1 < xch->i1; s1++)
			if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
				return -1;

		for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
			/*
			 * Merge previous with current change atom.
			 */
			for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
				if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
					return -1;

			/*
			 * Removes lines from the first file.
			 */
			for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
				if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
					return -1;

			/*
			 * Adds lines from the second file.
			 */
			for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
				if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
					return -1;

			if (xch == xche)
				break;
			s1 = xch->i1 + xch->chg1;
			s2 = xch->i2 + xch->chg2;
		}

		/*
		 * Emit post-context.
		 */
		for (s1 = xche->i1 + xche->chg1; s1 < e1; s1++)
			if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
				return -1;
	}

	return 0;
}