Merge branch 'fc/apply-p2-get-header-name'
[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 }