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, see |
17 | * <http://www.gnu.org/licenses/>. |
18 | * |
19 | * Davide Libenzi <davidel@xmailserver.org> |
20 | * |
21 | */ |
22 | |
23 | #include "xinclude.h" |
24 | |
25 | static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) { |
26 | |
27 | *rec = xdf->recs[ri]->ptr; |
28 | |
29 | return xdf->recs[ri]->size; |
30 | } |
31 | |
32 | |
33 | static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) { |
34 | long size, psize = (long)strlen(pre); |
35 | char const *rec; |
36 | |
37 | size = xdl_get_rec(xdf, ri, &rec); |
38 | if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) { |
39 | |
40 | return -1; |
41 | } |
42 | |
43 | return 0; |
44 | } |
45 | |
46 | |
47 | /* |
48 | * Starting at the passed change atom, find the latest change atom to be included |
49 | * inside the differential hunk according to the specified configuration. |
50 | * Also advance xscr if the first changes must be discarded. |
51 | */ |
52 | xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg) |
53 | { |
54 | xdchange_t *xch, *xchp, *lxch; |
55 | long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen; |
56 | long max_ignorable = xecfg->ctxlen; |
57 | unsigned long ignored = 0; /* number of ignored blank lines */ |
58 | |
59 | /* remove ignorable changes that are too far before other changes */ |
60 | for (xchp = *xscr; xchp && xchp->ignore; xchp = xchp->next) { |
61 | xch = xchp->next; |
62 | |
63 | if (xch == NULL || |
64 | xch->i1 - (xchp->i1 + xchp->chg1) >= max_ignorable) |
65 | *xscr = xch; |
66 | } |
67 | |
68 | if (*xscr == NULL) |
69 | return NULL; |
70 | |
71 | lxch = *xscr; |
72 | |
73 | for (xchp = *xscr, xch = xchp->next; xch; xchp = xch, xch = xch->next) { |
74 | long distance = xch->i1 - (xchp->i1 + xchp->chg1); |
75 | if (distance > max_common) |
76 | break; |
77 | |
78 | if (distance < max_ignorable && (!xch->ignore || lxch == xchp)) { |
79 | lxch = xch; |
80 | ignored = 0; |
81 | } else if (distance < max_ignorable && xch->ignore) { |
82 | ignored += xch->chg2; |
83 | } else if (lxch != xchp && |
84 | xch->i1 + (long)ignored - (lxch->i1 + lxch->chg1) > max_common) { |
85 | break; |
86 | } else if (!xch->ignore) { |
87 | lxch = xch; |
88 | ignored = 0; |
89 | } else { |
90 | ignored += xch->chg2; |
91 | } |
92 | } |
93 | |
94 | return lxch; |
95 | } |
96 | |
97 | |
98 | #if 0 |
99 | static long def_ff(const char *rec, long len, char *buf, long sz, void *priv UNUSED) |
100 | { |
101 | if (len > 0 && |
102 | (isalpha((unsigned char)*rec) || /* identifier? */ |
103 | *rec == '_' || /* also identifier? */ |
104 | *rec == '$')) { /* identifiers from VMS and other esoterico */ |
105 | if (len > sz) |
106 | len = sz; |
107 | while (0 < len && isspace((unsigned char)rec[len - 1])) |
108 | len--; |
109 | memcpy(buf, rec, len); |
110 | return len; |
111 | } |
112 | return -1; |
113 | } |
114 | #endif |
115 | |
116 | #if 0 |
117 | static long match_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri, |
118 | char *buf, long sz) |
119 | { |
120 | const char *rec; |
121 | long len = xdl_get_rec(xdf, ri, &rec); |
122 | if (!xecfg->find_func) |
123 | return def_ff(rec, len, buf, sz, xecfg->find_func_priv); |
124 | return xecfg->find_func(rec, len, buf, sz, xecfg->find_func_priv); |
125 | } |
126 | #endif |
127 | |
128 | #if 0 |
129 | static int is_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri) |
130 | { |
131 | char dummy[1]; |
132 | return match_func_rec(xdf, xecfg, ri, dummy, sizeof(dummy)) >= 0; |
133 | } |
134 | #endif |
135 | |
136 | struct func_line { |
137 | long len; |
138 | char buf[80]; |
139 | }; |
140 | |
141 | #if 0 |
142 | static long get_func_line(xdfenv_t *xe, xdemitconf_t const *xecfg, |
143 | struct func_line *func_line, long start, long limit) |
144 | { |
145 | long l, size, step = (start > limit) ? -1 : 1; |
146 | char *buf, dummy[1]; |
147 | |
148 | buf = func_line ? func_line->buf : dummy; |
149 | size = func_line ? sizeof(func_line->buf) : sizeof(dummy); |
150 | |
151 | for (l = start; l != limit && 0 <= l && l < xe->xdf1.nrec; l += step) { |
152 | long len = match_func_rec(&xe->xdf1, xecfg, l, buf, size); |
153 | if (len >= 0) { |
154 | if (func_line) |
155 | func_line->len = len; |
156 | return l; |
157 | } |
158 | } |
159 | return -1; |
160 | } |
161 | #endif |
162 | |
163 | #if 0 |
164 | static int is_empty_rec(xdfile_t *xdf, long ri) |
165 | { |
166 | const char *rec; |
167 | long len = xdl_get_rec(xdf, ri, &rec); |
168 | |
169 | while (len > 0 && XDL_ISSPACE(*rec)) { |
170 | rec++; |
171 | len--; |
172 | } |
173 | return !len; |
174 | } |
175 | #endif |
176 | |
177 | int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb, |
178 | xdemitconf_t const *xecfg) { |
179 | long s1, s2, e1, e2, lctx; |
180 | xdchange_t *xch, *xche; |
181 | #if 0 |
182 | long funclineprev = -1; |
183 | #endif |
184 | struct func_line func_line; |
185 | |
186 | func_line.len = 0; |
187 | |
188 | for (xch = xscr; xch; xch = xche->next) { |
189 | xche = xdl_get_hunk(&xch, xecfg); |
190 | if (!xch) |
191 | break; |
192 | |
193 | s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0); |
194 | s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0); |
195 | |
196 | #if 0 |
197 | if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) { |
198 | long fs1, i1 = xch->i1; |
199 | |
200 | /* Appended chunk? */ |
201 | if (i1 >= xe->xdf1.nrec) { |
202 | long i2 = xch->i2; |
203 | |
204 | /* |
205 | * We don't need additional context if |
206 | * a whole function was added. |
207 | */ |
208 | while (i2 < xe->xdf2.nrec) { |
209 | if (is_func_rec(&xe->xdf2, xecfg, i2)) |
210 | goto post_context_calculation; |
211 | i2++; |
212 | } |
213 | |
214 | /* |
215 | * Otherwise get more context from the |
216 | * pre-image. |
217 | */ |
218 | i1 = xe->xdf1.nrec - 1; |
219 | } |
220 | |
221 | fs1 = get_func_line(xe, xecfg, NULL, i1, -1); |
222 | while (fs1 > 0 && !is_empty_rec(&xe->xdf1, fs1 - 1) && |
223 | !is_func_rec(&xe->xdf1, xecfg, fs1 - 1)) |
224 | fs1--; |
225 | if (fs1 < 0) |
226 | fs1 = 0; |
227 | if (fs1 < s1) { |
228 | s2 -= s1 - fs1; |
229 | s1 = fs1; |
230 | } |
231 | } |
232 | |
233 | post_context_calculation: |
234 | #endif |
235 | lctx = xecfg->ctxlen; |
236 | lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1)); |
237 | lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2)); |
238 | |
239 | e1 = xche->i1 + xche->chg1 + lctx; |
240 | e2 = xche->i2 + xche->chg2 + lctx; |
241 | |
242 | #if 0 |
243 | if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) { |
244 | long fe1 = get_func_line(xe, xecfg, NULL, |
245 | xche->i1 + xche->chg1, |
246 | xe->xdf1.nrec); |
247 | while (fe1 > 0 && is_empty_rec(&xe->xdf1, fe1 - 1)) |
248 | fe1--; |
249 | if (fe1 < 0) |
250 | fe1 = xe->xdf1.nrec; |
251 | if (fe1 > e1) { |
252 | e2 += fe1 - e1; |
253 | e1 = fe1; |
254 | } |
255 | |
256 | /* |
257 | * Overlap with next change? Then include it |
258 | * in the current hunk and start over to find |
259 | * its new end. |
260 | */ |
261 | if (xche->next) { |
262 | long l = XDL_MIN(xche->next->i1, |
263 | xe->xdf1.nrec - 1); |
264 | if (l - xecfg->ctxlen <= e1 || |
265 | get_func_line(xe, xecfg, NULL, l, e1) < 0) { |
266 | xche = xche->next; |
267 | goto post_context_calculation; |
268 | } |
269 | } |
270 | } |
271 | #endif |
272 | |
273 | /* |
274 | * Emit current hunk header. |
275 | */ |
276 | |
277 | #if 0 |
278 | if (xecfg->flags & XDL_EMIT_FUNCNAMES) { |
279 | get_func_line(xe, xecfg, &func_line, |
280 | s1 - 1, funclineprev); |
281 | funclineprev = s1 - 1; |
282 | } |
283 | #endif |
284 | if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2, |
285 | func_line.buf, func_line.len, ecb) < 0) |
286 | return -1; |
287 | |
288 | /* |
289 | * Emit pre-context. |
290 | */ |
291 | for (; s2 < xch->i2; s2++) |
292 | if (xdl_emit_record(&xe->xdf2, s2, " " , ecb) < 0) |
293 | return -1; |
294 | |
295 | for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) { |
296 | /* |
297 | * Merge previous with current change atom. |
298 | */ |
299 | for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++) |
300 | if (xdl_emit_record(&xe->xdf2, s2, " " , ecb) < 0) |
301 | return -1; |
302 | |
303 | /* |
304 | * Removes lines from the first file. |
305 | */ |
306 | for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++) |
307 | if (xdl_emit_record(&xe->xdf1, s1, "-" , ecb) < 0) |
308 | return -1; |
309 | |
310 | /* |
311 | * Adds lines from the second file. |
312 | */ |
313 | for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++) |
314 | if (xdl_emit_record(&xe->xdf2, s2, "+" , ecb) < 0) |
315 | return -1; |
316 | |
317 | if (xch == xche) |
318 | break; |
319 | s1 = xch->i1 + xch->chg1; |
320 | s2 = xch->i2 + xch->chg2; |
321 | } |
322 | |
323 | /* |
324 | * Emit post-context. |
325 | */ |
326 | for (s2 = xche->i2 + xche->chg2; s2 < e2; s2++) |
327 | if (xdl_emit_record(&xe->xdf2, s2, " " , ecb) < 0) |
328 | return -1; |
329 | } |
330 | |
331 | return 0; |
332 | } |
333 | |