Annotation of mandoc/apropos_db.c, Revision 1.4
1.4 ! kristaps 1: /* $Id: apropos_db.c,v 1.3 2011/11/13 11:10:27 schwarze Exp $ */
1.1 schwarze 2: /*
3: * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
1.3 schwarze 4: * Copyright (c) 2011 Ingo Schwarze <schwarze@openbsd.org>
1.1 schwarze 5: *
6: * Permission to use, copy, modify, and distribute this software for any
7: * purpose with or without fee is hereby granted, provided that the above
8: * copyright notice and this permission notice appear in all copies.
9: *
10: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17: */
18: #include <assert.h>
19: #include <fcntl.h>
20: #include <regex.h>
21: #include <stdarg.h>
22: #include <stdlib.h>
23: #include <string.h>
24:
25: #ifdef __linux__
26: # include <db_185.h>
27: #else
28: # include <db.h>
29: #endif
30:
1.2 schwarze 31: #include "mandocdb.h"
1.1 schwarze 32: #include "apropos_db.h"
33: #include "mandoc.h"
34:
35: struct expr {
1.3 schwarze 36: int regex;
1.1 schwarze 37: int mask;
38: char *v;
39: regex_t re;
40: };
41:
42: struct type {
43: int mask;
44: const char *name;
45: };
46:
47: static const struct type types[] = {
1.2 schwarze 48: { TYPE_An, "An" },
49: { TYPE_Cd, "Cd" },
50: { TYPE_Er, "Er" },
51: { TYPE_Ev, "Ev" },
52: { TYPE_Fn, "Fn" },
53: { TYPE_Fn, "Fo" },
54: { TYPE_In, "In" },
55: { TYPE_Nd, "Nd" },
56: { TYPE_Nm, "Nm" },
57: { TYPE_Pa, "Pa" },
58: { TYPE_St, "St" },
59: { TYPE_Va, "Va" },
60: { TYPE_Va, "Vt" },
61: { TYPE_Xr, "Xr" },
62: { INT_MAX, "any" },
1.1 schwarze 63: { 0, NULL }
64: };
65:
66: static DB *btree_open(void);
67: static int btree_read(const DBT *, const struct mchars *, char **);
1.3 schwarze 68: static int exprexec(const struct expr *, char *, int);
1.1 schwarze 69: static DB *index_open(void);
70: static int index_read(const DBT *, const DBT *,
71: const struct mchars *, struct rec *);
72: static void norm_string(const char *,
73: const struct mchars *, char **);
74: static size_t norm_utf8(unsigned int, char[7]);
75:
76: /*
77: * Open the keyword mandoc-db database.
78: */
79: static DB *
80: btree_open(void)
81: {
82: BTREEINFO info;
83: DB *db;
84:
85: memset(&info, 0, sizeof(BTREEINFO));
86: info.flags = R_DUP;
87:
1.2 schwarze 88: db = dbopen(MANDOC_DB, O_RDONLY, 0, DB_BTREE, &info);
1.1 schwarze 89: if (NULL != db)
90: return(db);
91:
92: return(NULL);
93: }
94:
95: /*
96: * Read a keyword from the database and normalise it.
97: * Return 0 if the database is insane, else 1.
98: */
99: static int
100: btree_read(const DBT *v, const struct mchars *mc, char **buf)
101: {
102:
103: /* Sanity: are we nil-terminated? */
104:
105: assert(v->size > 0);
106: if ('\0' != ((char *)v->data)[(int)v->size - 1])
107: return(0);
108:
109: norm_string((char *)v->data, mc, buf);
110: return(1);
111: }
112:
113: /*
114: * Take a Unicode codepoint and produce its UTF-8 encoding.
115: * This isn't the best way to do this, but it works.
116: * The magic numbers are from the UTF-8 packaging.
117: * They're not as scary as they seem: read the UTF-8 spec for details.
118: */
119: static size_t
120: norm_utf8(unsigned int cp, char out[7])
121: {
122: size_t rc;
123:
124: rc = 0;
125:
126: if (cp <= 0x0000007F) {
127: rc = 1;
128: out[0] = (char)cp;
129: } else if (cp <= 0x000007FF) {
130: rc = 2;
131: out[0] = (cp >> 6 & 31) | 192;
132: out[1] = (cp & 63) | 128;
133: } else if (cp <= 0x0000FFFF) {
134: rc = 3;
135: out[0] = (cp >> 12 & 15) | 224;
136: out[1] = (cp >> 6 & 63) | 128;
137: out[2] = (cp & 63) | 128;
138: } else if (cp <= 0x001FFFFF) {
139: rc = 4;
140: out[0] = (cp >> 18 & 7) | 240;
141: out[1] = (cp >> 12 & 63) | 128;
142: out[2] = (cp >> 6 & 63) | 128;
143: out[3] = (cp & 63) | 128;
144: } else if (cp <= 0x03FFFFFF) {
145: rc = 5;
146: out[0] = (cp >> 24 & 3) | 248;
147: out[1] = (cp >> 18 & 63) | 128;
148: out[2] = (cp >> 12 & 63) | 128;
149: out[3] = (cp >> 6 & 63) | 128;
150: out[4] = (cp & 63) | 128;
151: } else if (cp <= 0x7FFFFFFF) {
152: rc = 6;
153: out[0] = (cp >> 30 & 1) | 252;
154: out[1] = (cp >> 24 & 63) | 128;
155: out[2] = (cp >> 18 & 63) | 128;
156: out[3] = (cp >> 12 & 63) | 128;
157: out[4] = (cp >> 6 & 63) | 128;
158: out[5] = (cp & 63) | 128;
159: } else
160: return(0);
161:
162: out[rc] = '\0';
163: return(rc);
164: }
165:
166: /*
167: * Normalise strings from the index and database.
168: * These strings are escaped as defined by mandoc_char(7) along with
169: * other goop in mandoc.h (e.g., soft hyphens).
170: * This function normalises these into a nice UTF-8 string.
171: * Returns 0 if the database is fucked.
172: */
173: static void
174: norm_string(const char *val, const struct mchars *mc, char **buf)
175: {
176: size_t sz, bsz;
177: char utfbuf[7];
178: const char *seq, *cpp;
179: int len, u, pos;
180: enum mandoc_esc esc;
181: static const char res[] = { '\\', '\t',
182: ASCII_NBRSP, ASCII_HYPH, '\0' };
183:
184: /* Pre-allocate by the length of the input */
185:
186: bsz = strlen(val) + 1;
187: *buf = mandoc_realloc(*buf, bsz);
188: pos = 0;
189:
190: while ('\0' != *val) {
191: /*
192: * Halt on the first escape sequence.
193: * This also halts on the end of string, in which case
194: * we just copy, fallthrough, and exit the loop.
195: */
196: if ((sz = strcspn(val, res)) > 0) {
197: memcpy(&(*buf)[pos], val, sz);
198: pos += (int)sz;
199: val += (int)sz;
200: }
201:
202: if (ASCII_HYPH == *val) {
203: (*buf)[pos++] = '-';
204: val++;
205: continue;
206: } else if ('\t' == *val || ASCII_NBRSP == *val) {
207: (*buf)[pos++] = ' ';
208: val++;
209: continue;
210: } else if ('\\' != *val)
211: break;
212:
213: /* Read past the slash. */
214:
215: val++;
216: u = 0;
217:
218: /*
219: * Parse the escape sequence and see if it's a
220: * predefined character or special character.
221: */
222:
223: esc = mandoc_escape(&val, &seq, &len);
224: if (ESCAPE_ERROR == esc)
225: break;
226:
227: /*
228: * XXX - this just does UTF-8, but we need to know
229: * beforehand whether we should do text substitution.
230: */
231:
232: switch (esc) {
233: case (ESCAPE_SPECIAL):
234: if (0 != (u = mchars_spec2cp(mc, seq, len)))
235: break;
236: /* FALLTHROUGH */
237: default:
238: continue;
239: }
240:
241: /*
242: * If we have a Unicode codepoint, try to convert that
243: * to a UTF-8 byte string.
244: */
245:
246: cpp = utfbuf;
247: if (0 == (sz = norm_utf8(u, utfbuf)))
248: continue;
249:
250: /* Copy the rendered glyph into the stream. */
251:
252: sz = strlen(cpp);
253: bsz += sz;
254:
255: *buf = mandoc_realloc(*buf, bsz);
256:
257: memcpy(&(*buf)[pos], cpp, sz);
258: pos += (int)sz;
259: }
260:
261: (*buf)[pos] = '\0';
262: }
263:
264: /*
265: * Open the filename-index mandoc-db database.
266: * Returns NULL if opening failed.
267: */
268: static DB *
269: index_open(void)
270: {
271: DB *db;
272:
1.2 schwarze 273: db = dbopen(MANDOC_IDX, O_RDONLY, 0, DB_RECNO, NULL);
1.1 schwarze 274: if (NULL != db)
275: return(db);
276:
277: return(NULL);
278: }
279:
280: /*
281: * Safely unpack from an index file record into the structure.
282: * Returns 1 if an entry was unpacked, 0 if the database is insane.
283: */
284: static int
285: index_read(const DBT *key, const DBT *val,
286: const struct mchars *mc, struct rec *rec)
287: {
288: size_t left;
289: char *np, *cp;
290:
291: #define INDEX_BREAD(_dst) \
292: do { \
293: if (NULL == (np = memchr(cp, '\0', left))) \
294: return(0); \
295: norm_string(cp, mc, &(_dst)); \
296: left -= (np - cp) + 1; \
297: cp = np + 1; \
298: } while (/* CONSTCOND */ 0)
299:
300: left = val->size;
301: cp = (char *)val->data;
302:
303: rec->rec = *(recno_t *)key->data;
304:
305: INDEX_BREAD(rec->file);
306: INDEX_BREAD(rec->cat);
307: INDEX_BREAD(rec->title);
308: INDEX_BREAD(rec->arch);
309: INDEX_BREAD(rec->desc);
310: return(1);
311: }
312:
313: /*
314: * Search the mandocdb database for the expression "expr".
315: * Filter out by "opts".
316: * Call "res" with the results, which may be zero.
317: */
318: void
319: apropos_search(const struct opts *opts, const struct expr *expr,
320: void *arg, void (*res)(struct rec *, size_t, void *))
321: {
322: int i, len, root, leaf;
323: DBT key, val;
324: DB *btree, *idx;
325: struct mchars *mc;
326: int ch;
327: char *buf;
328: recno_t rec;
329: struct rec *recs;
330: struct rec srec;
331:
332: root = -1;
333: leaf = -1;
334: btree = NULL;
335: idx = NULL;
336: mc = NULL;
337: buf = NULL;
338: recs = NULL;
339: len = 0;
340:
341: memset(&srec, 0, sizeof(struct rec));
342:
343: /* XXX: error out with bad regexp? */
344:
345: mc = mchars_alloc();
346:
347: /* XXX: return fact that we've errored? */
348:
349: if (NULL == (btree = btree_open()))
350: goto out;
351: if (NULL == (idx = index_open()))
352: goto out;
353:
354: while (0 == (ch = (*btree->seq)(btree, &key, &val, R_NEXT))) {
355: /*
356: * Low-water mark for key and value.
357: * The key must have something in it, and the value must
358: * have the correct tags/recno mix.
359: */
360: if (key.size < 2 || 8 != val.size)
361: break;
362: if ( ! btree_read(&key, mc, &buf))
363: break;
364:
1.3 schwarze 365: if ( ! exprexec(expr, buf, *(int *)val.data))
1.1 schwarze 366: continue;
367:
368: memcpy(&rec, val.data + 4, sizeof(recno_t));
369:
370: /*
371: * O(log n) scan for prior records. Since a record
372: * number is unbounded, this has decent performance over
373: * a complex hash function.
374: */
375:
376: for (leaf = root; leaf >= 0; )
377: if (rec > recs[leaf].rec && recs[leaf].rhs >= 0)
378: leaf = recs[leaf].rhs;
379: else if (rec < recs[leaf].rec && recs[leaf].lhs >= 0)
380: leaf = recs[leaf].lhs;
381: else
382: break;
383:
384: if (leaf >= 0 && recs[leaf].rec == rec)
385: continue;
386:
387: /*
388: * Now we actually extract the manpage's metadata from
389: * the index database.
390: */
391:
392: key.data = &rec;
393: key.size = sizeof(recno_t);
394:
395: if (0 != (*idx->get)(idx, &key, &val, 0))
396: break;
397:
398: srec.lhs = srec.rhs = -1;
399: if ( ! index_read(&key, &val, mc, &srec))
400: break;
401:
402: if (opts->cat && strcasecmp(opts->cat, srec.cat))
403: continue;
404: if (opts->arch && strcasecmp(opts->arch, srec.arch))
405: continue;
406:
407: recs = mandoc_realloc
408: (recs, (len + 1) * sizeof(struct rec));
409:
410: memcpy(&recs[len], &srec, sizeof(struct rec));
411:
412: /* Append to our tree. */
413:
414: if (leaf >= 0) {
415: if (rec > recs[leaf].rec)
416: recs[leaf].rhs = len;
417: else
418: recs[leaf].lhs = len;
419: } else
420: root = len;
421:
422: memset(&srec, 0, sizeof(struct rec));
423: len++;
424: }
425:
426: if (1 == ch)
427: (*res)(recs, len, arg);
428:
429: /* XXX: else? corrupt database error? */
430: out:
431: for (i = 0; i < len; i++) {
432: free(recs[i].file);
433: free(recs[i].cat);
434: free(recs[i].title);
435: free(recs[i].arch);
436: free(recs[i].desc);
437: }
438:
439: free(srec.file);
440: free(srec.cat);
441: free(srec.title);
442: free(srec.arch);
443: free(srec.desc);
444:
445: if (mc)
446: mchars_free(mc);
447: if (btree)
448: (*btree->close)(btree);
449: if (idx)
450: (*idx->close)(idx);
451:
452: free(buf);
453: free(recs);
454: }
455:
456: struct expr *
1.4 ! kristaps 457: exprcomp(char *buf)
1.1 schwarze 458: {
459: struct expr *p;
460: struct expr e;
1.3 schwarze 461: char *key;
462: int i, icase;
1.1 schwarze 463:
1.4 ! kristaps 464: if ('\0' == *buf)
1.1 schwarze 465: return(NULL);
466:
1.3 schwarze 467: /*
468: * Choose regex or substring match.
469: */
470:
1.4 ! kristaps 471: if (NULL == (e.v = strpbrk(buf, "=~"))) {
1.3 schwarze 472: e.regex = 0;
1.4 ! kristaps 473: e.v = buf;
1.3 schwarze 474: } else {
475: e.regex = '~' == *e.v;
476: *e.v++ = '\0';
477: }
1.1 schwarze 478:
1.3 schwarze 479: /*
480: * Determine the record types to search for.
481: */
482:
483: icase = 0;
484: e.mask = 0;
1.4 ! kristaps 485: if (buf < e.v) {
! 486: while (NULL != (key = strsep(&buf, ","))) {
1.3 schwarze 487: if ('i' == key[0] && '\0' == key[1]) {
488: icase = REG_ICASE;
489: continue;
490: }
491: i = 0;
492: while (types[i].mask &&
1.4 ! kristaps 493: strcmp(types[i].name, key))
1.3 schwarze 494: i++;
495: e.mask |= types[i].mask;
496: }
497: }
498: if (0 == e.mask)
499: e.mask = TYPE_Nm | TYPE_Nd;
1.1 schwarze 500:
1.3 schwarze 501: if (e.regex &&
502: regcomp(&e.re, e.v, REG_EXTENDED | REG_NOSUB | icase))
1.1 schwarze 503: return(NULL);
504:
1.3 schwarze 505: e.v = mandoc_strdup(e.v);
1.1 schwarze 506:
507: p = mandoc_calloc(1, sizeof(struct expr));
508: memcpy(p, &e, sizeof(struct expr));
509: return(p);
510: }
511:
512: void
513: exprfree(struct expr *p)
514: {
515:
516: if (NULL == p)
517: return;
518:
1.3 schwarze 519: if (p->regex)
1.1 schwarze 520: regfree(&p->re);
521:
522: free(p->v);
523: free(p);
524: }
525:
526: static int
1.3 schwarze 527: exprexec(const struct expr *p, char *cp, int mask)
1.1 schwarze 528: {
529:
1.3 schwarze 530: if ( ! (mask & p->mask))
531: return(0);
1.1 schwarze 532:
1.3 schwarze 533: if (p->regex)
534: return(0 == regexec(&p->re, cp, 0, NULL, 0));
535: else
536: return(NULL != strcasestr(cp, p->v));
1.1 schwarze 537: }
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