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1.2 ! kristaps 1: /* $Id: db.c,v 1.1 2011/11/09 01:24:23 kristaps Exp $ */
1.1 kristaps 2: /*
3: * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17: #include <assert.h>
18: #include <fcntl.h>
19: #include <regex.h>
20: #include <stdarg.h>
21: #include <stdlib.h>
22: #include <string.h>
23:
24: #ifdef __linux__
25: # include <db_185.h>
26: #else
27: # include <db.h>
28: #endif
29:
30: #include "apropos.h"
31: #include "mandoc.h"
32:
1.2 ! kristaps 33: enum match {
! 34: MATCH_REGEX,
! 35: MATCH_REGEXCASE,
! 36: MATCH_STR,
! 37: MATCH_STRCASE
! 38: };
! 39:
! 40: struct expr {
! 41: enum match match;
! 42: int mask;
! 43: char *v;
! 44: regex_t re;
! 45: };
! 46:
! 47: struct type {
! 48: int mask;
! 49: const char *name;
! 50: };
! 51:
! 52: static const struct type types[] = {
! 53: { TYPE_NAME, "name" },
! 54: { TYPE_FUNCTION, "func" },
! 55: { TYPE_UTILITY, "utility" },
! 56: { TYPE_INCLUDES, "incl" },
! 57: { TYPE_VARIABLE, "var" },
! 58: { TYPE_STANDARD, "stand" },
! 59: { TYPE_AUTHOR, "auth" },
! 60: { TYPE_CONFIG, "conf" },
! 61: { TYPE_DESC, "desc" },
! 62: { TYPE_XREF, "xref" },
! 63: { TYPE_PATH, "path" },
! 64: { TYPE_ENV, "env" },
! 65: { TYPE_ERR, "err" },
! 66: { INT_MAX, "all" },
! 67: { 0, NULL }
! 68: };
! 69:
1.1 kristaps 70: static DB *btree_open(void);
71: static int btree_read(const DBT *, const struct mchars *, char **);
1.2 ! kristaps 72: static int exprexec(const struct expr *, char *);
1.1 kristaps 73: static DB *index_open(void);
74: static int index_read(const DBT *, const DBT *,
75: const struct mchars *, struct rec *);
76: static void norm_string(const char *,
77: const struct mchars *, char **);
78: static size_t norm_utf8(unsigned int, char[7]);
79:
80: /*
81: * Open the keyword mandoc-db database.
82: */
83: static DB *
84: btree_open(void)
85: {
86: BTREEINFO info;
87: DB *db;
88:
89: memset(&info, 0, sizeof(BTREEINFO));
90: info.flags = R_DUP;
91:
92: db = dbopen("mandoc.db", O_RDONLY, 0, DB_BTREE, &info);
93: if (NULL != db)
94: return(db);
95:
96: return(NULL);
97: }
98:
99: /*
100: * Read a keyword from the database and normalise it.
101: * Return 0 if the database is insane, else 1.
102: */
103: static int
104: btree_read(const DBT *v, const struct mchars *mc, char **buf)
105: {
106:
107: /* Sanity: are we nil-terminated? */
108:
109: assert(v->size > 0);
110: if ('\0' != ((char *)v->data)[(int)v->size - 1])
111: return(0);
112:
113: norm_string((char *)v->data, mc, buf);
114: return(1);
115: }
116:
117: /*
118: * Take a Unicode codepoint and produce its UTF-8 encoding.
119: * This isn't the best way to do this, but it works.
120: * The magic numbers are from the UTF-8 packaging.
121: * They're not as scary as they seem: read the UTF-8 spec for details.
122: */
123: static size_t
124: norm_utf8(unsigned int cp, char out[7])
125: {
126: size_t rc;
127:
128: rc = 0;
129:
130: if (cp <= 0x0000007F) {
131: rc = 1;
132: out[0] = (char)cp;
133: } else if (cp <= 0x000007FF) {
134: rc = 2;
135: out[0] = (cp >> 6 & 31) | 192;
136: out[1] = (cp & 63) | 128;
137: } else if (cp <= 0x0000FFFF) {
138: rc = 3;
139: out[0] = (cp >> 12 & 15) | 224;
140: out[1] = (cp >> 6 & 63) | 128;
141: out[2] = (cp & 63) | 128;
142: } else if (cp <= 0x001FFFFF) {
143: rc = 4;
144: out[0] = (cp >> 18 & 7) | 240;
145: out[1] = (cp >> 12 & 63) | 128;
146: out[2] = (cp >> 6 & 63) | 128;
147: out[3] = (cp & 63) | 128;
148: } else if (cp <= 0x03FFFFFF) {
149: rc = 5;
150: out[0] = (cp >> 24 & 3) | 248;
151: out[1] = (cp >> 18 & 63) | 128;
152: out[2] = (cp >> 12 & 63) | 128;
153: out[3] = (cp >> 6 & 63) | 128;
154: out[4] = (cp & 63) | 128;
155: } else if (cp <= 0x7FFFFFFF) {
156: rc = 6;
157: out[0] = (cp >> 30 & 1) | 252;
158: out[1] = (cp >> 24 & 63) | 128;
159: out[2] = (cp >> 18 & 63) | 128;
160: out[3] = (cp >> 12 & 63) | 128;
161: out[4] = (cp >> 6 & 63) | 128;
162: out[5] = (cp & 63) | 128;
163: } else
164: return(0);
165:
166: out[rc] = '\0';
167: return(rc);
168: }
169:
170: /*
171: * Normalise strings from the index and database.
172: * These strings are escaped as defined by mandoc_char(7) along with
173: * other goop in mandoc.h (e.g., soft hyphens).
174: * This function normalises these into a nice UTF-8 string.
175: * Returns 0 if the database is fucked.
176: */
177: static void
178: norm_string(const char *val, const struct mchars *mc, char **buf)
179: {
180: size_t sz, bsz;
181: char utfbuf[7];
182: const char *seq, *cpp;
183: int len, u, pos;
184: enum mandoc_esc esc;
185: static const char res[] = { '\\', '\t',
186: ASCII_NBRSP, ASCII_HYPH, '\0' };
187:
188: /* Pre-allocate by the length of the input */
189:
190: bsz = strlen(val) + 1;
191: *buf = mandoc_realloc(*buf, bsz);
192: pos = 0;
193:
194: while ('\0' != *val) {
195: /*
196: * Halt on the first escape sequence.
197: * This also halts on the end of string, in which case
198: * we just copy, fallthrough, and exit the loop.
199: */
200: if ((sz = strcspn(val, res)) > 0) {
201: memcpy(&(*buf)[pos], val, sz);
202: pos += (int)sz;
203: val += (int)sz;
204: }
205:
206: if (ASCII_HYPH == *val) {
207: (*buf)[pos++] = '-';
208: val++;
209: continue;
210: } else if ('\t' == *val || ASCII_NBRSP == *val) {
211: (*buf)[pos++] = ' ';
212: val++;
213: continue;
214: } else if ('\\' != *val)
215: break;
216:
217: /* Read past the slash. */
218:
219: val++;
220: u = 0;
221:
222: /*
223: * Parse the escape sequence and see if it's a
224: * predefined character or special character.
225: */
226:
227: esc = mandoc_escape(&val, &seq, &len);
228: if (ESCAPE_ERROR == esc)
229: break;
230:
231: /*
232: * XXX - this just does UTF-8, but we need to know
233: * beforehand whether we should do text substitution.
234: */
235:
236: switch (esc) {
237: case (ESCAPE_SPECIAL):
238: if (0 != (u = mchars_spec2cp(mc, seq, len)))
239: break;
240: /* FALLTHROUGH */
241: default:
242: continue;
243: }
244:
245: /*
246: * If we have a Unicode codepoint, try to convert that
247: * to a UTF-8 byte string.
248: */
249:
250: cpp = utfbuf;
251: if (0 == (sz = norm_utf8(u, utfbuf)))
252: continue;
253:
254: /* Copy the rendered glyph into the stream. */
255:
256: sz = strlen(cpp);
257: bsz += sz;
258:
259: *buf = mandoc_realloc(*buf, bsz);
260:
261: memcpy(&(*buf)[pos], cpp, sz);
262: pos += (int)sz;
263: }
264:
265: (*buf)[pos] = '\0';
266: }
267:
268: /*
269: * Open the filename-index mandoc-db database.
270: * Returns NULL if opening failed.
271: */
272: static DB *
273: index_open(void)
274: {
275: DB *db;
276:
277: db = dbopen("mandoc.index", O_RDONLY, 0, DB_RECNO, NULL);
278: if (NULL != db)
279: return(db);
280:
281: return(NULL);
282: }
283:
284: /*
285: * Safely unpack from an index file record into the structure.
286: * Returns 1 if an entry was unpacked, 0 if the database is insane.
287: */
288: static int
289: index_read(const DBT *key, const DBT *val,
290: const struct mchars *mc, struct rec *rec)
291: {
292: size_t left;
293: char *np, *cp;
294:
295: #define INDEX_BREAD(_dst) \
296: do { \
297: if (NULL == (np = memchr(cp, '\0', left))) \
298: return(0); \
299: norm_string(cp, mc, &(_dst)); \
300: left -= (np - cp) + 1; \
301: cp = np + 1; \
302: } while (/* CONSTCOND */ 0)
303:
304: left = val->size;
305: cp = (char *)val->data;
306:
307: rec->rec = *(recno_t *)key->data;
308:
309: INDEX_BREAD(rec->file);
310: INDEX_BREAD(rec->cat);
311: INDEX_BREAD(rec->title);
312: INDEX_BREAD(rec->arch);
313: INDEX_BREAD(rec->desc);
314: return(1);
315: }
316:
317: /*
1.2 ! kristaps 318: * Search the mandocdb database for the expression "expr".
1.1 kristaps 319: * Filter out by "opts".
320: * Call "res" with the results, which may be zero.
321: */
322: void
1.2 ! kristaps 323: apropos_search(const struct opts *opts, const struct expr *expr,
! 324: void *arg, void (*res)(struct rec *, size_t, void *))
1.1 kristaps 325: {
326: int i, len, root, leaf;
327: DBT key, val;
328: DB *btree, *idx;
329: struct mchars *mc;
330: int ch;
331: char *buf;
332: recno_t rec;
333: struct rec *recs;
334: struct rec srec;
335:
336: root = -1;
337: leaf = -1;
338: btree = NULL;
339: idx = NULL;
340: mc = NULL;
341: buf = NULL;
342: recs = NULL;
343: len = 0;
344:
345: memset(&srec, 0, sizeof(struct rec));
346:
347: /* XXX: error out with bad regexp? */
348:
349: mc = mchars_alloc();
350:
351: /* XXX: return fact that we've errored? */
352:
353: if (NULL == (btree = btree_open()))
354: goto out;
355: if (NULL == (idx = index_open()))
356: goto out;
357:
358: while (0 == (ch = (*btree->seq)(btree, &key, &val, R_NEXT))) {
359: /*
360: * Low-water mark for key and value.
361: * The key must have something in it, and the value must
362: * have the correct tags/recno mix.
363: */
364: if (key.size < 2 || 8 != val.size)
365: break;
366: if ( ! btree_read(&key, mc, &buf))
367: break;
1.2 ! kristaps 368:
! 369: if ( ! exprexec(expr, buf))
1.1 kristaps 370: continue;
371:
372: memcpy(&rec, val.data + 4, sizeof(recno_t));
373:
374: /*
375: * O(log n) scan for prior records. Since a record
376: * number is unbounded, this has decent performance over
377: * a complex hash function.
378: */
379:
380: for (leaf = root; leaf >= 0; )
381: if (rec > recs[leaf].rec && recs[leaf].rhs >= 0)
382: leaf = recs[leaf].rhs;
383: else if (rec < recs[leaf].rec && recs[leaf].lhs >= 0)
384: leaf = recs[leaf].lhs;
385: else
386: break;
387:
388: if (leaf >= 0 && recs[leaf].rec == rec)
389: continue;
390:
391: /*
392: * Now we actually extract the manpage's metadata from
393: * the index database.
394: */
395:
396: key.data = &rec;
397: key.size = sizeof(recno_t);
398:
399: if (0 != (*idx->get)(idx, &key, &val, 0))
400: break;
401:
402: srec.lhs = srec.rhs = -1;
403: if ( ! index_read(&key, &val, mc, &srec))
404: break;
405:
406: if (opts->cat && strcasecmp(opts->cat, srec.cat))
407: continue;
408: if (opts->arch && strcasecmp(opts->arch, srec.arch))
409: continue;
410:
411: recs = mandoc_realloc
412: (recs, (len + 1) * sizeof(struct rec));
413:
414: memcpy(&recs[len], &srec, sizeof(struct rec));
415:
416: /* Append to our tree. */
417:
418: if (leaf >= 0) {
419: if (rec > recs[leaf].rec)
420: recs[leaf].rhs = len;
421: else
422: recs[leaf].lhs = len;
423: } else
424: root = len;
425:
426: memset(&srec, 0, sizeof(struct rec));
427: len++;
428: }
429:
430: if (1 == ch)
431: (*res)(recs, len, arg);
432:
433: /* XXX: else? corrupt database error? */
434: out:
435: for (i = 0; i < len; i++) {
436: free(recs[i].file);
437: free(recs[i].cat);
438: free(recs[i].title);
439: free(recs[i].arch);
440: free(recs[i].desc);
441: }
442:
443: free(srec.file);
444: free(srec.cat);
445: free(srec.title);
446: free(srec.arch);
447: free(srec.desc);
448:
449: if (mc)
450: mchars_free(mc);
451: if (btree)
452: (*btree->close)(btree);
453: if (idx)
454: (*idx->close)(idx);
455:
456: free(buf);
457: free(recs);
1.2 ! kristaps 458: }
! 459:
! 460: struct expr *
! 461: exprcomp(int cs, char *argv[], int argc)
! 462: {
! 463: struct expr *p;
! 464: struct expr e;
! 465: int i, ch;
! 466:
! 467: if (3 != argc)
! 468: return(NULL);
! 469:
! 470: if (0 == strcmp("-eq", argv[0]))
! 471: e.match = cs ? MATCH_STRCASE : MATCH_STR;
! 472: else if (0 == strcmp("-ieq", argv[0]))
! 473: e.match = MATCH_STRCASE;
! 474: else if (0 == strcmp("-re", argv[0]))
! 475: e.match = cs ? MATCH_REGEXCASE : MATCH_REGEX;
! 476: else if (0 == strcmp("-ire", argv[0]))
! 477: e.match = MATCH_REGEXCASE;
! 478: else
! 479: return(NULL);
! 480:
! 481: for (i = 0; 0 != types[i].mask; i++)
! 482: if (0 == strcmp(types[i].name, argv[1]))
! 483: break;
! 484:
! 485: if (0 == (e.mask = types[i].mask))
! 486: return(NULL);
! 487:
! 488: e.v = mandoc_strdup(argv[2]);
! 489:
! 490: if (MATCH_REGEX == e.match || MATCH_REGEXCASE == e.match) {
! 491: ch = REG_EXTENDED | REG_NOSUB;
! 492: if (MATCH_REGEXCASE == e.match)
! 493: ch |= REG_ICASE;
! 494: if (regcomp(&e.re, e.v, ch))
! 495: return(NULL);
! 496: }
! 497:
! 498: p = mandoc_calloc(1, sizeof(struct expr));
! 499: memcpy(p, &e, sizeof(struct expr));
! 500: return(p);
! 501: }
! 502:
! 503: void
! 504: exprfree(struct expr *p)
! 505: {
! 506:
! 507: if (NULL == p)
! 508: return;
! 509:
! 510: if (MATCH_REGEX == p->match)
! 511: regfree(&p->re);
! 512:
! 513: free(p->v);
! 514: free(p);
! 515: }
! 516:
! 517: static int
! 518: exprexec(const struct expr *p, char *cp)
! 519: {
! 520:
! 521: if (MATCH_STR == p->match)
! 522: return(0 == strcmp(p->v, cp));
! 523: else if (MATCH_STRCASE == p->match)
! 524: return(0 == strcasecmp(p->v, cp));
! 525:
! 526: assert(MATCH_REGEX == p->match);
! 527: return(0 == regexec(&p->re, cp, 0, NULL, 0));
1.1 kristaps 528: }