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authorIngo Schwarze <schwarze@openbsd.org>2011-11-13 10:12:05 +0000
committerIngo Schwarze <schwarze@openbsd.org>2011-11-13 10:12:05 +0000
commit120222d1fe68dc5dc2dbd314cdbafe2b0bbed0ab (patch)
treed3603d9e422a736c30e83b766b46522e6de8f418 /apropos_db.c
parent341c5fea045ed3029b82199c23481d39059b8f92 (diff)
downloadmandoc-120222d1fe68dc5dc2dbd314cdbafe2b0bbed0ab.tar.gz
Less misleading file names; ok kristaps@.
Diffstat (limited to 'apropos_db.c')
-rw-r--r--apropos_db.c541
1 files changed, 541 insertions, 0 deletions
diff --git a/apropos_db.c b/apropos_db.c
new file mode 100644
index 00000000..30b9217e
--- /dev/null
+++ b/apropos_db.c
@@ -0,0 +1,541 @@
+/* $Id$ */
+/*
+ * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include <assert.h>
+#include <fcntl.h>
+#include <regex.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef __linux__
+# include <db_185.h>
+#else
+# include <db.h>
+#endif
+
+#include "apropos_db.h"
+#include "mandoc.h"
+
+enum match {
+ MATCH_REGEX,
+ MATCH_REGEXCASE,
+ MATCH_STR,
+ MATCH_STRCASE
+};
+
+struct expr {
+ enum match match;
+ int mask;
+ char *v;
+ regex_t re;
+};
+
+struct type {
+ int mask;
+ const char *name;
+};
+
+static const struct type types[] = {
+ { TYPE_NAME, "name" },
+ { TYPE_FUNCTION, "func" },
+ { TYPE_UTILITY, "utility" },
+ { TYPE_INCLUDES, "incl" },
+ { TYPE_VARIABLE, "var" },
+ { TYPE_STANDARD, "stand" },
+ { TYPE_AUTHOR, "auth" },
+ { TYPE_CONFIG, "conf" },
+ { TYPE_DESC, "desc" },
+ { TYPE_XREF, "xref" },
+ { TYPE_PATH, "path" },
+ { TYPE_ENV, "env" },
+ { TYPE_ERR, "err" },
+ { INT_MAX, "all" },
+ { 0, NULL }
+};
+
+static DB *btree_open(void);
+static int btree_read(const DBT *, const struct mchars *, char **);
+static int exprexec(const struct expr *, char *);
+static DB *index_open(void);
+static int index_read(const DBT *, const DBT *,
+ const struct mchars *, struct rec *);
+static void norm_string(const char *,
+ const struct mchars *, char **);
+static size_t norm_utf8(unsigned int, char[7]);
+
+/*
+ * Open the keyword mandoc-db database.
+ */
+static DB *
+btree_open(void)
+{
+ BTREEINFO info;
+ DB *db;
+
+ memset(&info, 0, sizeof(BTREEINFO));
+ info.flags = R_DUP;
+
+ db = dbopen("mandoc.db", O_RDONLY, 0, DB_BTREE, &info);
+ if (NULL != db)
+ return(db);
+
+ return(NULL);
+}
+
+/*
+ * Read a keyword from the database and normalise it.
+ * Return 0 if the database is insane, else 1.
+ */
+static int
+btree_read(const DBT *v, const struct mchars *mc, char **buf)
+{
+
+ /* Sanity: are we nil-terminated? */
+
+ assert(v->size > 0);
+ if ('\0' != ((char *)v->data)[(int)v->size - 1])
+ return(0);
+
+ norm_string((char *)v->data, mc, buf);
+ return(1);
+}
+
+/*
+ * Take a Unicode codepoint and produce its UTF-8 encoding.
+ * This isn't the best way to do this, but it works.
+ * The magic numbers are from the UTF-8 packaging.
+ * They're not as scary as they seem: read the UTF-8 spec for details.
+ */
+static size_t
+norm_utf8(unsigned int cp, char out[7])
+{
+ size_t rc;
+
+ rc = 0;
+
+ if (cp <= 0x0000007F) {
+ rc = 1;
+ out[0] = (char)cp;
+ } else if (cp <= 0x000007FF) {
+ rc = 2;
+ out[0] = (cp >> 6 & 31) | 192;
+ out[1] = (cp & 63) | 128;
+ } else if (cp <= 0x0000FFFF) {
+ rc = 3;
+ out[0] = (cp >> 12 & 15) | 224;
+ out[1] = (cp >> 6 & 63) | 128;
+ out[2] = (cp & 63) | 128;
+ } else if (cp <= 0x001FFFFF) {
+ rc = 4;
+ out[0] = (cp >> 18 & 7) | 240;
+ out[1] = (cp >> 12 & 63) | 128;
+ out[2] = (cp >> 6 & 63) | 128;
+ out[3] = (cp & 63) | 128;
+ } else if (cp <= 0x03FFFFFF) {
+ rc = 5;
+ out[0] = (cp >> 24 & 3) | 248;
+ out[1] = (cp >> 18 & 63) | 128;
+ out[2] = (cp >> 12 & 63) | 128;
+ out[3] = (cp >> 6 & 63) | 128;
+ out[4] = (cp & 63) | 128;
+ } else if (cp <= 0x7FFFFFFF) {
+ rc = 6;
+ out[0] = (cp >> 30 & 1) | 252;
+ out[1] = (cp >> 24 & 63) | 128;
+ out[2] = (cp >> 18 & 63) | 128;
+ out[3] = (cp >> 12 & 63) | 128;
+ out[4] = (cp >> 6 & 63) | 128;
+ out[5] = (cp & 63) | 128;
+ } else
+ return(0);
+
+ out[rc] = '\0';
+ return(rc);
+}
+
+/*
+ * Normalise strings from the index and database.
+ * These strings are escaped as defined by mandoc_char(7) along with
+ * other goop in mandoc.h (e.g., soft hyphens).
+ * This function normalises these into a nice UTF-8 string.
+ * Returns 0 if the database is fucked.
+ */
+static void
+norm_string(const char *val, const struct mchars *mc, char **buf)
+{
+ size_t sz, bsz;
+ char utfbuf[7];
+ const char *seq, *cpp;
+ int len, u, pos;
+ enum mandoc_esc esc;
+ static const char res[] = { '\\', '\t',
+ ASCII_NBRSP, ASCII_HYPH, '\0' };
+
+ /* Pre-allocate by the length of the input */
+
+ bsz = strlen(val) + 1;
+ *buf = mandoc_realloc(*buf, bsz);
+ pos = 0;
+
+ while ('\0' != *val) {
+ /*
+ * Halt on the first escape sequence.
+ * This also halts on the end of string, in which case
+ * we just copy, fallthrough, and exit the loop.
+ */
+ if ((sz = strcspn(val, res)) > 0) {
+ memcpy(&(*buf)[pos], val, sz);
+ pos += (int)sz;
+ val += (int)sz;
+ }
+
+ if (ASCII_HYPH == *val) {
+ (*buf)[pos++] = '-';
+ val++;
+ continue;
+ } else if ('\t' == *val || ASCII_NBRSP == *val) {
+ (*buf)[pos++] = ' ';
+ val++;
+ continue;
+ } else if ('\\' != *val)
+ break;
+
+ /* Read past the slash. */
+
+ val++;
+ u = 0;
+
+ /*
+ * Parse the escape sequence and see if it's a
+ * predefined character or special character.
+ */
+
+ esc = mandoc_escape(&val, &seq, &len);
+ if (ESCAPE_ERROR == esc)
+ break;
+
+ /*
+ * XXX - this just does UTF-8, but we need to know
+ * beforehand whether we should do text substitution.
+ */
+
+ switch (esc) {
+ case (ESCAPE_SPECIAL):
+ if (0 != (u = mchars_spec2cp(mc, seq, len)))
+ break;
+ /* FALLTHROUGH */
+ default:
+ continue;
+ }
+
+ /*
+ * If we have a Unicode codepoint, try to convert that
+ * to a UTF-8 byte string.
+ */
+
+ cpp = utfbuf;
+ if (0 == (sz = norm_utf8(u, utfbuf)))
+ continue;
+
+ /* Copy the rendered glyph into the stream. */
+
+ sz = strlen(cpp);
+ bsz += sz;
+
+ *buf = mandoc_realloc(*buf, bsz);
+
+ memcpy(&(*buf)[pos], cpp, sz);
+ pos += (int)sz;
+ }
+
+ (*buf)[pos] = '\0';
+}
+
+/*
+ * Open the filename-index mandoc-db database.
+ * Returns NULL if opening failed.
+ */
+static DB *
+index_open(void)
+{
+ DB *db;
+
+ db = dbopen("mandoc.index", O_RDONLY, 0, DB_RECNO, NULL);
+ if (NULL != db)
+ return(db);
+
+ return(NULL);
+}
+
+/*
+ * Safely unpack from an index file record into the structure.
+ * Returns 1 if an entry was unpacked, 0 if the database is insane.
+ */
+static int
+index_read(const DBT *key, const DBT *val,
+ const struct mchars *mc, struct rec *rec)
+{
+ size_t left;
+ char *np, *cp;
+
+#define INDEX_BREAD(_dst) \
+ do { \
+ if (NULL == (np = memchr(cp, '\0', left))) \
+ return(0); \
+ norm_string(cp, mc, &(_dst)); \
+ left -= (np - cp) + 1; \
+ cp = np + 1; \
+ } while (/* CONSTCOND */ 0)
+
+ left = val->size;
+ cp = (char *)val->data;
+
+ rec->rec = *(recno_t *)key->data;
+
+ INDEX_BREAD(rec->file);
+ INDEX_BREAD(rec->cat);
+ INDEX_BREAD(rec->title);
+ INDEX_BREAD(rec->arch);
+ INDEX_BREAD(rec->desc);
+ return(1);
+}
+
+/*
+ * Search the mandocdb database for the expression "expr".
+ * Filter out by "opts".
+ * Call "res" with the results, which may be zero.
+ */
+void
+apropos_search(const struct opts *opts, const struct expr *expr,
+ void *arg, void (*res)(struct rec *, size_t, void *))
+{
+ int i, len, root, leaf;
+ DBT key, val;
+ DB *btree, *idx;
+ struct mchars *mc;
+ int ch;
+ char *buf;
+ recno_t rec;
+ struct rec *recs;
+ struct rec srec;
+
+ root = -1;
+ leaf = -1;
+ btree = NULL;
+ idx = NULL;
+ mc = NULL;
+ buf = NULL;
+ recs = NULL;
+ len = 0;
+
+ memset(&srec, 0, sizeof(struct rec));
+
+ /* XXX: error out with bad regexp? */
+
+ mc = mchars_alloc();
+
+ /* XXX: return fact that we've errored? */
+
+ if (NULL == (btree = btree_open()))
+ goto out;
+ if (NULL == (idx = index_open()))
+ goto out;
+
+ while (0 == (ch = (*btree->seq)(btree, &key, &val, R_NEXT))) {
+ /*
+ * Low-water mark for key and value.
+ * The key must have something in it, and the value must
+ * have the correct tags/recno mix.
+ */
+ if (key.size < 2 || 8 != val.size)
+ break;
+ if ( ! btree_read(&key, mc, &buf))
+ break;
+
+ if ( ! exprexec(expr, buf))
+ continue;
+
+ memcpy(&rec, val.data + 4, sizeof(recno_t));
+
+ /*
+ * O(log n) scan for prior records. Since a record
+ * number is unbounded, this has decent performance over
+ * a complex hash function.
+ */
+
+ for (leaf = root; leaf >= 0; )
+ if (rec > recs[leaf].rec && recs[leaf].rhs >= 0)
+ leaf = recs[leaf].rhs;
+ else if (rec < recs[leaf].rec && recs[leaf].lhs >= 0)
+ leaf = recs[leaf].lhs;
+ else
+ break;
+
+ if (leaf >= 0 && recs[leaf].rec == rec)
+ continue;
+
+ /*
+ * Now we actually extract the manpage's metadata from
+ * the index database.
+ */
+
+ key.data = &rec;
+ key.size = sizeof(recno_t);
+
+ if (0 != (*idx->get)(idx, &key, &val, 0))
+ break;
+
+ srec.lhs = srec.rhs = -1;
+ if ( ! index_read(&key, &val, mc, &srec))
+ break;
+
+ if (opts->cat && strcasecmp(opts->cat, srec.cat))
+ continue;
+ if (opts->arch && strcasecmp(opts->arch, srec.arch))
+ continue;
+
+ recs = mandoc_realloc
+ (recs, (len + 1) * sizeof(struct rec));
+
+ memcpy(&recs[len], &srec, sizeof(struct rec));
+
+ /* Append to our tree. */
+
+ if (leaf >= 0) {
+ if (rec > recs[leaf].rec)
+ recs[leaf].rhs = len;
+ else
+ recs[leaf].lhs = len;
+ } else
+ root = len;
+
+ memset(&srec, 0, sizeof(struct rec));
+ len++;
+ }
+
+ if (1 == ch)
+ (*res)(recs, len, arg);
+
+ /* XXX: else? corrupt database error? */
+out:
+ for (i = 0; i < len; i++) {
+ free(recs[i].file);
+ free(recs[i].cat);
+ free(recs[i].title);
+ free(recs[i].arch);
+ free(recs[i].desc);
+ }
+
+ free(srec.file);
+ free(srec.cat);
+ free(srec.title);
+ free(srec.arch);
+ free(srec.desc);
+
+ if (mc)
+ mchars_free(mc);
+ if (btree)
+ (*btree->close)(btree);
+ if (idx)
+ (*idx->close)(idx);
+
+ free(buf);
+ free(recs);
+}
+
+struct expr *
+exprcomp(int cs, char *argv[], int argc)
+{
+ struct expr *p;
+ struct expr e;
+ int i, pos, ch;
+
+ pos = 0;
+
+ if (pos > argc)
+ return(NULL);
+
+ for (i = 0; 0 != types[i].mask; i++)
+ if (0 == strcmp(types[i].name, argv[pos]))
+ break;
+
+ if (0 == (e.mask = types[i].mask))
+ return(NULL);
+
+ if (++pos > argc--)
+ return(NULL);
+
+ if ('-' != *argv[pos])
+ e.match = cs ? MATCH_STRCASE : MATCH_STR;
+ else if (0 == strcmp("-eq", argv[pos]))
+ e.match = cs ? MATCH_STRCASE : MATCH_STR;
+ else if (0 == strcmp("-ieq", argv[pos]))
+ e.match = MATCH_STRCASE;
+ else if (0 == strcmp("-re", argv[pos]))
+ e.match = cs ? MATCH_REGEXCASE : MATCH_REGEX;
+ else if (0 == strcmp("-ire", argv[pos]))
+ e.match = MATCH_REGEXCASE;
+ else
+ return(NULL);
+
+ if ('-' == *argv[pos])
+ pos++;
+
+ if (pos > argc--)
+ return(NULL);
+
+ e.v = mandoc_strdup(argv[pos]);
+
+ if (MATCH_REGEX == e.match || MATCH_REGEXCASE == e.match) {
+ ch = REG_EXTENDED | REG_NOSUB;
+ if (MATCH_REGEXCASE == e.match)
+ ch |= REG_ICASE;
+ if (regcomp(&e.re, e.v, ch))
+ return(NULL);
+ }
+
+ p = mandoc_calloc(1, sizeof(struct expr));
+ memcpy(p, &e, sizeof(struct expr));
+ return(p);
+}
+
+void
+exprfree(struct expr *p)
+{
+
+ if (NULL == p)
+ return;
+
+ if (MATCH_REGEX == p->match)
+ regfree(&p->re);
+
+ free(p->v);
+ free(p);
+}
+
+static int
+exprexec(const struct expr *p, char *cp)
+{
+
+ if (MATCH_STR == p->match)
+ return(0 == strcmp(p->v, cp));
+ else if (MATCH_STRCASE == p->match)
+ return(0 == strcasecmp(p->v, cp));
+
+ assert(MATCH_REGEX == p->match);
+ return(0 == regexec(&p->re, cp, 0, NULL, 0));
+}