Less misleading file names; ok kristaps@.

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));
+}