Return to mansearch.c CVS log

Up to [cvsweb.bsd.lv] / mandoc

Next speed optimization step for the new apropos(1).
Split manual names out of the common "keys" table into their
own "names" table.  This reduces standard apropos(1) search
times (i.e. searching for names and descriptions only) by
typically about 70% for the full /usr/share/man database.
(Yes, that multiplies with the previous optimization step,
so both together have reduced search times by a factor of
more than six.  I'm not done yet, expect more to come.)

Even with the minimal databases built with makewhatis(8) -Q,
this step still reduces search times by 15-20%.  For both cases,
database sizes and build times hardly change (+/-2%).

/*	$Id: mansearch.c,v 1.27 2014/04/10 02:46:21 schwarze Exp $ */
/*
 * Copyright (c) 2012 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2013, 2014 Ingo Schwarze <schwarze@openbsd.org>
 *
 * 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.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <assert.h>
#include <fcntl.h>
#include <getopt.h>
#include <limits.h>
#include <regex.h>
#include <stdio.h>
#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#ifdef HAVE_OHASH
#include <ohash.h>
#else
#include "compat_ohash.h"
#endif
#include <sqlite3.h>

#include "mandoc.h"
#include "mandoc_aux.h"
#include "manpath.h"
#include "mansearch.h"

extern int mansearch_keymax;
extern const char *const mansearch_keynames[];

#define	SQL_BIND_TEXT(_db, _s, _i, _v) \
	do { if (SQLITE_OK != sqlite3_bind_text \
		((_s), (_i)++, (_v), -1, SQLITE_STATIC)) \
		fprintf(stderr, "%s\n", sqlite3_errmsg((_db))); \
	} while (0)
#define	SQL_BIND_INT64(_db, _s, _i, _v) \
	do { if (SQLITE_OK != sqlite3_bind_int64 \
		((_s), (_i)++, (_v))) \
		fprintf(stderr, "%s\n", sqlite3_errmsg((_db))); \
	} while (0)
#define	SQL_BIND_BLOB(_db, _s, _i, _v) \
	do { if (SQLITE_OK != sqlite3_bind_blob \
		((_s), (_i)++, (&_v), sizeof(_v), SQLITE_STATIC)) \
		fprintf(stderr, "%s\n", sqlite3_errmsg((_db))); \
	} while (0)

struct	expr {
	uint64_t 	 bits;    /* type-mask */
	const char	*substr;  /* to search for, if applicable */
	regex_t		 regexp;  /* compiled regexp, if applicable */
	int		 open;    /* opening parentheses before */
	int		 and;	  /* logical AND before */
	int		 close;   /* closing parentheses after */
	struct expr	*next;    /* next in sequence */
};

struct	match {
	uint64_t	 id; /* identifier in database */
	char		*desc; /* manual page description */
	int		 form; /* 0 == catpage */
};

static	void		 buildnames(struct manpage *, sqlite3 *,
				sqlite3_stmt *, uint64_t,
				const char *, int form);
static	char		*buildoutput(sqlite3 *, sqlite3_stmt *,
				 uint64_t, uint64_t);
static	void		*hash_alloc(size_t, void *);
static	void		 hash_free(void *, size_t, void *);
static	void		*hash_halloc(size_t, void *);
static	struct expr	*exprcomp(const struct mansearch *, 
				int, char *[]);
static	void		 exprfree(struct expr *);
static	struct expr	*exprspec(struct expr *, uint64_t,
				 const char *, const char *);
static	struct expr	*exprterm(const struct mansearch *, char *, int);
static	void		 sql_append(char **sql, size_t *sz,
				const char *newstr, int count);
static	void		 sql_match(sqlite3_context *context,
				int argc, sqlite3_value **argv);
static	void		 sql_regexp(sqlite3_context *context,
				int argc, sqlite3_value **argv);
static	char		*sql_statement(const struct expr *);

int
mansearch(const struct mansearch *search,
		const struct manpaths *paths,
		int argc, char *argv[],
		const char *outkey,
		struct manpage **res, size_t *sz)
{
	int		 fd, rc, c, indexbit;
	int64_t		 id;
	uint64_t	 outbit, iterbit;
	char		 buf[PATH_MAX];
	char		*sql;
	struct manpage	*mpage;
	struct expr	*e, *ep;
	sqlite3		*db;
	sqlite3_stmt	*s, *s2;
	struct match	*mp;
	struct ohash_info info;
	struct ohash	 htab;
	unsigned int	 idx;
	size_t		 i, j, cur, maxres;

	memset(&info, 0, sizeof(struct ohash_info));

	info.halloc = hash_halloc;
	info.alloc = hash_alloc;
	info.hfree = hash_free;
	info.key_offset = offsetof(struct match, id);

	*sz = cur = maxres = 0;
	sql = NULL;
	*res = NULL;
	fd = -1;
	e = NULL;
	rc = 0;

	if (0 == argc)
		goto out;
	if (NULL == (e = exprcomp(search, argc, argv)))
		goto out;

	outbit = 0;
	if (NULL != outkey) {
		for (indexbit = 0, iterbit = 1;
		     indexbit < mansearch_keymax;
		     indexbit++, iterbit <<= 1) {
			if (0 == strcasecmp(outkey,
			    mansearch_keynames[indexbit])) {
				outbit = iterbit;
				break;
			}
		}
	}

	/*
	 * Save a descriptor to the current working directory.
	 * Since pathnames in the "paths" variable might be relative,
	 * and we'll be chdir()ing into them, we need to keep a handle
	 * on our current directory from which to start the chdir().
	 */

	if (NULL == getcwd(buf, PATH_MAX)) {
		perror(NULL);
		goto out;
	} else if (-1 == (fd = open(buf, O_RDONLY, 0))) {
		perror(buf);
		goto out;
	}

	sql = sql_statement(e);

	/*
	 * Loop over the directories (containing databases) for us to
	 * search.
	 * Don't let missing/bad databases/directories phase us.
	 * In each, try to open the resident database and, if it opens,
	 * scan it for our match expression.
	 */

	for (i = 0; i < paths->sz; i++) {
		if (-1 == fchdir(fd)) {
			perror(buf);
			free(*res);
			break;
		} else if (-1 == chdir(paths->paths[i])) {
			perror(paths->paths[i]);
			continue;
		} 

		c =  sqlite3_open_v2
			(MANDOC_DB, &db, 
			 SQLITE_OPEN_READONLY, NULL);

		if (SQLITE_OK != c) {
			perror(MANDOC_DB);
			sqlite3_close(db);
			continue;
		}

		/*
		 * Define the SQL functions for substring
		 * and regular expression matching.
		 */

		c = sqlite3_create_function(db, "match", 2,
		    SQLITE_ANY, NULL, sql_match, NULL, NULL);
		assert(SQLITE_OK == c);
		c = sqlite3_create_function(db, "regexp", 2,
		    SQLITE_ANY, NULL, sql_regexp, NULL, NULL);
		assert(SQLITE_OK == c);

		j = 1;
		c = sqlite3_prepare_v2(db, sql, -1, &s, NULL);
		if (SQLITE_OK != c)
			fprintf(stderr, "%s\n", sqlite3_errmsg(db));

		for (ep = e; NULL != ep; ep = ep->next) {
			if (NULL == ep->substr) {
				SQL_BIND_BLOB(db, s, j, ep->regexp);
			} else
				SQL_BIND_TEXT(db, s, j, ep->substr);
			if (0 == ((TYPE_Nd | TYPE_Nm) & ep->bits))
				SQL_BIND_INT64(db, s, j, ep->bits);
		}

		memset(&htab, 0, sizeof(struct ohash));
		ohash_init(&htab, 4, &info);

		/*
		 * Hash each entry on its [unique] document identifier.
		 * This is a uint64_t.
		 * Instead of using a hash function, simply convert the
		 * uint64_t to a uint32_t, the hash value's type.
		 * This gives good performance and preserves the
		 * distribution of buckets in the table.
		 */
		while (SQLITE_ROW == (c = sqlite3_step(s))) {
			id = sqlite3_column_int64(s, 2);
			idx = ohash_lookup_memory
				(&htab, (char *)&id,
				 sizeof(uint64_t), (uint32_t)id);

			if (NULL != ohash_find(&htab, idx))
				continue;

			mp = mandoc_calloc(1, sizeof(struct match));
			mp->id = id;
			mp->form = sqlite3_column_int(s, 1);
			if (TYPE_Nd == outbit)
				mp->desc = mandoc_strdup(
				    sqlite3_column_text(s, 0));
			ohash_insert(&htab, idx, mp);
		}

		if (SQLITE_DONE != c)
			fprintf(stderr, "%s\n", sqlite3_errmsg(db));

		sqlite3_finalize(s);

		c = sqlite3_prepare_v2(db, 
		    "SELECT * FROM mlinks WHERE pageid=?"
		    " ORDER BY sec, arch, name",
		    -1, &s, NULL);
		if (SQLITE_OK != c)
			fprintf(stderr, "%s\n", sqlite3_errmsg(db));

		c = sqlite3_prepare_v2(db,
		    "SELECT * FROM keys WHERE pageid=? AND bits & ?",
		    -1, &s2, NULL);
		if (SQLITE_OK != c)
			fprintf(stderr, "%s\n", sqlite3_errmsg(db));

		for (mp = ohash_first(&htab, &idx);
				NULL != mp;
				mp = ohash_next(&htab, &idx)) {
			if (cur + 1 > maxres) {
				maxres += 1024;
				*res = mandoc_realloc
					(*res, maxres * sizeof(struct manpage));
			}
			mpage = *res + cur;
			mpage->form = mp->form;
			buildnames(mpage, db, s, mp->id,
			    paths->paths[i], mp->form);
			mpage->output = TYPE_Nd & outbit ?
			    mp->desc : outbit ?
			    buildoutput(db, s2, mp->id, outbit) : NULL;

			free(mp);
			cur++;
		}

		sqlite3_finalize(s);
		sqlite3_finalize(s2);
		sqlite3_close(db);
		ohash_delete(&htab);
	}
	rc = 1;
out:
	exprfree(e);
	if (-1 != fd)
		close(fd);
	free(sql);
	*sz = cur;
	return(rc);
}

static void
buildnames(struct manpage *mpage, sqlite3 *db, sqlite3_stmt *s,
		uint64_t id, const char *path, int form)
{
	char		*newnames, *prevsec, *prevarch;
	const char	*oldnames, *sep1, *name, *sec, *sep2, *arch, *fsec;
	size_t		 i;
	int		 c;

	mpage->file = NULL;
	mpage->names = NULL;
	prevsec = prevarch = NULL;
	i = 1;
	SQL_BIND_INT64(db, s, i, id);
	while (SQLITE_ROW == (c = sqlite3_step(s))) {

		/* Decide whether we already have some names. */

		if (NULL == mpage->names) {
			oldnames = "";
			sep1 = "";
		} else {
			oldnames = mpage->names;
			sep1 = ", ";
		}

		/* Fetch the next name. */

		sec = sqlite3_column_text(s, 0);
		arch = sqlite3_column_text(s, 1);
		name = sqlite3_column_text(s, 2);

		/* If the section changed, append the old one. */

		if (NULL != prevsec &&
		    (strcmp(sec, prevsec) ||
		     strcmp(arch, prevarch))) {
			sep2 = '\0' == *prevarch ? "" : "/";
			mandoc_asprintf(&newnames, "%s(%s%s%s)",
			    oldnames, prevsec, sep2, prevarch);
			free(mpage->names);
			oldnames = mpage->names = newnames;
			free(prevsec);
			free(prevarch);
			prevsec = prevarch = NULL;
		}

		/* Save the new section, to append it later. */

		if (NULL == prevsec) {
			prevsec = mandoc_strdup(sec);
			prevarch = mandoc_strdup(arch);
		}

		/* Append the new name. */

		mandoc_asprintf(&newnames, "%s%s%s",
		    oldnames, sep1, name);
		free(mpage->names);
		mpage->names = newnames;

		/* Also save the first file name encountered. */

		if (NULL != mpage->file)
			continue;

		if (form) {
			sep1 = "man";
			fsec = sec;
		} else {
			sep1 = "cat";
			fsec = "0";
		}
		sep2 = '\0' == *arch ? "" : "/";
		mandoc_asprintf(&mpage->file, "%s/%s%s%s%s/%s.%s",
		    path, sep1, sec, sep2, arch, name, fsec);
	}
	if (SQLITE_DONE != c)
		fprintf(stderr, "%s\n", sqlite3_errmsg(db));
	sqlite3_reset(s);

	/* Append one final section to the names. */

	if (NULL != prevsec) {
		sep2 = '\0' == *prevarch ? "" : "/";
		mandoc_asprintf(&newnames, "%s(%s%s%s)",
		    mpage->names, prevsec, sep2, prevarch);
		free(mpage->names);
		mpage->names = newnames;
		free(prevsec);
		free(prevarch);
	}
}

static char *
buildoutput(sqlite3 *db, sqlite3_stmt *s, uint64_t id, uint64_t outbit)
{
	char		*output, *newoutput;
	const char	*oldoutput, *sep1, *data;
	size_t		 i;
	int		 c;

	output = NULL;
	i = 1;
	SQL_BIND_INT64(db, s, i, id);
	SQL_BIND_INT64(db, s, i, outbit);
	while (SQLITE_ROW == (c = sqlite3_step(s))) {
		if (NULL == output) {
			oldoutput = "";
			sep1 = "";
		} else {
			oldoutput = output;
			sep1 = " # ";
		}
		data = sqlite3_column_text(s, 1);
		mandoc_asprintf(&newoutput, "%s%s%s",
		    oldoutput, sep1, data);
		free(output);
		output = newoutput;
	}
	if (SQLITE_DONE != c)
		fprintf(stderr, "%s\n", sqlite3_errmsg(db));
	sqlite3_reset(s);
	return(output);
}

/*
 * Implement substring match as an application-defined SQL function.
 * Using the SQL LIKE or GLOB operators instead would be a bad idea
 * because that would require escaping metacharacters in the string
 * being searched for.
 */
static void
sql_match(sqlite3_context *context, int argc, sqlite3_value **argv)
{

	assert(2 == argc);
	sqlite3_result_int(context, NULL != strcasestr(
	    (const char *)sqlite3_value_text(argv[1]),
	    (const char *)sqlite3_value_text(argv[0])));
}

/*
 * Implement regular expression match
 * as an application-defined SQL function.
 */
static void
sql_regexp(sqlite3_context *context, int argc, sqlite3_value **argv)
{

	assert(2 == argc);
	sqlite3_result_int(context, !regexec(
	    (regex_t *)sqlite3_value_blob(argv[0]),
	    (const char *)sqlite3_value_text(argv[1]),
	    0, NULL, 0));
}

static void
sql_append(char **sql, size_t *sz, const char *newstr, int count)
{
	size_t		 newsz;

	newsz = 1 < count ? (size_t)count : strlen(newstr);
	*sql = mandoc_realloc(*sql, *sz + newsz + 1);
	if (1 < count)
		memset(*sql + *sz, *newstr, (size_t)count);
	else
		memcpy(*sql + *sz, newstr, newsz);
	*sz += newsz;
	(*sql)[*sz] = '\0';
}

/*
 * Prepare the search SQL statement.
 */
static char *
sql_statement(const struct expr *e)
{
	char		*sql;
	size_t		 sz;
	int		 needop;

	sql = mandoc_strdup("SELECT * FROM mpages WHERE ");
	sz = strlen(sql);

	for (needop = 0; NULL != e; e = e->next) {
		if (e->and)
			sql_append(&sql, &sz, " AND ", 1);
		else if (needop)
			sql_append(&sql, &sz, " OR ", 1);
		if (e->open)
			sql_append(&sql, &sz, "(", e->open);
		sql_append(&sql, &sz,
		    TYPE_Nd & e->bits
		    ? (NULL == e->substr
			? "desc REGEXP ?"
			: "desc MATCH ?")
		    : TYPE_Nm == e->bits
		    ? (NULL == e->substr
			? "id IN (SELECT pageid FROM names "
			  "WHERE name REGEXP ?)"
			: "id IN (SELECT pageid FROM names "
			  "WHERE name MATCH ?)")
		    : (NULL == e->substr
			? "id IN (SELECT pageid FROM keys "
			  "WHERE key REGEXP ? AND bits & ?)"
			: "id IN (SELECT pageid FROM keys "
			  "WHERE key MATCH ? AND bits & ?)"), 1);
		if (e->close)
			sql_append(&sql, &sz, ")", e->close);
		needop = 1;
	}

	return(sql);
}

/*
 * Compile a set of string tokens into an expression.
 * Tokens in "argv" are assumed to be individual expression atoms (e.g.,
 * "(", "foo=bar", etc.).
 */
static struct expr *
exprcomp(const struct mansearch *search, int argc, char *argv[])
{
	uint64_t	 mask;
	int		 i, toopen, logic, igncase, toclose;
	struct expr	*first, *prev, *cur, *next;

	first = cur = NULL;
	logic = igncase = toclose = 0;
	toopen = 1;

	for (i = 0; i < argc; i++) {
		if (0 == strcmp("(", argv[i])) {
			if (igncase)
				goto fail;
			toopen++;
			toclose++;
			continue;
		} else if (0 == strcmp(")", argv[i])) {
			if (toopen || logic || igncase || NULL == cur)
				goto fail;
			cur->close++;
			if (0 > --toclose)
				goto fail;
			continue;
		} else if (0 == strcmp("-a", argv[i])) {
			if (toopen || logic || igncase || NULL == cur)
				goto fail;
			logic = 1;
			continue;
		} else if (0 == strcmp("-o", argv[i])) {
			if (toopen || logic || igncase || NULL == cur)
				goto fail;
			logic = 2;
			continue;
		} else if (0 == strcmp("-i", argv[i])) {
			if (igncase)
				goto fail;
			igncase = 1;
			continue;
		}
		next = exprterm(search, argv[i], !igncase);
		if (NULL == next)
			goto fail;
		if (NULL == first)
			first = next;
		else
			cur->next = next;
		prev = cur = next;

		/*
		 * Searching for descriptions must be split out
		 * because they are stored in the mpages table,
		 * not in the keys table.
		 */

		for (mask = TYPE_Nm; mask <= TYPE_Nd; mask <<= 1) {
			if (mask & cur->bits && ~mask & cur->bits) {
				next = mandoc_calloc(1,
				    sizeof(struct expr));
				memcpy(next, cur, sizeof(struct expr));
				prev->open = 1;
				cur->bits = mask;
				cur->next = next;
				cur = next;
				cur->bits &= ~mask;
			}
		}
		prev->and = (1 == logic);
		prev->open += toopen;
		if (cur != prev)
			cur->close = 1;

		toopen = logic = igncase = 0;
	}
	if (toopen || logic || igncase || toclose)
		goto fail;

	cur->close++;
	cur = exprspec(cur, TYPE_arch, search->arch, "^(%s|any)$");
	exprspec(cur, TYPE_sec, search->sec, "^%s$");

	return(first);

fail:
	if (NULL != first)
		exprfree(first);
	return(NULL);
}

static struct expr *
exprspec(struct expr *cur, uint64_t key, const char *value,
		const char *format)
{
	char	 errbuf[BUFSIZ];
	char	*cp;
	int	 irc;

	if (NULL == value)
		return(cur);

	mandoc_asprintf(&cp, format, value);
	cur->next = mandoc_calloc(1, sizeof(struct expr));
	cur = cur->next;
	cur->and = 1;
	cur->bits = key;
	if (0 != (irc = regcomp(&cur->regexp, cp,
	    REG_EXTENDED | REG_NOSUB | REG_ICASE))) {
		regerror(irc, &cur->regexp, errbuf, sizeof(errbuf));
		fprintf(stderr, "regcomp: %s\n", errbuf);
		cur->substr = value;
	}
	free(cp);
	return(cur);
}

static struct expr *
exprterm(const struct mansearch *search, char *buf, int cs)
{
	char		 errbuf[BUFSIZ];
	struct expr	*e;
	char		*key, *v;
	uint64_t	 iterbit;
	int		 i, irc;

	if ('\0' == *buf)
		return(NULL);

	e = mandoc_calloc(1, sizeof(struct expr));

	/*"whatis" mode uses an opaque string and default fields. */

	if (MANSEARCH_WHATIS & search->flags) {
		e->substr = buf;
		e->bits = search->deftype;
		return(e);
	}

	/*
	 * If no =~ is specified, search with equality over names and
	 * descriptions.
	 * If =~ begins the phrase, use name and description fields.
	 */

	if (NULL == (v = strpbrk(buf, "=~"))) {
		e->substr = buf;
		e->bits = search->deftype;
		return(e);
	} else if (v == buf)
		e->bits = search->deftype;

	if ('~' == *v++) {
		if (NULL != strstr(buf, "arch"))
			cs = 0;
		if (0 != (irc = regcomp(&e->regexp, v,
		    REG_EXTENDED | REG_NOSUB | (cs ? 0 : REG_ICASE)))) {
			regerror(irc, &e->regexp, errbuf, sizeof(errbuf));
			fprintf(stderr, "regcomp: %s\n", errbuf);
			free(e);
			return(NULL);
		}
	} else
		e->substr = v;
	v[-1] = '\0';

	/*
	 * Parse out all possible fields.
	 * If the field doesn't resolve, bail.
	 */

	while (NULL != (key = strsep(&buf, ","))) {
		if ('\0' == *key)
			continue;
		for (i = 0, iterbit = 1;
		     i < mansearch_keymax;
		     i++, iterbit <<= 1) {
			if (0 == strcasecmp(key,
			    mansearch_keynames[i])) {
				e->bits |= iterbit;
				break;
			}
		}
		if (i == mansearch_keymax) {
			if (strcasecmp(key, "any")) {
				free(e);
				return(NULL);
			}
			e->bits |= ~0ULL;
		}
	}

	return(e);
}

static void
exprfree(struct expr *p)
{
	struct expr	*pp;

	while (NULL != p) {
		pp = p->next;
		free(p);
		p = pp;
	}
}

static void *
hash_halloc(size_t sz, void *arg)
{

	return(mandoc_calloc(sz, 1));
}

static void *
hash_alloc(size_t sz, void *arg)
{

	return(mandoc_malloc(sz));
}

static void
hash_free(void *p, size_t sz, void *arg)
{

	free(p);
}