mpd/src/SongFilter.cxx

/*
 * Copyright (C) 2003-2012 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "SongFilter.hxx"
#include "Song.hxx"
#include "tag/Tag.hxx"

#include <glib.h>

#include <assert.h>
#include <string.h>
#include <stdlib.h>

#define LOCATE_TAG_FILE_KEY     "file"
#define LOCATE_TAG_FILE_KEY_OLD "filename"
#define LOCATE_TAG_ANY_KEY      "any"

unsigned
locate_parse_type(const char *str)
{
	if (0 == g_ascii_strcasecmp(str, LOCATE_TAG_FILE_KEY) ||
	    0 == g_ascii_strcasecmp(str, LOCATE_TAG_FILE_KEY_OLD))
		return LOCATE_TAG_FILE_TYPE;

	if (0 == g_ascii_strcasecmp(str, LOCATE_TAG_ANY_KEY))
		return LOCATE_TAG_ANY_TYPE;

	return tag_name_parse_i(str);
}

SongFilter::Item::Item(unsigned _tag, const char *_value, bool _fold_case)
	:tag(_tag), fold_case(_fold_case),
	 value(fold_case
	       ? g_utf8_casefold(_value, -1)
	       : g_strdup(_value))
{
}

SongFilter::Item::~Item()
{
	g_free(value);
}

bool
SongFilter::Item::StringMatch(const char *s) const
{
	assert(value != nullptr);
	assert(s != nullptr);

	if (fold_case) {
		char *p = g_utf8_casefold(s, -1);
		const bool result = strstr(p, value) != NULL;
		g_free(p);
		return result;
	} else {
		return strcmp(s, value) == 0;
	}
}

bool
SongFilter::Item::Match(const TagItem &item) const
{
	return (tag == LOCATE_TAG_ANY_TYPE || (unsigned)item.type == tag) &&
		StringMatch(item.value);
}

bool
SongFilter::Item::Match(const Tag &_tag) const
{
	bool visited_types[TAG_NUM_OF_ITEM_TYPES];
	std::fill_n(visited_types, TAG_NUM_OF_ITEM_TYPES, false);

	for (unsigned i = 0; i < _tag.num_items; i++) {
		visited_types[_tag.items[i]->type] = true;

		if (Match(*_tag.items[i]))
			return true;
	}

	/** If the search critieron was not visited during the sweep
	 * through the song's tag, it means this field is absent from
	 * the tag or empty. Thus, if the searched string is also
	 *  empty (first char is a \0), then it's a match as well and
	 *  we should return true.
	 */
	if (*value == 0 && tag < TAG_NUM_OF_ITEM_TYPES &&
	    !visited_types[tag])
		return true;

	return false;
}

bool
SongFilter::Item::Match(const Song &song) const
{
	if (tag == LOCATE_TAG_FILE_TYPE || tag == LOCATE_TAG_ANY_TYPE) {
		char *uri = song.GetURI();
		const bool result = StringMatch(uri);
		g_free(uri);

		if (result || tag == LOCATE_TAG_FILE_TYPE)
			return result;
	}

	return song.tag != NULL && Match(*song.tag);
}

SongFilter::SongFilter(unsigned tag, const char *value, bool fold_case)
{
	items.push_back(Item(tag, value, fold_case));
}

SongFilter::~SongFilter()
{
	/* this destructor exists here just so it won't get inlined */
}

bool
SongFilter::Parse(const char *tag_string, const char *value, bool fold_case)
{
	unsigned tag = locate_parse_type(tag_string);
	if (tag == TAG_NUM_OF_ITEM_TYPES)
		return false;

	items.push_back(Item(tag, value, fold_case));
	return true;
}

bool
SongFilter::Parse(unsigned argc, char *argv[], bool fold_case)
{
	if (argc == 0 || argc % 2 != 0)
		return false;

	for (unsigned i = 0; i < argc; i += 2)
		if (!Parse(argv[i], argv[i + 1], fold_case))
			return false;

	return true;
}

bool
SongFilter::Match(const Song &song) const
{
	for (const auto &i : items)
		if (!i.Match(song))
			return false;

	return true;
}