mpd/src/song/Filter.hxx
2021-01-01 19:54:28 +01:00

113 lines
2.7 KiB
C++

/*
* Copyright 2003-2021 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.
*/
#ifndef MPD_SONG_FILTER_HXX
#define MPD_SONG_FILTER_HXX
#include "AndSongFilter.hxx"
#include "util/Compiler.h"
#include <cstdint>
#include <string>
#include <string_view>
/**
* Special value for the db_selection_print() sort parameter.
*/
#define SORT_TAG_LAST_MODIFIED (TAG_NUM_OF_ITEM_TYPES + 3)
template<typename T> struct ConstBuffer;
enum TagType : uint8_t;
struct LightSong;
class SongFilter {
AndSongFilter and_filter;
public:
SongFilter() = default;
gcc_nonnull(3)
SongFilter(TagType tag, const char *value, bool fold_case=false);
~SongFilter();
SongFilter(SongFilter &&) = default;
SongFilter &operator=(SongFilter &&) = default;
/**
* Convert this object into an "expression". This is
* only useful for debugging.
*/
std::string ToExpression() const noexcept;
private:
static ISongFilterPtr ParseExpression(const char *&s, bool fold_case=false);
gcc_nonnull(2,3)
void Parse(const char *tag, const char *value, bool fold_case=false);
public:
/**
* Throws on error.
*/
void Parse(ConstBuffer<const char *> args, bool fold_case=false);
void Optimize() noexcept;
gcc_pure
bool Match(const LightSong &song) const noexcept;
const auto &GetItems() const noexcept {
return and_filter.GetItems();
}
gcc_pure
bool IsEmpty() const noexcept {
return and_filter.IsEmpty();
}
/**
* Is there at least one item with "fold case" enabled?
*/
gcc_pure
bool HasFoldCase() const noexcept;
/**
* Does this filter contain constraints other than "base"?
*/
gcc_pure
bool HasOtherThanBase() const noexcept;
/**
* Returns the "base" specification (if there is one) or
* nullptr.
*/
gcc_pure
const char *GetBase() const noexcept;
/**
* Create a copy of the filter with the given prefix stripped
* from all #LOCATE_TAG_BASE_TYPE items. This is used to
* filter songs in mounted databases.
*/
SongFilter WithoutBasePrefix(std::string_view prefix) const noexcept;
};
#endif