A queue of songs. More...

#include <Queue.hxx>

Collaboration diagram for Queue:

Data Structures
struct	Item
	One element of the queue: basically a song plus some queue specific information attached. More...

Public Member Functions
	Queue (unsigned max_length)

	~Queue ()
	Deinitializes a queue object. More...

	Queue (const Queue &)=delete

Queue &	operator= (const Queue &)=delete

unsigned	GetLength () const

bool	IsEmpty () const
	Determine if the queue is empty, i.e. More...

bool	IsFull () const
	Determine if the maximum number of songs has been reached. More...

bool	IsValidPosition (unsigned position) const
	Is that a valid position number? More...

bool	IsValidOrder (unsigned _order) const
	Is that a valid order number? More...

int	IdToPosition (unsigned id) const

int	PositionToId (unsigned position) const

gcc_pure unsigned	OrderToPosition (unsigned _order) const

gcc_pure unsigned	PositionToOrder (unsigned position) const

gcc_pure uint8_t	GetPriorityAtPosition (unsigned position) const

const Item &	GetOrderItem (unsigned i) const

uint8_t	GetOrderPriority (unsigned i) const

DetachedSong &	Get (unsigned position) const
	Returns the song at the specified position. More...

DetachedSong &	GetOrder (unsigned _order) const
	Returns the song at the specified order number. More...

bool	IsNewerAtPosition (unsigned position, uint32_t _version) const
	Is the song at the specified position newer than the specified version? More...

gcc_pure int	GetNextOrder (unsigned order) const
	Returns the order number following the specified one. More...

void	IncrementVersion ()
	Increments the queue's version number. More...

void	ModifyAtPosition (unsigned position)
	Marks the specified song as "modified". More...

void	ModifyAtOrder (unsigned order)
	Marks the specified song as "modified". More...

unsigned	Append (DetachedSong &&song, uint8_t priority)
	Appends a song to the queue and returns its position. More...

void	SwapPositions (unsigned position1, unsigned position2)
	Swaps two songs, addressed by their position. More...

void	SwapOrders (unsigned order1, unsigned order2)
	Swaps two songs, addressed by their order number. More...

void	MoveOrder (unsigned from_order, unsigned to_order)
	Moves a song to a new position in the "order" list. More...

void	MovePostion (unsigned from, unsigned to)
	Moves a song to a new position. More...

void	MoveRange (unsigned start, unsigned end, unsigned to)
	Moves a range of songs to a new position. More...

void	DeletePosition (unsigned position)
	Removes a song from the playlist. More...

void	Clear ()
	Removes all songs from the playlist. More...

void	RestoreOrder ()
	Initializes the "order" array, and restores "normal" order. More...

void	ShuffleOrderRange (unsigned start, unsigned end)
	Shuffle the order of items in the specified range, ignoring their priorities. More...

void	ShuffleOrderRangeWithPriority (unsigned start, unsigned end)
	Shuffle the order of items in the specified range, taking their priorities into account. More...

void	ShuffleOrder ()
	Shuffles the virtual order of songs, but does not move them physically. More...

void	ShuffleOrderFirst (unsigned start, unsigned end)

void	ShuffleOrderLast (unsigned start, unsigned end)
	Shuffles the virtual order of the last song in the specified (order) range. More...

void	ShuffleRange (unsigned start, unsigned end)
	Shuffles a (position) range in the queue. More...

bool	SetPriority (unsigned position, uint8_t priority, int after_order, bool reorder=true)

bool	SetPriorityRange (unsigned start_position, unsigned end_position, uint8_t priority, int after_order)

Data Fields
unsigned	max_length
	configured maximum length of the queue More...

unsigned	length
	number of songs in the queue More...

uint32_t	version
	the current version number More...

Item *	items
	all songs in "position" order More...

unsigned *	order
	map order numbers to positions More...

IdTable	id_table
	map song ids to positions More...

bool	repeat
	repeat playback when the end of the queue has been reached? More...

bool	single
	play only current song. More...

bool	consume
	remove each played files. More...

bool	random
	play back songs in random order? More...

LazyRandomEngine	rand
	random number generator for shuffle and random mode More...

Static Public Attributes
static constexpr unsigned	HASH_MULT = 4
	reserve max_length * HASH_MULT elements in the id number space More...

Detailed Description

A queue of songs.

This is the backend of the playlist: it contains an ordered list of songs.

Songs can be addressed in three possible ways:

the position in the queue
the unique id (which stays the same, regardless of moves)
the order number (which only differs from "position" in random mode)

Definition at line 44 of file Queue.hxx.

Constructor & Destructor Documentation

Queue::Queue ( unsigned max_length )

explicit

Queue::~Queue ( )

Deinitializes a queue object.

It does not free the queue pointer itself.

Queue::Queue ( const Queue & )

delete

Member Function Documentation

unsigned Queue::Append	(	DetachedSong &&	song,
		uint8_t	priority
	)

Appends a song to the queue and returns its position.

Prior to that, the caller must check if the queue is already full.

If a song is not in the database (determined by Song::IsInDatabase()), it is freed when removed from the queue.

Parameters

priority the priority of this new queue item

void Queue::Clear ( )

Removes all songs from the playlist.

void Queue::DeletePosition ( unsigned position )

Removes a song from the playlist.

DetachedSong& Queue::Get ( unsigned position ) const

inline

Returns the song at the specified position.

Definition at line 203 of file Queue.hxx.

unsigned Queue::GetLength ( ) const

inline

Definition at line 117 of file Queue.hxx.

gcc_pure int Queue::GetNextOrder ( unsigned order ) const

Returns the order number following the specified one.

This takes end of queue and "repeat" mode into account.

Returns: the next order number, or -1 to stop playback

DetachedSong& Queue::GetOrder ( unsigned _order ) const

inline

Returns the song at the specified order number.

Definition at line 212 of file Queue.hxx.

const Item& Queue::GetOrderItem ( unsigned i ) const

inline

Definition at line 190 of file Queue.hxx.

uint8_t Queue::GetOrderPriority ( unsigned i ) const

inline

Definition at line 196 of file Queue.hxx.

gcc_pure uint8_t Queue::GetPriorityAtPosition ( unsigned position ) const

inline

Definition at line 184 of file Queue.hxx.

int Queue::IdToPosition ( unsigned id ) const

inline

Definition at line 153 of file Queue.hxx.

void Queue::IncrementVersion ( )

Increments the queue's version number.

This handles integer overflow well.

bool Queue::IsEmpty ( ) const

inline

Determine if the queue is empty, i.e.

there are no songs.

Definition at line 126 of file Queue.hxx.

bool Queue::IsFull ( ) const

inline

Determine if the maximum number of songs has been reached.

Definition at line 133 of file Queue.hxx.

bool Queue::IsNewerAtPosition	(	unsigned	position,
		uint32_t	_version
	)		const

inline

Is the song at the specified position newer than the specified version?

Definition at line 220 of file Queue.hxx.

bool Queue::IsValidOrder ( unsigned _order ) const

inline

Is that a valid order number?

Definition at line 149 of file Queue.hxx.

bool Queue::IsValidPosition ( unsigned position ) const

inline

Is that a valid position number?

Definition at line 142 of file Queue.hxx.

void Queue::ModifyAtOrder ( unsigned order )

Marks the specified song as "modified".

Call IncrementVersion() after all modifications have been made. number.

void Queue::ModifyAtPosition ( unsigned position )

inline

Marks the specified song as "modified".

Call IncrementVersion() after all modifications have been made. number.

Definition at line 248 of file Queue.hxx.

void Queue::MoveOrder	(	unsigned	from_order,
		unsigned	to_order
	)

Moves a song to a new position in the "order" list.

void Queue::MovePostion	(	unsigned	from,
		unsigned	to
	)

Moves a song to a new position.

void Queue::MoveRange	(	unsigned	start,
		unsigned	end,
		unsigned	to
	)

Moves a range of songs to a new position.

Queue& Queue::operator= ( const Queue & )

delete

gcc_pure unsigned Queue::OrderToPosition ( unsigned _order ) const

inline

Definition at line 165 of file Queue.hxx.

int Queue::PositionToId ( unsigned position ) const

inline

Definition at line 157 of file Queue.hxx.

gcc_pure unsigned Queue::PositionToOrder ( unsigned position ) const

inline

Definition at line 172 of file Queue.hxx.

void Queue::RestoreOrder ( )

inline

Initializes the "order" array, and restores "normal" order.

Definition at line 313 of file Queue.hxx.

bool Queue::SetPriority	(	unsigned	position,
		uint8_t	priority,
		int	after_order,
		bool	reorder = `true`
	)

bool Queue::SetPriorityRange	(	unsigned	start_position,
		unsigned	end_position,
		uint8_t	priority,
		int	after_order
	)

void Queue::ShuffleOrder ( )

Shuffles the virtual order of songs, but does not move them physically.

This is used in random mode.

void Queue::ShuffleOrderFirst	(	unsigned	start,
		unsigned	end
	)

void Queue::ShuffleOrderLast	(	unsigned	start,
		unsigned	end
	)

Shuffles the virtual order of the last song in the specified (order) range.

This is used in random mode after a song has been appended by queue_append().

void Queue::ShuffleOrderRange	(	unsigned	start,
		unsigned	end
	)

Shuffle the order of items in the specified range, ignoring their priorities.

void Queue::ShuffleOrderRangeWithPriority	(	unsigned	start,
		unsigned	end
	)

Shuffle the order of items in the specified range, taking their priorities into account.

void Queue::ShuffleRange	(	unsigned	start,
		unsigned	end
	)

Shuffles a (position) range in the queue.

The songs are physically shuffled, not by using the "order" mapping.

void Queue::SwapOrders	(	unsigned	order1,
		unsigned	order2
	)

inline

Swaps two songs, addressed by their order number.

Definition at line 281 of file Queue.hxx.

void Queue::SwapPositions	(	unsigned	position1,
		unsigned	position2
	)

Swaps two songs, addressed by their position.

Field Documentation

bool Queue::consume

remove each played files.

Definition at line 98 of file Queue.hxx.

constexpr unsigned Queue::HASH_MULT = 4

static

reserve max_length * HASH_MULT elements in the id number space

Definition at line 49 of file Queue.hxx.

IdTable Queue::id_table

map song ids to positions

Definition at line 88 of file Queue.hxx.

Item* Queue::items

all songs in "position" order

Definition at line 82 of file Queue.hxx.

unsigned Queue::length

number of songs in the queue

Definition at line 76 of file Queue.hxx.

unsigned Queue::max_length

configured maximum length of the queue

Definition at line 73 of file Queue.hxx.

unsigned* Queue::order

map order numbers to positions

Definition at line 85 of file Queue.hxx.

LazyRandomEngine Queue::rand

random number generator for shuffle and random mode

Definition at line 104 of file Queue.hxx.

bool Queue::random

play back songs in random order?

Definition at line 101 of file Queue.hxx.

bool Queue::repeat

repeat playback when the end of the queue has been reached?

Definition at line 92 of file Queue.hxx.

bool Queue::single

play only current song.

Definition at line 95 of file Queue.hxx.

uint32_t Queue::version

the current version number

Definition at line 79 of file Queue.hxx.

The documentation for this struct was generated from the following file:

queue/Queue.hxx

Data Structures

Public Member Functions

Data Fields

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Field Documentation