aboutsummaryrefslogblamecommitdiffstats
path: root/src/queue/Queue.cxx
blob: 039af096e1cbd725c64abf8bfaa3c8163c71c90f (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
  
                                                          










                                                                       



                                                                          

   
                   
                    
                           
 
                                  

                                            

                                         
                                          


                        
                      
 

 
               


                

                       


   
                                          
 
                                
 




                                                    







                                           
                         


                                                            
                  
 


                                                     
 
                            



         
                                     
 
                                
 
                                          
                                   

 
        
                                                    
 
                          
 



                                                      
                                                      
                     
                               
                                 
 
                                   




                  
                                                            
 

                                           
 
                                                      
 

                                           
 

                                      

 
    
                                              
 
                                     



                                                
                                     



                                                
                                     


                              
                                  
                        
                                    


                                 








                                                              

                 


    
                                                           
 
                              

                                                
                                          


                                                                                    
                                               



                                                                                                         
                                                  
                                               



                                                           
                                                                 

                                                        

         
                     


                                                                                     







                                                                           



                 
    
                                                        
 

                                    
 
                                                                   


                                                                
                                                

                                                                
                                                

         
                                        

 
    
                                        
 
                                  
 
                                    
 

                                                          
 
                 


                                 
                           


                                          
                                                    
                                     


                                                   

                                                  


                                                


                                             


    
              
 
                                               
                                       
 
                                  
 
                                         

         
                   

 
           
                                                                        
 
                                 
                              

                                     
 
                                                           

                                                           




                                                                        

 
    
                                                      
 
                       
                             
                              
 

                                                       






                                                               
                                                                  
 
                       
                             
                              




                                               
                                                       


                                             
                                                         

                                                    
                                                             




                                                                      
                                                          





                                                  
                                            


    
                     
 
                                                 

 
    
                                                      
 



                                                                             


    
                                                     
 



                                                                             


    
                                                 

                             
                              
 

                          
                                                


                                                                              
                                     

         
 
        
                                                                
                                                      
 

                                      
 

                                                             
                                                    

                                                                     

         
                      

 
        
                                                                      
 

                                      
 

                                                             
                                                    
                                               
                                               

         
                                    


    

                                                                        
 
                                  
 
                                      



                                              
                                

                                  
                                


                                                         
                                                    
                               
                                                    


                                                            
                                                     




                                                                     
                                                             
                                                
                                                       










                                                                   
                                                                     
                                                        

                                  
                                     


                                                         
                                                                               
                                    
                                                                 




                    
                                                                       
                                                          
 
                                               
                                       


                                             
                                                   


                                                                  
                                                              

                             
                                                                  



                        
/*
 * Copyright (C) 2003-2014 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 "Queue.hxx"
#include "DetachedSong.hxx"

Queue::Queue(unsigned _max_length)
	:max_length(_max_length), length(0),
	 version(1),
	 items(new Item[max_length]),
	 order(new unsigned[max_length]),
	 id_table(max_length * HASH_MULT),
	 repeat(false),
	 single(false),
	 consume(false),
	 random(false)
{
}

Queue::~Queue()
{
	Clear();

	delete[] items;
	delete[] order;
}

int
Queue::GetNextOrder(unsigned _order) const
{
	assert(_order < length);

	if (single && repeat && !consume)
		return _order;
	else if (_order + 1 < length)
		return _order + 1;
	else if (repeat && (_order > 0 || !consume))
		/* restart at first song */
		return 0;
	else
		/* end of queue */
		return -1;
}

void
Queue::IncrementVersion()
{
	static unsigned long max = ((uint32_t) 1 << 31) - 1;

	version++;

	if (version >= max) {
		for (unsigned i = 0; i < length; i++)
			items[i].version = 0;

		version = 1;
	}
}

void
Queue::ModifyAtOrder(unsigned _order)
{
	assert(_order < length);

	unsigned position = order[_order];
	ModifyAtPosition(position);
}

unsigned
Queue::Append(DetachedSong &&song, uint8_t priority)
{
	assert(!IsFull());

	const unsigned position = length++;
	const unsigned id = id_table.Insert(position);

	auto &item = items[position];
	item.song = new DetachedSong(std::move(song));
	item.id = id;
	item.version = version;
	item.priority = priority;

	order[position] = position;

	return id;
}

void
Queue::SwapPositions(unsigned position1, unsigned position2)
{
	unsigned id1 = items[position1].id;
	unsigned id2 = items[position2].id;

	std::swap(items[position1], items[position2]);

	items[position1].version = version;
	items[position2].version = version;

	id_table.Move(id1, position2);
	id_table.Move(id2, position1);
}

void
Queue::MovePostion(unsigned from, unsigned to)
{
	const Item tmp = items[from];

	/* move songs to one less in from->to */

	for (unsigned i = from; i < to; i++)
		MoveItemTo(i + 1, i);

	/* move songs to one more in to->from */

	for (unsigned i = from; i > to; i--)
		MoveItemTo(i - 1, i);

	/* put song at _to_ */

	id_table.Move(tmp.id, to);
	items[to] = tmp;
	items[to].version = version;

	/* now deal with order */

	if (random) {
		for (unsigned i = 0; i < length; i++) {
			if (order[i] > from && order[i] <= to)
				order[i]--;
			else if (order[i] < from &&
				 order[i] >= to)
				order[i]++;
			else if (from == order[i])
				order[i] = to;
		}
	}
}

void
Queue::MoveRange(unsigned start, unsigned end, unsigned to)
{
	Item tmp[end - start];
	// Copy the original block [start,end-1]
	for (unsigned i = start; i < end; i++)
		tmp[i - start] = items[i];

	// If to > start, we need to move to-start items to start, starting from end
	for (unsigned i = end; i < end + to - start; i++)
		MoveItemTo(i, start + i - end);

	// If to < start, we need to move start-to items to newend (= end + to - start), starting from to
	// This is the same as moving items from start-1 to to (decreasing), with start-1 going to end-1
	// We have to iterate in this order to avoid writing over something we haven't yet moved
	for (int i = start - 1; i >= int(to); i--)
		MoveItemTo(i, i + end - start);

	// Copy the original block back in, starting at to.
	for (unsigned i = start; i< end; i++)
	{
		id_table.Move(tmp[i - start].id, to + i - start);
		items[to + i - start] = tmp[i-start];
		items[to + i - start].version = version;
	}

	if (random) {
		// Update the positions in the queue.
		// Note that the ranges for these cases are the same as the ranges of
		// the loops above.
		for (unsigned i = 0; i < length; i++) {
			if (order[i] >= end && order[i] < to + end - start)
				order[i] -= end - start;
			else if (order[i] < start &&
				 order[i] >= to)
				order[i] += end - start;
			else if (start <= order[i] && order[i] < end)
				order[i] += to - start;
		}
	}
}

void
Queue::MoveOrder(unsigned from_order, unsigned to_order)
{
	assert(from_order < length);
	assert(to_order <= length);

	const unsigned from_position = OrderToPosition(from_order);

	if (from_order < to_order) {
		for (unsigned i = from_order; i < to_order; ++i)
			order[i] = order[i + 1];
	} else {
		for (unsigned i = from_order; i > to_order; --i)
			order[i] = order[i - 1];
	}

	order[to_order] = from_position;
}

void
Queue::DeletePosition(unsigned position)
{
	assert(position < length);

	delete items[position].song;

	const unsigned id = PositionToId(position);
	const unsigned _order = PositionToOrder(position);

	--length;

	/* release the song id */

	id_table.Erase(id);

	/* delete song from songs array */

	for (unsigned i = position; i < length; i++)
		MoveItemTo(i + 1, i);

	/* delete the entry from the order array */

	for (unsigned i = _order; i < length; i++)
		order[i] = order[i + 1];

	/* readjust values in the order array */

	for (unsigned i = 0; i < length; i++)
		if (order[i] > position)
			--order[i];
}

void
Queue::Clear()
{
	for (unsigned i = 0; i < length; i++) {
		Item *item = &items[i];

		delete item->song;

		id_table.Erase(item->id);
	}

	length = 0;
}

static void
queue_sort_order_by_priority(Queue *queue, unsigned start, unsigned end)
{
	assert(queue != nullptr);
	assert(queue->random);
	assert(start <= end);
	assert(end <= queue->length);

	auto cmp = [queue](unsigned a_pos, unsigned b_pos){
		const Queue::Item &a = queue->items[a_pos];
		const Queue::Item &b = queue->items[b_pos];

		return a.priority > b.priority;
	};

	std::stable_sort(queue->order + start, queue->order + end, cmp);
}

void
Queue::ShuffleOrderRange(unsigned start, unsigned end)
{
	assert(random);
	assert(start <= end);
	assert(end <= length);

	rand.AutoCreate();
	std::shuffle(order + start, order + end, rand);
}

/**
 * Sort the "order" of items by priority, and then shuffle each
 * priority group.
 */
void
Queue::ShuffleOrderRangeWithPriority(unsigned start, unsigned end)
{
	assert(random);
	assert(start <= end);
	assert(end <= length);

	if (start == end)
		return;

	/* first group the range by priority */
	queue_sort_order_by_priority(this, start, end);

	/* now shuffle each priority group */
	unsigned group_start = start;
	uint8_t group_priority = GetOrderPriority(start);

	for (unsigned i = start + 1; i < end; ++i) {
		const uint8_t priority = GetOrderPriority(i);
		assert(priority <= group_priority);

		if (priority != group_priority) {
			/* start of a new group - shuffle the one that
			   has just ended */
			ShuffleOrderRange(group_start, i);
			group_start = i;
			group_priority = priority;
		}
	}

	/* shuffle the last group */
	ShuffleOrderRange(group_start, end);
}

void
Queue::ShuffleOrder()
{
	ShuffleOrderRangeWithPriority(0, length);
}

void
Queue::ShuffleOrderFirst(unsigned start, unsigned end)
{
	rand.AutoCreate();

	std::uniform_int_distribution<unsigned> distribution(start, end - 1);
	SwapOrders(start, distribution(rand));
}

void
Queue::ShuffleOrderLast(unsigned start, unsigned end)
{
	rand.AutoCreate();

	std::uniform_int_distribution<unsigned> distribution(start, end - 1);
	SwapOrders(end - 1, distribution(rand));
}

void
Queue::ShuffleRange(unsigned start, unsigned end)
{
	assert(start <= end);
	assert(end <= length);

	rand.AutoCreate();

	for (unsigned i = start; i < end; i++) {
		std::uniform_int_distribution<unsigned> distribution(start,
								     end - 1);
		unsigned ri = distribution(rand);
		SwapPositions(i, ri);
	}
}

unsigned
Queue::FindPriorityOrder(unsigned start_order, uint8_t priority,
			 unsigned exclude_order) const
{
	assert(random);
	assert(start_order <= length);

	for (unsigned i = start_order; i < length; ++i) {
		const unsigned position = OrderToPosition(i);
		const Item *item = &items[position];
		if (item->priority <= priority && i != exclude_order)
			return i;
	}

	return length;
}

unsigned
Queue::CountSamePriority(unsigned start_order, uint8_t priority) const
{
	assert(random);
	assert(start_order <= length);

	for (unsigned i = start_order; i < length; ++i) {
		const unsigned position = OrderToPosition(i);
		const Item *item = &items[position];
		if (item->priority != priority)
			return i - start_order;
	}

	return length - start_order;
}

bool
Queue::SetPriority(unsigned position, uint8_t priority, int after_order,
		   bool reorder)
{
	assert(position < length);

	Item *item = &items[position];
	uint8_t old_priority = item->priority;
	if (old_priority == priority)
		return false;

	item->version = version;
	item->priority = priority;

	if (!random || !reorder)
		/* don't reorder if not in random mode */
		return true;

	unsigned _order = PositionToOrder(position);
	if (after_order >= 0) {
		if (_order == (unsigned)after_order)
			/* don't reorder the current song */
			return true;

		if (_order < (unsigned)after_order) {
			/* the specified song has been played already
			   - enqueue it only if its priority has just
			   become bigger than the current one's */

			const unsigned after_position =
				OrderToPosition(after_order);
			const Item *after_item =
				&items[after_position];
			if (old_priority > after_item->priority ||
			    priority <= after_item->priority)
				/* priority hasn't become bigger */
				return true;
		}
	}

	/* move the item to the beginning of the priority group (or
	   create a new priority group) */

	const unsigned before_order =
		FindPriorityOrder(after_order + 1, priority, _order);
	const unsigned new_order = before_order > _order
		? before_order - 1
		: before_order;
	MoveOrder(_order, new_order);

	/* shuffle the song within that priority group */

	const unsigned priority_count = CountSamePriority(new_order, priority);
	assert(priority_count >= 1);
	ShuffleOrderFirst(new_order, new_order + priority_count);

	return true;
}

bool
Queue::SetPriorityRange(unsigned start_position, unsigned end_position,
			uint8_t priority, int after_order)
{
	assert(start_position <= end_position);
	assert(end_position <= length);

	bool modified = false;
	int after_position = after_order >= 0
		? (int)OrderToPosition(after_order)
		: -1;
	for (unsigned i = start_position; i < end_position; ++i) {
		after_order = after_position >= 0
			? (int)PositionToOrder(after_position)
			: -1;

		modified |= SetPriority(i, priority, after_order);
	}

	return modified;
}