aboutsummaryrefslogtreecommitdiffstats
path: root/src/Queue.cxx
blob: 99b545ab137c9cdd97dcac30f17b7d56cb39de09 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
/*
 * 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)
{
	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)
		/* 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;
}