Queue*: move to queue/

src/queue/Queue.cxx

@@ -0,0 +1,482 @@
+/*
+ * 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;
+}