File diff r13824:e07224f20e59 → r13825:5de0a5d39b9e
src/pathfinder/npf/queue.cpp
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new file 100644
 
/* $Id$ */
 

	
 
/*
 
 * This file is part of OpenTTD.
 
 * OpenTTD 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, version 2.
 
 * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 
 */
 

	
 
/** @file queue.cpp Implementation of the Queue/Hash. */
 

	
 
#include "../../stdafx.h"
 
#include "../../core/alloc_func.hpp"
 
#include "queue.h"
 

	
 

	
 
/*
 
 * Insertion Sorter
 
 */
 

	
 
static void InsSort_Clear(Queue *q, bool free_values)
 
{
 
	InsSortNode *node = q->data.inssort.first;
 
	InsSortNode *prev;
 

	
 
	while (node != NULL) {
 
		if (free_values) free(node->item);
 
		prev = node;
 
		node = node->next;
 
		free(prev);
 
	}
 
	q->data.inssort.first = NULL;
 
}
 

	
 
static void InsSort_Free(Queue *q, bool free_values)
 
{
 
	q->clear(q, free_values);
 
}
 

	
 
static bool InsSort_Push(Queue *q, void *item, int priority)
 
{
 
	InsSortNode *newnode = MallocT<InsSortNode>(1);
 

	
 
	newnode->item = item;
 
	newnode->priority = priority;
 
	if (q->data.inssort.first == NULL ||
 
			q->data.inssort.first->priority >= priority) {
 
		newnode->next = q->data.inssort.first;
 
		q->data.inssort.first = newnode;
 
	} else {
 
		InsSortNode *node = q->data.inssort.first;
 
		while (node != NULL) {
 
			if (node->next == NULL || node->next->priority >= priority) {
 
				newnode->next = node->next;
 
				node->next = newnode;
 
				break;
 
			}
 
			node = node->next;
 
		}
 
	}
 
	return true;
 
}
 

	
 
static void *InsSort_Pop(Queue *q)
 
{
 
	InsSortNode *node = q->data.inssort.first;
 
	void *result;
 

	
 
	if (node == NULL) return NULL;
 
	result = node->item;
 
	q->data.inssort.first = q->data.inssort.first->next;
 
	assert(q->data.inssort.first == NULL || q->data.inssort.first->priority >= node->priority);
 
	free(node);
 
	return result;
 
}
 

	
 
static bool InsSort_Delete(Queue *q, void *item, int priority)
 
{
 
	return false;
 
}
 

	
 
void init_InsSort(Queue *q)
 
{
 
	q->push = InsSort_Push;
 
	q->pop = InsSort_Pop;
 
	q->del = InsSort_Delete;
 
	q->clear = InsSort_Clear;
 
	q->free = InsSort_Free;
 
	q->data.inssort.first = NULL;
 
}
 

	
 

	
 
/*
 
 * Binary Heap
 
 * For information, see: http://www.policyalmanac.org/games/binaryHeaps.htm
 
 */
 

	
 
#define BINARY_HEAP_BLOCKSIZE (1 << BINARY_HEAP_BLOCKSIZE_BITS)
 
#define BINARY_HEAP_BLOCKSIZE_MASK (BINARY_HEAP_BLOCKSIZE - 1)
 

	
 
/* To make our life easy, we make the next define
 
 *  Because Binary Heaps works with array from 1 to n,
 
 *  and C with array from 0 to n-1, and we don't like typing
 
 *  q->data.binaryheap.elements[i - 1] every time, we use this define. */
 
#define BIN_HEAP_ARR(i) q->data.binaryheap.elements[((i) - 1) >> BINARY_HEAP_BLOCKSIZE_BITS][((i) - 1) & BINARY_HEAP_BLOCKSIZE_MASK]
 

	
 
static void BinaryHeap_Clear(Queue *q, bool free_values)
 
{
 
	/* Free all items if needed and free all but the first blocks of memory */
 
	uint i;
 
	uint j;
 

	
 
	for (i = 0; i < q->data.binaryheap.blocks; i++) {
 
		if (q->data.binaryheap.elements[i] == NULL) {
 
			/* No more allocated blocks */
 
			break;
 
		}
 
		/* For every allocated block */
 
		if (free_values) {
 
			for (j = 0; j < (1 << BINARY_HEAP_BLOCKSIZE_BITS); j++) {
 
				/* For every element in the block */
 
				if ((q->data.binaryheap.size >> BINARY_HEAP_BLOCKSIZE_BITS) == i &&
 
						(q->data.binaryheap.size & BINARY_HEAP_BLOCKSIZE_MASK) == j) {
 
					break; // We're past the last element
 
				}
 
				free(q->data.binaryheap.elements[i][j].item);
 
			}
 
		}
 
		if (i != 0) {
 
			/* Leave the first block of memory alone */
 
			free(q->data.binaryheap.elements[i]);
 
			q->data.binaryheap.elements[i] = NULL;
 
		}
 
	}
 
	q->data.binaryheap.size = 0;
 
	q->data.binaryheap.blocks = 1;
 
}
 

	
 
static void BinaryHeap_Free(Queue *q, bool free_values)
 
{
 
	uint i;
 

	
 
	q->clear(q, free_values);
 
	for (i = 0; i < q->data.binaryheap.blocks; i++) {
 
		if (q->data.binaryheap.elements[i] == NULL) break;
 
		free(q->data.binaryheap.elements[i]);
 
	}
 
	free(q->data.binaryheap.elements);
 
}
 

	
 
static bool BinaryHeap_Push(Queue *q, void *item, int priority)
 
{
 
#ifdef QUEUE_DEBUG
 
	printf("[BinaryHeap] Pushing an element. There are %d elements left\n", q->data.binaryheap.size);
 
#endif
 

	
 
	if (q->data.binaryheap.size == q->data.binaryheap.max_size) return false;
 
	assert(q->data.binaryheap.size < q->data.binaryheap.max_size);
 

	
 
	if (q->data.binaryheap.elements[q->data.binaryheap.size >> BINARY_HEAP_BLOCKSIZE_BITS] == NULL) {
 
		/* The currently allocated blocks are full, allocate a new one */
 
		assert((q->data.binaryheap.size & BINARY_HEAP_BLOCKSIZE_MASK) == 0);
 
		q->data.binaryheap.elements[q->data.binaryheap.size >> BINARY_HEAP_BLOCKSIZE_BITS] = MallocT<BinaryHeapNode>(BINARY_HEAP_BLOCKSIZE);
 
		q->data.binaryheap.blocks++;
 
#ifdef QUEUE_DEBUG
 
		printf("[BinaryHeap] Increasing size of elements to %d nodes\n", q->data.binaryheap.blocks *  BINARY_HEAP_BLOCKSIZE);
 
#endif
 
	}
 

	
 
	/* Add the item at the end of the array */
 
	BIN_HEAP_ARR(q->data.binaryheap.size + 1).priority = priority;
 
	BIN_HEAP_ARR(q->data.binaryheap.size + 1).item = item;
 
	q->data.binaryheap.size++;
 

	
 
	/* Now we are going to check where it belongs. As long as the parent is
 
	 * bigger, we switch with the parent */
 
	{
 
		BinaryHeapNode temp;
 
		int i;
 
		int j;
 

	
 
		i = q->data.binaryheap.size;
 
		while (i > 1) {
 
			/* Get the parent of this object (divide by 2) */
 
			j = i / 2;
 
			/* Is the parent bigger then the current, switch them */
 
			if (BIN_HEAP_ARR(i).priority <= BIN_HEAP_ARR(j).priority) {
 
				temp = BIN_HEAP_ARR(j);
 
				BIN_HEAP_ARR(j) = BIN_HEAP_ARR(i);
 
				BIN_HEAP_ARR(i) = temp;
 
				i = j;
 
			} else {
 
				/* It is not, we're done! */
 
				break;
 
			}
 
		}
 
	}
 

	
 
	return true;
 
}
 

	
 
static bool BinaryHeap_Delete(Queue *q, void *item, int priority)
 
{
 
	uint i = 0;
 

	
 
#ifdef QUEUE_DEBUG
 
	printf("[BinaryHeap] Deleting an element. There are %d elements left\n", q->data.binaryheap.size);
 
#endif
 

	
 
	/* First, we try to find the item.. */
 
	do {
 
		if (BIN_HEAP_ARR(i + 1).item == item) break;
 
		i++;
 
	} while (i < q->data.binaryheap.size);
 
	/* We did not find the item, so we return false */
 
	if (i == q->data.binaryheap.size) return false;
 

	
 
	/* Now we put the last item over the current item while decreasing the size of the elements */
 
	q->data.binaryheap.size--;
 
	BIN_HEAP_ARR(i + 1) = BIN_HEAP_ARR(q->data.binaryheap.size + 1);
 

	
 
	/* Now the only thing we have to do, is resort it..
 
	 * On place i there is the item to be sorted.. let's start there */
 
	{
 
		uint j;
 
		BinaryHeapNode temp;
 
		/* Because of the fact that Binary Heap uses array from 1 to n, we need to
 
		 * increase i by 1
 
		 */
 
		i++;
 

	
 
		for (;;) {
 
			j = i;
 
			/* Check if we have 2 childs */
 
			if (2 * j + 1 <= q->data.binaryheap.size) {
 
				/* Is this child smaller than the parent? */
 
				if (BIN_HEAP_ARR(j).priority >= BIN_HEAP_ARR(2 * j).priority) i = 2 * j;
 
				/* Yes, we _need_ to use i here, not j, because we want to have the smallest child
 
				 *  This way we get that straight away! */
 
				if (BIN_HEAP_ARR(i).priority >= BIN_HEAP_ARR(2 * j + 1).priority) i = 2 * j + 1;
 
			/* Do we have one child? */
 
			} else if (2 * j <= q->data.binaryheap.size) {
 
				if (BIN_HEAP_ARR(j).priority >= BIN_HEAP_ARR(2 * j).priority) i = 2 * j;
 
			}
 

	
 
			/* One of our childs is smaller than we are, switch */
 
			if (i != j) {
 
				temp = BIN_HEAP_ARR(j);
 
				BIN_HEAP_ARR(j) = BIN_HEAP_ARR(i);
 
				BIN_HEAP_ARR(i) = temp;
 
			} else {
 
				/* None of our childs is smaller, so we stay here.. stop :) */
 
				break;
 
			}
 
		}
 
	}
 

	
 
	return true;
 
}
 

	
 
static void *BinaryHeap_Pop(Queue *q)
 
{
 
	void *result;
 

	
 
#ifdef QUEUE_DEBUG
 
	printf("[BinaryHeap] Popping an element. There are %d elements left\n", q->data.binaryheap.size);
 
#endif
 

	
 
	if (q->data.binaryheap.size == 0) return NULL;
 

	
 
	/* The best item is always on top, so give that as result */
 
	result = BIN_HEAP_ARR(1).item;
 
	/* And now we should get rid of this item... */
 
	BinaryHeap_Delete(q, BIN_HEAP_ARR(1).item, BIN_HEAP_ARR(1).priority);
 

	
 
	return result;
 
}
 

	
 
void init_BinaryHeap(Queue *q, uint max_size)
 
{
 
	assert(q != NULL);
 
	q->push = BinaryHeap_Push;
 
	q->pop = BinaryHeap_Pop;
 
	q->del = BinaryHeap_Delete;
 
	q->clear = BinaryHeap_Clear;
 
	q->free = BinaryHeap_Free;
 
	q->data.binaryheap.max_size = max_size;
 
	q->data.binaryheap.size = 0;
 
	/* We malloc memory in block of BINARY_HEAP_BLOCKSIZE
 
	 *   It autosizes when it runs out of memory */
 
	q->data.binaryheap.elements = CallocT<BinaryHeapNode*>((max_size - 1) / BINARY_HEAP_BLOCKSIZE + 1);
 
	q->data.binaryheap.elements[0] = MallocT<BinaryHeapNode>(BINARY_HEAP_BLOCKSIZE);
 
	q->data.binaryheap.blocks = 1;
 
#ifdef QUEUE_DEBUG
 
	printf("[BinaryHeap] Initial size of elements is %d nodes\n", BINARY_HEAP_BLOCKSIZE);
 
#endif
 
}
 

	
 
/* Because we don't want anyone else to bother with our defines */
 
#undef BIN_HEAP_ARR
 

	
 
/*
 
 * Hash
 
 */
 

	
 
void init_Hash(Hash *h, Hash_HashProc *hash, uint num_buckets)
 
{
 
	/* Allocate space for the Hash, the buckets and the bucket flags */
 
	uint i;
 

	
 
	assert(h != NULL);
 
#ifdef HASH_DEBUG
 
	debug("Allocated hash: %p", h);
 
#endif
 
	h->hash = hash;
 
	h->size = 0;
 
	h->num_buckets = num_buckets;
 
	h->buckets = (HashNode*)MallocT<byte>(num_buckets * (sizeof(*h->buckets) + sizeof(*h->buckets_in_use)));
 
#ifdef HASH_DEBUG
 
	debug("Buckets = %p", h->buckets);
 
#endif
 
	h->buckets_in_use = (bool*)(h->buckets + num_buckets);
 
	for (i = 0; i < num_buckets; i++) h->buckets_in_use[i] = false;
 
}
 

	
 

	
 
void delete_Hash(Hash *h, bool free_values)
 
{
 
	uint i;
 

	
 
	/* Iterate all buckets */
 
	for (i = 0; i < h->num_buckets; i++) {
 
		if (h->buckets_in_use[i]) {
 
			HashNode *node;
 

	
 
			/* Free the first value */
 
			if (free_values) free(h->buckets[i].value);
 
			node = h->buckets[i].next;
 
			while (node != NULL) {
 
				HashNode *prev = node;
 

	
 
				node = node->next;
 
				/* Free the value */
 
				if (free_values) free(prev->value);
 
				/* Free the node */
 
				free(prev);
 
			}
 
		}
 
	}
 
	free(h->buckets);
 
	/* No need to free buckets_in_use, it is always allocated in one
 
	 * malloc with buckets */
 
#ifdef HASH_DEBUG
 
	debug("Freeing Hash: %p", h);
 
#endif
 
}
 

	
 
#ifdef HASH_STATS
 
static void stat_Hash(const Hash *h)
 
{
 
	uint used_buckets = 0;
 
	uint max_collision = 0;
 
	uint max_usage = 0;
 
	uint usage[200];
 
	uint i;
 

	
 
	for (i = 0; i < lengthof(usage); i++) usage[i] = 0;
 
	for (i = 0; i < h->num_buckets; i++) {
 
		uint collision = 0;
 
		if (h->buckets_in_use[i]) {
 
			const HashNode *node;
 

	
 
			used_buckets++;
 
			for (node = &h->buckets[i]; node != NULL; node = node->next) collision++;
 
			if (collision > max_collision) max_collision = collision;
 
		}
 
		if (collision >= lengthof(usage)) collision = lengthof(usage) - 1;
 
		usage[collision]++;
 
		if (collision > 0 && usage[collision] >= max_usage) {
 
			max_usage = usage[collision];
 
		}
 
	}
 
	printf(
 
		"---\n"
 
		"Hash size: %d\n"
 
		"Nodes used: %d\n"
 
		"Non empty buckets: %d\n"
 
		"Max collision: %d\n",
 
		h->num_buckets, h->size, used_buckets, max_collision
 
	);
 
	printf("{ ");
 
	for (i = 0; i <= max_collision; i++) {
 
		if (usage[i] > 0) {
 
			printf("%d:%d ", i, usage[i]);
 
#if 0
 
			if (i > 0) {
 
				uint j;
 

	
 
				for (j = 0; j < usage[i] * 160 / 800; j++) putchar('#');
 
			}
 
			printf("\n");
 
#endif
 
		}
 
	}
 
	printf ("}\n");
 
}
 
#endif
 

	
 
void clear_Hash(Hash *h, bool free_values)
 
{
 
	uint i;
 

	
 
#ifdef HASH_STATS
 
	if (h->size > 2000) stat_Hash(h);
 
#endif
 

	
 
	/* Iterate all buckets */
 
	for (i = 0; i < h->num_buckets; i++) {
 
		if (h->buckets_in_use[i]) {
 
			HashNode *node;
 

	
 
			h->buckets_in_use[i] = false;
 
			/* Free the first value */
 
			if (free_values) free(h->buckets[i].value);
 
			node = h->buckets[i].next;
 
			while (node != NULL) {
 
				HashNode *prev = node;
 

	
 
				node = node->next;
 
				if (free_values) free(prev->value);
 
				free(prev);
 
			}
 
		}
 
	}
 
	h->size = 0;
 
}
 

	
 
/** Finds the node that that saves this key pair. If it is not
 
 * found, returns NULL. If it is found, *prev is set to the
 
 * node before the one found, or if the node found was the first in the bucket
 
 * to NULL. If it is not found, *prev is set to the last HashNode in the
 
 * bucket, or NULL if it is empty. prev can also be NULL, in which case it is
 
 * not used for output.
 
 */
 
static HashNode *Hash_FindNode(const Hash *h, uint key1, uint key2, HashNode** prev_out)
 
{
 
	uint hash = h->hash(key1, key2);
 
	HashNode *result = NULL;
 

	
 
#ifdef HASH_DEBUG
 
	debug("Looking for %u, %u", key1, key2);
 
#endif
 
	/* Check if the bucket is empty */
 
	if (!h->buckets_in_use[hash]) {
 
		if (prev_out != NULL) *prev_out = NULL;
 
		result = NULL;
 
	/* Check the first node specially */
 
	} else if (h->buckets[hash].key1 == key1 && h->buckets[hash].key2 == key2) {
 
		/* Save the value */
 
		result = h->buckets + hash;
 
		if (prev_out != NULL) *prev_out = NULL;
 
#ifdef HASH_DEBUG
 
		debug("Found in first node: %p", result);
 
#endif
 
	/* Check all other nodes */
 
	} else {
 
		HashNode *prev = h->buckets + hash;
 
		HashNode *node;
 

	
 
		for (node = prev->next; node != NULL; node = node->next) {
 
			if (node->key1 == key1 && node->key2 == key2) {
 
				/* Found it */
 
				result = node;
 
#ifdef HASH_DEBUG
 
				debug("Found in other node: %p", result);
 
#endif
 
				break;
 
			}
 
			prev = node;
 
		}
 
		if (prev_out != NULL) *prev_out = prev;
 
	}
 
#ifdef HASH_DEBUG
 
	if (result == NULL) debug("Not found");
 
#endif
 
	return result;
 
}
 

	
 
void *Hash_Delete(Hash *h, uint key1, uint key2)
 
{
 
	void *result;
 
	HashNode *prev; // Used as output var for below function call
 
	HashNode *node = Hash_FindNode(h, key1, key2, &prev);
 

	
 
	if (node == NULL) {
 
		/* not found */
 
		result = NULL;
 
	} else if (prev == NULL) {
 
		/* It is in the first node, we can't free that one, so we free
 
		 * the next one instead (if there is any)*/
 
		/* Save the value */
 
		result = node->value;
 
		if (node->next != NULL) {
 
			HashNode *next = node->next;
 
			/* Copy the second to the first */
 
			*node = *next;
 
			/* Free the second */
 
#ifndef NOFREE
 
			free(next);
 
#endif
 
		} else {
 
			/* This was the last in this bucket
 
			 * Mark it as empty */
 
			uint hash = h->hash(key1, key2);
 
			h->buckets_in_use[hash] = false;
 
		}
 
	} else {
 
		/* It is in another node
 
		 * Save the value */
 
		result = node->value;
 
		/* Link previous and next nodes */
 
		prev->next = node->next;
 
		/* Free the node */
 
#ifndef NOFREE
 
		free(node);
 
#endif
 
	}
 
	if (result != NULL) h->size--;
 
	return result;
 
}
 

	
 

	
 
void *Hash_Set(Hash *h, uint key1, uint key2, void *value)
 
{
 
	HashNode *prev;
 
	HashNode *node = Hash_FindNode(h, key1, key2, &prev);
 

	
 
	if (node != NULL) {
 
		/* Found it */
 
		void *result = node->value;
 

	
 
		node->value = value;
 
		return result;
 
	}
 
	/* It is not yet present, let's add it */
 
	if (prev == NULL) {
 
		/* The bucket is still empty */
 
		uint hash = h->hash(key1, key2);
 
		h->buckets_in_use[hash] = true;
 
		node = h->buckets + hash;
 
	} else {
 
		/* Add it after prev */
 
		node = MallocT<HashNode>(1);
 
		prev->next = node;
 
	}
 
	node->next = NULL;
 
	node->key1 = key1;
 
	node->key2 = key2;
 
	node->value = value;
 
	h->size++;
 
	return NULL;
 
}
 

	
 
void *Hash_Get(const Hash *h, uint key1, uint key2)
 
{
 
	HashNode *node = Hash_FindNode(h, key1, key2, NULL);
 

	
 
#ifdef HASH_DEBUG
 
	debug("Found node: %p", node);
 
#endif
 
	return (node != NULL) ? node->value : NULL;
 
}
 

	
 
uint Hash_Size(const Hash *h)
 
{
 
	return h->size;
 
}