/* $Id$ */ /* * 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.h Simple Queue/Hash implementations. */ #ifndef QUEUE_H #define QUEUE_H //#define NOFREE //#define QUEUE_DEBUG //#define HASH_DEBUG //#define HASH_STATS struct Queue; typedef bool Queue_PushProc(Queue *q, void *item, int priority); typedef void *Queue_PopProc(Queue *q); typedef bool Queue_DeleteProc(Queue *q, void *item, int priority); typedef void Queue_ClearProc(Queue *q, bool free_values); typedef void Queue_FreeProc(Queue *q, bool free_values); struct InsSortNode { void *item; int priority; InsSortNode *next; }; struct BinaryHeapNode { void *item; int priority; }; struct Queue { /* * Pushes an element into the queue, at the appropriate place for the queue. * Requires the queue pointer to be of an appropriate type, of course. */ Queue_PushProc *push; /* * Pops the first element from the queue. What exactly is the first element, * is defined by the exact type of queue. */ Queue_PopProc *pop; /* * Deletes the item from the queue. priority should be specified if * known, which speeds up the deleting for some queue's. Should be -1 * if not known. */ Queue_DeleteProc *del; /* Clears the queue, by removing all values from it. It's state is * effectively reset. If free_items is true, each of the items cleared * in this way are free()'d. */ Queue_ClearProc *clear; /* Frees the queue, by reclaiming all memory allocated by it. After * this it is no longer usable. If free_items is true, any remaining * items are free()'d too. */ Queue_FreeProc *free; union { struct { InsSortNode *first; } inssort; struct { uint max_size; uint size; uint blocks; ///< The amount of blocks for which space is reserved in elements BinaryHeapNode **elements; } binaryheap; } data; }; /** * Insertion Sorter */ /* Initializes a inssort and allocates internal memory. There is no maximum * size */ void init_InsSort(Queue *q); /* * Binary Heap * For information, see: * http://www.policyalmanac.org/games/binaryHeaps.htm */ /* The amount of elements that will be malloc'd at a time */ #define BINARY_HEAP_BLOCKSIZE_BITS 10 /** Initializes a binary heap and allocates internal memory for maximum of * max_size elements */ void init_BinaryHeap(Queue *q, uint max_size); /* * Hash */ struct HashNode { uint key1; uint key2; void *value; HashNode *next; }; /** * Generates a hash code from the given key pair. You should make sure that * the resulting range is clearly defined. */ typedef uint Hash_HashProc(uint key1, uint key2); struct Hash { /* The hash function used */ Hash_HashProc *hash; /* The amount of items in the hash */ uint size; /* The number of buckets allocated */ uint num_buckets; /* A pointer to an array of num_buckets buckets. */ HashNode *buckets; /* A pointer to an array of numbuckets booleans, which will be true if * there are any Nodes in the bucket */ bool *buckets_in_use; }; /* Call these function to manipulate a hash */ /** Deletes the value with the specified key pair from the hash and returns * that value. Returns NULL when the value was not present. The value returned * is _not_ free()'d! */ void *Hash_Delete(Hash *h, uint key1, uint key2); /** Sets the value associated with the given key pair to the given value. * Returns the old value if the value was replaced, NULL when it was not yet present. */ void *Hash_Set(Hash *h, uint key1, uint key2, void *value); /** Gets the value associated with the given key pair, or NULL when it is not * present. */ void *Hash_Get(const Hash *h, uint key1, uint key2); /* Call these function to create/destroy a hash */ /** Builds a new hash in an existing struct. Make sure that hash() always * returns a hash less than num_buckets! Call delete_hash after use */ void init_Hash(Hash *h, Hash_HashProc *hash, uint num_buckets); /** * Deletes the hash and cleans up. Only cleans up memory allocated by new_Hash * & friends. If free is true, it will call free() on all the values that * are left in the hash. */ void delete_Hash(Hash *h, bool free_values); /** * Cleans the hash, but keeps the memory allocated */ void clear_Hash(Hash *h, bool free_values); /** * Gets the current size of the Hash */ uint Hash_Size(const Hash *h); #endif /* QUEUE_H */