107 lines
3.4 KiB
C
107 lines
3.4 KiB
C
/*
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* Copyright (C) 2022-2024 Jordan Bancino <@jordan:bancino.net>
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*
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* Permission is hereby granted, free of charge, to any person
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* obtaining a copy of this software and associated documentation files
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* (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge,
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* publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#ifndef CYTOPLASM_QUEUE_H
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#define CYTOPLASM_QUEUE_H
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/***
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* @Nm Queue
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* @Nd A simple static queue data structure.
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* @Dd November 25 2022
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* @Xr Array HashMap
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*
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* .Nm
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* implements a simple queue data structure that is statically sized.
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* This implementation does not actually store the values of the items
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* in it; it only stores pointers to the data. As such, you will have
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* to manually maintain data and make sure it remains valid as long as
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* it is in the queue. The advantage of this is that
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* .Nm
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* doesn't have to copy data, and thus doesn't care how big the data
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* is. Furthermore, any arbitrary data can be stored in the queue.
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* .Pp
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* This queue implementation operates on the heap. It is a circular
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* queue, and it does not grow as it is used. Once the size is set,
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* the queue never gets any bigger.
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*/
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#include <stddef.h>
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#include <stdbool.h>
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/**
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* These functions operate on a queue structure that is opaque to the
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* caller.
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*/
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typedef struct Queue Queue;
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/**
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* Allocate a new queue that is able to store the specified number of
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* items in it.
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*/
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extern Queue * QueueCreate(size_t);
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/**
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* Free the memory associated with the specified queue structure. Note
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* that this function does not free any of the values stored in the
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* queue; it is the caller's job to manage memory for each item.
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* Typically, the caller would dequeue all the items in the queue and
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* deal with them before freeing the queue itself.
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*/
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extern void QueueFree(Queue *);
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/**
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* Push an element into the queue. This function returns a boolean
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* value indicating whether or not the push succeeded. Pushing items
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* into the queue will fail if the queue is full.
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*/
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extern bool QueuePush(Queue *, void *);
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/**
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* Pop an element out of the queue. This function returns NULL if the
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* queue is empty. Otherwise, it returns a pointer to the item that is
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* next up in the queue.
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*/
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extern void * QueuePop(Queue *);
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/**
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* Retrieve a pointer to the item that is next up in the queue without
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* actually discarding it, such that the next call to
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* .Fn QueuePeek
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* or
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* .Fn QueuePop
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* will return the same pointer.
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*/
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extern void * QueuePeek(Queue *);
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/**
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* Determine whether or not the queue is full.
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*/
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extern bool QueueFull(Queue *);
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/**
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* Determine whether or not the queue is empty.
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*/
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extern bool QueueEmpty(Queue *);
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#endif
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