a simple c queue
Revision 0:8b473c4a0afc, committed 2015-02-14
- Comitter:
- danilob
- Date:
- Sat Feb 14 23:25:22 2015 +0000
- Commit message:
- it has been improved
Changed in this revision
queue.c | Show annotated file Show diff for this revision Revisions of this file |
queue.h | Show annotated file Show diff for this revision Revisions of this file |
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/queue.c Sat Feb 14 23:25:22 2015 +0000 @@ -0,0 +1,198 @@ +/* + * queue.c + * + * Created on: Jan 15, 2015 + * Author: danilob + */ + + +#include <stdio.h> +#include <stdlib.h> +#include "queue.h" + +//auxiliar function to handle the reset of Index in neede for the queue +queue_index_t incrementIndex(queue_index_t index, queue_size_t size) //functionw ill increment queue index +{ + if(index == size-1) + index = 0; + else + index++; + return index; +} + +// Standard queue implementation that leaves one spot empty so easier to check for full/empty. +void queue_init(queue_t* q, queue_size_t size) { + q->indexIn = 0; + q->indexOut = 0; + q->elementCount = 0; + q->size = size+1; // Add one additional location for the empty location. + q->data = (queue_data_t *) malloc(q->size * sizeof(queue_data_t)); +} + +queue_size_t queue_size(queue_t* q); + +// Returns true if the queue is full. +bool queueFull(queue_t* q) +{ + if(q->elementCount == q->size-1) + return 1; + return 0; +} + +// Returns true if the queue is empty. +bool queue_empty(queue_t* q) +{ + if(q->elementCount == (queue_size_t)0) + return 1; + return 0; +} + +// Pushes a new element into the queue. Reports an error if the queue is full. +void queue_push(queue_t* q, queue_data_t value) +{ + if(queueFull(q)) + printf("Cannot insert, full queue!\n\r"); // This prints on the console. + else + { + q->data[q->indexIn] = value; + q->elementCount++; + q->indexIn = incrementIndex(q->indexIn, q->size); + } + +} + +// Removes the oldest element in the queue. +queue_data_t queue_pop(queue_t* q) +{ + queue_data_t rdata; + if(queue_empty(q)) + printf("Queue is empty\n\r"); // This prints on the console. + else + { + rdata = q->data[q->indexOut]; + q->elementCount--; + q->indexOut = incrementIndex(q->indexOut, q->size); + return rdata; + } + return 0; +} + +// Pushes a new element into the queue, making room by removing the oldest element. +void queue_overwritePush(queue_t* q, queue_data_t value) +{ + if(queueFull(q)) + { + printf("warning Queue is being overwritten\n\r"); // This prints on the console. + q->data[q->indexIn] = value; + q->indexIn = incrementIndex(q->indexIn, q->size); + q->indexOut = incrementIndex(q->indexOut, q->size); + } + else + queue_push(q,value); +} + +// Provides random-access read capability to the queue. +// Low-valued indexes access older queue elements while higher-value indexes access newer elements +// (according to the order that they were added). +queue_data_t queue_readElementAt(queue_t* q, queue_index_t index) +{ + if(queue_empty(q)) + printf("Queue is empty\n\r"); // This prints on the console. + else + { + if(index < q->elementCount) + { + if((index + q->indexOut) < q->size-1) + return q->data[index+ q->indexOut]; + else + return q->data[q->size - (index+ q->indexOut) -1]; + } + else + printf("index out of bounds\n\r"); + } + return 0; +} + +// Returns a count of the elements currently contained in the queue. +queue_size_t queue_elementCount(queue_t* q) +{ + return q->elementCount; +} + +// Prints the current contents of the queue. Handy for debugging. +void queue_print(queue_t* q) +{ + queue_index_t indexOutTmp; + if(queue_empty(q)) + printf("Queue is empty.\n\r"); + else + { + for (indexOutTmp = q->indexOut; indexOutTmp != q->indexIn; indexOutTmp = incrementIndex(indexOutTmp, q->size)) + printf("%lf\n\r", q->data[indexOutTmp]); + } +} + +// Performs a comprehensive test of all queue functions. +int queue_runTest() +{ + queue_t q; + queue_init(&q, 3); + queue_pop(&q); + + queue_push(&q, 1); + printf("Element count : %lf \n\r",queue_elementCount(&q)); + queue_push(&q, 2); + printf("Element count : %lf\n\r",queue_elementCount(&q)); + queue_push(&q, 3); + printf("Element count : %lf\n\r",queue_elementCount(&q)); + queue_push(&q, 6); + + printf("printing contents of queue.\n\r"); + queue_print(&q); + printf("done printing contents of queue.\n\r"); + + printf("%lf\n\r", queue_pop(&q)); + queue_push(&q, 4); + printf("%lf\n\r", queue_pop(&q)); + queue_push(&q, 5); + printf("%lf\n\r", queue_pop(&q)); + + printf("printing contents of queue.\n\r"); + queue_print(&q); + printf("done printing contents of queue.\n\r"); + + printf("%lf\n\r", queue_pop(&q)); + printf("%lf\n\r", queue_pop(&q)); + printf("%lf\n\r", queue_pop(&q)); + + queue_overwritePush(&q,7); + queue_overwritePush(&q,8); + queue_overwritePush(&q,9); + queue_overwritePush(&q,10); + queue_overwritePush(&q,11); + + printf("printing contents of queue.\n\r"); + queue_print(&q); + printf("done printing contents of queue.\n\r"); + + printf("%lf\n\r", queue_pop(&q)); + printf("%lf\n\r",queue_readElementAt(&q, 3)); + printf("%lf\n\r",queue_readElementAt(&q, 2)); + printf("%lf\n\r",queue_readElementAt(&q, 1)); + printf("%lf\n\r",queue_readElementAt(&q, 0)); + + printf("%lf\n\r", queue_pop(&q)); + + printf("%lf\n\r",queue_readElementAt(&q, 3)); + printf("%lf\n\r",queue_readElementAt(&q, 2)); + printf("%lf\n\r",queue_readElementAt(&q, 1)); + printf("%lf\n\r",queue_readElementAt(&q, 0)); + + printf("done testing queue working!.\n\r"); + return 1; +} +// Just free the malloc'd storage. +void gueue_garbageCollect(queue_t* q) +{ + free(q->data); +}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/queue.h Sat Feb 14 23:25:22 2015 +0000 @@ -0,0 +1,65 @@ +/* + * queue.h + * + * Created on: Jan 15, 2015 + * Author: danilob + */ + +#ifndef QUEUE_H_ +#define QUEUE_H_ + +#include <stdint.h> +#include <stdbool.h> + +typedef uint32_t queue_index_t; +typedef double queue_data_t; +typedef uint32_t queue_size_t; + +typedef struct { + queue_index_t indexIn; + queue_index_t indexOut; + queue_size_t size; + queue_size_t elementCount; + queue_data_t * data; +} queue_t; + +// Allocates the memory to you queue (the data* pointer) and initializes all parts of the data structure. +void queue_init(queue_t* q, queue_size_t size); + +// Returns the size of the queue.. +queue_size_t queue_size(queue_t* q); + +// Returns true if the queue is full. +bool queueFull(queue_t* q); + +// Returns true if the queue is empty. +bool queue_empty(queue_t* q); + +// Pushes a new element into the queue. Reports an error if the queue is full. +void queue_push(queue_t* q, queue_data_t value); + +// Removes the oldest element in the queue. +queue_data_t queue_pop(queue_t* q); + +// Pushes a new element into the queue, making room by removing the oldest element. +void queue_overwritePush(queue_t* q, queue_data_t value); + +// Provides random-access read capability to the queue. +// Low-valued indexes access older queue elements while higher-value indexes access newer elements +// (according to the order that they were added). +queue_data_t queue_readElementAt(queue_t* q, queue_index_t index); + +// Returns a count of the elements currently contained in the queue. +queue_size_t queue_elementCount(queue_t* q); + +// Frees the storage that you malloc'd before. +void gueue_garbageCollect(queue_t* q); + +// Prints the current contents of the queue. Handy for debugging. +void queue_print(queue_t* q); + +// Performs a comprehensive test of all queue functions. +int queue_runTest(); + + +#endif /* QUEUE_H_ */