Follow-up to previous commit: Added static_queue which has fixed capacity

Author: ravi688

static_queue.c

@@ -0,0 +1,62 @@
+#include "static_queue.h"
+#include <stdlib.h> // malloc
+#include <string.h> // memset
+
+static_queue_t* static_queue_create(int element_size, int capacity)
+{
+	static_queue_t* queue = (static_queue_t*)malloc(sizeof(static_queue_t));
+	memset(queue, 0, sizeof(static_queue_t));
+	queue->capacity = capacity;
+	queue->element_size	= element_size;
+	queue->buffer = malloc(queue->element_size * queue->capacity);
+	memset(queue->buffer, 0, queue->element_size * queue->capacity);
+	// points to the next vacant place at which new element can be pushed
+	queue->front = 0;
+	// points to the next filled place from which an element can be popped
+	queue->back = 0;
+	return queue;	
+}
+
+void static_queue_destroy(static_queue_t* queue)
+{
+	free(queue->buffer);
+	free(queue);
+}
+
+void static_queue_push(static_queue_t* queue, void* value)
+{
+	if(queue->front >= queue->capacity)
+	{
+		// make a vacant place on the left most side
+		if(queue->back == 0)
+			queue->back = 1;
+
+		// shift all the elements to the left most to fill the vacant places on the back side
+		memmove(queue->buffer, queue->buffer + queue->back, queue->element_size * (queue->front - queue->back));
+		queue->front -= queue->back;
+		queue->back = 0;
+	}
+	memcpy(queue->buffer + queue->front * queue->element_size, value, queue->element_size);
+	queue->front += 1;
+}
+
+bool static_queue_pop(static_queue_t* queue, void* value)
+{
+	if(static_queue_get_count(queue) > 0)
+	{
+		memcpy(value, queue->buffer + queue->back * queue->element_size, queue->element_size);
+		queue->back += 1;
+		return true;
+	}
+	return false;
+}
+
+bool static_queue_is_empty(static_queue_t* queue)
+{
+	return static_queue_get_count(queue) <= 0;
+}
+
+int static_queue_get_count(static_queue_t* queue)
+{
+	return queue->front - queue->back;
+}

static_queue.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <stdbool.h>
+
+typedef struct static_queue_t
+{
+	void* buffer;
+	int capacity;
+	int front;
+	int back;
+	int element_size;
+} static_queue_t;
+
+// constructors and destructors
+static_queue_t* static_queue_create(int element_size, int capacity);
+void static_queue_destroy(static_queue_t* queue);
+
+// algorithms 
+void static_queue_push(static_queue_t* queue, void* value);
+bool static_queue_pop(static_queue_t* queue, void* value);
+bool static_queue_is_empty(static_queue_t* queue);
+int static_queue_get_count(static_queue_t* queue);