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queue.h
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queue.h
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#ifndef queue_h_INCLUDED
#define queue_h_INCLUDED
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/time.h>
#include "ioctl.h"
struct circ_queue_node {
char byte;
long timestamp; // stored in jiffies
};
struct circ_queue {
struct circ_queue_node *buffer;
struct circ_queue_node *begin, *end;
size_t size;
size_t count;
};
struct circ_queue_node *decrement_node(struct circ_queue_node *node, struct circ_queue queue)
{
// If node is at the beginning of the buffer, go to the end of the buffer
if (node == queue.buffer) {
node = queue.buffer + queue.size - 1;
} else {
node--;
}
return node;
}
void copy_node(struct circ_queue_node *to, struct circ_queue_node from)
{
to->byte = from.byte;
to->timestamp = from.timestamp;
}
size_t circ_queue_count(struct circ_queue queue)
{
return queue.count;
}
void circ_queue_print(struct circ_queue queue)
{
printk(KERN_INFO "Buffer: %llx Start: %llx End: %llx Size: %zu Capacity:%zu\n",
queue.buffer, queue.begin, queue.end, queue.count, queue.size);
}
struct circ_queue circ_queue_init(size_t size)
{
struct circ_queue_node *buffer = vmalloc(size * sizeof(*buffer));
struct circ_queue queue = {
.buffer = buffer,
.begin = buffer + size - 1,
.end = buffer + size - 1,
.size = size,
.count = 0
};
return queue;
}
void circ_queue_free(struct circ_queue queue)
{
vfree(queue.buffer);
queue.buffer = queue.begin = queue.end = NULL;
queue.size = 0;
}
bool circ_queue_push(struct circ_queue *queue, struct circ_queue_node node)
{
if (circ_queue_count(*queue) == queue->size) {
return false;
}
copy_node(queue->begin, node);
queue->begin = decrement_node(queue->begin, *queue);
queue->count++;
return true;
}
bool circ_queue_peek(struct circ_queue *queue, struct circ_queue_node *node)
{
if (circ_queue_count(*queue) == 0) {
return false;
}
copy_node(node, *queue->end);
return true;
}
bool circ_queue_pop(struct circ_queue *queue, struct circ_queue_node *node)
{
if (!circ_queue_peek(queue, node)) {
return false;
}
queue->end = decrement_node(queue->end, *queue);
queue->count--;
return true;
}
#endif // queue_h_INCLUDED