System info & network

code/lib/queue.h

@@ -0,0 +1,93 @@
+#ifndef _PIUMA_LIB_QUEUE_H_
+#define _PIUMA_LIB_QUEUE_H_
+
+#include "types.h"
+#include <assert.h>
+
+struct queue_header
+{
+	u64 start;
+	u64 size;
+
+	u64 capacity;
+};
+
+
+#define QUEUE_HEADER_PTR(queue) ((queue_header *)(((u8*)queue) - sizeof(queue_header)))
+
+#define QUEUE_TYPE(type) type *
+#define Queue_Alloc(alloc_func, type, capacity) ((type*) _queue_alloc(alloc_func, sizeof(type), capacity))
+#define Queue_Free(free_func, queue) free_func(QUEUE_HEADER_PTR(queue))
+
+#define Queue_Pop(queue) (queue[_queue_pop_index((u8*)queue)])
+#define Queue_Push(queue, element) { queue[_queue_at_index((u8*)queue, QUEUE_HEADER_PTR(queue)->size)] = element; _queue_push_fix_indices((u8*)queue); }
+#define Queue_At(queue, index) (queue[_queue_at_index((u8*)queue, index)])
+#define Queue_Size(queue) _queue_size((u8*)queue)
+#define Queue_Capacity(queue) _queue_capacity((u8*)queue)
+
+
+
+typedef void * (*alloc_func_t)(u64);
+typedef void (*free_func_t)(void *);
+
+inline u8 * _queue_alloc(alloc_func_t alloc_func, u64 sizeof_type, u64 capacity)
+{
+	u8 *data;
+	queue_header *header;
+
+	data   = (u8 *)alloc_func(sizeof(queue_header) + sizeof_type * capacity);
+	header = (queue_header *)data;
+
+	header->capacity = capacity;
+	header->start    = 0;
+	header->size     = 0;
+
+	return data + sizeof(queue_header);
+}
+
+inline u64 _queue_pop_index(u8 *queue)
+{
+	queue_header *header = QUEUE_HEADER_PTR(queue);
+	assert(header->size > 0);
+
+	u64 element_index = header->start;
+	header->start = (header->start + 1) % header->capacity;
+	header->size--;
+
+	return element_index;
+}
+
+inline void _queue_push_fix_indices(u8 *queue)
+{
+	queue_header *header = QUEUE_HEADER_PTR(queue);
+
+	header->size++;
+	if(header->size > header->capacity)
+	{
+		// Queue is full. Remove oldest element
+		header->start = (header->start + 1) % header->capacity;
+		header->size  = header->capacity;
+	}
+}
+
+inline u64 _queue_at_index(u8 *queue, u64 index)
+{
+	queue_header *header = QUEUE_HEADER_PTR(queue);
+
+	return (header->start + index) % header->capacity;
+}
+
+inline u64 _queue_size(u8 *queue)
+{
+	queue_header *header = QUEUE_HEADER_PTR(queue);
+	return header->size;
+}
+
+inline u64 _queue_capacity(u8 *queue)
+{
+	queue_header *header = QUEUE_HEADER_PTR(queue);
+	return header->capacity;
+}
+
+
+#endif