/************************************************************//**
*
*	@file: platform_io_internal.c
*	@author: Martin Fouilleul
*	@date: 11/06/2023
*
*****************************************************************/

#include"platform_io_internal.h"

file_table __globalFileTable = {0};

file_slot* file_slot_alloc(file_table* table)
{
	file_slot* slot = list_pop_entry(&table->freeList, file_slot, freeListElt);
	if(!slot && table->nextSlot < ORCA_MAX_FILE_SLOTS)
	{
		slot = &table->slots[table->nextSlot];
		slot->generation = 1;
		table->nextSlot++;
	}

	u32 tmpGeneration = slot->generation;
	memset(slot, 0, sizeof(file_slot));
	slot->generation = tmpGeneration;

	return(slot);
}

void file_slot_recycle(file_table* table, file_slot* slot)
{
	slot->generation++;
	list_push(&table->freeList, &slot->freeListElt);
}

file_handle file_handle_from_slot(file_table* table, file_slot* slot)
{
	u64 index = slot - table->slots;
	u64 generation = slot->generation;
	file_handle handle = {.h = (generation<<32) | index };
	return(handle);
}

file_slot* file_slot_from_handle(file_table* table, file_handle handle)
{
	file_slot* slot = 0;

	u64 index = handle.h & 0xffffffff;
	u64 generation = handle.h>>32;

	if(index < table->nextSlot)
	{
		file_slot* candidate = &table->slots[index];
		if(candidate->generation == generation)
		{
			slot = candidate;
		}
	}
	return(slot);
}

io_cmp io_wait_single_req(io_req* req)
{
	return(io_wait_single_req_with_table(req, &__globalFileTable));
}