virtualx-engine-docs/_downloads/bc54982daa1be2e5b495d74f01a098f1/resource_queue.gd
2024-10-23 09:41:33 -07:00

166 lines
3.2 KiB
GDScript

extends Node
var thread
var mutex
var semaphore
var exit_thread = false
var time_max = 100 # Milliseconds.
var queue = []
var pending = {}
func _lock(_caller):
mutex.lock()
func _unlock(_caller):
mutex.unlock()
func _post(_caller):
semaphore.post()
func _wait(_caller):
semaphore.wait()
func queue_resource(path, p_in_front = false):
_lock("queue_resource")
if path in pending:
_unlock("queue_resource")
return
elif ResourceLoader.has_cached(path):
var res = ResourceLoader.load(path)
pending[path] = res
_unlock("queue_resource")
return
else:
var res = ResourceLoader.load_interactive(path)
res.set_meta("path", path)
if p_in_front:
queue.insert(0, res)
else:
queue.push_back(res)
pending[path] = res
_post("queue_resource")
_unlock("queue_resource")
return
func cancel_resource(path):
_lock("cancel_resource")
if path in pending:
if pending[path] is ResourceInteractiveLoader:
queue.erase(pending[path])
pending.erase(path)
_unlock("cancel_resource")
func get_progress(path):
_lock("get_progress")
var ret = -1
if path in pending:
if pending[path] is ResourceInteractiveLoader:
ret = float(pending[path].get_stage()) / float(pending[path].get_stage_count())
else:
ret = 1.0
_unlock("get_progress")
return ret
func is_ready(path):
var ret
_lock("is_ready")
if path in pending:
ret = !(pending[path] is ResourceInteractiveLoader)
else:
ret = false
_unlock("is_ready")
return ret
func _wait_for_resource(res, path):
_unlock("wait_for_resource")
while true:
VisualServer.sync()
OS.delay_usec(16000) # Wait approximately 1 frame.
_lock("wait_for_resource")
if queue.size() == 0 || queue[0] != res:
return pending[path]
_unlock("wait_for_resource")
func get_resource(path):
_lock("get_resource")
if path in pending:
if pending[path] is ResourceInteractiveLoader:
var res = pending[path]
if res != queue[0]:
var pos = queue.find(res)
queue.remove(pos)
queue.insert(0, res)
res = _wait_for_resource(res, path)
pending.erase(path)
_unlock("return")
return res
else:
var res = pending[path]
pending.erase(path)
_unlock("return")
return res
else:
_unlock("return")
return ResourceLoader.load(path)
func thread_process():
_wait("thread_process")
_lock("process")
while queue.size() > 0:
var res = queue[0]
_unlock("process_poll")
var ret = res.poll()
_lock("process_check_queue")
if ret == ERR_FILE_EOF || ret != OK:
var path = res.get_meta("path")
if path in pending: # Else, it was already retrieved.
pending[res.get_meta("path")] = res.get_resource()
# Something might have been put at the front of the queue while
# we polled, so use erase instead of remove.
queue.erase(res)
_unlock("process")
func thread_func(_u):
while true:
mutex.lock()
var should_exit = exit_thread # Protect with Mutex.
mutex.unlock()
if should_exit:
break
thread_process()
func start():
mutex = Mutex.new()
semaphore = Semaphore.new()
thread = Thread.new()
thread.start(self, "thread_func", 0)
# Triggered by calling "get_tree().quit()".
func _exit_tree():
mutex.lock()
exit_thread = true # Protect with Mutex.
mutex.unlock()
# Unblock by posting.
semaphore.post()
# Wait until it exits.
thread.wait_to_finish()