291 lines
8.3 KiB
GDScript
291 lines
8.3 KiB
GDScript
@tool
|
|
|
|
# Used to store temporary images on disk.
|
|
# This is useful for undo/redo as image edition can quickly fill up memory.
|
|
|
|
# Image data is stored in archive files together,
|
|
# because when dealing with many images it speeds up filesystem I/O on Windows.
|
|
# If the file exceeds a predefined size, a new one is created.
|
|
# Writing to disk is performed from a thread, to leave the main thread responsive.
|
|
# However if you want to obtain an image back while it didn't save yet, the main thread will block.
|
|
# When the application or plugin is closed, the files get cleared.
|
|
|
|
const HT_Logger = preload("./logger.gd")
|
|
const HT_Errors = preload("./errors.gd")
|
|
|
|
const CACHE_FILE_SIZE_THRESHOLD = 1048576
|
|
# For debugging
|
|
const USE_THREAD = true
|
|
|
|
var _cache_dir := ""
|
|
var _next_id := 0
|
|
var _session_id := ""
|
|
var _cache_image_info := {}
|
|
var _logger = HT_Logger.get_for(self)
|
|
var _current_cache_file_index := 0
|
|
var _cache_file_offset := 0
|
|
|
|
var _saving_thread := Thread.new()
|
|
var _save_queue := []
|
|
var _save_queue_mutex := Mutex.new()
|
|
var _save_semaphore := Semaphore.new()
|
|
var _save_thread_running := false
|
|
|
|
|
|
func _init(cache_dir: String):
|
|
assert(cache_dir != "")
|
|
_cache_dir = cache_dir
|
|
var rng := RandomNumberGenerator.new()
|
|
rng.randomize()
|
|
for i in 16:
|
|
_session_id += str(rng.randi() % 10)
|
|
_logger.debug(str("Image cache session ID: ", _session_id))
|
|
if not DirAccess.dir_exists_absolute(_cache_dir):
|
|
var err := DirAccess.make_dir_absolute(_cache_dir)
|
|
if err != OK:
|
|
_logger.error("Could not create directory {0}: {1}" \
|
|
.format([_cache_dir, HT_Errors.get_message(err)]))
|
|
_save_thread_running = true
|
|
if USE_THREAD:
|
|
_saving_thread.start(_save_thread_func)
|
|
|
|
|
|
# TODO Cannot cleanup the cache in destructor!
|
|
# Godot doesn't allow me to call clear()...
|
|
# https://github.com/godotengine/godot/issues/31166
|
|
func _notification(what: int):
|
|
if what == NOTIFICATION_PREDELETE:
|
|
#clear()
|
|
_save_thread_running = false
|
|
_save_semaphore.post()
|
|
if USE_THREAD:
|
|
_saving_thread.wait_to_finish()
|
|
|
|
|
|
func _create_new_cache_file(fpath: String):
|
|
var f := FileAccess.open(fpath, FileAccess.WRITE)
|
|
if f == null:
|
|
var err = FileAccess.get_open_error()
|
|
_logger.error("Failed to create new cache file {0}: {1}" \
|
|
.format([fpath, HT_Errors.get_message(err)]))
|
|
return
|
|
|
|
|
|
func _get_current_cache_file_name() -> String:
|
|
return _cache_dir.path_join(str(_session_id, "_", _current_cache_file_index, ".cache"))
|
|
|
|
|
|
func save_image(im: Image) -> int:
|
|
assert(im != null)
|
|
if im.has_mipmaps():
|
|
# TODO Add support for this? Didn't need it so far
|
|
_logger.error("Caching an image with mipmaps, this isn't supported")
|
|
|
|
var fpath := _get_current_cache_file_name()
|
|
if _next_id == 0:
|
|
# First file
|
|
_create_new_cache_file(fpath)
|
|
|
|
var id := _next_id
|
|
_next_id += 1
|
|
|
|
var item := {
|
|
# Duplicate the image so we are sure nothing funny will happen to it
|
|
# while the thread saves it
|
|
"image": im.duplicate(),
|
|
"path": fpath,
|
|
"data_offset": _cache_file_offset,
|
|
"saved": false
|
|
}
|
|
|
|
_cache_file_offset += _get_image_data_size(im)
|
|
if _cache_file_offset >= CACHE_FILE_SIZE_THRESHOLD:
|
|
_cache_file_offset = 0
|
|
_current_cache_file_index += 1
|
|
_create_new_cache_file(_get_current_cache_file_name())
|
|
|
|
_cache_image_info[id] = item
|
|
|
|
_save_queue_mutex.lock()
|
|
_save_queue.append(item)
|
|
_save_queue_mutex.unlock()
|
|
|
|
_save_semaphore.post()
|
|
|
|
if not USE_THREAD:
|
|
var before = Time.get_ticks_msec()
|
|
while len(_save_queue) > 0:
|
|
_save_thread_func()
|
|
if Time.get_ticks_msec() - before > 10_000:
|
|
_logger.error("Taking to long to empty save queue in non-threaded mode!")
|
|
|
|
return id
|
|
|
|
|
|
static func _get_image_data_size(im: Image) -> int:
|
|
return 1 + 4 + 4 + 4 + len(im.get_data())
|
|
|
|
|
|
static func _write_image(f: FileAccess, im: Image):
|
|
f.store_8(im.get_format())
|
|
f.store_32(im.get_width())
|
|
f.store_32(im.get_height())
|
|
var data : PackedByteArray = im.get_data()
|
|
f.store_32(len(data))
|
|
f.store_buffer(data)
|
|
|
|
|
|
static func _read_image(f: FileAccess) -> Image:
|
|
var format := f.get_8()
|
|
var width := f.get_32()
|
|
var height := f.get_32()
|
|
var data_size := f.get_32()
|
|
var data := f.get_buffer(data_size)
|
|
var im := Image.create_from_data(width, height, false, format, data)
|
|
return im
|
|
|
|
|
|
func load_image(id: int) -> Image:
|
|
var info := _cache_image_info[id] as Dictionary
|
|
|
|
var timeout := 5.0
|
|
var time_before := Time.get_ticks_msec()
|
|
# We could just grab `image`, because the thread only reads it.
|
|
# However it's still not safe to do that if we write or even lock it,
|
|
# so we have to assume it still has ownership of it.
|
|
while not info.saved:
|
|
OS.delay_msec(8.0)
|
|
_logger.debug("Waiting for cached image {0}...".format([id]))
|
|
if Time.get_ticks_msec() - time_before > timeout:
|
|
_logger.error("Could not get image {0} from cache. Something went wrong.".format([id]))
|
|
return null
|
|
|
|
var fpath := info.path as String
|
|
|
|
var f := FileAccess.open(fpath, FileAccess.READ)
|
|
if f == null:
|
|
var err := FileAccess.get_open_error()
|
|
_logger.error("Could not load cached image from {0}: {1}" \
|
|
.format([fpath, HT_Errors.get_message(err)]))
|
|
return null
|
|
|
|
f.seek(info.data_offset)
|
|
var im = _read_image(f)
|
|
f = null # close file
|
|
|
|
assert(im != null)
|
|
return im
|
|
|
|
|
|
func clear():
|
|
_logger.debug("Clearing image cache")
|
|
|
|
var dir := DirAccess.open(_cache_dir)
|
|
if dir == null:
|
|
#var err = DirAccess.get_open_error()
|
|
_logger.error("Could not open image file cache directory '{0}'" \
|
|
.format([_cache_dir]))
|
|
return
|
|
|
|
dir.include_hidden = false
|
|
dir.include_navigational = false
|
|
|
|
var err := dir.list_dir_begin()
|
|
if err != OK:
|
|
_logger.error("Could not start list_dir_begin in '{0}'".format([_cache_dir]))
|
|
return
|
|
|
|
# Delete all cache files
|
|
while true:
|
|
var fpath := dir.get_next()
|
|
if fpath == "":
|
|
break
|
|
if fpath.ends_with(".cache"):
|
|
_logger.debug(str("Deleting ", fpath))
|
|
err = dir.remove(fpath)
|
|
if err != OK:
|
|
_logger.error("Failed to delete cache file '{0}': {1}" \
|
|
.format([_cache_dir.path_join(fpath), HT_Errors.get_message(err)]))
|
|
|
|
_cache_image_info.clear()
|
|
|
|
|
|
func _save_thread_func():
|
|
# Threads keep a reference to the object of the function they run.
|
|
# So if the object is a Reference, and that reference owns the thread... we get a cycle.
|
|
# We can break the cycle by removing 1 to the count inside the thread.
|
|
# The thread's reference will never die unexpectedly because we stop and destroy the thread
|
|
# in the destructor of the reference.
|
|
# If that workaround explodes one day, another way could be to use an intermediary instance
|
|
# extending Object, and run a function on that instead.
|
|
#
|
|
# I added this in Godot 3, and it seems to still be relevant in Godot 4 because if I don't
|
|
# do it, objects are leaking.
|
|
#
|
|
# BUT it seems to end up triggering a crash in debug Godot builds due to unrefing RefCounted
|
|
# with refcount == 0, so I guess it's wrong now?
|
|
# So basically, either I do it and I risk a crash,
|
|
# or I don't do it and then it causes a leak...
|
|
# TODO Make this shit use `Object`
|
|
#
|
|
# if USE_THREAD:
|
|
# unreference()
|
|
|
|
while _save_thread_running:
|
|
_save_queue_mutex.lock()
|
|
var to_save := _save_queue.duplicate(false)
|
|
_save_queue.clear()
|
|
_save_queue_mutex.unlock()
|
|
|
|
if len(to_save) == 0:
|
|
if USE_THREAD:
|
|
_save_semaphore.wait()
|
|
continue
|
|
|
|
var f : FileAccess
|
|
var path := ""
|
|
|
|
for item in to_save:
|
|
# Keep re-using the same file if we did not change path.
|
|
# It makes I/Os faster.
|
|
if item.path != path:
|
|
# Close previous file
|
|
f = null
|
|
|
|
path = item.path
|
|
|
|
f = FileAccess.open(path, FileAccess.READ_WRITE)
|
|
if f == null:
|
|
var err := FileAccess.get_open_error()
|
|
call_deferred("_on_error", "Could not open file {0}: {1}" \
|
|
.format([path, HT_Errors.get_message(err)]))
|
|
path = ""
|
|
continue
|
|
|
|
f.seek(item.data_offset)
|
|
_write_image(f, item.image)
|
|
# Notify main thread.
|
|
# The thread does not modify data, only reads it.
|
|
call_deferred("_on_image_saved", item)
|
|
|
|
# Workaround some weird behavior in Godot 4:
|
|
# when the next loop runs, `f` IS NOT CLEANED UP. A reference is still held before `var f`
|
|
# is reached, which means the file is still locked while the thread is waiting on the
|
|
# semaphore... so I have to explicitely "close" the file here.
|
|
f = null
|
|
|
|
if not USE_THREAD:
|
|
break
|
|
|
|
|
|
func _on_error(msg: String):
|
|
_logger.error(msg)
|
|
|
|
|
|
func _on_image_saved(item: Dictionary):
|
|
_logger.debug(str("Saved ", item.path))
|
|
item.saved = true
|
|
# Should remove image from memory (for usually being last reference)
|
|
item.image = null
|
|
|
|
|