
# Objective Simplify implementing some asset traits without Box::pin(async move{}) shenanigans. Fixes (in part) https://github.com/bevyengine/bevy/issues/11308 ## Solution Use async-fn in traits when possible in all traits. Traits with return position impl trait are not object safe however, and as AssetReader and AssetWriter are both used with dynamic dispatch, you need a Boxed version of these futures anyway. In the future, Rust is [adding ](https://blog.rust-lang.org/2023/12/21/async-fn-rpit-in-traits.html)proc macros to generate these traits automatically, and at some point in the future dyn traits should 'just work'. Until then.... this seemed liked the right approach given more ErasedXXX already exist, but, no clue if there's plans here! Especially since these are public now, it's a bit of an unfortunate API, and means this is a breaking change. In theory this saves some performance when these traits are used with static dispatch, but, seems like most code paths go through dynamic dispatch, which boxes anyway. I also suspect a bunch of the lifetime annotations on these function could be simplified now as the BoxedFuture was often the only thing returned which needed a lifetime annotation, but I'm not touching that for now as traits + lifetimes can be so tricky. This is a revival of [pull/11362](https://github.com/bevyengine/bevy/pull/11362) after a spectacular merge f*ckup, with updates to the latest Bevy. Just to recap some discussion: - Overall this seems like a win for code quality, especially when implementing these traits, but a loss for having to deal with ErasedXXX variants. - `ConditionalSend` was the preferred name for the trait that might be Send, to deal with wasm platforms. - When reviewing be sure to disable whitespace difference, as that's 95% of the PR. ## Changelog - AssetReader, AssetWriter, AssetLoader, AssetSaver and Process now use async-fn in traits rather than boxed futures. ## Migration Guide - Custom implementations of AssetReader, AssetWriter, AssetLoader, AssetSaver and Process should switch to async fn rather than returning a bevy_utils::BoxedFuture. - Simultaniously, to use dynamic dispatch on these traits you should instead use dyn ErasedXXX.
654 lines
26 KiB
Rust
654 lines
26 KiB
Rust
use crate::{
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io::{AssetReaderError, MissingAssetSourceError, MissingProcessedAssetReaderError, Reader},
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meta::{
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loader_settings_meta_transform, AssetHash, AssetMeta, AssetMetaDyn, ProcessedInfoMinimal,
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Settings,
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},
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path::AssetPath,
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Asset, AssetLoadError, AssetServer, AssetServerMode, Assets, Handle, LoadedUntypedAsset,
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UntypedAssetId, UntypedHandle,
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};
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use bevy_ecs::world::World;
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use bevy_utils::{BoxedFuture, ConditionalSendFuture, CowArc, HashMap, HashSet};
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use downcast_rs::{impl_downcast, Downcast};
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use futures_lite::AsyncReadExt;
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use ron::error::SpannedError;
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use serde::{Deserialize, Serialize};
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use std::{
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any::{Any, TypeId},
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path::{Path, PathBuf},
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};
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use thiserror::Error;
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/// Loads an [`Asset`] from a given byte [`Reader`]. This can accept [`AssetLoader::Settings`], which configure how the [`Asset`]
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/// should be loaded.
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pub trait AssetLoader: Send + Sync + 'static {
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/// The top level [`Asset`] loaded by this [`AssetLoader`].
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type Asset: crate::Asset;
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/// The settings type used by this [`AssetLoader`].
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type Settings: Settings + Default + Serialize + for<'a> Deserialize<'a>;
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/// The type of [error](`std::error::Error`) which could be encountered by this loader.
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type Error: Into<Box<dyn std::error::Error + Send + Sync + 'static>>;
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/// Asynchronously loads [`AssetLoader::Asset`] (and any other labeled assets) from the bytes provided by [`Reader`].
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fn load<'a>(
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&'a self,
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reader: &'a mut Reader,
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settings: &'a Self::Settings,
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load_context: &'a mut LoadContext,
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) -> impl ConditionalSendFuture<Output = Result<Self::Asset, Self::Error>>;
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/// Returns a list of extensions supported by this [`AssetLoader`], without the preceding dot.
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/// Note that users of this [`AssetLoader`] may choose to load files with a non-matching extension.
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fn extensions(&self) -> &[&str] {
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&[]
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}
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}
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/// Provides type-erased access to an [`AssetLoader`].
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pub trait ErasedAssetLoader: Send + Sync + 'static {
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/// Asynchronously loads the asset(s) from the bytes provided by [`Reader`].
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fn load<'a>(
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&'a self,
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reader: &'a mut Reader,
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meta: Box<dyn AssetMetaDyn>,
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load_context: LoadContext<'a>,
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) -> BoxedFuture<
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'a,
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Result<ErasedLoadedAsset, Box<dyn std::error::Error + Send + Sync + 'static>>,
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>;
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/// Returns a list of extensions supported by this asset loader, without the preceding dot.
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fn extensions(&self) -> &[&str];
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/// Deserializes metadata from the input `meta` bytes into the appropriate type (erased as [`Box<dyn AssetMetaDyn>`]).
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fn deserialize_meta(&self, meta: &[u8]) -> Result<Box<dyn AssetMetaDyn>, DeserializeMetaError>;
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/// Returns the default meta value for the [`AssetLoader`] (erased as [`Box<dyn AssetMetaDyn>`]).
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fn default_meta(&self) -> Box<dyn AssetMetaDyn>;
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/// Returns the type name of the [`AssetLoader`].
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fn type_name(&self) -> &'static str;
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/// Returns the [`TypeId`] of the [`AssetLoader`].
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fn type_id(&self) -> TypeId;
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/// Returns the type name of the top-level [`Asset`] loaded by the [`AssetLoader`].
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fn asset_type_name(&self) -> &'static str;
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/// Returns the [`TypeId`] of the top-level [`Asset`] loaded by the [`AssetLoader`].
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fn asset_type_id(&self) -> TypeId;
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}
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impl<L> ErasedAssetLoader for L
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where
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L: AssetLoader + Send + Sync,
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{
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/// Processes the asset in an asynchronous closure.
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fn load<'a>(
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&'a self,
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reader: &'a mut Reader,
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meta: Box<dyn AssetMetaDyn>,
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mut load_context: LoadContext<'a>,
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) -> BoxedFuture<
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'a,
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Result<ErasedLoadedAsset, Box<dyn std::error::Error + Send + Sync + 'static>>,
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> {
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Box::pin(async move {
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let settings = meta
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.loader_settings()
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.expect("Loader settings should exist")
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.downcast_ref::<L::Settings>()
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.expect("AssetLoader settings should match the loader type");
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let asset = <L as AssetLoader>::load(self, reader, settings, &mut load_context)
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.await
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.map_err(|error| error.into())?;
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Ok(load_context.finish(asset, Some(meta)).into())
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})
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}
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fn extensions(&self) -> &[&str] {
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<L as AssetLoader>::extensions(self)
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}
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fn deserialize_meta(&self, meta: &[u8]) -> Result<Box<dyn AssetMetaDyn>, DeserializeMetaError> {
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let meta = AssetMeta::<L, ()>::deserialize(meta)?;
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Ok(Box::new(meta))
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}
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fn default_meta(&self) -> Box<dyn AssetMetaDyn> {
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Box::new(AssetMeta::<L, ()>::new(crate::meta::AssetAction::Load {
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loader: self.type_name().to_string(),
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settings: L::Settings::default(),
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}))
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}
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fn type_name(&self) -> &'static str {
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std::any::type_name::<L>()
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}
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fn type_id(&self) -> TypeId {
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TypeId::of::<L>()
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}
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fn asset_type_name(&self) -> &'static str {
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std::any::type_name::<L::Asset>()
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}
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fn asset_type_id(&self) -> TypeId {
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TypeId::of::<L::Asset>()
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}
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}
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pub(crate) struct LabeledAsset {
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pub(crate) asset: ErasedLoadedAsset,
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pub(crate) handle: UntypedHandle,
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}
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/// The successful result of an [`AssetLoader::load`] call. This contains the loaded "root" asset and any other "labeled" assets produced
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/// by the loader. It also holds the input [`AssetMeta`] (if it exists) and tracks dependencies:
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/// * normal dependencies: dependencies that must be loaded as part of this asset load (ex: assets a given asset has handles to).
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/// * Loader dependencies: dependencies whose actual asset values are used during the load process
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pub struct LoadedAsset<A: Asset> {
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pub(crate) value: A,
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pub(crate) dependencies: HashSet<UntypedAssetId>,
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pub(crate) loader_dependencies: HashMap<AssetPath<'static>, AssetHash>,
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pub(crate) labeled_assets: HashMap<CowArc<'static, str>, LabeledAsset>,
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pub(crate) meta: Option<Box<dyn AssetMetaDyn>>,
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}
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impl<A: Asset> LoadedAsset<A> {
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/// Create a new loaded asset. This will use [`VisitAssetDependencies`](crate::VisitAssetDependencies) to populate `dependencies`.
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pub fn new_with_dependencies(value: A, meta: Option<Box<dyn AssetMetaDyn>>) -> Self {
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let mut dependencies = HashSet::new();
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value.visit_dependencies(&mut |id| {
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dependencies.insert(id);
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});
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LoadedAsset {
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value,
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dependencies,
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loader_dependencies: HashMap::default(),
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labeled_assets: HashMap::default(),
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meta,
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}
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}
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}
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impl<A: Asset> From<A> for LoadedAsset<A> {
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fn from(asset: A) -> Self {
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LoadedAsset::new_with_dependencies(asset, None)
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}
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}
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/// A "type erased / boxed" counterpart to [`LoadedAsset`]. This is used in places where the loaded type is not statically known.
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pub struct ErasedLoadedAsset {
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pub(crate) value: Box<dyn AssetContainer>,
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pub(crate) dependencies: HashSet<UntypedAssetId>,
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pub(crate) loader_dependencies: HashMap<AssetPath<'static>, AssetHash>,
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pub(crate) labeled_assets: HashMap<CowArc<'static, str>, LabeledAsset>,
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pub(crate) meta: Option<Box<dyn AssetMetaDyn>>,
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}
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impl<A: Asset> From<LoadedAsset<A>> for ErasedLoadedAsset {
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fn from(asset: LoadedAsset<A>) -> Self {
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ErasedLoadedAsset {
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value: Box::new(asset.value),
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dependencies: asset.dependencies,
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loader_dependencies: asset.loader_dependencies,
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labeled_assets: asset.labeled_assets,
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meta: asset.meta,
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}
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}
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}
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impl ErasedLoadedAsset {
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/// Cast (and take ownership) of the [`Asset`] value of the given type. This will return [`Some`] if
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/// the stored type matches `A` and [`None`] if it does not.
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pub fn take<A: Asset>(self) -> Option<A> {
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self.value.downcast::<A>().map(|a| *a).ok()
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}
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/// Retrieves a reference to the internal [`Asset`] type, if it matches the type `A`. Otherwise returns [`None`].
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pub fn get<A: Asset>(&self) -> Option<&A> {
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self.value.downcast_ref::<A>()
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}
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/// Retrieves the [`TypeId`] of the stored [`Asset`] type.
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pub fn asset_type_id(&self) -> TypeId {
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(*self.value).type_id()
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}
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/// Retrieves the `type_name` of the stored [`Asset`] type.
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pub fn asset_type_name(&self) -> &'static str {
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self.value.asset_type_name()
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}
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/// Returns the [`ErasedLoadedAsset`] for the given label, if it exists.
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pub fn get_labeled(
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&self,
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label: impl Into<CowArc<'static, str>>,
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) -> Option<&ErasedLoadedAsset> {
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self.labeled_assets.get(&label.into()).map(|a| &a.asset)
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}
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/// Iterate over all labels for "labeled assets" in the loaded asset
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pub fn iter_labels(&self) -> impl Iterator<Item = &str> {
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self.labeled_assets.keys().map(|s| &**s)
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}
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}
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/// A type erased container for an [`Asset`] value that is capable of inserting the [`Asset`] into a [`World`]'s [`Assets`] collection.
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pub trait AssetContainer: Downcast + Any + Send + Sync + 'static {
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fn insert(self: Box<Self>, id: UntypedAssetId, world: &mut World);
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fn asset_type_name(&self) -> &'static str;
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}
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impl_downcast!(AssetContainer);
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impl<A: Asset> AssetContainer for A {
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fn insert(self: Box<Self>, id: UntypedAssetId, world: &mut World) {
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world.resource_mut::<Assets<A>>().insert(id.typed(), *self);
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}
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fn asset_type_name(&self) -> &'static str {
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std::any::type_name::<A>()
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}
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}
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/// An error that occurs when attempting to call [`LoadContext::load_direct`]
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#[derive(Error, Debug)]
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#[error("Failed to load dependency {dependency:?} {error}")]
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pub struct LoadDirectError {
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pub dependency: AssetPath<'static>,
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pub error: AssetLoadError,
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}
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/// An error that occurs while deserializing [`AssetMeta`].
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#[derive(Error, Debug, Clone)]
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pub enum DeserializeMetaError {
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#[error("Failed to deserialize asset meta: {0:?}")]
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DeserializeSettings(#[from] SpannedError),
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#[error("Failed to deserialize minimal asset meta: {0:?}")]
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DeserializeMinimal(SpannedError),
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}
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/// A context that provides access to assets in [`AssetLoader`]s, tracks dependencies, and collects asset load state.
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/// Any asset state accessed by [`LoadContext`] will be tracked and stored for use in dependency events and asset preprocessing.
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pub struct LoadContext<'a> {
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asset_server: &'a AssetServer,
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should_load_dependencies: bool,
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populate_hashes: bool,
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asset_path: AssetPath<'static>,
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dependencies: HashSet<UntypedAssetId>,
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/// Direct dependencies used by this loader.
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loader_dependencies: HashMap<AssetPath<'static>, AssetHash>,
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labeled_assets: HashMap<CowArc<'static, str>, LabeledAsset>,
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}
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impl<'a> LoadContext<'a> {
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/// Creates a new [`LoadContext`] instance.
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pub(crate) fn new(
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asset_server: &'a AssetServer,
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asset_path: AssetPath<'static>,
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should_load_dependencies: bool,
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populate_hashes: bool,
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) -> Self {
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Self {
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asset_server,
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asset_path,
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populate_hashes,
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should_load_dependencies,
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dependencies: HashSet::default(),
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loader_dependencies: HashMap::default(),
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labeled_assets: HashMap::default(),
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}
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}
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/// Begins a new labeled asset load. Use the returned [`LoadContext`] to load
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/// dependencies for the new asset and call [`LoadContext::finish`] to finalize the asset load.
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/// When finished, make sure you call [`LoadContext::add_labeled_asset`] to add the results back to the parent
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/// context.
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/// Prefer [`LoadContext::labeled_asset_scope`] when possible, which will automatically add
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/// the labeled [`LoadContext`] back to the parent context.
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/// [`LoadContext::begin_labeled_asset`] exists largely to enable parallel asset loading.
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///
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/// See [`AssetPath`] for more on labeled assets.
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///
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/// ```no_run
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/// # use bevy_asset::{Asset, LoadContext};
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/// # use bevy_reflect::TypePath;
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/// # #[derive(Asset, TypePath, Default)]
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/// # struct Image;
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/// # let load_context: LoadContext = panic!();
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/// let mut handles = Vec::new();
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/// for i in 0..2 {
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/// let mut labeled = load_context.begin_labeled_asset();
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/// handles.push(std::thread::spawn(move || {
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/// (i.to_string(), labeled.finish(Image::default(), None))
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/// }));
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/// }
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/// for handle in handles {
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/// let (label, loaded_asset) = handle.join().unwrap();
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/// load_context.add_loaded_labeled_asset(label, loaded_asset);
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/// }
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/// ```
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pub fn begin_labeled_asset(&self) -> LoadContext {
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LoadContext::new(
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self.asset_server,
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self.asset_path.clone(),
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self.should_load_dependencies,
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self.populate_hashes,
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)
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}
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/// Creates a new [`LoadContext`] for the given `label`. The `load` function is responsible for loading an [`Asset`] of
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/// type `A`. `load` will be called immediately and the result will be used to finalize the [`LoadContext`], resulting in a new
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/// [`LoadedAsset`], which is registered under the `label` label.
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///
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/// This exists to remove the need to manually call [`LoadContext::begin_labeled_asset`] and then manually register the
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/// result with [`LoadContext::add_labeled_asset`].
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///
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/// See [`AssetPath`] for more on labeled assets.
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pub fn labeled_asset_scope<A: Asset>(
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&mut self,
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label: String,
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load: impl FnOnce(&mut LoadContext) -> A,
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) -> Handle<A> {
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let mut context = self.begin_labeled_asset();
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let asset = load(&mut context);
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let loaded_asset = context.finish(asset, None);
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self.add_loaded_labeled_asset(label, loaded_asset)
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}
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/// This will add the given `asset` as a "labeled [`Asset`]" with the `label` label.
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///
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/// # Warning
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///
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/// This will not assign dependencies to the given `asset`. If adding an asset
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/// with dependencies generated from calls such as [`LoadContext::load`], use
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/// [`LoadContext::labeled_asset_scope`] or [`LoadContext::begin_labeled_asset`] to generate a
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/// new [`LoadContext`] to track the dependencies for the labeled asset.
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///
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/// See [`AssetPath`] for more on labeled assets.
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pub fn add_labeled_asset<A: Asset>(&mut self, label: String, asset: A) -> Handle<A> {
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self.labeled_asset_scope(label, |_| asset)
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}
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/// Add a [`LoadedAsset`] that is a "labeled sub asset" of the root path of this load context.
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/// This can be used in combination with [`LoadContext::begin_labeled_asset`] to parallelize
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/// sub asset loading.
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///
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/// See [`AssetPath`] for more on labeled assets.
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pub fn add_loaded_labeled_asset<A: Asset>(
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&mut self,
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label: impl Into<CowArc<'static, str>>,
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loaded_asset: LoadedAsset<A>,
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) -> Handle<A> {
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let label = label.into();
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let loaded_asset: ErasedLoadedAsset = loaded_asset.into();
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let labeled_path = self.asset_path.clone().with_label(label.clone());
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let handle = self
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.asset_server
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.get_or_create_path_handle(labeled_path, None);
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self.labeled_assets.insert(
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label,
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LabeledAsset {
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asset: loaded_asset,
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handle: handle.clone().untyped(),
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},
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);
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handle
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}
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/// Returns `true` if an asset with the label `label` exists in this context.
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///
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/// See [`AssetPath`] for more on labeled assets.
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pub fn has_labeled_asset<'b>(&self, label: impl Into<CowArc<'b, str>>) -> bool {
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let path = self.asset_path.clone().with_label(label.into());
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!self.asset_server.get_handles_untyped(&path).is_empty()
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}
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/// "Finishes" this context by populating the final [`Asset`] value (and the erased [`AssetMeta`] value, if it exists).
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/// The relevant asset metadata collected in this context will be stored in the returned [`LoadedAsset`].
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pub fn finish<A: Asset>(self, value: A, meta: Option<Box<dyn AssetMetaDyn>>) -> LoadedAsset<A> {
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LoadedAsset {
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value,
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dependencies: self.dependencies,
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loader_dependencies: self.loader_dependencies,
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labeled_assets: self.labeled_assets,
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meta,
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}
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}
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/// Gets the source path for this load context.
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pub fn path(&self) -> &Path {
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self.asset_path.path()
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}
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/// Gets the source asset path for this load context.
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pub fn asset_path(&self) -> &AssetPath<'static> {
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&self.asset_path
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}
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/// Reads the asset at the given path and returns its bytes
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pub async fn read_asset_bytes<'b, 'c>(
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&'b mut self,
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path: impl Into<AssetPath<'c>>,
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) -> Result<Vec<u8>, ReadAssetBytesError> {
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let path = path.into();
|
|
let source = self.asset_server.get_source(path.source())?;
|
|
let asset_reader = match self.asset_server.mode() {
|
|
AssetServerMode::Unprocessed { .. } => source.reader(),
|
|
AssetServerMode::Processed { .. } => source.processed_reader()?,
|
|
};
|
|
let mut reader = asset_reader.read(path.path()).await?;
|
|
let hash = if self.populate_hashes {
|
|
// NOTE: ensure meta is read while the asset bytes reader is still active to ensure transactionality
|
|
// See `ProcessorGatedReader` for more info
|
|
let meta_bytes = asset_reader.read_meta_bytes(path.path()).await?;
|
|
let minimal: ProcessedInfoMinimal = ron::de::from_bytes(&meta_bytes)
|
|
.map_err(DeserializeMetaError::DeserializeMinimal)?;
|
|
let processed_info = minimal
|
|
.processed_info
|
|
.ok_or(ReadAssetBytesError::MissingAssetHash)?;
|
|
processed_info.full_hash
|
|
} else {
|
|
Default::default()
|
|
};
|
|
let mut bytes = Vec::new();
|
|
reader
|
|
.read_to_end(&mut bytes)
|
|
.await
|
|
.map_err(|source| ReadAssetBytesError::Io {
|
|
path: path.path().to_path_buf(),
|
|
source,
|
|
})?;
|
|
self.loader_dependencies.insert(path.clone_owned(), hash);
|
|
Ok(bytes)
|
|
}
|
|
|
|
/// Retrieves a handle for the asset at the given path and adds that path as a dependency of the asset.
|
|
/// If the current context is a normal [`AssetServer::load`], an actual asset load will be kicked off immediately, which ensures the load happens
|
|
/// as soon as possible.
|
|
/// "Normal loads" kicked from within a normal Bevy App will generally configure the context to kick off loads immediately.
|
|
/// If the current context is configured to not load dependencies automatically (ex: [`AssetProcessor`](crate::processor::AssetProcessor)),
|
|
/// a load will not be kicked off automatically. It is then the calling context's responsibility to begin a load if necessary.
|
|
pub fn load<'b, A: Asset>(&mut self, path: impl Into<AssetPath<'b>>) -> Handle<A> {
|
|
let path = path.into().to_owned();
|
|
let handle = if self.should_load_dependencies {
|
|
self.asset_server.load(path)
|
|
} else {
|
|
self.asset_server.get_or_create_path_handle(path, None)
|
|
};
|
|
self.dependencies.insert(handle.id().untyped());
|
|
handle
|
|
}
|
|
|
|
/// Retrieves a handle for the asset at the given path and adds that path as a dependency of the asset without knowing its type.
|
|
pub fn load_untyped<'b>(
|
|
&mut self,
|
|
path: impl Into<AssetPath<'b>>,
|
|
) -> Handle<LoadedUntypedAsset> {
|
|
let path = path.into().to_owned();
|
|
let handle = if self.should_load_dependencies {
|
|
self.asset_server.load_untyped(path)
|
|
} else {
|
|
self.asset_server.get_or_create_path_handle(path, None)
|
|
};
|
|
self.dependencies.insert(handle.id().untyped());
|
|
handle
|
|
}
|
|
|
|
/// Loads the [`Asset`] of type `A` at the given `path` with the given [`AssetLoader::Settings`] settings `S`. This is a "deferred"
|
|
/// load. If the settings type `S` does not match the settings expected by `A`'s asset loader, an error will be printed to the log
|
|
/// and the asset load will fail.
|
|
pub fn load_with_settings<'b, A: Asset, S: Settings + Default>(
|
|
&mut self,
|
|
path: impl Into<AssetPath<'b>>,
|
|
settings: impl Fn(&mut S) + Send + Sync + 'static,
|
|
) -> Handle<A> {
|
|
let path = path.into();
|
|
let handle = if self.should_load_dependencies {
|
|
self.asset_server.load_with_settings(path.clone(), settings)
|
|
} else {
|
|
self.asset_server
|
|
.get_or_create_path_handle(path, Some(loader_settings_meta_transform(settings)))
|
|
};
|
|
self.dependencies.insert(handle.id().untyped());
|
|
handle
|
|
}
|
|
|
|
/// Returns a handle to an asset of type `A` with the label `label`. This [`LoadContext`] must produce an asset of the
|
|
/// given type and the given label or the dependencies of this asset will never be considered "fully loaded". However you
|
|
/// can call this method before _or_ after adding the labeled asset.
|
|
pub fn get_label_handle<'b, A: Asset>(
|
|
&mut self,
|
|
label: impl Into<CowArc<'b, str>>,
|
|
) -> Handle<A> {
|
|
let path = self.asset_path.clone().with_label(label);
|
|
let handle = self.asset_server.get_or_create_path_handle::<A>(path, None);
|
|
self.dependencies.insert(handle.id().untyped());
|
|
handle
|
|
}
|
|
|
|
/// Loads the asset at the given `path` directly. This is an async function that will wait until the asset is fully loaded before
|
|
/// returning. Use this if you need the _value_ of another asset in order to load the current asset. For example, if you are
|
|
/// deriving a new asset from the referenced asset, or you are building a collection of assets. This will add the `path` as a
|
|
/// "load dependency".
|
|
///
|
|
/// If the current loader is used in a [`Process`] "asset preprocessor", such as a [`LoadTransformAndSave`] preprocessor,
|
|
/// changing a "load dependency" will result in re-processing of the asset.
|
|
///
|
|
/// [`Process`]: crate::processor::Process
|
|
/// [`LoadTransformAndSave`]: crate::processor::LoadTransformAndSave
|
|
pub async fn load_direct<'b>(
|
|
&mut self,
|
|
path: impl Into<AssetPath<'b>>,
|
|
) -> Result<ErasedLoadedAsset, LoadDirectError> {
|
|
let path = path.into().into_owned();
|
|
let to_error = |e: AssetLoadError| -> LoadDirectError {
|
|
LoadDirectError {
|
|
dependency: path.clone(),
|
|
error: e,
|
|
}
|
|
};
|
|
let loaded_asset = {
|
|
let (meta, loader, mut reader) = self
|
|
.asset_server
|
|
.get_meta_loader_and_reader(&path, None)
|
|
.await
|
|
.map_err(to_error)?;
|
|
self.asset_server
|
|
.load_with_meta_loader_and_reader(
|
|
&path,
|
|
meta,
|
|
&*loader,
|
|
&mut *reader,
|
|
false,
|
|
self.populate_hashes,
|
|
)
|
|
.await
|
|
.map_err(to_error)?
|
|
};
|
|
let info = loaded_asset
|
|
.meta
|
|
.as_ref()
|
|
.and_then(|m| m.processed_info().as_ref());
|
|
let hash = info.map(|i| i.full_hash).unwrap_or(Default::default());
|
|
self.loader_dependencies.insert(path, hash);
|
|
Ok(loaded_asset)
|
|
}
|
|
|
|
/// Loads the asset at the given `path` directly from the provided `reader`. This is an async function that will wait until the asset is fully loaded before
|
|
/// returning. Use this if you need the _value_ of another asset in order to load the current asset, and that value comes from your [`Reader`].
|
|
/// For example, if you are deriving a new asset from the referenced asset, or you are building a collection of assets. This will add the `path` as a
|
|
/// "load dependency".
|
|
///
|
|
/// If the current loader is used in a [`Process`] "asset preprocessor", such as a [`LoadTransformAndSave`] preprocessor,
|
|
/// changing a "load dependency" will result in re-processing of the asset.
|
|
///
|
|
/// [`Process`]: crate::processor::Process
|
|
/// [`LoadTransformAndSave`]: crate::processor::LoadTransformAndSave
|
|
pub async fn load_direct_with_reader<'b>(
|
|
&mut self,
|
|
reader: &mut Reader<'_>,
|
|
path: impl Into<AssetPath<'b>>,
|
|
) -> Result<ErasedLoadedAsset, LoadDirectError> {
|
|
let path = path.into().into_owned();
|
|
|
|
let loader = self
|
|
.asset_server
|
|
.get_path_asset_loader(&path)
|
|
.await
|
|
.map_err(|error| LoadDirectError {
|
|
dependency: path.clone(),
|
|
error: error.into(),
|
|
})?;
|
|
|
|
let meta = loader.default_meta();
|
|
|
|
let loaded_asset = self
|
|
.asset_server
|
|
.load_with_meta_loader_and_reader(
|
|
&path,
|
|
meta,
|
|
&*loader,
|
|
reader,
|
|
false,
|
|
self.populate_hashes,
|
|
)
|
|
.await
|
|
.map_err(|error| LoadDirectError {
|
|
dependency: path.clone(),
|
|
error,
|
|
})?;
|
|
|
|
let info = loaded_asset
|
|
.meta
|
|
.as_ref()
|
|
.and_then(|m| m.processed_info().as_ref());
|
|
|
|
let hash = info.map(|i| i.full_hash).unwrap_or_default();
|
|
|
|
self.loader_dependencies.insert(path, hash);
|
|
|
|
Ok(loaded_asset)
|
|
}
|
|
}
|
|
|
|
/// An error produced when calling [`LoadContext::read_asset_bytes`]
|
|
#[derive(Error, Debug)]
|
|
pub enum ReadAssetBytesError {
|
|
#[error(transparent)]
|
|
DeserializeMetaError(#[from] DeserializeMetaError),
|
|
#[error(transparent)]
|
|
AssetReaderError(#[from] AssetReaderError),
|
|
#[error(transparent)]
|
|
MissingAssetSourceError(#[from] MissingAssetSourceError),
|
|
#[error(transparent)]
|
|
MissingProcessedAssetReaderError(#[from] MissingProcessedAssetReaderError),
|
|
/// Encountered an I/O error while loading an asset.
|
|
#[error("Encountered an io error while loading asset at `{path}`: {source}")]
|
|
Io {
|
|
path: PathBuf,
|
|
#[source]
|
|
source: std::io::Error,
|
|
},
|
|
#[error("The LoadContext for this read_asset_bytes call requires hash metadata, but it was not provided. This is likely an internal implementation error.")]
|
|
MissingAssetHash,
|
|
}
|