Crate shred

Shared resource dispatcher

This library allows to dispatch systems, which can have interdependencies, shared and exclusive resource access, in parallel.

Examples

extern crate shred;

use shred::{DispatcherBuilder, Read, Resource, ResourceId, System, SystemData, World, Write};

#[derive(Debug, Default)]
struct ResA;

#[derive(Debug, Default)]
struct ResB;

#[derive(SystemData)] // Provided with `shred-derive` feature
struct Data<'a> {
    a: Read<'a, ResA>,
    b: Write<'a, ResB>,
}

struct EmptySystem;

impl<'a> System<'a> for EmptySystem {
    type SystemData = Data<'a>;

    fn run(&mut self, bundle: Data<'a>) {
        println!("{:?}", &*bundle.a);
        println!("{:?}", &*bundle.b);
    }
}

let mut world = World::empty();
let mut dispatcher = DispatcherBuilder::new()
    .with(EmptySystem, "empty", &[])
    .build();
world.insert(ResA);
world.insert(ResB);

dispatcher.dispatch(&mut world);

Once you are more familiar with how system data and parallelization works, you can take look at a more flexible and performant way to dispatch: ParSeq. Using it is bit trickier, but it allows dispatching without any virtual function calls.

Modules

cell	Helper module for some internals, most users don't need to interact with it.

Macros

par	The par! macro may be used to easily create a structure which runs things in parallel.
seq	The seq! macro may be used to easily create a structure which runs things sequentially.

Structs

AsyncDispatcher	Like, Dispatcher but works asynchronously.
BatchAccessor	The BatchAccessor is used to notify the main dispatcher of the read and write resources of the Systems contained in the batch ("sub systems").
BatchUncheckedWorld	The BatchUncheckedWorld wraps an instance of the world. You have to specify this as SystemData for a System implementing BatchController.
DefaultBatchControllerSystem	The DefaultBatchControllerSystem is a simple implementation that will dispatch the inner dispatcher one time.
DefaultProvider	A SetupHandler that simply uses the default implementation.
Dispatcher	The dispatcher struct, allowing systems to be executed in parallel.
DispatcherBuilder	Builder for the Dispatcher.
Entry	An entry to a resource of the World struct. This is similar to the Entry API found in the standard library.
Fetch	Allows to fetch a resource in a system immutably.
FetchMut	Allows to fetch a resource in a system mutably.
MetaIter	An iterator for the MetaTable.
MetaIterMut	A mutable iterator for the MetaTable.
MetaTable	The MetaTable which allows to store object-safe trait implementations for resources.
PanicHandler	A setup handler that simply does nothing and thus will cause a panic on fetching.
Par	Runs two tasks in parallel. These two tasks are called head and tail in the following documentation.
ParSeq	A dispatcher intended to be used with Par and Seq structures.
Read	Allows to fetch a resource in a system immutably.
ResourceId	The id of a Resource, which simply wraps a type id and a "dynamic ID". The "dynamic ID" is usually just left 0, and, unless such documentation says otherwise, other libraries will assume that it is always 0; non-zero IDs are only used for special resource types that are specifically defined in a more dynamic way, such that resource types can essentially be created at run time, without having different static types.
Seq	Runs two tasks sequentially. These two tasks are called head and tail in the following documentation.
StaticAccessor	The static accessor that is used for SystemData.
World	A Resource container, which provides methods to insert, access and manage the contained resources.
Write	Allows to fetch a resource in a system mutably.

Enums

AccessorCow	Either an Accessor of the system T or a reference to it.
RunningTime

Traits

Accessor	A trait for accessing read/write multiple resources from a system. This can be used to create dynamic systems that don't specify what they fetch at compile-time.
BatchController	The BatchController is the additional trait that a normal System must implement in order to be used as a system controlling the execution of a batch.
CastFrom	Helper trait for the MetaTable. This trait is required to be implemented for a trait to be compatible with the meta table.
DynamicSystemData	A struct implementing system data indicates that it bundles some resources which are required for the execution.
Resource	A resource is a data slot which lives in the World can only be accessed according to Rust's typical borrowing model (one writer xor multiple readers).
RunNow	Trait for fetching data and running systems. Automatically implemented for systems.
RunWithPool	Similar to RunNow except additionally taking in a rayon::ThreadPool for parallelism.
SetupHandler	A setup handler performing the fetching of T.
System	A System, executed with a set of required Resources.
SystemData	A static system data that can specify its dependencies at statically (at compile-time). Most system data is a SystemData, the DynamicSystemData type is only needed for very special setups.

Type Definitions

ReadExpect	Allows to fetch a resource in a system immutably. This will panic if the resource does not exist. Usage of Read or Option<Read> is therefore recommended.
Resources	Deprecated Alias for World for easier migration to the new version. Will be removed in the future.
WriteExpect	Allows to fetch a resource in a system mutably. This will panic if the resource does not exist. Usage of Write or Option<Write> is therefore recommended.

Derive Macros

SystemData

A reexport of the #[derive(SystemData] macro provided by shred-derive. This requires that the shred-derive feature is enabled. Used to #[derive] the trait SystemData.