ca3947911e
* Refactor the internals of `Store<T>` This commit is an overdue refactoring and renaming of some internals of the `Store` type in Wasmtime. The actual implementation of `Store<T>` has evolved from the original implementation to the point where some of the aspects of how things are structured no longer makes sense. There's also always been a lot of unnecessary gymnastics when trying to get access to various store pieces depending on where you are in `wasmtime`. This refactoring aims to simplify all this and make the internals much easier to read/write. The following changes were made: * The `StoreOpaque<'_>` type is deleted, along with the `opaque()` method. * The `StoreInnermost` type was renamed to `StoreOpaque`. `StoreOpaque<'_>` is dead. Long live `StoreOpaque`. This renaming and a few small tweaks means that this type now suffices for all consumers. * The `AsContextMut` and `AsContext` traits are now implemented for `StoreInner<T>`. These changes, while subtly small, help clean up a lot of the internals of `wasmtime`. There's a lot less verbose `&mut store.as_context_mut().opaque()` now. Additionally many methods can simply start with `let store = store.as_context_mut().0;` and use things internally. One of the nicer aspects of using references directly is that the compiler automatically reborrows references as necessary meaning there's lots of less manual reborrowing. The main motivation for this change was actually somewhat roundabout where I found that when `StoreOpaque<'_>` was being captured in closures and iterators it's 3 pointers wide which is a lot of data to move around. Now things capture over `&mut StoreOpaque` which is just one nice and small pointer to move around. In any case though I've long wanted to revisit the design of these internals to improve the ergonomics. It's not expected that this change alone will really have all that much impact on the performance of `wasmtime`. Finally a doc comment was added to `store.rs` to try to explain all the `Store`-related types since there are a nontrivial amount. * Rustfmt
wasmtime
A standalone runtime for WebAssembly
A Bytecode Alliance project
Guide | Contributing | Website | Chat
Installation
The Wasmtime CLI can be installed on Linux and macOS with a small install script:
$ curl https://wasmtime.dev/install.sh -sSf | bash
Windows or otherwise interested users can download installers and binaries directly from the GitHub Releases page.
Example
If you've got the Rust compiler installed then you can take some Rust source code:
fn main() {
println!("Hello, world!");
}
and compile/run it with:
$ rustup target add wasm32-wasi
$ rustc hello.rs --target wasm32-wasi
$ wasmtime hello.wasm
Hello, world!
Features
-
Lightweight. Wasmtime is a standalone runtime for WebAssembly that scales with your needs. It fits on tiny chips as well as makes use of huge servers. Wasmtime can be embedded into almost any application too.
-
Fast. Wasmtime is built on the optimizing Cranelift code generator to quickly generate high-quality machine code at runtime.
-
Configurable. Whether you need to precompile your wasm ahead of time, generate code blazingly fast with Lightbeam, or interpret it at runtime, Wasmtime has you covered for all your wasm-executing needs.
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WASI. Wasmtime supports a rich set of APIs for interacting with the host environment through the WASI standard.
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Standards Compliant. Wasmtime passes the official WebAssembly test suite, implements the official C API of wasm, and implements future proposals to WebAssembly as well. Wasmtime developers are intimately engaged with the WebAssembly standards process all along the way too.
Language Support
You can use Wasmtime from a variety of different languages through embeddings of the implementation:
- Rust - the
wasmtimecrate - C - the
wasm.h,wasi.h, andwasmtime.hheaders - [C++] - the
wasmtime-cpprepository - Python - the
wasmtimePyPI package - .NET - the
WasmtimeNuGet package - Go - the
wasmtime-gorepository
Documentation
📚 Read the Wasmtime guide here! 📚
The wasmtime guide is the best starting point to learn about what Wasmtime can do for you or help answer your questions about Wasmtime. If you're curious in contributing to Wasmtime, it can also help you do that!
It's Wasmtime.