* support dynamic function calls in component model This addresses #4310, introducing a new `component::values::Val` type for representing component values dynamically, as well as `component::types::Type` for representing the corresponding interface types. It also adds a `call` method to `component::func::Func`, which takes a slice of `Val`s as parameters and returns a `Result<Val>` representing the result. Note that I've moved `post_return` and `call_raw` from `TypedFunc` to `Func` since there was nothing specific to `TypedFunc` about them, and I wanted to reuse them. The code in both is unchanged beyond the trivial tweaks to make them fit in their new home. Signed-off-by: Joel Dice <joel.dice@fermyon.com> * order variants and match cases more consistently Signed-off-by: Joel Dice <joel.dice@fermyon.com> * implement lift for String, Box<str>, etc. This also removes the redundant `store` parameter from `Type::load`. Signed-off-by: Joel Dice <joel.dice@fermyon.com> * implement code review feedback This fixes a few issues: - Bad offset calculation when lowering - Missing variant padding - Style issues regarding `types::Handle` - Missed opportunities to reuse `Lift` and `Lower` impls It also adds forwarding `Lift` impls for `Box<[T]>`, `Vec<T>`, etc. Signed-off-by: Joel Dice <joel.dice@fermyon.com> * move `new_*` methods to specific `types` structs Per review feedback, I've moved `Type::new_record` to `Record::new_val` and added a `Type::unwrap_record` method; likewise for the other kinds of types. Signed-off-by: Joel Dice <joel.dice@fermyon.com> * make tuple, option, and expected type comparisons recursive These types should compare as equal across component boundaries as long as their type parameters are equal. Signed-off-by: Joel Dice <joel.dice@fermyon.com> * improve error diagnostic in `Type::check` We now distinguish between more failure cases to provide an informative error message. Signed-off-by: Joel Dice <joel.dice@fermyon.com> * address review feedback - Remove `WasmStr::to_str_from_memory` and `WasmList::get_from_memory` - add `try_new` methods to various `values` types - avoid using `ExactSizeIterator::len` where we can't trust it - fix over-constrained bounds on forwarded `ComponentType` impls Signed-off-by: Joel Dice <joel.dice@fermyon.com> * rearrange code per review feedback - Move functions from `types` to `values` module so we can make certain struct fields private - Rename `try_new` to just `new` Signed-off-by: Joel Dice <joel.dice@fermyon.com> * remove special-case equality test for tuples, options, and expecteds Instead, I've added a FIXME comment and will open an issue to do recursive structural equality testing. Signed-off-by: Joel Dice <joel.dice@fermyon.com>
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
-
Fast. Wasmtime is built on the optimizing Cranelift code generator to quickly generate high-quality machine code either at runtime or ahead-of-time. Wasmtime's runtime is also optimized for cases such as efficient instantiation, low-overhead transitions between the embedder and wasm, and scalability of concurrent instances.
-
Secure. Wasmtime's development is strongly focused on the correctness of its implementation with 24/7 fuzzing donated by Google's OSS Fuzz, leveraging Rust's API and runtime safety guarantees, careful design of features and APIs through an RFC process, a security policy in place for when things go wrong, and a release policy for patching older versions as well. We follow best practices for defense-in-depth and known protections and mitigations for issues like Spectre. Finally, we're working to push the state-of-the-art by collaborating with academic researchers to formally verify critical parts of Wasmtime and Cranelift.
-
Configurable. Wastime supports a rich set of APIs and build time configuration to provide many options such as further means of restricting WebAssembly beyond its basic guarantees such as its CPU and Memory consumption. Wasmtime also runs in tiny environments all the way up to massive servers with many concurrent instances.
-
WASI. Wasmtime supports a rich set of APIs for interacting with the host environment through the WASI standard.
-
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, CMake orwasmtimeConan package - C++ - the
wasmtime-cpprepository or usewasmtime-cppConan package - 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.