Files
wasmtime/crates/wasi-nn
Tanya L. Crenshaw b06ed39c1e Fixes #2418: Enhance wiggle to generate its UserErrorConverstion trait with a function that returns Result<abi_err, String> (#2419)
* Enhance wiggle to generate its UserErrorConverstion trait with a function that returns
a Result<abi_err, String>.  This enhancement allows hostcall implementations using wiggle
to return an actionable error to the instance (the abi_err) or to terminate the instance
using the String as fatal error information.

* Enhance wiggle to generate its UserErrorConverstion trait with a function that returns
a Result<abi_err, String>.  This enhancement allows hostcall implementations using wiggle
to return an actionable error to the instance (the abi_err) or to terminate the instance
using the String as fatal error information.

* Enhance the wiggle/wasmtime integration to leverage new work in ab7e9c6.  Hostcall
implementations generated by wiggle now return an Result<abi_error, Trap>.  As a
result, hostcalls experiencing fatal errors may trap, thereby terminating the
wasmtime instance.  This enhancement has been performed for both wasi snapshot1
and wasi snapshot0.

* Update wasi-nn crate to reflect enhancement in issue #2418.

* Update wiggle test-helpers for wiggle enhancement made in issue #2418.

* Address PR feedback; omit verbose return statement.

* Address PR feedback; manually format within a proc macro.

* Address PR feedback; manually format proc macro.

* Restore return statements to wasi.rs.

* Restore return statements in funcs.rs.

* Address PR feedback; omit TODO and fix formatting.

* Ok-wrap error type in assert statement.
2020-11-24 14:06:57 -06:00
..

wasmtime-wasi-nn

This crate enables support for the wasi-nn API in Wasmtime. Currently it contains an implementation of wasi-nn using OpenVINO™ but in the future it could support multiple machine learning backends. Since the wasi-nn API is expected to be an optional feature of WASI, this crate is currently separate from the wasi-common crate. This crate is experimental and its API, functionality, and location could quickly change.

Use

Use the Wasmtime APIs to instantiate a Wasm module and link in the WasiNn implementation as follows:

let wasi_nn = WasiNn::new(&store, WasiNnCtx::new()?);
wasi_nn.add_to_linker(&mut linker)?;

Build

This crate should build as usual (i.e. cargo build) but note that using an existing installation of OpenVINO™, rather than building from source, will drastically improve the build times. See the openvino crate for more information

Example

An end-to-end example demonstrating ML classification is included in examples:

  • tests/wasi-nn-rust-bindings contains ergonomic bindings for writing Rust code against the wasi-nn APIs
  • tests/classification-example contains a standalone Rust project that uses the wasi-nn APIs and is compiled to the wasm32-wasi target using the wasi-nn-rust-bindings

Run the example from the Wasmtime project directory:

ci/run-wasi-nn-example.sh