Let's get the last changes in this week for a release. Will hold this PR
until all changes we want are in.
Release checklist:
- [x] test: updates across CI to test for Host Function output /
integration (#219)
- this should probably look something like a grep for some kind of
output proving guest/host interop?
- [x] Fix for userData pointer issue in Go host functions (#220)
- [x] docs: Host Functions in SDKs
- [ ] sdk: C
- [ ] sdk: C++
- [ ] sdk: Python
- [ ] sdk: Node
- [ ] sdk: Go
- [ ] sdk: Rust
- [x] docs: Manifest property names (http `headers` & memory
`max_pages`)
- [ ] blog: announcing v0.2.0, including host functions, Zig SDK/PDK,
Java SDK, .NET SDK, + ...
Hi,
We want to use Extism on our project
[Otoroshi](https://github.com/MAIF/otoroshi) but we need to run it on
jdk11
This pull request makes everything run smoothly on jdk11
If you have any suggestion about this pull request, i'm open to it
Thanks for your time
- New types:
- `ExtismValType` - Enum of WebAssembly types
- `ExtismValUnion` - A union of the possible WebAssembly types
- `ExtismVal` - A struct with `ExtismValType` and `ExtismValUnion`
- `ExtismFunction` - The host function wrapper type
- `ExtismFunctionType` - The type of the host function callback
- `ExtismCurrentPlugin` - Provides access to the currently running
plugin from inside a host function
- New functions:
- `extism_function_new` - Create a new `ExtismFunction`
- `extism_function_free` - Free an `ExtismFunction`
- `extism_current_plugin_memory`, `extism_current_plugin_memory_alloc`,
`extism_current_plugin_memory_free`,
`extism_current_plugin_memory_length` - Manage plugin memory from inside
a host functions
- Updated functions
- `extism_plugin_new` and `extsim_plugin_update` - now accept two extra
parameters for `ExtismFunction*` array and length of that array
## Notes
- Host functions take a user-data argument, which is owned by the
resulting `ExtismFunction` and will be cleaned up when
`extism_function_free` is called (if a cleanup function was passed in
with the user data)
- Host functions in every SDK require working with `ExtismVal` arguments
directly, this is pretty low-level for what is kind of a high-level
feature. We could work on adding some types to the SDKs that make
working with pointers to plugin data more accessible, maybe something
similar to how the Rust PDK handes input/output data.
- In each language the host functions more-or-less share a signature:
`(CurrentPlugin plugin, Val inputs[], Val outputs[], userData)`
- C, C++, OCaml and Go take a single userData argument but Python and
Node take a "rest" argument which allows passing any number of user-data
values
- Go requires the host function to be exported:
f9eb5ed839/go/main.go (L13-L26)
- Zig and Ruby should be relatively simple to add host functions to next
but I haven't really looked into Elixir, .NET or Java yet.
- Also closes#20
