Before `extern "C"` was needed to include the header in C++ code. Now
that's included inside, so it's easier and cleaner to include in c++
projects like the `cpp-sdk`.
- Uses `tracing` instead of `log` crate
- Uses `tracing-subscriber` instead of `fern`
- This allows us to automatically capture `log` events using
`tracing-subscriber`
- Breaking: Makes `extism::set_log_file` private and only used through
the C API, Rust users should use `tracing-subscriber` to determine which
filters/levels to log.
- Adds `extism::set_log_callback` function to set a callback that can be
used for custom logging from Rust.
- Adds `bool extism_log_custom(const char *level)` and
`extism_log_drain(void (*fn)(const char *s, size_t length)` to the C API
to enable custom sinks in other SDKs
My initial goal was to make logging configurable for each plugin instead
of global but wasn't able to accomplish that in this PR (still looking
into it)
- Switches from `log4rs` to `fern` - this significantly simplifies the
logging code
- Also considered `simplelog`
- Adds `plugin.id` to the logs whenever available
- Uses `extism::plugin::$id` target for functions logged from the PDK
- Adds `extism-convert` crate with `ToBytes`, `FromBytes` and
`FromBytesOwned` traits
- This serves as a single interface for reading/writing rich types from
WebAssembly linear memory.
- Supports `Json` and `Msgpack` and `Protobuf` encodings out-of-the-box
- Updates `Plugin::call` to take `ToBytes` as the input argument and
return a `FromBytes` value
- Adds `host_fn!` macro to simplify host function creation
- Cleans up generated documentation a little
- PR for the Rust PDK: https://github.com/extism/rust-pdk/pull/31
- Adds a `typed_plugin!` macro to implement type-safe wrappers around
`Plugin`
- After this we should focus on adding similar type-conversion helpers
to the SDKs and other PDKs to make it easier to use across languages.
For example, a Python host running a Rust plugin using Msgpack encoded
types.
## Examples
### Calling a function
Instead of the untyped, bytes-only `call` function:
```rust
let output = plugin.call("func_name", "my data").unwrap();
let output: MyType = serde_json::from_slice(&output).unwrap();
```
We can now use richer types to encode/decode our values directly when
using `call`:
```rust
let Json(output) = plugin.call::<_, Json<MyType>>("func_name", "my data").unwrap();
```
### Allocating inside of a host function
The same interface works for host functions, so instead of:
```rust
fn hello_world(
plugin: &mut CurrentPlugin,
inputs: &[Val],
outputs: &mut [Val],
_user_data: UserData,
) -> Result<(), Error> {
let handle = plugin.memory_handle_val(&inputs[0])?;
let input = plugin.memory_read_str(handle)?;
let output = plugin.memory_alloc_bytes(&input).unwrap();
outputs[0] = output.into();
Ok(())
}
```
Becomes:
```rust
fn hello_world(
plugin: &mut CurrentPlugin,
inputs: &[Val],
outputs: &mut [Val],
_user_data: UserData,
) -> Result<(), Error> {
let my_value: String = plugin.memory_get_val(&inputs[0])?;
let output = plugin.memory_new(&my_value)?;
outputs[0] = plugin.memory_to_val(output);
Ok(())
}
```
Although this isn't much of an improvement, using the `host_fn` macro,
we can really begin to see how the above function is really just an
identity function:
```rust
host_fn!(hello_world(a: String) -> String {
a
});
```
### typed_plugin!
`typed_plugin!` is used to make a typed wrapper around a Plugin:
```rust
/// Create the typed plugin
typed_plugin!(Testing {
count_vowels(&str) -> Json<Count>
});
/// Create the `Plugin` and convert it to `Testing` wrapper
let mut plugin: Testing = Plugin::new(WASM, [f], true).unwrap().into();
/// Call the `count_vowels` function:
let Json(output0): Json<Count> = plugin.count_vowels("abc123")?;
```
It could make sense to convert `host_fn` and/or `typed_plugin` to
proc-macros at some point, but for now they work and provide some
flexibility in experimenting with the interfaces. Another future update
could be to figure out a nice way to make it so input can be written in
multiple chunks, so the entire input doesn't have to get copied into
memory at once.
- Removes the `ExtismContext` type from runtime and all SDKs
- Removed SDK functions: `extism_context_new`, `extism_context_reset`,
`extism_context_free`
- All SDKs have been updated, but there are still some TODOs below
- Removes `extism_plugin_update`
- Plugins can no longer be updated - a new plugin should be created
instead
- Adds `extism_plugin_id` to uniquely identify plugins
- Merges the `extism-runtime` and `extism` crates (there is no longer an
`extism-runtime` crate)
- Makes `extism::Manifest` an alias for `extism_manifest::Manifest`
instead of a distinct type
- Adds `MemoryHandle` type to SDKs to refer to blocks of Extism memory
that can be accessed in host functions
- Improves thread-safety of Plugins, adds C++ test to call a single
plugin from multiple threads.
- Expands wasmtime bounds to include 12.0
This PR adds the `kernel` directory which contains a port of the Extism
memory allocator compiled to WebAssembly and removes
`runtime/src/memory.rs` completely.
Being able to re-use memory functions as a WASM module allows us to
begin to experiment with porting Extism to new runtimes!
This is in a draft state while I'm verifying some of these changes.
EIP: https://github.com/extism/proposals/pull/8
This PR makes minor breaking changes to several SDKs, but not to runtime
C API. The threadsafety updates in the Rust SDK are kind of specific to
Rust, I'm not sure if it makes sense to add the locks to all the other
SDKs at this point. For the most part the `Context` and `Plugin` types
in the SDKs should be safe to use protected by a mutex but they aren't
inherently threadsafe. That kind of locking should probably be done by
the user.
- Runtime
- improve thread safety
- reinstantiates less
- fixes a potential resource exhaustion bug from re-instantiating using
the same store too many times
- Rust SDK
- adds `Send` and `Sync` implementations for `Context`
- adds test sharing a context between threads
- adds `Plugin::call_map` to call a plugin and handle the output with
the lock held
- adds testing sharing an `Arc<Mutex<Plugin>>` between threads
- adds `Plugin::create` and `Plugin::create_from_manifest` to create a
plugin without a `Context`
- Python
- BREAKING
- changes `Plugin` constructor to take `context` as an optional named
argument, to update use `Plugin(data, context=context)` instead
- Ruby
- BREAKING
- changes `Plugin` constructor to take `context` as an optional named
argument, to update use `Plugin.new(data, context=context)` instead
- Go
- adds `NewPlugin` and `NewPluginFromManifest` functions
- Node
- BREAKING
- changes `Plugin` constructor to take `context` as an optional named
argument, to update use `new Plugin(data, wasi, config, host, context)`
instead of `new Plugin(context, data, wasi, functions, config)` (most
people are probably using `context.plugin` instead of the Plugin
constructor anyway)
- OCaml
- BREAKING
- changes `Plugin.create` and `Plugin.of_manifest` to take `context` as
an optional named argument, to update `Plugin.create ~context data` and
`Plugin.of_manifest ~context data` instead
- Haskell
- adds `createPlugin` and `createPluginFromManifest` functions
- Elixir
- adds `Plugin.new` to make a plugin without going through
`Context.new_plugin`
- Java
- adds new `Plugin` constructors without a `Context` argument
- C++
- BREAKING
- Updates `Plugin` constructor to take an optional context as the last
argument, instead of requiring it to be the first argument
- Use `Plugin(wasm, wasi, functions, ctx)` instead of `Plugin(ctx, wasm,
wasi, functions)`
- Zig
- Adds `Plugin.create` and `Plugin.createWithManifest` to create plugins
in their own context.
---------
Co-authored-by: zach <zach@dylib.so>
Co-authored-by: Benjamin Eckel <bhelx@simst.im>
- 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
- Adds `ExtismContext` instead of global `PLUGINS` registry
- Adds `extism_context_new`, `extism_context_free` and
`extism_context_reset`
- Requires updating nearly every SDK function to add context parameter
- Renames some SDK functions to follow better naming conventions
- `extism_plugin_register` -> `extism_plugin_new`
- `extism_output_get` -> `extism_plugin_output_data`
- `extism_output_length` -> `extism_plugin_output_length`
- `extism_call` -> `extism_plugin_call`
- Updates `extism_error` to return the context error when -1 issued for
the plug-in ID
- Adds `extism_plugin_free` to remove an existing plugin
- Updates SDKs to include these functions
- Updates SDK examples and comments
Co-authored-by: Steve Manuel <steve@dylib.so>
