Evan AlmloffandJonathan Kelley
519ec9d294
* add a default head method through eval * remove the old document trait * implement document for each platform * pull out document into a dedicated crate to cut down on shared dependencies --------- Co-authored-by: Jonathan Kelley <jkelleyrtp@gmail.com>
75 lines
2.5 KiB
Rust
75 lines
2.5 KiB
Rust
#![doc = include_str!("../docs/eval.md")]
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use crate::error::EvalError;
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use generational_box::GenerationalBox;
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use std::future::{poll_fn, Future, IntoFuture};
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use std::pin::Pin;
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use std::task::{Context, Poll};
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#[doc = include_str!("../docs/eval.md")]
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pub struct Eval {
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evaluator: GenerationalBox<Box<dyn Evaluator>>,
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}
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impl Eval {
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/// Create this eval from a dynamic evaluator
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pub fn new(evaluator: GenerationalBox<Box<dyn Evaluator + 'static>>) -> Self {
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Self { evaluator }
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}
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/// Wait until the javascript task is finished and return the result
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pub async fn join<T: serde::de::DeserializeOwned>(self) -> Result<T, EvalError> {
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let json_value = poll_fn(|cx| match self.evaluator.try_write() {
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Ok(mut evaluator) => evaluator.poll_join(cx),
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Err(_) => Poll::Ready(Err(EvalError::Finished)),
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})
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.await?;
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serde_json::from_value(json_value).map_err(EvalError::Serialization)
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}
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/// Send a message to the javascript task
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pub fn send(&self, data: impl serde::Serialize) -> Result<(), EvalError> {
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match self.evaluator.try_read() {
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Ok(evaluator) => {
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evaluator.send(serde_json::to_value(data).map_err(EvalError::Serialization)?)
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}
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Err(_) => Err(EvalError::Finished),
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}
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}
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/// Receive a message from the javascript task
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pub async fn recv<T: serde::de::DeserializeOwned>(&mut self) -> Result<T, EvalError> {
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let json_value = poll_fn(|cx| match self.evaluator.try_write() {
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Ok(mut evaluator) => evaluator.poll_recv(cx),
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Err(_) => Poll::Ready(Err(EvalError::Finished)),
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})
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.await?;
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serde_json::from_value(json_value).map_err(EvalError::Serialization)
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}
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}
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impl IntoFuture for Eval {
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type Output = Result<serde_json::Value, EvalError>;
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type IntoFuture = Pin<Box<dyn Future<Output = Self::Output>>>;
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fn into_future(self) -> Self::IntoFuture {
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Box::pin(self.join().into_future())
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}
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}
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/// The platform's evaluator.
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pub trait Evaluator {
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/// Sends a message to the evaluated JavaScript.
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fn send(&self, data: serde_json::Value) -> Result<(), EvalError>;
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/// Receive any queued messages from the evaluated JavaScript.
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fn poll_recv(
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&mut self,
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context: &mut Context<'_>,
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) -> Poll<Result<serde_json::Value, EvalError>>;
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/// Gets the return value of the JavaScript
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fn poll_join(
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&mut self,
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context: &mut Context<'_>,
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) -> Poll<Result<serde_json::Value, EvalError>>;
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}
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