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denoland-deno/cli/ops/dispatch_json.rs
Bartek Iwańczuk 4e1abb4f3a
refactor: use OpError instead of ErrBox for errors in ops (#4058)
To better reflect changes in error types in JS from #3662 this PR changes 
default error type used in ops from "ErrBox" to "OpError".

"OpError" is a type that can be sent over to JSON; it has all 
information needed to construct error in JavaScript. That
made "GetErrorKind" trait useless and so it was removed altogether.

To provide compatibility with previous use of "ErrBox" an implementation of
"From<ErrBox> for OpError" was added, however, it is an escape hatch and
ops implementors should strive to use "OpError" directly.
2020-02-23 14:51:29 -05:00

105 lines
2.9 KiB
Rust

// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
use crate::op_error::OpError;
use deno_core::*;
use futures::future::FutureExt;
pub use serde_derive::Deserialize;
use serde_json::json;
pub use serde_json::Value;
use std::future::Future;
use std::pin::Pin;
pub type JsonResult = Result<Value, OpError>;
pub type AsyncJsonOp = Pin<Box<dyn Future<Output = JsonResult>>>;
pub enum JsonOp {
Sync(Value),
Async(AsyncJsonOp),
/// AsyncUnref is the variation of Async, which doesn't block the program
/// exiting.
AsyncUnref(AsyncJsonOp),
}
fn json_err(err: OpError) -> Value {
json!({
"message": err.msg,
"kind": err.kind as u32,
})
}
fn serialize_result(promise_id: Option<u64>, result: JsonResult) -> Buf {
let value = match result {
Ok(v) => json!({ "ok": v, "promiseId": promise_id }),
Err(err) => json!({ "err": json_err(err), "promiseId": promise_id }),
};
serde_json::to_vec(&value).unwrap().into_boxed_slice()
}
#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
struct AsyncArgs {
promise_id: Option<u64>,
}
pub fn json_op<D>(d: D) -> impl Fn(&[u8], Option<ZeroCopyBuf>) -> CoreOp
where
D: Fn(Value, Option<ZeroCopyBuf>) -> Result<JsonOp, OpError>,
{
move |control: &[u8], zero_copy: Option<ZeroCopyBuf>| {
let async_args: AsyncArgs = match serde_json::from_slice(control) {
Ok(args) => args,
Err(e) => {
let buf = serialize_result(None, Err(OpError::from(e)));
return CoreOp::Sync(buf);
}
};
let promise_id = async_args.promise_id;
let is_sync = promise_id.is_none();
let result = serde_json::from_slice(control)
.map_err(OpError::from)
.and_then(|args| d(args, zero_copy));
// Convert to CoreOp
match result {
Ok(JsonOp::Sync(sync_value)) => {
assert!(promise_id.is_none());
CoreOp::Sync(serialize_result(promise_id, Ok(sync_value)))
}
Ok(JsonOp::Async(fut)) => {
assert!(promise_id.is_some());
let fut2 = fut.then(move |result| {
futures::future::ok(serialize_result(promise_id, result))
});
CoreOp::Async(fut2.boxed_local())
}
Ok(JsonOp::AsyncUnref(fut)) => {
assert!(promise_id.is_some());
let fut2 = fut.then(move |result| {
futures::future::ok(serialize_result(promise_id, result))
});
CoreOp::AsyncUnref(fut2.boxed_local())
}
Err(sync_err) => {
let buf = serialize_result(promise_id, Err(sync_err));
if is_sync {
CoreOp::Sync(buf)
} else {
CoreOp::Async(futures::future::ok(buf).boxed_local())
}
}
}
}
}
pub fn blocking_json<F>(is_sync: bool, f: F) -> Result<JsonOp, OpError>
where
F: 'static + Send + FnOnce() -> JsonResult,
{
if is_sync {
Ok(JsonOp::Sync(f()?))
} else {
let fut = async move { tokio::task::spawn_blocking(f).await.unwrap() };
Ok(JsonOp::Async(fut.boxed_local()))
}
}