1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
use crate::error::AnyError;use crate::gotham_state::GothamState;use crate::resources::ResourceTable;use crate::runtime::GetErrorClassFn;use crate::runtime::JsRuntimeState;use crate::OpDecl;use crate::OpsTracker;use anyhow::Error;use futures::future::maybe_done;use futures::future::FusedFuture;use futures::future::MaybeDone;use futures::ready;use futures::task::noop_waker;use futures::Future;use serde::Serialize;use std::cell::RefCell;use std::ops::Deref;use std::ops::DerefMut;use std::pin::Pin;use std::rc::Rc;use std::rc::Weak;use std::task::Context;use std::task::Poll;
/// Wrapper around a Future, which causes that Future to be polled immediately.////// Background: ops are stored in a `FuturesUnordered` structure which polls/// them, but without the `OpCall` wrapper this doesn't happen until the next/// turn of the event loop, which is too late for certain ops.pub struct OpCall<T>(MaybeDone<Pin<Box<dyn Future<Output = T>>>>);
pub enum EagerPollResult<T> {  Ready(T),  Pending(OpCall<T>),}
impl<T> OpCall<T> {  /// Wraps a future, and polls the inner future immediately.  /// This should be the default choice for ops.  pub fn eager(fut: impl Future<Output = T> + 'static) -> EagerPollResult<T> {    let boxed = Box::pin(fut) as Pin<Box<dyn Future<Output = T>>>;    let mut inner = maybe_done(boxed);    let waker = noop_waker();    let mut cx = Context::from_waker(&waker);    let mut pinned = Pin::new(&mut inner);    let poll = pinned.as_mut().poll(&mut cx);    match poll {      Poll::Ready(_) => EagerPollResult::Ready(pinned.take_output().unwrap()),      _ => EagerPollResult::Pending(Self(inner)),    }  }
  /// Wraps a future; the inner future is polled the usual way (lazily).  pub fn lazy(fut: impl Future<Output = T> + 'static) -> Self {    let boxed = Box::pin(fut) as Pin<Box<dyn Future<Output = T>>>;    let inner = maybe_done(boxed);    Self(inner)  }
  /// Create a future by specifying its output. This is basically the same as  /// `async { value }` or `futures::future::ready(value)`.  pub fn ready(value: T) -> Self {    Self(MaybeDone::Done(value))  }}
impl<T> Future for OpCall<T> {  type Output = T;
  fn poll(    self: std::pin::Pin<&mut Self>,    cx: &mut std::task::Context<'_>,  ) -> std::task::Poll<Self::Output> {    // TODO(piscisaureus): safety comment    #[allow(clippy::undocumented_unsafe_blocks)]    let inner = unsafe { &mut self.get_unchecked_mut().0 };    let mut pinned = Pin::new(inner);    ready!(pinned.as_mut().poll(cx));    Poll::Ready(pinned.as_mut().take_output().unwrap())  }}
impl<F> FusedFuture for OpCall<F>where  F: Future,{  fn is_terminated(&self) -> bool {    self.0.is_terminated()  }}
pub type PromiseId = i32;pub type OpAsyncFuture = OpCall<(PromiseId, OpId, OpResult)>;pub type OpFn =  fn(&mut v8::HandleScope, v8::FunctionCallbackArguments, v8::ReturnValue);pub type OpId = usize;
pub enum Op {  Sync(OpResult),  Async(OpAsyncFuture),  NotFound,}
pub enum OpResult {  Ok(serde_v8::SerializablePkg),  Err(OpError),}
impl OpResult {  pub fn to_v8<'a>(    &mut self,    scope: &mut v8::HandleScope<'a>,  ) -> Result<v8::Local<'a, v8::Value>, serde_v8::Error> {    match self {      Self::Ok(x) => x.to_v8(scope),      Self::Err(err) => serde_v8::to_v8(scope, err),    }  }}
#[derive(Debug, Serialize)]#[serde(rename_all = "camelCase")]pub struct OpError {  #[serde(rename = "$err_class_name")]  class_name: &'static str,  message: String,  code: Option<&'static str>,}
impl OpError {  pub fn new(get_class: GetErrorClassFn, err: Error) -> Self {    Self {      class_name: (get_class)(&err),      message: format!("{:#}", err),      code: crate::error_codes::get_error_code(&err),    }  }}
pub fn to_op_result<R: Serialize + 'static>(  get_class: GetErrorClassFn,  result: Result<R, Error>,) -> OpResult {  match result {    Ok(v) => OpResult::Ok(v.into()),    Err(err) => OpResult::Err(OpError::new(get_class, err)),  }}
// TODO(@AaronO): optimize OpCtx(s) mem usage ?pub struct OpCtx {  pub id: OpId,  pub state: Rc<RefCell<OpState>>,  pub decl: OpDecl,  pub runtime_state: Weak<RefCell<JsRuntimeState>>,}
/// Maintains the resources and ops inside a JS runtime.pub struct OpState {  pub resource_table: ResourceTable,  pub get_error_class_fn: GetErrorClassFn,  pub tracker: OpsTracker,  pub last_fast_op_error: Option<AnyError>,  gotham_state: GothamState,}
impl OpState {  pub fn new(ops_count: usize) -> OpState {    OpState {      resource_table: Default::default(),      get_error_class_fn: &|_| "Error",      gotham_state: Default::default(),      last_fast_op_error: None,      tracker: OpsTracker::new(ops_count),    }  }}
impl Deref for OpState {  type Target = GothamState;
  fn deref(&self) -> &Self::Target {    &self.gotham_state  }}
impl DerefMut for OpState {  fn deref_mut(&mut self) -> &mut Self::Target {    &mut self.gotham_state  }}