Struct deno::Isolate

pub struct Isolate { /* fields omitted */ }

A single execution context of JavaScript. Corresponds roughly to the "Web Worker" concept in the DOM. An Isolate is a Future that can be used with Tokio. The Isolate future complete when there is an error or when all pending ops have completed.

Ops are created in JavaScript by calling Deno.core.dispatch(), and in Rust by implementing deno::Dispatch::dispatch. An async Op corresponds exactly to a Promise in JavaScript.

Methods

impl Isolate

pub fn new(startup_data: StartupData, will_snapshot: bool) -> Self

startup_data defines the snapshot or script used at startup to initialize the isolate.

pub fn set_dispatch<F>(&mut self, f: F) where
    F: Fn(&[u8], Option<PinnedBuf>) -> CoreOp + Send + Sync + 'static, 

Defines the how Deno.core.dispatch() acts. Called whenever Deno.core.dispatch() is called in JavaScript. zero_copy_buf corresponds to the second argument of Deno.core.dispatch().

pub fn set_dyn_import<F>(&mut self, f: F) where
    F: Fn(&str, &str) -> DynImportFuture + Send + Sync + 'static, 

pub fn set_js_error_create<F>(&mut self, f: F) where
    F: Fn(V8Exception) -> ErrBox + 'static, 

Allows a callback to be set whenever a V8 exception is made. This allows the caller to wrap the V8Exception into an error. By default this callback is set to CoreJSError::from_v8_exception.

pub fn shared_isolate_handle(&mut self) -> IsolateHandle

Get a thread safe handle on the isolate.

pub fn execute(
    &mut self,
    js_filename: &str,
    js_source: &str
) -> Result<(), ErrBox>

Executes traditional JavaScript code (traditional = not ES modules)

ErrBox can be downcast to a type that exposes additional information about the V8 exception. By default this type is CoreJSError, however it may be a different type if Isolate::set_js_error_create() has been used.

pub fn mod_new(
    &self,
    main: bool,
    name: &str,
    source: &str
) -> Result<deno_mod, ErrBox>

Low-level module creation.

pub fn mod_get_imports(&self, id: deno_mod) -> Vec<String>

pub fn snapshot(&self) -> Result<deno_snapshot<'static>, ErrBox>

Takes a snapshot. The isolate should have been created with will_snapshot set to true.

ErrBox can be downcast to a type that exposes additional information about the V8 exception. By default this type is CoreJSError, however it may be a different type if Isolate::set_js_error_create() has been used.

impl Isolate

pub fn mod_instantiate(
    &mut self,
    id: deno_mod,
    resolve_fn: &mut (dyn FnMut(&str, deno_mod) -> deno_mod + 'a)
) -> Result<(), ErrBox>

Instanciates a ES module

ErrBox can be downcast to a type that exposes additional information about the V8 exception. By default this type is CoreJSError, however it may be a different type if Isolate::set_js_error_create() has been used.

pub fn mod_evaluate(&mut self, id: deno_mod) -> Result<(), ErrBox>

Evaluates an already instantiated ES module.

ErrBox can be downcast to a type that exposes additional information about the V8 exception. By default this type is CoreJSError, however it may be a different type if Isolate::set_js_error_create() has been used.

Trait Implementations

impl Drop for Isolate

fn drop(&mut self)

Executes the destructor for this type.

impl Send for Isolate

impl Future for Isolate

type Item = ()

The type of value that this future will resolved with if it is successful.

type Error = ErrBox

The type of error that this future will resolve with if it fails in a normal fashion.

fn poll(&mut self) -> Poll<(), ErrBox>

Query this future to see if its value has become available, registering interest if it is not.

fn wait(self) -> Result<Self::Item, Self::Error>

Block the current thread until this future is resolved.

fn map<F, U>(self, f: F) -> Map<Self, F> where
    F: FnOnce(Self::Item) -> U, 

Map this future's result to a different type, returning a new future of the resulting type.

fn map_err<F, E>(self, f: F) -> MapErr<Self, F> where
    F: FnOnce(Self::Error) -> E, 

Map this future's error to a different error, returning a new future.

fn from_err<E>(self) -> FromErr<Self, E> where
    E: From<Self::Error>, 

Map this future's error to any error implementing From for this future's Error, returning a new future.

fn then<F, B>(self, f: F) -> Then<Self, B, F> where
    B: IntoFuture,
    F: FnOnce(Result<Self::Item, Self::Error>) -> B, 

Chain on a computation for when a future finished, passing the result of the future to the provided closure f.

fn and_then<F, B>(self, f: F) -> AndThen<Self, B, F> where
    B: IntoFuture<Error = Self::Error>,
    F: FnOnce(Self::Item) -> B, 

Execute another future after this one has resolved successfully.

fn or_else<F, B>(self, f: F) -> OrElse<Self, B, F> where
    B: IntoFuture<Item = Self::Item>,
    F: FnOnce(Self::Error) -> B, 

Execute another future if this one resolves with an error.

fn select<B>(self, other: B) -> Select<Self, <B as IntoFuture>::Future> where
    B: IntoFuture<Item = Self::Item, Error = Self::Error>, 

Waits for either one of two futures to complete.

fn select2<B>(self, other: B) -> Select2<Self, <B as IntoFuture>::Future> where
    B: IntoFuture, 

Waits for either one of two differently-typed futures to complete.

fn join<B>(self, other: B) -> Join<Self, <B as IntoFuture>::Future> where
    B: IntoFuture<Error = Self::Error>, 

Joins the result of two futures, waiting for them both to complete.

fn join3<B, C>(
    self,
    b: B,
    c: C
) -> Join3<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future> where
    B: IntoFuture<Error = Self::Error>,
    C: IntoFuture<Error = Self::Error>, 

Same as join, but with more futures.

fn join4<B, C, D>(
    self,
    b: B,
    c: C,
    d: D
) -> Join4<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future, <D as IntoFuture>::Future> where
    B: IntoFuture<Error = Self::Error>,
    C: IntoFuture<Error = Self::Error>,
    D: IntoFuture<Error = Self::Error>, 

Same as join, but with more futures.

fn join5<B, C, D, E>(
    self,
    b: B,
    c: C,
    d: D,
    e: E
) -> Join5<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future, <D as IntoFuture>::Future, <E as IntoFuture>::Future> where
    B: IntoFuture<Error = Self::Error>,
    C: IntoFuture<Error = Self::Error>,
    D: IntoFuture<Error = Self::Error>,
    E: IntoFuture<Error = Self::Error>, 

Same as join, but with more futures.

fn into_stream(self) -> IntoStream<Self>

Convert this future into a single element stream.

fn flatten(self) -> Flatten<Self> where
    Self::Item: IntoFuture,
    <Self::Item as IntoFuture>::Error: From<Self::Error>, 

Flatten the execution of this future when the successful result of this future is itself another future.

fn flatten_stream(self) -> FlattenStream<Self> where
    Self::Item: Stream,
    <Self::Item as Stream>::Error == Self::Error, 

Flatten the execution of this future when the successful result of this future is a stream.

fn fuse(self) -> Fuse<Self>

Fuse a future such that poll will never again be called once it has completed.

fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: FnOnce(&Self::Item), 

Do something with the item of a future, passing it on.

fn catch_unwind(self) -> CatchUnwind<Self> where
    Self: UnwindSafe, 

Catches unwinding panics while polling the future.

fn shared(self) -> Shared<Self>

Create a cloneable handle to this future where all handles will resolve to the same result.