Viewing file:  v8-promise.h (5.17 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef INCLUDE_V8_PROMISE_H_
#define INCLUDE_V8_PROMISE_H_
#include "v8-local-handle.h" // NOLINT(build/include_directory)
#include "v8-object.h" // NOLINT(build/include_directory)
#include "v8config.h" // NOLINT(build/include_directory)
namespace v8 {
class Context;
#ifndef V8_PROMISE_INTERNAL_FIELD_COUNT
// The number of required internal fields can be defined by embedder.
#define V8_PROMISE_INTERNAL_FIELD_COUNT 0
#endif
/**
* An instance of the built-in Promise constructor (ES6 draft).
*/
class V8_EXPORT Promise : public Object {
public:
/**
* State of the promise. Each value corresponds to one of the possible values
* of the [[PromiseState]] field.
*/
enum PromiseState { kPending, kFulfilled, kRejected };
class V8_EXPORT Resolver : public Object {
public:
/**
* Create a new resolver, along with an associated promise in pending state.
*/
static V8_WARN_UNUSED_RESULT MaybeLocal<Resolver> New(
Local<Context> context);
/**
* Extract the associated promise.
*/
Local<Promise> GetPromise();
/**
* Resolve/reject the associated promise with a given value.
* Ignored if the promise is no longer pending.
*/
V8_WARN_UNUSED_RESULT Maybe<bool> Resolve(Local<Context> context,
Local<Value> value);
V8_WARN_UNUSED_RESULT Maybe<bool> Reject(Local<Context> context,
Local<Value> value);
V8_INLINE static Resolver* Cast(Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Promise::Resolver*>(value);
}
private:
Resolver();
static void CheckCast(Value* obj);
};
/**
* Register a resolution/rejection handler with a promise.
* The handler is given the respective resolution/rejection value as
* an argument. If the promise is already resolved/rejected, the handler is
* invoked at the end of turn.
*/
V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Catch(Local<Context> context,
Local<Function> handler);
V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Then(Local<Context> context,
Local<Function> handler);
V8_WARN_UNUSED_RESULT MaybeLocal<Promise> Then(Local<Context> context,
Local<Function> on_fulfilled,
Local<Function> on_rejected);
/**
* Returns true if the promise has at least one derived promise, and
* therefore resolve/reject handlers (including default handler).
*/
bool HasHandler() const;
/**
* Returns the content of the [[PromiseResult]] field. The Promise must not
* be pending.
*/
Local<Value> Result();
/**
* Returns the value of the [[PromiseState]] field.
*/
PromiseState State();
/**
* Marks this promise as handled to avoid reporting unhandled rejections.
*/
void MarkAsHandled();
/**
* Marks this promise as silent to prevent pausing the debugger when the
* promise is rejected.
*/
void MarkAsSilent();
V8_INLINE static Promise* Cast(Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Promise*>(value);
}
static const int kEmbedderFieldCount = V8_PROMISE_INTERNAL_FIELD_COUNT;
private:
Promise();
static void CheckCast(Value* obj);
};
/**
* PromiseHook with type kInit is called when a new promise is
* created. When a new promise is created as part of the chain in the
* case of Promise.then or in the intermediate promises created by
* Promise.{race, all}/AsyncFunctionAwait, we pass the parent promise
* otherwise we pass undefined.
*
* PromiseHook with type kResolve is called at the beginning of
* resolve or reject function defined by CreateResolvingFunctions.
*
* PromiseHook with type kBefore is called at the beginning of the
* PromiseReactionJob.
*
* PromiseHook with type kAfter is called right at the end of the
* PromiseReactionJob.
*/
enum class PromiseHookType { kInit, kResolve, kBefore, kAfter };
using PromiseHook = void (*)(PromiseHookType type, Local<Promise> promise,
Local<Value> parent);
// --- Promise Reject Callback ---
enum PromiseRejectEvent {
kPromiseRejectWithNoHandler = 0,
kPromiseHandlerAddedAfterReject = 1,
kPromiseRejectAfterResolved = 2,
kPromiseResolveAfterResolved = 3,
};
class PromiseRejectMessage {
public:
PromiseRejectMessage(Local<Promise> promise, PromiseRejectEvent event,
Local<Value> value)
: promise_(promise), event_(event), value_(value) {}
V8_INLINE Local<Promise> GetPromise() const { return promise_; }
V8_INLINE PromiseRejectEvent GetEvent() const { return event_; }
V8_INLINE Local<Value> GetValue() const { return value_; }
private:
Local<Promise> promise_;
PromiseRejectEvent event_;
Local<Value> value_;
};
using PromiseRejectCallback = void (*)(PromiseRejectMessage message);
} // namespace v8
#endif // INCLUDE_V8_PROMISE_H_
|