File: Promise.h

package info (click to toggle)
thunderbird 1:60.8.0-1~deb9u1
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 2,339,208 kB
  • sloc: cpp: 5,456,704; ansic: 2,360,384; python: 596,095; asm: 340,963; java: 326,291; xml: 258,664; sh: 84,366; makefile: 23,702; perl: 17,317; objc: 3,768; yacc: 1,766; ada: 1,681; lex: 1,364; pascal: 1,264; cs: 879; exp: 527; php: 436; lisp: 258; ruby: 153; awk: 152; sed: 53; csh: 27
file content (201 lines) | stat: -rw-r--r-- 7,238 bytes parent folder | download | duplicates (7)
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
195
196
197
198
199
200
201
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_Promise_h
#define mozilla_dom_Promise_h

#include "mozilla/Attributes.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/TypeTraits.h"
#include "mozilla/dom/BindingDeclarations.h"
#include "nsCycleCollectionParticipant.h"
#include "mozilla/dom/PromiseBinding.h"
#include "mozilla/dom/ToJSValue.h"
#include "mozilla/WeakPtr.h"
#include "nsWrapperCache.h"
#include "nsAutoPtr.h"
#include "js/TypeDecls.h"
#include "jspubtd.h"

class nsIGlobalObject;

namespace mozilla {
namespace dom {

class AnyCallback;
class MediaStreamError;
class PromiseInit;
class PromiseNativeHandler;
class PromiseDebugging;

#define NS_PROMISE_IID                               \
  {                                                  \
    0x1b8d6215, 0x3e67, 0x43ba, {                    \
      0x8a, 0xf9, 0x31, 0x5e, 0x8f, 0xce, 0x75, 0x65 \
    }                                                \
  }

class Promise : public nsISupports, public SupportsWeakPtr<Promise> {
  friend class PromiseTask;
  friend class PromiseWorkerProxy;
  friend class PromiseWorkerProxyRunnable;

 public:
  NS_DECLARE_STATIC_IID_ACCESSOR(NS_PROMISE_IID)
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(Promise)
  MOZ_DECLARE_WEAKREFERENCE_TYPENAME(Promise)

  // Promise creation tries to create a JS reflector for the Promise, so is
  // fallible.  Furthermore, we don't want to do JS-wrapping on a 0-refcount
  // object, so we addref before doing that and return the addrefed pointer
  // here.
  static already_AddRefed<Promise> Create(nsIGlobalObject* aGlobal,
                                          ErrorResult& aRv);

  // Reports a rejected Promise by sending an error report.
  static void ReportRejectedPromise(JSContext* aCx, JS::HandleObject aPromise);

  typedef void (Promise::*MaybeFunc)(JSContext* aCx,
                                     JS::Handle<JS::Value> aValue);

  void MaybeResolve(JSContext* aCx, JS::Handle<JS::Value> aValue);
  void MaybeReject(JSContext* aCx, JS::Handle<JS::Value> aValue);

  // Helpers for using Promise from C++.
  // Most DOM objects are handled already.  To add a new type T, add a
  // ToJSValue overload in ToJSValue.h.
  // aArg is a const reference so we can pass rvalues like integer constants
  template <typename T>
  void MaybeResolve(const T& aArg) {
    MaybeSomething(aArg, &Promise::MaybeResolve);
  }

  void MaybeResolveWithUndefined();

  inline void MaybeReject(nsresult aArg) {
    MOZ_ASSERT(NS_FAILED(aArg));
    MaybeSomething(aArg, &Promise::MaybeReject);
  }

  inline void MaybeReject(ErrorResult& aArg) {
    MOZ_ASSERT(aArg.Failed());
    MaybeSomething(aArg, &Promise::MaybeReject);
  }

  void MaybeReject(const RefPtr<MediaStreamError>& aArg);

  void MaybeRejectWithUndefined();

  // DO NOT USE MaybeRejectBrokenly with in new code.  Promises should be
  // rejected with Error instances.
  // Note: MaybeRejectBrokenly is a template so we can use it with DOMException
  // without instantiating the DOMException specialization of MaybeSomething in
  // every translation unit that includes this header, because that would
  // require use to include DOMException.h either here or in all those
  // translation units.
  template <typename T>
  void MaybeRejectBrokenly(const T& aArg);  // Not implemented by default; see
                                            // specializations in the .cpp for
                                            // the T values we support.

  // WebIDL

  nsIGlobalObject* GetParentObject() const { return mGlobal; }

  // Do the equivalent of Promise.resolve in the compartment of aGlobal.  The
  // compartment of aCx is ignored.  Errors are reported on the ErrorResult; if
  // aRv comes back !Failed(), this function MUST return a non-null value.
  static already_AddRefed<Promise> Resolve(nsIGlobalObject* aGlobal,
                                           JSContext* aCx,
                                           JS::Handle<JS::Value> aValue,
                                           ErrorResult& aRv);

  // Do the equivalent of Promise.reject in the compartment of aGlobal.  The
  // compartment of aCx is ignored.  Errors are reported on the ErrorResult; if
  // aRv comes back !Failed(), this function MUST return a non-null value.
  static already_AddRefed<Promise> Reject(nsIGlobalObject* aGlobal,
                                          JSContext* aCx,
                                          JS::Handle<JS::Value> aValue,
                                          ErrorResult& aRv);

  // Do the equivalent of Promise.all in the current compartment of aCx.  Errors
  // are reported on the ErrorResult; if aRv comes back !Failed(), this function
  // MUST return a non-null value.
  static already_AddRefed<Promise> All(
      JSContext* aCx, const nsTArray<RefPtr<Promise>>& aPromiseList,
      ErrorResult& aRv);

  void Then(
      JSContext* aCx,
      // aCalleeGlobal may not be in the compartment of aCx, when called over
      // Xrays.
      JS::Handle<JSObject*> aCalleeGlobal, AnyCallback* aResolveCallback,
      AnyCallback* aRejectCallback, JS::MutableHandle<JS::Value> aRetval,
      ErrorResult& aRv);

  JSObject* PromiseObj() const { return mPromiseObj; }

  void AppendNativeHandler(PromiseNativeHandler* aRunnable);

  JSObject* GlobalJSObject() const;

  JSCompartment* Compartment() const;

  // Create a dom::Promise from a given SpiderMonkey Promise object.
  // aPromiseObj MUST be in the compartment of aGlobal's global JS object.
  static already_AddRefed<Promise> CreateFromExisting(
      nsIGlobalObject* aGlobal, JS::Handle<JSObject*> aPromiseObj);

  enum class PromiseState { Pending, Resolved, Rejected };

  PromiseState State() const;

 protected:
  struct PromiseCapability;

  // Do NOT call this unless you're Promise::Create or
  // Promise::CreateFromExisting.  I wish we could enforce that from inside this
  // class too, somehow.
  explicit Promise(nsIGlobalObject* aGlobal);

  virtual ~Promise();

  // Do JS-wrapping after Promise creation.  Passing null for aDesiredProto will
  // use the default prototype for the sort of Promise we have.
  void CreateWrapper(JS::Handle<JSObject*> aDesiredProto, ErrorResult& aRv);

 private:
  template <typename T>
  void MaybeSomething(T& aArgument, MaybeFunc aFunc) {
    MOZ_ASSERT(PromiseObj());  // It was preserved!

    AutoEntryScript aes(mGlobal, "Promise resolution or rejection");
    JSContext* cx = aes.cx();

    JS::Rooted<JS::Value> val(cx);
    if (!ToJSValue(cx, aArgument, &val)) {
      HandleException(cx);
      return;
    }

    (this->*aFunc)(cx, val);
  }

  void HandleException(JSContext* aCx);

  RefPtr<nsIGlobalObject> mGlobal;

  JS::Heap<JSObject*> mPromiseObj;
};

NS_DEFINE_STATIC_IID_ACCESSOR(Promise, NS_PROMISE_IID)

}  // namespace dom
}  // namespace mozilla

#endif  // mozilla_dom_Promise_h