1/*
2 * Copyright (C) 2013 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef ScriptPromiseResolver_h
32#define ScriptPromiseResolver_h
33
34#include "bindings/v8/ScopedPersistent.h"
35#include "bindings/v8/ScriptObject.h"
36#include "bindings/v8/ScriptState.h"
37#include "bindings/v8/ScriptValue.h"
38#include "wtf/RefPtr.h"
39
40#include <v8.h>
41
42namespace WebCore {
43
44class ScriptExecutionContext;
45
46// ScriptPromiseResolver is a class for accessing PromiseResolver methods
47// (fulfill / resolve / reject) from C++ world.
48// ScriptPromiseResolver holds a Promise and a PromiseResolver.
49// All methods of this class must be called from the main thread.
50// Here is a typical usage:
51//  1. Create a ScriptPromiseResolver.
52//  2. Pass the promise object of the holder to a JavaScript program
53//     (such as XMLHttpRequest return value).
54//  3. Detach the promise object if you no long need it.
55//  4. Call fulfill or reject when the operation completes or
56//     the operation fails respectively.
57//
58// Most methods including constructors must be called within a v8 context.
59// To use ScriptPromiseResolver out of a v8 context the caller must
60// enter a v8 context, for example by using ScriptScope and ScriptState.
61//
62class ScriptPromiseResolver : public RefCounted<ScriptPromiseResolver> {
63    WTF_MAKE_NONCOPYABLE(ScriptPromiseResolver);
64public:
65    static PassRefPtr<ScriptPromiseResolver> create(ScriptExecutionContext*);
66    static PassRefPtr<ScriptPromiseResolver> create();
67
68    // A ScriptPromiseResolver should be fulfilled / resolved / rejected before
69    // its destruction.
70    // A ScriptPromiseResolver can be destructed safely without
71    // entering a v8 context.
72    ~ScriptPromiseResolver();
73
74    // Detach the promise object and reject the resolver object with undefined.
75    void detach();
76
77    // Detach the promise object.
78    void detachPromise() { m_promise.clear(); }
79
80    // Return true if the following conditions are met:
81    //  - The resolver object is not detached.
82    //  - The resolver's promise object is in pending state.
83    //  - The resolver's resolved flag is not set.
84    bool isPending() const;
85
86    ScriptObject promise()
87    {
88        ASSERT(v8::Context::InContext());
89        return ScriptObject(ScriptState::current(), m_promise.newLocal(m_isolate));
90    }
91
92    // Fulfill with a C++ object which can be converted to a v8 object by toV8.
93    template<typename T>
94    inline void fulfill(PassRefPtr<T>);
95    // Resolve with a C++ object which can be converted to a v8 object by toV8.
96    template<typename T>
97    inline void resolve(PassRefPtr<T>);
98    // Reject with a C++ object which can be converted to a v8 object by toV8.
99    template<typename T>
100    inline void reject(PassRefPtr<T>);
101
102    void fulfill(ScriptValue);
103    void resolve(ScriptValue);
104    void reject(ScriptValue);
105
106private:
107    ScriptPromiseResolver(v8::Handle<v8::Object> creationContext, v8::Isolate*);
108    void fulfill(v8::Handle<v8::Value>);
109    void resolve(v8::Handle<v8::Value>);
110    void reject(v8::Handle<v8::Value>);
111
112    v8::Isolate* m_isolate;
113    ScopedPersistent<v8::Object> m_promise;
114    ScopedPersistent<v8::Object> m_resolver;
115    bool isPendingInternal() const;
116};
117
118template<typename T>
119void ScriptPromiseResolver::fulfill(PassRefPtr<T> value)
120{
121    ASSERT(v8::Context::InContext());
122    fulfill(toV8(value.get(), v8::Object::New(), m_isolate));
123}
124
125template<typename T>
126void ScriptPromiseResolver::resolve(PassRefPtr<T> value)
127{
128    ASSERT(v8::Context::InContext());
129    resolve(toV8(value.get(), v8::Object::New(), m_isolate));
130}
131
132template<typename T>
133void ScriptPromiseResolver::reject(PassRefPtr<T> value)
134{
135    ASSERT(v8::Context::InContext());
136    reject(toV8(value.get(), v8::Object::New(), m_isolate));
137}
138
139} // namespace WebCore
140
141
142#endif // ScriptPromiseResolver_h
143