Support Promises event-based instrumentation on backend.

Source/core/inspector/PromiseTracker.cpp

Index: Source/core/inspector/PromiseTracker.cpp
diff --git a/Source/core/inspector/PromiseTracker.cpp b/Source/core/inspector/PromiseTracker.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..0b8979e6b3a1c8cd921d560879a29563656ebdaa
--- /dev/null
+++ b/Source/core/inspector/PromiseTracker.cpp
@@ -0,0 +1,153 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/inspector/PromiseTracker.h"
+
+#include "bindings/core/v8/ScriptCallStackFactory.h"
+#include "bindings/core/v8/ScriptState.h"
+
+namespace blink {
+
+struct PromiseTracker::PromiseDataWrapper {

[aandrey, 2014/08/04 16:58:47]

wrap into an anonymous namespace

[Alexandra Mikhaylova, 2014/08/06 13:28:39]

How can it be compliant with the private method PromiseTracker::didRemovePromise
then?

+    WTF_MAKE_NONCOPYABLE(PromiseDataWrapper);
+public:
+    PromiseDataWrapper(WeakPtr<PromiseData> data)
+        : m_data(data)
+    {
+    }
+
+    WeakPtr<PromiseData> m_data;
+
+    static void didRemovePromise(const v8::WeakCallbackData<v8::Object, PromiseDataWrapper>& data)
+    {
+        OwnPtr<PromiseDataWrapper> wrapper = adoptPtr(data.GetParameter());
+        WeakPtr<PromiseData> promiseData = wrapper->m_data;
+        if (!(promiseData.get() && promiseData->m_promiseTracker->isEnabled()))

[aandrey, 2014/08/04 16:58:48]

if (!promiseData)
    return;
PromiseTracker* tracker = promiseData->m_promiseTracker;
if (!tracker->isEnabled())
    return;

[Alexandra Mikhaylova, 2014/08/06 13:28:39]

Done.

+            return;
+
+        promiseData->m_promiseTracker->didRemovePromise(promiseData->m_scriptState.get(), promiseData->m_promise);
+    }
+};
+
+PromiseTracker::PromiseData::PromiseData(const ScopedPersistent<v8::Object>& promise, const ScopedPersistent<v8::Object>& parentPromise, int status, ScriptState* scriptState, PromiseTracker* tracker, bool captureStack)
+    : m_scriptState(scriptState)
+    , m_promiseTracker(tracker)
+    , m_promise(scriptState->isolate(), promise.newLocal(scriptState->isolate()))

[aandrey, 2014/08/04 16:58:48]

make copy constructor on ScopedPersistent

[Alexandra Mikhaylova, 2014/08/06 13:28:39]

Switched back to v8::Handle instead.

+    , m_parentPromise(scriptState->isolate(), parentPromise.newLocal(scriptState->isolate()))
+    , m_status(status)
+    , m_weakPtrFactory(this)
+{
+    if (captureStack) {
+        v8::Isolate* isolate = scriptState->isolate();
+        v8::Handle<v8::StackTrace> stackTrace(v8::StackTrace::CurrentStackTrace(isolate, 1));
+        RefPtrWillBeRawPtr<ScriptCallStack> stack = createScriptCallStack(stackTrace, 1, isolate);
+        if (stack->size())
+            m_callFrame = stack->at(0);
+    }
+    PromiseDataWrapper* wrapper = new PromiseDataWrapper(m_weakPtrFactory.createWeakPtr());
+    m_promise.setWeak(wrapper, &PromiseTracker::PromiseDataWrapper::didRemovePromise);
+}
+
+void PromiseTracker::enable()
+{
+    m_isEnabled = true;
+}
+
+void PromiseTracker::disable()
+{
+    m_isEnabled = false;
+    clear();
+}
+
+void PromiseTracker::clear()
+{
+    m_promiseDataMap.clear();
+}
+
+PromiseTracker::PromiseDataVector* PromiseTracker::promiseVector(ScriptState* scriptState, const ScopedPersistent<v8::Object>& promise)
+{
+    ASSERT(isEnabled());
+
+    int promiseHash = promise.newLocal(scriptState->isolate())->GetIdentityHash();
+    PromiseDataMap::iterator it = m_promiseDataMap.find(promiseHash);
+    if (it != m_promiseDataMap.end())
+        return &it->value;
+    return &m_promiseDataMap.add(promiseHash, PromiseDataVector()).storedValue->value;
+}
+
+void PromiseTracker::didReceiveV8PromiseEvent(ScriptState* scriptState, const ScopedPersistent<v8::Object>& promise, const ScopedPersistent<v8::Object>& parentPromise, int status)
+{
+    ASSERT(isEnabled());
+
+    if (status != 0) {
+        didUpdatePromiseStatus(scriptState, promise, status);
+    } else if (!parentPromise.isEmpty()) {
+        didUpdatePromiseParent(scriptState, promise, parentPromise);
+    } else {
+        didCreatePromise(scriptState, promise);
+    }
+}
+
+void PromiseTracker::didCreatePromise(ScriptState* scriptState, const ScopedPersistent<v8::Object>& promise)
+{
+    PromiseDataVector* vector = promiseVector(scriptState, promise);
+    vector->append(adoptRef(new PromiseData(promise, ScopedPersistent<v8::Object>(), 0, scriptState, this, true)));
+}
+
+void PromiseTracker::didUpdatePromiseParent(ScriptState* scriptState, const ScopedPersistent<v8::Object>& promise, const ScopedPersistent<v8::Object>& parentPromise)
+{
+    PromiseDataVector* vector = promiseVector(scriptState, promise);
+    bool found = false;
+    for (size_t index = 0; index < vector->size(); ++index) {
+        RefPtr<PromiseData> data = (*vector)[index];

[aandrey, 2014/08/04 16:58:48]

vector->at(index)

[Alexandra Mikhaylova, 2014/08/06 13:28:39]

Done.

+        if (data->m_promise == promise) {
+            found = true;
+            v8::Isolate* isolate = scriptState->isolate();
+            data->m_parentPromise.set(isolate, parentPromise.newLocal(isolate));

[aandrey, 2014/08/04 16:58:48]

should be no newLocal() call

[Alexandra Mikhaylova, 2014/08/06 13:28:39]

Done.

+            break;
+        }
+    }
+    if (!found)
+        vector->append(adoptRef(new PromiseData(promise, parentPromise, 0, scriptState, this)));
+}
+
+void PromiseTracker::didUpdatePromiseStatus(ScriptState* scriptState, const ScopedPersistent<v8::Object>& promise, int status)
+{
+    PromiseDataVector* vector = promiseVector(scriptState, promise);
+    bool found = false;
+    for (size_t index = 0; index < vector->size(); ++index) {
+        RefPtr<PromiseData> data = (*vector)[index];
+        if (data->m_promise == promise) {
+            found = true;
+            data->m_status = status;
+            break;
+        }
+    }
+    if (!found)
+        vector->append(adoptRef(new PromiseData(promise, ScopedPersistent<v8::Object>(), status, scriptState, this)));
+}
+
+void PromiseTracker::didRemovePromise(ScriptState* scriptState, ScopedPersistent<v8::Object>& promise)
+{
+    ASSERT(isEnabled());
+
+    int promiseHash = promise.newLocal(scriptState->isolate())->GetIdentityHash();

[aandrey, 2014/08/04 16:58:48]

we can remove m_scriptState if we cache the identity hash

[Alexandra Mikhaylova, 2014/08/06 13:28:39]

Done.

+
+    PromiseDataVector* vector = promiseVector(scriptState, promise);
+    ASSERT(vector->size() >= 1);
+    bool found = false;
+    for (size_t index = 0; index < vector->size(); ++index) {
+        RefPtr<PromiseData> data = (*vector)[index];
+        if (data->m_promise == promise) {
+            found = true;
+            vector->remove(index);

[aandrey, 2014/08/04 16:58:48]

too much code duplication

+            break;
+        }
+    }
+    if (vector->size() == 0)
+        m_promiseDataMap.remove(promiseHash);
+}
+
+} // namespace blink