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..f03732988fb800e1556a3a32dcf9f7925b15e605
--- /dev/null
+++ b/Source/core/inspector/PromiseTracker.cpp
@@ -0,0 +1,115 @@
+// 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 {
+
+static int indexOf(PromiseTracker::PromiseDataVector* vector, const ScopedPersistent<v8::Object>& promise)
+{
+    for (size_t index = 0; index < vector->size(); ++index) {
+        if (vector->at(index)->promise() == promise)
+            return index;
+    }
+    return -1;
+}
+
+namespace {
+
+struct PromiseDataWrapper {

[yurys, 2014/08/26 14:06:36]

Let's make it a class.

[Alexandra Mikhaylova, 2014/08/28 13:29:46]

Done.

+    PromiseDataWrapper(WeakPtr<PromiseTracker::PromiseData> data, PromiseTracker::PromiseDataMap* map)
+        : m_data(data)
+        , m_promiseDataMap(map)
+    {
+    }
+
+    static void didRemovePromise(const v8::WeakCallbackData<v8::Object, PromiseDataWrapper>& data)
+    {
+        OwnPtr<PromiseDataWrapper> wrapper = adoptPtr(data.GetParameter());
+        WeakPtr<PromiseTracker::PromiseData> promiseData = wrapper->m_data;
+        if (!promiseData)
+            return;
+        PromiseTracker::PromiseDataMap* map = wrapper->m_promiseDataMap;
+        int promiseHash = promiseData->promiseHash();
+        PromiseTracker::PromiseDataVector* vector = &map->find(promiseHash)->value;
+        int index = indexOf(vector, promiseData->promise());
+        ASSERT(index >= 0);
+        vector->remove(index);
+        if (vector->size() == 0)
+            map->remove(promiseHash);
+    }
+

[yurys, 2014/08/26 14:06:36]

These fields should be private.

[Alexandra Mikhaylova, 2014/08/28 13:29:46]

Done.

+    WeakPtr<PromiseTracker::PromiseData> m_data;
+    PromiseTracker::PromiseDataMap* m_promiseDataMap;
+};
+
+}
+
+PromiseTracker::PromiseData::PromiseData(v8::Isolate* isolate, int promiseHash, v8::Handle<v8::Object> promise)
+    : m_promiseHash(promiseHash)
+    , m_promise(isolate, promise)
+    , m_status(0)
+    , m_weakPtrFactory(this)
+{
+}
+
+void PromiseTracker::enable()
+{
+    m_isEnabled = true;
+}
+
+void PromiseTracker::disable()
+{
+    m_isEnabled = false;
+    clear();
+}
+
+void PromiseTracker::clear()
+{
+    m_promiseDataMap.clear();
+}
+
+void PromiseTracker::didReceiveV8PromiseEvent(ScriptState* scriptState, v8::Handle<v8::Object> promise, v8::Handle<v8::Value> parentPromise, int status)
+{
+    ASSERT(isEnabled());
+
+    int promiseHash = promise->GetIdentityHash();
+    PromiseDataVector* vector;
+    PromiseDataMap::iterator it = m_promiseDataMap.find(promiseHash);
+    if (it != m_promiseDataMap.end())
+        vector = &it->value;
+    else
+        vector = &m_promiseDataMap.add(promiseHash, PromiseDataVector()).storedValue->value;
+
+    v8::Isolate* isolate = scriptState->isolate();
+    RefPtr<PromiseData> data;
+    int index = indexOf(vector, ScopedPersistent<v8::Object>(isolate, promise));
+    if (index == -1) {
+        data = adoptRef(new PromiseData(isolate, promiseHash, promise));
+        PromiseDataWrapper* wrapper = new PromiseDataWrapper(data->m_weakPtrFactory.createWeakPtr(), &m_promiseDataMap);

[yurys, 2014/08/26 14:06:36]

adoptPtr(...).leakPtr() or better assign to an OwnPtr and release it below.

[Alexandra Mikhaylova, 2014/08/28 13:29:46]

Assigned to an OwnPtr and used leakPtr() below since setWeak needs a raw
pointer.

+        data->m_promise.setWeak(wrapper, &PromiseDataWrapper::didRemovePromise);
+        vector->append(data);
+    } else {
+        data = vector->at(index);
+    }
+
+    if (!parentPromise.IsEmpty()) {
+        ASSERT(parentPromise->IsObject());
+        data->m_parentPromise.set(isolate, parentPromise->ToObject());
+    } else {
+        data->m_status = status;
+        if (!status) {
+            v8::Handle<v8::StackTrace> stackTrace(v8::StackTrace::CurrentStackTrace(isolate, 1));
+            RefPtrWillBeRawPtr<ScriptCallStack> stack = createScriptCallStack(stackTrace, 1, isolate);
+            if (stack->size())
+                data->m_callFrame = stack->at(0);
+        }
+    }
+}
+
+} // namespace blink