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..8887fdc374d2316f6555465a9a1b14b8d2599428
--- /dev/null
+++ b/Source/core/inspector/PromiseTracker.cpp
@@ -0,0 +1,110 @@
+// 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 {
+
+namespace {
+
+struct PromiseDataWrapper {
+    WTF_MAKE_NONCOPYABLE(PromiseDataWrapper);

[aandrey, 2014/08/07 17:12:47]

remove

[Alexandra Mikhaylova, 2014/08/08 12:20:22]

Done.

+public:

[aandrey, 2014/08/07 17:12:48]

remove

[Alexandra Mikhaylova, 2014/08/08 12:20:22]

Done.

+    PromiseDataWrapper(WeakPtr<PromiseTracker::PromiseData> data, PromiseTracker::PromiseDataMap* map)
+        : m_data(data)
+        , m_map(map)
+    {
+    }
+
+    static void didRemovePromise(const v8::WeakCallbackData<v8::Object, PromiseDataWrapper>& data)
+    {
+        OwnPtr<PromiseDataWrapper> wrapper = adoptPtr(data.GetParameter());
+        WeakPtr<PromiseTracker::PromiseData> promiseData = wrapper->m_data;
+        PromiseTracker::PromiseDataMap* map = wrapper->m_map;

[aandrey, 2014/08/07 17:12:48]

nit: move below the if- check

[Alexandra Mikhaylova, 2014/08/08 12:20:22]

Done.

+        if (!promiseData)
+            return;
+        int promiseHash = promiseData->promiseHash();
+        PromiseTracker::PromiseDataVector* vector = &map->find(promiseHash)->value;

[aandrey, 2014/08/07 17:29:29]

can find nothing, add safety check

[Alexandra Mikhaylova, 2014/08/08 12:20:23]

It should find the correct vector, added an ASSERT below.

+        for (size_t index = 0; index < vector->size(); ++index) {
+            if (vector->at(index)->promise() == promiseData->promise()) {
+                vector->remove(index);
+                break;
+            }
+        }
+        if (vector->size() == 0)
+            map->remove(promiseHash);
+    }
+
+    WeakPtr<PromiseTracker::PromiseData> m_data;
+    PromiseTracker::PromiseDataMap* m_map;

[aandrey, 2014/08/07 17:12:47]

m_promiseDataMap

[Alexandra Mikhaylova, 2014/08/08 12:20:23]

Done.

+};
+
+}
+
+PromiseTracker::PromiseData::PromiseData(v8::Isolate* isolate, v8::Handle<v8::Object> promise, v8::Handle<v8::Object> parentPromise, int status, PromiseTracker* tracker, bool captureStack)
+    : m_promiseHash(promise->GetIdentityHash())
+    , m_promise(isolate, promise)
+    , m_parentPromise(isolate, parentPromise)
+    , m_status(status)
+    , m_weakPtrFactory(this)
+{
+    if (captureStack) {
+        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(), &tracker->m_promiseDataMap);

[aandrey, 2014/08/07 17:12:47]

maybe move this code into the tracker to remove PromiseTracker* ref from
constructor?

[Alexandra Mikhaylova, 2014/08/08 12:20:22]

Done.

+    m_promise.setWeak(wrapper, &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(int promiseHash)

[aandrey, 2014/08/07 17:12:47]

remove this method

[Alexandra Mikhaylova, 2014/08/08 12:20:22]

Done.

+{
+    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, v8::Handle<v8::Object> promise, v8::Handle<v8::Value> parentPromise, int status)
+{
+    ASSERT(isEnabled());
+
+    PromiseDataVector* vector = promiseVector(promise->GetIdentityHash());

[aandrey, 2014/08/07 17:12:47]

GetIdentityHash should be called once

[Alexandra Mikhaylova, 2014/08/08 12:20:23]

Done.

+    for (size_t index = 0; index < vector->size(); ++index) {
+        RefPtr<PromiseData> data = vector->at(index);

[aandrey, 2014/08/07 17:12:47]

still code dup. maybe create a static helper method:

static int indexOf(PromiseDataVector* vector, v8::Handle<v8::Object> promise)
{
  ...
}

[Alexandra Mikhaylova, 2014/08/08 12:20:22]

Introduced a static helper method, but it can't be used right here. I'll use it
in future CLs.

+        if (data->m_promise == promise) {
+            if (status != 0) {
+                data->m_status = status;
+            } else {
+                ASSERT(parentPromise->IsObject());
+                data->m_parentPromise.set(scriptState->isolate(), parentPromise->ToObject());
+            }
+            return;
+        }
+    }
+    vector->append(adoptRef(new PromiseData(scriptState->isolate(), promise, parentPromise->IsObject() ? parentPromise->ToObject() : v8::Handle<v8::Object>(), 0, this, status == 0 && !parentPromise->IsObject())));

[aandrey, 2014/08/07 17:12:47]

1) extract bool captureStack
2) status may not be 0

[aandrey, 2014/08/07 17:19:02]

check parentPromise.IsEmpty()

[Alexandra Mikhaylova, 2014/08/08 12:20:22]

1) Done.

2) Is status != 0, then it is not a new promise event, so we shouldn't capture
the stack.

[Alexandra Mikhaylova, 2014/08/08 12:20:22]

Done.

+}
+
+} // namespace blink