First version of PerformanceObserver

Source/core/timing/PerformanceObserverRegistration.cpp

+/*
+ * Copyright (C) 2015 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#include "core/timing/PerformanceObserverRegistration.h"
+
+#include "core/timing/PerformanceBase.h"
+
+namespace blink {
+
+PerformanceObserverRegistration* PerformanceObserverRegistration::create(PerformanceObserver& observer, PerformanceBase* performance, const HashSet<AtomicString>& typeFilter)
+{
+    return new PerformanceObserverRegistration(observer, performance, typeFilter);
+}
+
+PerformanceObserverRegistration::PerformanceObserverRegistration(PerformanceObserver& observer, PerformanceBase* performance, const HashSet<AtomicString>& typeFilter)
+    : m_observer(observer)
+    , m_performance(performance)
+    , m_typeFilter(typeFilter)
+    , m_referenceCount(0)
+{
+    m_performance->registerPerformanceObserver(this);
+    m_observer->observationStarted(this);
+}
+
+PerformanceObserverRegistration::~PerformanceObserverRegistration()
+{
+}
+
+void PerformanceObserverRegistration::dispose()
+{
+    if (!--m_referenceCount) {

[esprehn, 2015/07/18 22:24:16]

don't manually reference count, you want to use WeakHandles or something

+        m_observer->observationEnded(this);
+        m_observer.clear();
+    }
+}
+
+void PerformanceObserverRegistration::resetObservation(const HashSet<AtomicString>& typeFilter)
+{
+    ++m_referenceCount;
+    m_performance->unregisterPerformanceObserver(this);
+    m_typeFilter = typeFilter;
+    m_performance->registerPerformanceObserver(this);
+    --m_referenceCount;
+}
+
+void PerformanceObserverRegistration::unregister()
+{
+    ASSERT(m_performance);
+    m_performance->unregisterPerformanceObserver(this);
+    // The above line will cause this object to be deleted, so don't do any more in this function.
+}
+
+bool PerformanceObserverRegistration::shouldReceiveEntryFrom(const AtomicString& typeName) const
+{
+    return m_typeFilter.contains(typeName);
+}
+
+DEFINE_TRACE(PerformanceObserverRegistration)
+{
+    visitor->trace(m_observer);
+    visitor->trace(m_performance);
+}
+
+} // namespace blink