1 files changed, 162 insertions, 0 deletions
diff --git a/src/core/compositor/compositor.cpp b/src/core/compositor/compositor.cpp
new file mode 100644
index 000000000..4c0bd4c0d
--- /dev/null
+++ b/src/core/compositor/compositor.cpp
@@ -0,0 +1,162 @@
+// Copyright (C) 2020 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "compositor.h"
+
+#include "base/memory/ref_counted.h"
+#include "components/viz/common/surfaces/frame_sink_id.h"
+
+#include <QHash>
+#include <QMutex>
+#include <QQuickWindow>
+
+namespace QtWebEngineCore {
+
+// Compositor::Id
+
+Compositor::Id::Id(viz::FrameSinkId fid) : client_id(fid.client_id()), sink_id(fid.sink_id()) { }
+
+static size_t qHash(Compositor::Id id, size_t seed = 0)
+{
+    QtPrivate::QHashCombine hasher;
+    seed = hasher(seed, id.client_id);
+    seed = hasher(seed, id.sink_id);
+    return seed;
+}
+
+static bool operator==(Compositor::Id id1, Compositor::Id id2)
+{
+    return id1.client_id == id2.client_id && id1.sink_id == id2.sink_id;
+}
+
+// Compositor::Binding and Compositor::Bindings
+
+struct Compositor::Binding
+{
+    const Id id;
+    Compositor *compositor = nullptr;
+    Observer *observer = nullptr;
+
+    Binding(Id id) : id(id) { }
+    ~Binding();
+};
+
+class Compositor::BindingMap
+{
+public:
+    void lock() { m_mutex.lock(); }
+
+    void unlock() { m_mutex.unlock(); }
+
+    Binding *findOrCreate(Id id)
+    {
+        auto it = m_map.find(id);
+        if (it == m_map.end())
+            it = m_map.insert(id, new Binding(id));
+        return *it;
+    }
+
+    void remove(Id id) { m_map.remove(id); }
+
+private:
+    QMutex m_mutex;
+    QHash<Id, Binding *> m_map;
+} static g_bindings;
+
+Compositor::Binding::~Binding()
+{
+    g_bindings.remove(id);
+}
+
+// Compositor::Observer
+
+void Compositor::Observer::bind(Id id)
+{
+    DCHECK(!m_binding);
+    g_bindings.lock();
+    m_binding = g_bindings.findOrCreate(id);
+    DCHECK(!m_binding->observer);
+    m_binding->observer = this;
+    g_bindings.unlock();
+}
+
+void Compositor::Observer::unbind()
+{
+    DCHECK(m_binding);
+    g_bindings.lock();
+    m_binding->observer = nullptr;
+    if (m_binding->compositor == nullptr)
+        delete m_binding;
+    m_binding = nullptr;
+    g_bindings.unlock();
+}
+
+Compositor::Handle<Compositor> Compositor::Observer::compositor()
+{
+    g_bindings.lock();
+    if (m_binding && m_binding->compositor)
+        return m_binding->compositor; // delay unlock
+    g_bindings.unlock();
+    return nullptr;
+}
+
+// Compositor
+
+void Compositor::bind(Id id)
+{
+    DCHECK(!m_binding);
+    g_bindings.lock();
+    m_binding = g_bindings.findOrCreate(id);
+    DCHECK(!m_binding->compositor);
+    m_binding->compositor = this;
+    g_bindings.unlock();
+}
+
+void Compositor::unbind()
+{
+    DCHECK(m_binding);
+    g_bindings.lock();
+    m_binding->compositor = nullptr;
+    if (m_binding->observer == nullptr)
+        delete m_binding;
+    m_binding = nullptr;
+    g_bindings.unlock();
+}
+
+Compositor::Handle<Compositor::Observer> Compositor::observer()
+{
+    g_bindings.lock();
+    if (m_binding && m_binding->observer)
+        return m_binding->observer; // delay unlock
+    g_bindings.unlock();
+    return nullptr;
+}
+
+void Compositor::waitForTexture()
+{
+}
+
+void Compositor::releaseTexture()
+{
+}
+
+QSGTexture *Compositor::texture(QQuickWindow *, uint32_t textureOptions)
+{
+    Q_UNREACHABLE();
+    return nullptr;
+}
+
+bool Compositor::textureIsFlipped()
+{
+    Q_UNREACHABLE();
+    return false;
+}
+
+void Compositor::releaseResources() { }
+
+// static
+void Compositor::unlockBindings()
+{
+    g_bindings.unlock();
+}
+} // namespace QtWebEngineCore