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// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef COMPONENTS_VIZ_COMMON_SURFACES_CHILD_LOCAL_SURFACE_ID_ALLOCATOR_H_
#define COMPONENTS_VIZ_COMMON_SURFACES_CHILD_LOCAL_SURFACE_ID_ALLOCATOR_H_
#include <stdint.h>
#include "base/unguessable_token.h"
#include "components/viz/common/surfaces/local_surface_id.h"
#include "components/viz/common/surfaces/surface_id.h"
#include "components/viz/common/viz_common_export.h"
namespace viz {
// This is a helper class for generating local surface IDs for a single
// FrameSink. This is not threadsafe, to use from multiple threads wrap this
// class in a mutex.
// The parent embeds a child's surface. The child allocates a surface when it
// changes its contents or surface parameters, for example.
// This is that child allocator.
class VIZ_COMMON_EXPORT ChildLocalSurfaceIdAllocator {
public:
ChildLocalSurfaceIdAllocator();
ChildLocalSurfaceIdAllocator(const ChildLocalSurfaceIdAllocator&) = delete;
ChildLocalSurfaceIdAllocator& operator=(const ChildLocalSurfaceIdAllocator&) =
delete;
~ChildLocalSurfaceIdAllocator() = default;
// When a parent-allocated LocalSurfaceId arrives in the child, the child
// needs to update its understanding of the last generated message so the
// messages can continue to monotonically increase. Returns whether the
// current LocalSurfaceId has been updated.
bool UpdateFromParent(const LocalSurfaceId& parent_local_surface_id);
void GenerateId();
const LocalSurfaceId& GetCurrentLocalSurfaceId() const {
return current_local_surface_id_;
}
private:
LocalSurfaceId current_local_surface_id_;
};
} // namespace viz
#endif // COMPONENTS_VIZ_COMMON_SURFACES_CHILD_LOCAL_SURFACE_ID_ALLOCATOR_H_
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