components/performance_manager/public/graph/frame_node.h

// Copyright 2019 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.

#ifndef COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_GRAPH_FRAME_NODE_H_
#define COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_GRAPH_FRAME_NODE_H_

#include "base/callback_forward.h"
#include "base/containers/flat_set.h"
#include "base/types/strong_alias.h"
#include "components/performance_manager/public/execution_context_priority/execution_context_priority.h"
#include "components/performance_manager/public/graph/node.h"
#include "components/performance_manager/public/mojom/coordination_unit.mojom.h"
#include "components/performance_manager/public/mojom/lifecycle.mojom.h"
#include "content/public/browser/browsing_instance_id.h"
#include "content/public/browser/site_instance.h"
#include "third_party/abseil-cpp/absl/types/optional.h"
#include "third_party/blink/public/common/tokens/tokens.h"
#include "ui/gfx/geometry/rect.h"

class GURL;

namespace performance_manager {

class FrameNodeObserver;
class PageNode;
class ProcessNode;
class RenderFrameHostProxy;
class WorkerNode;

using execution_context_priority::PriorityAndReason;

// Frame nodes form a tree structure, each FrameNode at most has one parent
// that is a FrameNode. Conceptually, a FrameNode corresponds to a
// content::RenderFrameHost (RFH) in the browser, and a
// content::RenderFrameImpl / blink::LocalFrame in a renderer.
//
// TODO(crbug.com/1211368): The naming is misleading. In the browser,
// FrameTreeNode tracks state about a frame and RenderFrameHost tracks state
// about a document loaded into that frame, which can change over time.
// (Although RFH doesn't exactly track documents 1:1 either - see
// docs/render_document.md for more details.) The PM node types should be
// cleaned up to more accurately reflect this.
//
// Each RFH is part of a frame tree made up of content::FrameTreeNodes (FTNs).
// Note that a document in an FTN can be replaced with another, so it is
// possible to have multiple "sibling" FrameNodes corresponding to RFHs in the
// same FTN. Only one of these may contribute to the content being rendered,
// and this node is designated the "current" node in content terminology.
//
// This can occur, for example, when an in-flight navigation creates a new RFH.
// The new RFH will swap with the previously active RFH when the navigation
// commits, but until then the two will coexist for the same FTN.
//
// A swap is effectively atomic but will take place in two steps in the graph:
// the outgoing frame will first be marked as not current, and the incoming
// frame will be marked as current. As such, the graph invariant is that there
// will be 0 or 1 |is_current| FrameNode's for a given FTN.
//
// It is only valid to access this object on the sequence of the graph that owns
// it.
class FrameNode : public Node {
 public:
  using FrameNodeVisitor = base::RepeatingCallback<bool(const FrameNode*)>;
  using LifecycleState = mojom::LifecycleState;
  using Observer = FrameNodeObserver;
  using PageNodeVisitor = base::RepeatingCallback<bool(const PageNode*)>;
  using WorkerNodeVisitor = base::RepeatingCallback<bool(const WorkerNode*)>;

  class ObserverDefaultImpl;

  static const char* kDefaultPriorityReason;

  enum class Visibility {
    kUnknown,
    kVisible,
    kNotVisible,
  };

  FrameNode();

  FrameNode(const FrameNode&) = delete;
  FrameNode& operator=(const FrameNode&) = delete;

  ~FrameNode() override;

  // Returns the parent of this frame node. This may be null if this frame node
  // is the main (root) node of a frame tree. This is a constant over the
  // lifetime of the frame.
  virtual const FrameNode* GetParentFrameNode() const = 0;

  // Returns the page node to which this frame belongs. This is a constant over
  // the lifetime of the frame.
  virtual const PageNode* GetPageNode() const = 0;

  // Returns the process node with which this frame belongs. This is a constant
  // over the lifetime of the frame.
  virtual const ProcessNode* GetProcessNode() const = 0;

  // Gets the unique token associated with this frame. This is a constant over
  // the lifetime of the frame and unique across all frames for all time.
  virtual const blink::LocalFrameToken& GetFrameToken() const = 0;

  // Gets the ID of the browsing instance to which this frame belongs. This is a
  // constant over the lifetime of the frame.
  virtual content::BrowsingInstanceId GetBrowsingInstanceId() const = 0;

  // Gets the ID of the site instance to which this frame belongs. This is a
  // constant over the lifetime of the frame.
  virtual content::SiteInstanceId GetSiteInstanceId() const = 0;

  // A frame is a main frame if it has no parent FrameNode. This can be
  // called from any thread.
  virtual bool IsMainFrame() const = 0;

  // Visits the frame nodes that are children of this frame. The iteration is
  // halted if the visitor returns false. Returns true if every call to the
  // visitor returned true, false otherwise.
  virtual bool VisitChildFrameNodes(const FrameNodeVisitor& visitor) const = 0;

  // Returns the set of child frame associated with this frame. Note that this
  // incurs a full container copy of all child nodes. Please use
  // VisitChildFrameNodes when that makes sense.
  virtual const base::flat_set<const FrameNode*> GetChildFrameNodes() const = 0;

  // Visits the page nodes that have been opened by this frame. The iteration
  // is halted if the visitor returns false. Returns true if every call to the
  // visitor returned true, false otherwise.
  virtual bool VisitOpenedPageNodes(const PageNodeVisitor& visitor) const = 0;

  // Returns the set of opened pages associatted with this frame. Note that
  // this incurs a full container copy all the opened nodes. Please use
  // VisitOpenedPageNodes when that makes sense. This can change over the
  // lifetime of the frame.
  virtual const base::flat_set<const PageNode*> GetOpenedPageNodes() const = 0;

  // Visits the page nodes that have been embedded by this frame. The iteration
  // is halted if the visitor returns false. Returns true if every call to the
  // visitor returned true, false otherwise.
  virtual bool VisitEmbeddedPageNodes(const PageNodeVisitor& visitor) const = 0;

  // Returns the set of embedded pages associatted with this frame. Note that
  // this incurs a full container copy all the embedded nodes. Please use
  // VisitEmbeddedPageNodes when that makes sense. This can change over the
  // lifetime of the frame.
  virtual const base::flat_set<const PageNode*> GetEmbeddedPageNodes()
      const = 0;

  // Returns the current lifecycle state of this frame. See
  // FrameNodeObserver::OnFrameLifecycleStateChanged.
  virtual LifecycleState GetLifecycleState() const = 0;

  // Returns true if this frame had a non-empty before-unload handler at the
  // time of its last transition to the frozen lifecycle state. This is only
  // meaningful while the object is frozen.
  virtual bool HasNonemptyBeforeUnload() const = 0;

  // Returns the URL associated with this frame.
  // See FrameNodeObserver::OnURLChanged.
  virtual const GURL& GetURL() const = 0;

  // Returns true if this frame is current (is part of a content::FrameTree).
  // See FrameNodeObserver::OnIsCurrentChanged.
  virtual bool IsCurrent() const = 0;

  // Returns true if this frames use of the network is "almost idle", indicating
  // that it is not doing any heavy loading work.
  virtual bool GetNetworkAlmostIdle() const = 0;

  // Returns true if this frame is ad frame. This can change from false to true
  // over the lifetime of the frame, but once it is true it will always remain
  // true.
  virtual bool IsAdFrame() const = 0;

  // Returns true if this frame holds at least one Web Lock.
  virtual bool IsHoldingWebLock() const = 0;

  // Returns true if this frame holds at least one IndexedDB lock. An IndexedDB
  // lock is held by an active transaction or an active DB open request.
  virtual bool IsHoldingIndexedDBLock() const = 0;

  // Returns the child workers of this frame. These are either dedicated workers
  // or shared workers created by this frame, or a service worker that handles
  // this frame's network requests.
  virtual const base::flat_set<const WorkerNode*> GetChildWorkerNodes()
      const = 0;

  // Visits the child dedicated workers of this frame. The iteration is halted
  // if the visitor returns false. Returns true if every call to the visitor
  // returned true, false otherwise.
  //
  // The reason why we don't have a generic VisitChildWorkers method is that
  // a service/shared worker may appear as a child of multiple other nodes
  // and thus may be visited multiple times.
  virtual bool VisitChildDedicatedWorkers(
      const WorkerNodeVisitor& visitor) const = 0;

  // Returns the current priority of the frame, and the reason for the frame
  // having that particular priority.
  virtual const PriorityAndReason& GetPriorityAndReason() const = 0;

  // Returns true if at least one form of the frame has been interacted with.
  virtual bool HadFormInteraction() const = 0;

  // Returns true if the frame is audible, false otherwise.
  virtual bool IsAudible() const = 0;

  // Returns the intersection of this frame with the viewport. This is initially
  // null on node creation and is initialized during layout when the viewport
  // intersection is first calculated. May only be called for a child frame.
  virtual const absl::optional<gfx::Rect>& GetViewportIntersection() const = 0;

  // Returns true if the frame is visible. This value is based on the viewport
  // intersection of the frame, and the visibility of the page.
  virtual Visibility GetVisibility() const = 0;

  // Returns a proxy to the RenderFrameHost associated with this node. The
  // proxy may only be dereferenced on the UI thread.
  virtual const RenderFrameHostProxy& GetRenderFrameHostProxy() const = 0;
};

// Pure virtual observer interface. Derive from this if you want to be forced to
// implement the entire interface.
class FrameNodeObserver {
 public:
  FrameNodeObserver();

  FrameNodeObserver(const FrameNodeObserver&) = delete;
  FrameNodeObserver& operator=(const FrameNodeObserver&) = delete;

  virtual ~FrameNodeObserver();

  // Node lifetime notifications.

  // Called when a |frame_node| is added to the graph. Observers must not make
  // any property changes or cause re-entrant notifications during the scope of
  // this call. Instead, make property changes via a separate posted task.
  virtual void OnFrameNodeAdded(const FrameNode* frame_node) = 0;

  // Called before a |frame_node| is removed from the graph. Observers must not
  // make any property changes or cause re-entrant notifications during the
  // scope of this call.
  virtual void OnBeforeFrameNodeRemoved(const FrameNode* frame_node) = 0;

  // Notifications of property changes.

  // Invoked when the IsCurrent property changes.
  virtual void OnIsCurrentChanged(const FrameNode* frame_node) = 0;

  // Invoked when the NetworkAlmostIdle property changes.
  virtual void OnNetworkAlmostIdleChanged(const FrameNode* frame_node) = 0;

  // Invoked when the LifecycleState property changes.
  virtual void OnFrameLifecycleStateChanged(const FrameNode* frame_node) = 0;

  // Invoked when the URL property changes.
  virtual void OnURLChanged(const FrameNode* frame_node,
                            const GURL& previous_value) = 0;

  // Invoked when the IsAdFrame property changes.
  virtual void OnIsAdFrameChanged(const FrameNode* frame_node) = 0;

  // Invoked when the IsHoldingWebLock() property changes.
  virtual void OnFrameIsHoldingWebLockChanged(const FrameNode* frame_node) = 0;

  // Invoked when the IsHoldingIndexedDBLock() property changes.
  virtual void OnFrameIsHoldingIndexedDBLockChanged(
      const FrameNode* frame_node) = 0;

  // Invoked when the frame priority and reason changes.
  virtual void OnPriorityAndReasonChanged(
      const FrameNode* frame_node,
      const PriorityAndReason& previous_value) = 0;

  // Called when the frame receives a form interaction.
  virtual void OnHadFormInteractionChanged(const FrameNode* frame_node) = 0;

  // Invoked when the IsAudible property changes.
  virtual void OnIsAudibleChanged(const FrameNode* frame_node) = 0;

  // Invoked when a frame's intersection with the viewport changes
  virtual void OnViewportIntersectionChanged(const FrameNode* frame_node) = 0;

  // Invoked when the visibility property changes.
  virtual void OnFrameVisibilityChanged(
      const FrameNode* frame_node,
      FrameNode::Visibility previous_value) = 0;

  // Events with no property changes.

  // Invoked when a non-persistent notification has been issued by the frame.
  virtual void OnNonPersistentNotificationCreated(
      const FrameNode* frame_node) = 0;

  // Invoked when the frame has had a first contentful paint, as defined here:
  // https://developers.google.com/web/tools/lighthouse/audits/first-contentful-paint
  // This may not fire for all frames, depending on if the load is interrupted
  // or if the content is even visible. It will fire at most once for a given
  // frame. It will only fire for main-frame nodes.
  virtual void OnFirstContentfulPaint(
      const FrameNode* frame_node,
      base::TimeDelta time_since_navigation_start) = 0;
};

// Default implementation of observer that provides dummy versions of each
// function. Derive from this if you only need to implement a few of the
// functions.
class FrameNode::ObserverDefaultImpl : public FrameNodeObserver {
 public:
  ObserverDefaultImpl();

  ObserverDefaultImpl(const ObserverDefaultImpl&) = delete;
  ObserverDefaultImpl& operator=(const ObserverDefaultImpl&) = delete;

  ~ObserverDefaultImpl() override;

  // FrameNodeObserver implementation:
  void OnFrameNodeAdded(const FrameNode* frame_node) override {}
  void OnBeforeFrameNodeRemoved(const FrameNode* frame_node) override {}
  void OnIsCurrentChanged(const FrameNode* frame_node) override {}
  void OnNetworkAlmostIdleChanged(const FrameNode* frame_node) override {}
  void OnFrameLifecycleStateChanged(const FrameNode* frame_node) override {}
  void OnURLChanged(const FrameNode* frame_node,
                    const GURL& previous_value) override {}
  void OnIsAdFrameChanged(const FrameNode* frame_node) override {}
  void OnFrameIsHoldingWebLockChanged(const FrameNode* frame_node) override {}
  void OnFrameIsHoldingIndexedDBLockChanged(
      const FrameNode* frame_node) override {}
  void OnPriorityAndReasonChanged(
      const FrameNode* frame_node,
      const PriorityAndReason& previous_value) override {}
  void OnHadFormInteractionChanged(const FrameNode* frame_node) override {}
  void OnIsAudibleChanged(const FrameNode* frame_node) override {}
  void OnViewportIntersectionChanged(const FrameNode* frame_node) override {}
  void OnFrameVisibilityChanged(const FrameNode* frame_node,
                                FrameNode::Visibility previous_value) override {
  }
  void OnNonPersistentNotificationCreated(
      const FrameNode* frame_node) override {}
  void OnFirstContentfulPaint(
      const FrameNode* frame_node,
      base::TimeDelta time_since_navigation_start) override {}
};

}  // namespace performance_manager

#endif  // COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_GRAPH_FRAME_NODE_H_