chromium/components/performance_manager/public/graph/worker_node.h

// Copyright 2019 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_PERFORMANCE_MANAGER_PUBLIC_GRAPH_WORKER_NODE_H_
#define COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_GRAPH_WORKER_NODE_H_

#include <string>

#include "base/containers/flat_set.h"
#include "base/observer_list_types.h"
#include "base/types/token_type.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/graph/node_set_view.h"
#include "components/performance_manager/public/resource_attribution/worker_context.h"
#include "third_party/blink/public/common/tokens/tokens.h"

class GURL;

namespace url {
class Origin;
}

namespace performance_manager {

class WorkerNodeObserver;
class FrameNode;
class ProcessNode;

PriorityAndReason;

// Represents a running instance of a WorkerGlobalScope.
// See https://developer.mozilla.org/en-US/docs/Web/API/WorkerGlobalScope.
//
// A worker is the equivalent of a thread on the web platform. To do
// asynchronous work, a frame can create a dedicated worker or a shared worker
// with Javascript. Those workers can now be used by sending an asynchronous
// message using the postMessage() method, and replies can be received by
// registering a message handler on the worker object.
//
// One notable special case is that dedicated workers can be nested. That means
// that a dedicated worker can create another dedicated worker which is then
// only accessible from the parent worker.
//
// Service workers are different. Instead of being created by the javascript
// when needed, a service worker is registered once and affects all frames and
// dedicated/shared workers whose URL matches the scope of the service worker.
// A service worker is mainly used to intercept network requests and optionally
// serve the responses from a cache, making the web site work offline.
//
// A client, from the point of view of the worker, is the frame or worker that
// caused the worker to start running, either because it explicitly created it,
// or a service worker is registered to handle their network requests.
class WorkerNode : public TypedNode<WorkerNode> { … };

// Pure virtual observer interface. Derive from this if you want to be forced to
// implement the entire interface.
class WorkerNodeObserver : public base::CheckedObserver { … };

// 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 WorkerNode::ObserverDefaultImpl : public WorkerNodeObserver { … };

}  // namespace performance_manager

#endif  // COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_GRAPH_WORKER_NODE_H_