chromium/components/dom_distiller/core/task_tracker.h

// Copyright 2013 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_DOM_DISTILLER_CORE_TASK_TRACKER_H_
#define COMPONENTS_DOM_DISTILLER_CORE_TASK_TRACKER_H_

#include <string>
#include <vector>

#include "base/functional/bind.h"
#include "base/functional/callback.h"
#include "base/memory/raw_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "components/dom_distiller/core/article_distillation_update.h"
#include "components/dom_distiller/core/article_entry.h"
#include "components/dom_distiller/core/distiller.h"
#include "components/dom_distiller/core/proto/distilled_page.pb.h"

class GURL;

namespace dom_distiller {

class DistilledArticleProto;
class DistilledContentStore;

// A handle to a request to view a DOM distiller entry or URL. The request will
// be cancelled when the handle is destroyed.
class ViewerHandle { … };

// Interface for a DOM distiller entry viewer. Implement this to make a view
// request and receive the data for an entry when it becomes available.
class ViewRequestDelegate : public base::CheckedObserver { … };

// A TaskTracker manages the various tasks related to viewing, saving,
// distilling, and fetching an article's distilled content.
//
// There are two sources of distilled content, a Distiller and the BlobFetcher.
// At any time, at most one of each of these will be in-progress (if one
// finishes, the other will be cancelled).
//
// There are also two consumers of that content, a view request and a save
// request. There is at most one save request (i.e. we are either adding this to
// the reading list or we aren't), and may be multiple view requests. When
// the distilled content is ready, each of these requests will be notified.
//
// A view request is cancelled by deleting the corresponding ViewerHandle. Once
// all view requests are cancelled (and the save callback has been called if
// appropriate) the cancel callback will be called.
//
// After creating a TaskTracker, a consumer of distilled content should be added
// and at least one of the sources should be started.
class TaskTracker { … };

}  // namespace dom_distiller

#endif  // COMPONENTS_DOM_DISTILLER_CORE_TASK_TRACKER_H_