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content / browser / preloading / prerender / prerender_new_tab_handle.h [blame]
// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_PRELOADING_PRERENDER_PRERENDER_NEW_TAB_HANDLE_H_
#define CONTENT_BROWSER_PRELOADING_PRERENDER_PRERENDER_NEW_TAB_HANDLE_H_
#include <memory>
#include "content/browser/preloading/preloading_confidence.h"
#include "content/browser/preloading/prerender/prerender_attributes.h"
#include "content/common/frame.mojom-forward.h"
#include "content/public/browser/prerender_web_contents_delegate.h"
#include "content/public/browser/render_frame_host.h"
namespace content {
class BrowserContext;
class PrerenderCancellationReason;
class PrerenderHost;
class PrerenderHostRegistry;
class WebContentsImpl;
// PrerenderNewTabHandle creates a new WebContentsImpl instance, starts
// prerendering on that, and keeps the instance until the prerendered page is
// activated for navigation or cancelled for some reason. By starting
// prerendering in a new WebContentsImpl instance, this can serve a prerendered
// page to navigation in a new tab different from a tab of the page that
// triggered prerendering.
//
// PrerenderHostRegistry instantiates and owns PrerenderNewTabHandle in response
// to prerendering requests via Speculation Rules API. When navigation is about
// to start for a new tab, the navigation asks PrerenderHostRegistry if there is
// a PrerenderNewTabHandle instance that has a pre-created WebContentsImpl
// suitable for this navigation. If it's found, the navigation takes over the
// ownership of the pre-created WebContentsImpl instance and destroys the
// handle.
class PrerenderNewTabHandle {
public:
PrerenderNewTabHandle(const PrerenderAttributes& attributes,
BrowserContext& browser_context);
~PrerenderNewTabHandle();
// Starts prerendering in `web_contents_`. Returns the root FrameTreeNode id
// of the prerendered page, which can be used as the id of PrerenderHost, on
// success. Returns an invalid FrameTreeNodeId on failure.
FrameTreeNodeId StartPrerendering(
const PreloadingPredictor& creating_predictor,
const PreloadingPredictor& enacting_predictor,
PreloadingConfidence confidence);
// Cancels prerendering started in `web_contents_`.
void CancelPrerendering(const PrerenderCancellationReason& reason);
// Passes the ownership of `web_contents_` to the caller if it's available for
// new tab navigation with given params.
std::unique_ptr<WebContentsImpl> TakeWebContentsIfAvailable(
const mojom::CreateNewWindowParams& create_new_window_params,
const WebContents::CreateParams& web_contents_create_params);
// Returns PreloadingTriggerType.
PreloadingTriggerType trigger_type() const {
return attributes_.trigger_type;
}
// Returns SpeculationEagerness.
std::optional<blink::mojom::SpeculationEagerness> eagerness() const {
return attributes_.eagerness;
}
private:
PrerenderHostRegistry& GetPrerenderHostRegistry();
const PrerenderAttributes attributes_;
// Used for creating WebContentsImpl that contains a prerendered page for a
// new tab navigation.
WebContents::CreateParams web_contents_create_params_;
// Contains a prerendered page for a new tab navigation. This is valid until
// TakeWebContentsIfAvailable() is called.
std::unique_ptr<WebContentsImpl> web_contents_;
// This is a tentative instance of WebContentsDelegate for `web_contents_`
// until prerender activation. The delegate of `web_contents_` will be swapped
// with a proper one on prerender page activation.
//
// Note: WebContentsDelegate of the initiator WebContentsImpl is not available
// for `web_contents_`. This is because WebContentsDelegate can be specific to
// a tab, and `web_contents_` will be placed in a different tab from the
// initiator's tab.
std::unique_ptr<PrerenderWebContentsDelegate> web_contents_delegate_;
FrameTreeNodeId prerender_host_id_;
};
} // namespace content
#endif // CONTENT_BROWSER_PRELOADING_PRERENDER_PRERENDER_NEW_TAB_HANDLE_H_