Source/WebCore/loader/DocumentPrefetcher.h

/*
 * Copyright (C) 2025 Shopify Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
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 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
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#pragma once

#include "CachedRawResourceClient.h"
#include "CachedResourceHandle.h"
#include <optional>
#include <wtf/CompletionHandler.h>
#include <wtf/Forward.h>
#include <wtf/HashMap.h>
#include <wtf/URLHash.h>


namespace WebCore {

class CachedRawResource;
class DocumentLoader;
class LocalFrame;
class ResourceRequest;
class SecurityOrigin;

enum class ReferrerPolicy : uint8_t;

class DocumentPrefetcher : public RefCounted<DocumentPrefetcher>, public CachedRawResourceClient {
public:
    struct PrefetchedResourceData {
        // The resource needs to be here in order to be kept alive.
        CachedResourceHandle<CachedRawResource> resource;
        Box<NetworkLoadMetrics> metrics;
    };
    static Ref<DocumentPrefetcher> create(LocalFrame& frame) { return adoptRef(*new DocumentPrefetcher(frame)); }
    ~DocumentPrefetcher();

    // CachedResourceClient.
    void ref() const final { RefCounted::ref(); }
    void deref() const final { RefCounted::deref(); }

    void clear();
    void prefetch(const URL&, const Vector<String>& tags, std::optional<ReferrerPolicy>, bool lowPriority = false);
    void removePrefetch(const URL&);
    bool wasPrefetched(const URL&) const;
    Box<NetworkLoadMetrics> takePrefetchedResourceMetrics(const URL&);
    void clearPrefetchedResourcesExcept(const URL&);
    void clearPrefetchedResourcesForOrigin(const SecurityOrigin&);

    // CachedRawResourceClient
    void responseReceived(const CachedResource&, const ResourceResponse&, CompletionHandler<void()>&&) override;
    void notifyFinished(CachedResource&, const NetworkLoadMetrics&, LoadWillContinueInAnotherProcess = LoadWillContinueInAnotherProcess::No) override;
    void redirectReceived(CachedResource&, ResourceRequest&&, const ResourceResponse&, CompletionHandler<void(ResourceRequest&&)>&&) override;
    CachedResourceClientType resourceClientType() const override { return RawResourceType; }


private:
    explicit DocumentPrefetcher(LocalFrame&);

    WeakPtr<LocalFrame> m_frame;
    HashMap<URL, PrefetchedResourceData> m_prefetchedData;
};

} // namespace WebCore