LibWeb: Add class to represent "list of available images" from HTML spec

Userland/Libraries/LibWeb/HTML/ListOfAvailableImages.cpp

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2023, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/HTML/DecodedImageData.h>
+#include <LibWeb/HTML/ListOfAvailableImages.h>
+
+namespace Web::HTML {
+
+ListOfAvailableImages::ListOfAvailableImages() = default;
+ListOfAvailableImages::~ListOfAvailableImages() = default;
+
+bool ListOfAvailableImages::Key::operator==(Key const& other) const
+{
+    return url == other.url && mode == other.mode && origin == other.origin;
+}
+
+u32 ListOfAvailableImages::Key::hash() const
+{
+    if (!cached_hash.has_value()) {
+        u32 url_hash = Traits<AK::URL>::hash(url);
+        u32 mode_hash = static_cast<u32>(mode);
+        u32 origin_hash = 0;
+        if (origin.has_value())
+            origin_hash = Traits<HTML::Origin>::hash(origin.value());
+        cached_hash = pair_int_hash(url_hash, pair_int_hash(mode_hash, origin_hash));
+    }
+    return cached_hash.value();
+}
+
+ErrorOr<NonnullRefPtr<ListOfAvailableImages::Entry>> ListOfAvailableImages::Entry::create(NonnullRefPtr<DecodedImageData> image_data, bool ignore_higher_layer_caching)
+{
+    return adopt_nonnull_ref_or_enomem(new (nothrow) Entry(move(image_data), ignore_higher_layer_caching));
+}
+
+ListOfAvailableImages::Entry::Entry(NonnullRefPtr<DecodedImageData> data, bool ignore_higher_layer_caching)
+    : ignore_higher_layer_caching(ignore_higher_layer_caching)
+    , image_data(move(data))
+{
+}
+
+ListOfAvailableImages::Entry::~Entry() = default;
+
+ErrorOr<void> ListOfAvailableImages::add(Key const& key, NonnullRefPtr<DecodedImageData> image_data, bool ignore_higher_layer_caching)
+{
+    auto entry = TRY(Entry::create(move(image_data), ignore_higher_layer_caching));
+    TRY(m_images.try_set(key, move(entry)));
+    return {};
+}
+
+void ListOfAvailableImages::remove(Key const& key)
+{
+    m_images.remove(key);
+}
+
+RefPtr<ListOfAvailableImages::Entry> ListOfAvailableImages::get(Key const& key) const
+{
+    auto it = m_images.find(key);
+    if (it == m_images.end())
+        return nullptr;
+    return it->value;
+}
+
+}

Userland/Libraries/LibWeb/HTML/ListOfAvailableImages.h

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2023, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/HashMap.h>
+#include <AK/URL.h>
+#include <LibJS/Heap/Cell.h>
+#include <LibWeb/Forward.h>
+#include <LibWeb/HTML/CORSSettingAttribute.h>
+#include <LibWeb/HTML/Origin.h>
+
+namespace Web::HTML {
+
+// https://html.spec.whatwg.org/multipage/images.html#list-of-available-images
+class ListOfAvailableImages {
+public:
+    struct Key {
+        AK::URL url;
+        HTML::CORSSettingAttribute mode;
+        Optional<HTML::Origin> origin;
+
+        [[nodiscard]] bool operator==(Key const& other) const;
+        [[nodiscard]] u32 hash() const;
+
+    private:
+        mutable Optional<u32> cached_hash;
+    };
+
+    struct Entry final : public RefCounted<Entry> {
+        static ErrorOr<NonnullRefPtr<Entry>> create(NonnullRefPtr<DecodedImageData>, bool ignore_higher_layer_caching);
+        ~Entry();
+
+        bool ignore_higher_layer_caching { false };
+        NonnullRefPtr<DecodedImageData> image_data;
+
+    private:
+        Entry(NonnullRefPtr<DecodedImageData>, bool ignore_higher_layer_caching);
+    };
+
+    ListOfAvailableImages();
+    ~ListOfAvailableImages();
+
+    ErrorOr<void> add(Key const&, NonnullRefPtr<DecodedImageData>, bool ignore_higher_layer_caching);
+    void remove(Key const&);
+    [[nodiscard]] RefPtr<Entry> get(Key const&) const;
+
+private:
+    HashMap<Key, NonnullRefPtr<Entry>> m_images;
+};
+
+}
+
+namespace AK {
+
+template<>
+struct Traits<Web::HTML::ListOfAvailableImages::Key> : public GenericTraits<Web::HTML::ListOfAvailableImages::Key> {
+    static unsigned hash(Web::HTML::ListOfAvailableImages::Key const& key)
+    {
+        return key.hash();
+    }
+    static bool equals(Web::HTML::ListOfAvailableImages::Key const& a, Web::HTML::ListOfAvailableImages::Key const& b)
+    {
+        return a == b;
+    }
+};
+
+}