LibWeb: Implement performance.mark and performance.clearMarks

13 files changed, 341 insertions, 0 deletions

diff --git a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
index 1a63e2cf94..664bda2c73 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
@@ -45,6 +45,7 @@ static bool is_platform_object(Type const& type)
         "Node"sv,
         "Path2D"sv,
         "PerformanceEntry"sv,
+        "PerformanceMark"sv,
         "Range"sv,
         "ReadableStream"sv,
         "Request"sv,
@@ -3152,6 +3153,7 @@ using namespace Web::ResizeObserver;
 using namespace Web::Selection;
 using namespace Web::Streams;
 using namespace Web::UIEvents;
+using namespace Web::UserTiming;
 using namespace Web::URL;
 using namespace Web::XHR;
 using namespace Web::WebAssembly;
@@ -3387,6 +3389,7 @@ using namespace Web::Streams;
 using namespace Web::SVG;
 using namespace Web::UIEvents;
 using namespace Web::URL;
+using namespace Web::UserTiming;
 using namespace Web::WebSockets;
 using namespace Web::XHR;
 using namespace Web::WebAssembly;
@@ -3516,6 +3519,7 @@ using namespace Web::Selection;
 using namespace Web::XHR;
 using namespace Web::UIEvents;
 using namespace Web::URL;
+using namespace Web::UserTiming;
 using namespace Web::WebGL;
 using namespace Web::WebIDL;
 
@@ -3648,6 +3652,7 @@ using namespace Web::Streams;
 using namespace Web::SVG;
 using namespace Web::UIEvents;
 using namespace Web::URL;
+using namespace Web::UserTiming;
 using namespace Web::WebSockets;
 using namespace Web::XHR;
 using namespace Web::WebGL;
diff --git a/Userland/Libraries/LibWeb/CMakeLists.txt b/Userland/Libraries/LibWeb/CMakeLists.txt
index 50315e8ad7..e38b852908 100644
--- a/Userland/Libraries/LibWeb/CMakeLists.txt
+++ b/Userland/Libraries/LibWeb/CMakeLists.txt
@@ -448,6 +448,7 @@ set(SOURCES
     URL/URL.cpp
     URL/URLSearchParams.cpp
     URL/URLSearchParamsIterator.cpp
+    UserTiming/PerformanceMark.cpp
     WebAssembly/Instance.cpp
     WebAssembly/Memory.cpp
     WebAssembly/Module.cpp
diff --git a/Userland/Libraries/LibWeb/Forward.h b/Userland/Libraries/LibWeb/Forward.h
index 60d29430dd..b46ef74990 100644
--- a/Userland/Libraries/LibWeb/Forward.h
+++ b/Userland/Libraries/LibWeb/Forward.h
@@ -519,6 +519,10 @@ class URLSearchParams;
 class URLSearchParamsIterator;
 }
 
+namespace Web::UserTiming {
+class PerformanceMark;
+}
+
 namespace Web::Bindings {
 class Intrinsics;
 class OptionConstructor;
diff --git a/Userland/Libraries/LibWeb/HTML/Window.cpp b/Userland/Libraries/LibWeb/HTML/Window.cpp
index abdea88a59..37a7e5c4c6 100644
--- a/Userland/Libraries/LibWeb/HTML/Window.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Window.cpp
@@ -747,6 +747,7 @@ WebIDL::ExceptionOr<void> Window::initialize_web_interfaces(Badge<WindowEnvironm
     Object::set_prototype(&Bindings::ensure_web_prototype<Bindings::WindowPrototype>(realm, "Window"));
 
     MUST_OR_THROW_OOM(Bindings::WindowGlobalMixin::initialize(realm, *this));
+    MUST_OR_THROW_OOM(WindowOrWorkerGlobalScopeMixin::initialize(realm));
 
     return {};
 }
diff --git a/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.cpp b/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.cpp
index c5b85db129..5d9cc077d8 100644
--- a/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.cpp
+++ b/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.cpp
@@ -24,6 +24,8 @@
 #include <LibWeb/HTML/Window.h>
 #include <LibWeb/HTML/WindowOrWorkerGlobalScope.h>
 #include <LibWeb/Infra/Base64.h>
+#include <LibWeb/PerformanceTimeline/EntryTypes.h>
+#include <LibWeb/UserTiming/PerformanceMark.h>
 #include <LibWeb/WebIDL/AbstractOperations.h>
 #include <LibWeb/WebIDL/DOMException.h>
 #include <LibWeb/WebIDL/ExceptionOr.h>
@@ -32,6 +34,27 @@ namespace Web::HTML {
 
 WindowOrWorkerGlobalScopeMixin::~WindowOrWorkerGlobalScopeMixin() = default;
 
+// Please keep these in alphabetical order based on the entry type :^)
+#define ENUMERATE_SUPPORTED_PERFORMANCE_ENTRY_TYPES \
+    __ENUMERATE_SUPPORTED_PERFORMANCE_ENTRY_TYPES(PerformanceTimeline::EntryTypes::mark, UserTiming::PerformanceMark)
+
+JS::ThrowCompletionOr<void> WindowOrWorkerGlobalScopeMixin::initialize(JS::Realm& realm)
+{
+    auto& vm = realm.vm();
+
+#define __ENUMERATE_SUPPORTED_PERFORMANCE_ENTRY_TYPES(entry_type, cpp_class)                                                                     \
+    TRY_OR_THROW_OOM(vm, m_performance_entry_buffer_map.try_set(entry_type, PerformanceTimeline::PerformanceEntryTuple {                         \
+                                                                                .performance_entry_buffer = {},                                  \
+                                                                                .max_buffer_size = cpp_class::max_buffer_size(),                 \
+                                                                                .available_from_timeline = cpp_class::available_from_timeline(), \
+                                                                                .dropped_entries_count = 0,                                      \
+                                                                            }));
+    ENUMERATE_SUPPORTED_PERFORMANCE_ENTRY_TYPES
+#undef __ENUMERATE_SUPPORTED_PERFORMANCE_ENTRY_TYPES
+
+    return {};
+}
+
 void WindowOrWorkerGlobalScopeMixin::visit_edges(JS::Cell::Visitor& visitor)
 {
     for (auto& it : m_timers)
@@ -266,6 +289,72 @@ i32 WindowOrWorkerGlobalScopeMixin::run_timer_initialization_steps(TimerHandler
     return id;
 }
 
+// 1. https://www.w3.org/TR/performance-timeline/#dfn-relevant-performance-entry-tuple
+PerformanceTimeline::PerformanceEntryTuple& WindowOrWorkerGlobalScopeMixin::relevant_performance_entry_tuple(FlyString const& entry_type)
+{
+    // 1. Let map be the performance entry buffer map associated with globalObject.
+    // 2. Return the result of getting the value of an entry from map, given entryType as the key.
+    auto tuple = m_performance_entry_buffer_map.get(entry_type);
+
+    // This shouldn't be called with entry types that aren't in `ENUMERATE_SUPPORTED_PERFORMANCE_ENTRY_TYPES`.
+    VERIFY(tuple.has_value());
+    return tuple.value();
+}
+
+// https://www.w3.org/TR/performance-timeline/#dfn-queue-a-performanceentry
+WebIDL::ExceptionOr<void> WindowOrWorkerGlobalScopeMixin::queue_performance_entry(JS::NonnullGCPtr<PerformanceTimeline::PerformanceEntry> new_entry)
+{
+    auto& vm = new_entry->vm();
+
+    // FIXME: 1. Let interested observers be an initially empty set of PerformanceObserver objects.
+
+    // 2. Let entryType be newEntry’s entryType value.
+    auto const& entry_type = new_entry->entry_type();
+
+    // 3. Let relevantGlobal be newEntry's relevant global object.
+    // NOTE: Already is `this`.
+
+    // FIXME: 4. For each registered performance observer regObs in relevantGlobal's list of registered performance observer
+    //           objects:
+    //           1. If regObs's options list contains a PerformanceObserverInit options whose entryTypes member includes entryType
+    //              or whose type member equals to entryType:
+    //              1. If should add entry with newEntry and options returns true, append regObs's observer to interested observers.
+
+    // FIXME: 5. For each observer in interested observers:
+    //           1. Append newEntry to observer's observer buffer.
+
+    // 6. Let tuple be the relevant performance entry tuple of entryType and relevantGlobal.
+    auto& tuple = relevant_performance_entry_tuple(entry_type);
+
+    // 7. Let isBufferFull be the return value of the determine if a performance entry buffer is full algorithm with tuple
+    //    as input.
+    bool is_buffer_full = tuple.is_full();
+
+    // 8. Let shouldAdd be the result of should add entry with newEntry as input.
+    auto should_add = new_entry->should_add_entry();
+
+    // 9. If isBufferFull is false and shouldAdd is true, append newEntry to tuple's performance entry buffer.
+    if (!is_buffer_full && should_add == PerformanceTimeline::ShouldAddEntry::Yes)
+        TRY_OR_THROW_OOM(vm, tuple.performance_entry_buffer.try_append(JS::make_handle(new_entry)));
+
+    // FIXME: 10. Queue the PerformanceObserver task with relevantGlobal as input.
+    return {};
+}
+
+void WindowOrWorkerGlobalScopeMixin::clear_performance_entry_buffer(Badge<HighResolutionTime::Performance>, FlyString const& entry_type)
+{
+    auto& tuple = relevant_performance_entry_tuple(entry_type);
+    tuple.performance_entry_buffer.clear();
+}
+
+void WindowOrWorkerGlobalScopeMixin::remove_entries_from_performance_entry_buffer(Badge<HighResolutionTime::Performance>, FlyString const& entry_type, String entry_name)
+{
+    auto& tuple = relevant_performance_entry_tuple(entry_type);
+    tuple.performance_entry_buffer.remove_all_matching([&entry_name](JS::Handle<PerformanceTimeline::PerformanceEntry> const& entry) {
+        return entry->name() == entry_name;
+    });
+}
+
 // https://www.w3.org/TR/performance-timeline/#dfn-filter-buffer-by-name-and-type
 static ErrorOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> filter_buffer_by_name_and_type(Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>> const& buffer, Optional<String> name, Optional<String> type)
 {
diff --git a/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.h b/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.h
index c6c9133866..49328a5eb3 100644
--- a/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.h
+++ b/Userland/Libraries/LibWeb/HTML/WindowOrWorkerGlobalScope.h
@@ -47,9 +47,15 @@ public:
     void clear_timeout(i32);
     void clear_interval(i32);
 
+    PerformanceTimeline::PerformanceEntryTuple& relevant_performance_entry_tuple(FlyString const& entry_type);
+    WebIDL::ExceptionOr<void> queue_performance_entry(JS::NonnullGCPtr<PerformanceTimeline::PerformanceEntry> new_entry);
+    void clear_performance_entry_buffer(Badge<HighResolutionTime::Performance>, FlyString const& entry_type);
+    void remove_entries_from_performance_entry_buffer(Badge<HighResolutionTime::Performance>, FlyString const& entry_type, String entry_name);
+
     ErrorOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> filter_buffer_map_by_name_and_type(Optional<String> name, Optional<String> type) const;
 
 protected:
+    JS::ThrowCompletionOr<void> initialize(JS::Realm&);
     void visit_edges(JS::Cell::Visitor&);
 
 private:
diff --git a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp
index d3fc604d06..89a2178930 100644
--- a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp
+++ b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.cpp
@@ -11,6 +11,7 @@
 #include <LibWeb/HTML/Window.h>
 #include <LibWeb/HighResolutionTime/Performance.h>
 #include <LibWeb/NavigationTiming/PerformanceTiming.h>
+#include <LibWeb/PerformanceTimeline/EntryTypes.h>
 
 namespace Web::HighResolutionTime {
 
@@ -50,6 +51,44 @@ double Performance::time_origin() const
     return static_cast<double>(m_timer.origin_time().to_milliseconds());
 }
 
+// https://w3c.github.io/user-timing/#mark-method
+WebIDL::ExceptionOr<JS::NonnullGCPtr<UserTiming::PerformanceMark>> Performance::mark(String const& mark_name, UserTiming::PerformanceMarkOptions const& mark_options)
+{
+    auto& realm = this->realm();
+
+    // 1. Run the PerformanceMark constructor and let entry be the newly created object.
+    auto entry = TRY(UserTiming::PerformanceMark::construct_impl(realm, mark_name, mark_options));
+
+    // 2. Queue entry.
+    auto* window_or_worker = dynamic_cast<HTML::WindowOrWorkerGlobalScopeMixin*>(&realm.global_object());
+    VERIFY(window_or_worker);
+    TRY(window_or_worker->queue_performance_entry(entry));
+
+    // 3. Add entry to the performance entry buffer.
+    // FIXME: This seems to be a holdover from moving to the `queue` structure for PerformanceObserver, as this would cause a double append.
+
+    // 4. Return entry.
+    return entry;
+}
+
+void Performance::clear_marks(Optional<String> mark_name)
+{
+    auto& realm = this->realm();
+    auto* window_or_worker = dynamic_cast<HTML::WindowOrWorkerGlobalScopeMixin*>(&realm.global_object());
+    VERIFY(window_or_worker);
+
+    // 1. If markName is omitted, remove all PerformanceMark objects from the performance entry buffer.
+    if (!mark_name.has_value()) {
+        window_or_worker->clear_performance_entry_buffer({}, PerformanceTimeline::EntryTypes::mark);
+        return;
+    }
+
+    // 2. Otherwise, remove all PerformanceMark objects listed in the performance entry buffer whose name is markName.
+    window_or_worker->remove_entries_from_performance_entry_buffer({}, PerformanceTimeline::EntryTypes::mark, mark_name.value());
+
+    // 3. Return undefined.
+}
+
 // https://www.w3.org/TR/performance-timeline/#getentries-method
 WebIDL::ExceptionOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> Performance::get_entries() const
 {
diff --git a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.h b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.h
index 8aa087c89a..c49fdaeb33 100644
--- a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.h
+++ b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.h
@@ -9,6 +9,7 @@
 
 #include <LibCore/ElapsedTimer.h>
 #include <LibWeb/DOM/EventTarget.h>
+#include <LibWeb/UserTiming/PerformanceMark.h>
 
 namespace Web::HighResolutionTime {
 
@@ -23,6 +24,9 @@ public:
 
     JS::GCPtr<NavigationTiming::PerformanceTiming> timing();
 
+    WebIDL::ExceptionOr<JS::NonnullGCPtr<UserTiming::PerformanceMark>> mark(String const& mark_name, UserTiming::PerformanceMarkOptions const& mark_options = {});
+    void clear_marks(Optional<String> mark_name);
+
     WebIDL::ExceptionOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> get_entries() const;
     WebIDL::ExceptionOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> get_entries_by_type(String const& type) const;
     WebIDL::ExceptionOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> get_entries_by_name(String const& name, Optional<String> type) const;
diff --git a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.idl b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.idl
index 544026fb9b..9a8e74aaf1 100644
--- a/Userland/Libraries/LibWeb/HighResolutionTime/Performance.idl
+++ b/Userland/Libraries/LibWeb/HighResolutionTime/Performance.idl
@@ -2,6 +2,7 @@
 #import <HighResolutionTime/DOMHighResTimeStamp.idl>
 #import <NavigationTiming/PerformanceTiming.idl>
 #import <PerformanceTimeline/PerformanceEntry.idl>
+#import <UserTiming/PerformanceMark.idl>
 
 // https://www.w3.org/TR/performance-timeline/#dom-performanceentrylist
 typedef sequence<PerformanceEntry> PerformanceEntryList;
@@ -13,6 +14,14 @@ interface Performance : EventTarget {
     readonly attribute DOMHighResTimeStamp timeOrigin;
 
     readonly attribute PerformanceTiming timing;
+
+    // https://w3c.github.io/user-timing/#extensions-performance-interface
+    // "User Timing" extensions to the Performance interface
+    PerformanceMark mark(DOMString markName, optional PerformanceMarkOptions markOptions = {});
+    undefined clearMarks(optional DOMString markName);
+    // FIXME: PerformanceMeasure measure(DOMString measureName, optional (DOMString or PerformanceMeasureOptions) startOrMeasureOptions = {}, optional DOMString endMark);
+    // FIXME: undefined clearMeasures(optional DOMString measureName);
+
     // https://www.w3.org/TR/performance-timeline/#extensions-to-the-performance-interface
     // "Performance Timeline" extensions to the Performance interface
     PerformanceEntryList getEntries();
diff --git a/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.cpp b/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.cpp
new file mode 100644
index 0000000000..d2da66c87f
--- /dev/null
+++ b/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.cpp
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2023, Luke Wilde <lukew@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Bindings/PerformanceMarkPrototype.h>
+#include <LibWeb/HTML/StructuredSerialize.h>
+#include <LibWeb/HTML/Window.h>
+#include <LibWeb/HighResolutionTime/TimeOrigin.h>
+#include <LibWeb/NavigationTiming/EntryNames.h>
+#include <LibWeb/PerformanceTimeline/EntryTypes.h>
+#include <LibWeb/UserTiming/PerformanceMark.h>
+#include <LibWeb/WebIDL/ExceptionOr.h>
+
+namespace Web::UserTiming {
+
+PerformanceMark::PerformanceMark(JS::Realm& realm, String const& name, HighResolutionTime::DOMHighResTimeStamp start_time, HighResolutionTime::DOMHighResTimeStamp duration, JS::Value detail)
+    : PerformanceTimeline::PerformanceEntry(realm, name, start_time, duration)
+    , m_detail(detail)
+{
+}
+
+PerformanceMark::~PerformanceMark() = default;
+
+// https://w3c.github.io/user-timing/#dfn-performancemark-constructor
+WebIDL::ExceptionOr<JS::NonnullGCPtr<PerformanceMark>> PerformanceMark::construct_impl(JS::Realm& realm, String const& mark_name, Web::UserTiming::PerformanceMarkOptions const& mark_options)
+{
+    auto& current_global_object = realm.global_object();
+    auto& vm = realm.vm();
+
+    // 1. If the current global object is a Window object and markName uses the same name as a read only attribute in the PerformanceTiming interface, throw a SyntaxError.
+    if (is<HTML::Window>(current_global_object)) {
+        bool matched = false;
+
+#define __ENUMERATE_NAVIGATION_TIMING_ENTRY_NAME(name)   \
+    if (mark_name == NavigationTiming::EntryNames::name) \
+        matched = true;
+        ENUMERATE_NAVIGATION_TIMING_ENTRY_NAMES
+#undef __ENUMERATE_NAVIGATION_TIMING_ENTRY_NAME
+
+        if (matched)
+            return WebIDL::SyntaxError::create(realm, DeprecatedString::formatted("'{}' markName cannot be used in a Window context because it is part of the PerformanceTiming interface", mark_name));
+    }
+
+    // NOTE: Step 2 (creating the entry) is done after determining values, as we set the values once during creation and never change them after.
+
+    // 3. Set entry's name attribute to markName.
+    auto const& name = mark_name;
+
+    // 4. Set entry's entryType attribute to DOMString "mark".
+    // NOTE: Already done via the `entry_type` virtual function.
+
+    // 5. Set entry's startTime attribute as follows:
+    HighResolutionTime::DOMHighResTimeStamp start_time { 0.0 };
+
+    // 1. If markOptions's startTime member is present, then:
+    if (mark_options.start_time.has_value()) {
+        // 1. If markOptions's startTime is negative, throw a TypeError.
+        if (mark_options.start_time.value() < 0.0)
+            return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, "startTime cannot be negative"sv };
+
+        // 2. Otherwise, set entry's startTime to the value of markOptions's startTime.
+        start_time = mark_options.start_time.value();
+    }
+    // 2. Otherwise, set it to the value that would be returned by the Performance object's now() method.
+    else {
+        // FIXME: Performance#now doesn't currently use TimeOrigin's functions, update this and Performance#now to match Performance#now's specification.
+        start_time = HighResolutionTime::unsafe_shared_current_time();
+    }
+
+    // 6. Set entry's duration attribute to 0.
+    constexpr HighResolutionTime::DOMHighResTimeStamp duration = 0.0;
+
+    // 7. If markOptions's detail is null, set entry's detail to null.
+    JS::Value detail;
+    if (mark_options.detail.is_null()) {
+        detail = JS::js_null();
+    }
+    // 8. Otherwise:
+    else {
+        // 1. Let record be the result of calling the StructuredSerialize algorithm on markOptions's detail.
+        auto record = TRY(HTML::structured_serialize(vm, mark_options.detail));
+
+        // 2. Set entry's detail to the result of calling the StructuredDeserialize algorithm on record and the current realm.
+        detail = TRY(HTML::structured_deserialize(vm, record, realm, Optional<HTML::SerializationMemory> {}));
+    }
+
+    // 2. Create a new PerformanceMark object (entry) with the current global object's realm.
+    return MUST_OR_THROW_OOM(realm.heap().allocate<PerformanceMark>(realm, realm, name, start_time, duration, detail));
+}
+
+FlyString const& PerformanceMark::entry_type() const
+{
+    return PerformanceTimeline::EntryTypes::mark;
+}
+
+JS::ThrowCompletionOr<void> PerformanceMark::initialize(JS::Realm& realm)
+{
+    MUST_OR_THROW_OOM(Base::initialize(realm));
+    set_prototype(&Bindings::ensure_web_prototype<Bindings::PerformanceMarkPrototype>(realm, "PerformanceMark"));
+
+    return {};
+}
+
+void PerformanceMark::visit_edges(JS::Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_detail);
+}
+
+}
diff --git a/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.h b/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.h
new file mode 100644
index 0000000000..8a731739d9
--- /dev/null
+++ b/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2023, Luke Wilde <lukew@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/PerformanceTimeline/PerformanceEntry.h>
+
+namespace Web::UserTiming {
+
+// https://w3c.github.io/user-timing/#ref-for-dom-performancemarkoptions-1
+struct PerformanceMarkOptions {
+    JS::Value detail { JS::js_null() };
+    Optional<HighResolutionTime::DOMHighResTimeStamp> start_time;
+};
+
+// https://w3c.github.io/user-timing/#dom-performancemark
+class PerformanceMark final : public PerformanceTimeline::PerformanceEntry {
+    WEB_PLATFORM_OBJECT(PerformanceMark, PerformanceTimeline::PerformanceEntry);
+
+public:
+    virtual ~PerformanceMark();
+
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<PerformanceMark>> construct_impl(JS::Realm&, String const& mark_name, PerformanceMarkOptions const& mark_options = {});
+
+    // NOTE: These three functions are answered by the registry for the given entry type.
+    // https://w3c.github.io/timing-entrytypes-registry/#registry
+
+    // https://w3c.github.io/timing-entrytypes-registry/#dfn-availablefromtimeline
+    static PerformanceTimeline::AvailableFromTimeline available_from_timeline() { return PerformanceTimeline::AvailableFromTimeline::Yes; }
+
+    // https://w3c.github.io/timing-entrytypes-registry/#dfn-maxbuffersize
+    // NOTE: The empty state represents Infinite size.
+    static Optional<u64> max_buffer_size() { return OptionalNone {}; }
+
+    // https://w3c.github.io/timing-entrytypes-registry/#dfn-should-add-entry
+    virtual PerformanceTimeline::ShouldAddEntry should_add_entry() const override { return PerformanceTimeline::ShouldAddEntry::Yes; }
+
+    virtual FlyString const& entry_type() const override;
+
+    JS::Value detail() const { return m_detail; }
+
+private:
+    PerformanceMark(JS::Realm&, String const& name, HighResolutionTime::DOMHighResTimeStamp start_time, HighResolutionTime::DOMHighResTimeStamp duration, JS::Value detail);
+
+    virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
+    virtual void visit_edges(JS::Cell::Visitor&) override;
+
+    // https://w3c.github.io/user-timing/#dom-performancemark-detail
+    JS::Value m_detail { JS::js_null() };
+};
+
+}
diff --git a/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.idl b/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.idl
new file mode 100644
index 0000000000..0b93a6c636
--- /dev/null
+++ b/Userland/Libraries/LibWeb/UserTiming/PerformanceMark.idl
@@ -0,0 +1,14 @@
+#import <PerformanceTimeline/PerformanceEntry.idl>
+
+// https://w3c.github.io/user-timing/#dom-performancemark
+[Exposed=(Window,Worker), UseNewAKString]
+interface PerformanceMark : PerformanceEntry {
+    constructor(DOMString markName, optional PerformanceMarkOptions markOptions = {});
+    readonly attribute any detail;
+};
+
+// https://w3c.github.io/user-timing/#ref-for-dom-performancemarkoptions-1
+dictionary PerformanceMarkOptions {
+    any detail;
+    DOMHighResTimeStamp startTime;
+};
diff --git a/Userland/Libraries/LibWeb/idl_files.cmake b/Userland/Libraries/LibWeb/idl_files.cmake
index 126ff30302..9d79256c25 100644
--- a/Userland/Libraries/LibWeb/idl_files.cmake
+++ b/Userland/Libraries/LibWeb/idl_files.cmake
@@ -201,6 +201,7 @@ libweb_js_bindings(UIEvents/UIEvent)
 libweb_js_bindings(UIEvents/WheelEvent)
 libweb_js_bindings(URL/URL)
 libweb_js_bindings(URL/URLSearchParams ITERABLE)
+libweb_js_bindings(UserTiming/PerformanceMark)
 libweb_js_bindings(WebAssembly/Instance)
 libweb_js_bindings(WebAssembly/Memory)
 libweb_js_bindings(WebAssembly/Module)