LibWeb: Implement PerformanceObserver

Userland/Libraries/LibWeb/PerformanceTimeline/PerformanceObserverEntryList.cpp

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2023, Luke Wilde <lukew@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/QuickSort.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Bindings/PerformanceObserverEntryListPrototype.h>
+#include <LibWeb/PerformanceTimeline/PerformanceEntry.h>
+#include <LibWeb/PerformanceTimeline/PerformanceObserverEntryList.h>
+#include <LibWeb/WebIDL/ExceptionOr.h>
+
+namespace Web::PerformanceTimeline {
+
+PerformanceObserverEntryList::PerformanceObserverEntryList(JS::Realm& realm, Vector<JS::NonnullGCPtr<PerformanceTimeline::PerformanceEntry>>&& entry_list)
+    : Bindings::PlatformObject(realm)
+    , m_entry_list(move(entry_list))
+{
+}
+
+PerformanceObserverEntryList::~PerformanceObserverEntryList() = default;
+
+void PerformanceObserverEntryList::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    set_prototype(&Bindings::ensure_web_prototype<Bindings::PerformanceObserverEntryListPrototype>(realm, "PerformanceObserverEntryList"));
+}
+
+void PerformanceObserverEntryList::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    for (auto& entry : m_entry_list)
+        visitor.visit(entry);
+}
+
+// https://www.w3.org/TR/performance-timeline/#dfn-filter-buffer-by-name-and-type
+ErrorOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> filter_buffer_by_name_and_type(Vector<JS::NonnullGCPtr<PerformanceTimeline::PerformanceEntry>> const& buffer, Optional<String> name, Optional<String> type)
+{
+    // 1. Let result be an initially empty list.
+    Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>> result;
+
+    // 2. For each PerformanceEntry entry in buffer, run the following steps:
+    for (auto const& entry : buffer) {
+        // 1. If type is not null and if type is not identical to entry's entryType attribute, continue to next entry.
+        if (type.has_value() && type.value() != entry->entry_type())
+            continue;
+
+        // 2. If name is not null and if name is not identical to entry's name attribute, continue to next entry.
+        if (name.has_value() && name.value() != entry->name())
+            continue;
+
+        // 3. append entry to result.
+        TRY(result.try_append(entry));
+    }
+
+    // 3. Sort results's entries in chronological order with respect to startTime
+    quick_sort(result, [](auto const& left_entry, auto const& right_entry) {
+        return left_entry->start_time() < right_entry->start_time();
+    });
+
+    // 4. Return result.
+    return result;
+}
+
+// https://w3c.github.io/performance-timeline/#dom-performanceobserverentrylist-getentries
+WebIDL::ExceptionOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> PerformanceObserverEntryList::get_entries() const
+{
+    // Returns a PerformanceEntryList object returned by filter buffer by name and type algorithm with this's entry list,
+    // name and type set to null.
+    return TRY_OR_THROW_OOM(vm(), filter_buffer_by_name_and_type(m_entry_list, /* name= */ Optional<String> {}, /* type= */ Optional<String> {}));
+}
+
+// https://w3c.github.io/performance-timeline/#dom-performanceobserverentrylist-getentriesbytype
+WebIDL::ExceptionOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> PerformanceObserverEntryList::get_entries_by_type(String const& type) const
+{
+    // Returns a PerformanceEntryList object returned by filter buffer by name and type algorithm with this's entry list,
+    // name set to null, and type set to the method's input type parameter.
+    return TRY_OR_THROW_OOM(vm(), filter_buffer_by_name_and_type(m_entry_list, /* name= */ Optional<String> {}, type));
+}
+
+// https://w3c.github.io/performance-timeline/#dom-performanceobserverentrylist-getentriesbyname
+WebIDL::ExceptionOr<Vector<JS::Handle<PerformanceTimeline::PerformanceEntry>>> PerformanceObserverEntryList::get_entries_by_name(String const& name, Optional<String> type) const
+{
+    // Returns a PerformanceEntryList object returned by filter buffer by name and type algorithm with this's entry list,
+    // name set to the method input name parameter, and type set to null if optional entryType is omitted, or set to the
+    // method's input type parameter otherwise.
+    return TRY_OR_THROW_OOM(vm(), filter_buffer_by_name_and_type(m_entry_list, name, type));
+}
+
+}