third_party/WebKit/Source/core/timing/PerformanceObserver.cpp

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "core/timing/PerformanceObserver.h"

#include <algorithm>
#include "bindings/core/v8/ExceptionMessages.h"
#include "bindings/core/v8/ExceptionState.h"
#include "bindings/core/v8/V8BindingForCore.h"
#include "bindings/core/v8/v8_performance_observer_callback.h"
#include "core/dom/ExecutionContext.h"
#include "core/frame/LocalDOMWindow.h"
#include "core/frame/UseCounter.h"
#include "core/timing/DOMWindowPerformance.h"
#include "core/timing/Performance.h"
#include "core/timing/PerformanceEntry.h"
#include "core/timing/PerformanceObserverEntryList.h"
#include "core/timing/PerformanceObserverInit.h"
#include "core/timing/WorkerGlobalScopePerformance.h"
#include "core/workers/WorkerGlobalScope.h"
#include "platform/Timer.h"

namespace blink {

PerformanceObserver* PerformanceObserver::Create(
    ScriptState* script_state,
    V8PerformanceObserverCallback* callback) {
  LocalDOMWindow* window = ToLocalDOMWindow(script_state->GetContext());
  ExecutionContext* context = ExecutionContext::From(script_state);
  if (window) {
    UseCounter::Count(context, WebFeature::kPerformanceObserverForWindow);
    return new PerformanceObserver(
        context, DOMWindowPerformance::performance(*window), callback);
  }
  if (context->IsWorkerGlobalScope()) {
    UseCounter::Count(context, WebFeature::kPerformanceObserverForWorker);
    return new PerformanceObserver(context,
                                   WorkerGlobalScopePerformance::performance(
                                       *ToWorkerGlobalScope(context)),
                                   callback);
  }
  V8ThrowException::ThrowTypeError(
      script_state->GetIsolate(),
      ExceptionMessages::FailedToConstruct(
          "PerformanceObserver",
          "No 'worker' or 'window' in current context."));
  return nullptr;
}

PerformanceObserver::PerformanceObserver(
    ExecutionContext* execution_context,
    PerformanceBase* performance,
    V8PerformanceObserverCallback* callback)
    : ContextClient(execution_context),
      execution_context_(execution_context),
      callback_(callback),
      performance_(performance),
      filter_options_(PerformanceEntry::kInvalid),
      is_registered_(false) {
  DCHECK(performance_);
}

void PerformanceObserver::observe(const PerformanceObserverInit& observer_init,
                                  ExceptionState& exception_state) {
  if (!performance_) {
    exception_state.ThrowTypeError(
        "Window/worker may be destroyed? Performance target is invalid.");
    return;
  }

  PerformanceEntryTypeMask entry_types = PerformanceEntry::kInvalid;
  if (observer_init.hasEntryTypes() && observer_init.entryTypes().size()) {
    const Vector<String>& sequence = observer_init.entryTypes();
    for (const auto& entry_type_string : sequence)
      entry_types |= PerformanceEntry::ToEntryTypeEnum(entry_type_string);
  }
  if (entry_types == PerformanceEntry::kInvalid) {
    exception_state.ThrowTypeError(
        "A Performance Observer MUST have at least one valid entryType in its "
        "entryTypes attribute.");
    return;
  }
  filter_options_ = entry_types;
  if (is_registered_)
    performance_->UpdatePerformanceObserverFilterOptions();
  else
    performance_->RegisterPerformanceObserver(*this);
  is_registered_ = true;
}

void PerformanceObserver::disconnect() {
  performance_entries_.clear();
  if (performance_)
    performance_->UnregisterPerformanceObserver(*this);
  is_registered_ = false;
}

void PerformanceObserver::EnqueuePerformanceEntry(PerformanceEntry& entry) {
  performance_entries_.push_back(&entry);
  if (performance_)
    performance_->ActivateObserver(*this);
}

bool PerformanceObserver::HasPendingActivity() const {
  return is_registered_;
}

bool PerformanceObserver::ShouldBeSuspended() const {
  return execution_context_->IsContextSuspended();
}

void PerformanceObserver::Deliver() {
  DCHECK(!ShouldBeSuspended());

  if (performance_entries_.IsEmpty())
    return;

  PerformanceEntryVector performance_entries;
  performance_entries.swap(performance_entries_);
  PerformanceObserverEntryList* entry_list =
      new PerformanceObserverEntryList(performance_entries);
  callback_->call(this, entry_list, this);
}

void PerformanceObserver::Trace(blink::Visitor* visitor) {
  visitor->Trace(execution_context_);
  visitor->Trace(callback_);
  visitor->Trace(performance_);
  visitor->Trace(performance_entries_);
  ScriptWrappable::Trace(visitor);
  ContextClient::Trace(visitor);
}

void PerformanceObserver::TraceWrappers(
    const ScriptWrappableVisitor* visitor) const {
  visitor->TraceWrappers(callback_);
}

}  // namespace blink