third_party/WebKit/Source/core/streams/UnderlyingSourceBase.cpp

// Copyright 2016 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/streams/UnderlyingSourceBase.h"

#include "bindings/core/v8/ScriptPromise.h"
#include "bindings/core/v8/ScriptState.h"
#include "bindings/core/v8/ScriptValue.h"
#include "core/streams/ReadableStreamController.h"
#include <v8.h>

namespace blink {

ScriptPromise UnderlyingSourceBase::startWrapper(ScriptState* scriptState,
                                                 ScriptValue jsController) {
  // Cannot call start twice (e.g., cannot use the same UnderlyingSourceBase to
  // construct multiple streams).
  ASSERT(!m_controller);

  m_controller = new ReadableStreamController(jsController);

  return start(scriptState);
}

ScriptPromise UnderlyingSourceBase::start(ScriptState* scriptState) {
  return ScriptPromise::castUndefined(scriptState);
}

ScriptPromise UnderlyingSourceBase::pull(ScriptState* scriptState) {
  return ScriptPromise::castUndefined(scriptState);
}

ScriptPromise UnderlyingSourceBase::cancelWrapper(ScriptState* scriptState,
                                                  ScriptValue reason) {
  m_controller->noteHasBeenCanceled();
  return cancel(scriptState, reason);
}

ScriptPromise UnderlyingSourceBase::cancel(ScriptState* scriptState,
                                           ScriptValue reason) {
  return ScriptPromise::castUndefined(scriptState);
}

void UnderlyingSourceBase::notifyLockAcquired() {
  m_isStreamLocked = true;
}

void UnderlyingSourceBase::notifyLockReleased() {
  m_isStreamLocked = false;
}

bool UnderlyingSourceBase::hasPendingActivity() const {
  // This will return false within a finite time period _assuming_ that
  // consumers use the controller to close or error the stream.
  // Browser-created readable streams should always close or error within a
  // finite time period, due to timeouts etc.
  return m_controller && m_controller->isActive() && m_isStreamLocked;
}

void UnderlyingSourceBase::contextDestroyed() {
  if (m_controller) {
    m_controller->noteHasBeenCanceled();
    m_controller.clear();
  }
}

DEFINE_TRACE(UnderlyingSourceBase) {
  ActiveDOMObject::trace(visitor);
  visitor->trace(m_controller);
}

}  // namespace blink