third_party/WebKit/Source/core/xmlhttprequest/XMLHttpRequestProgressEventThrottle.cpp

/*
 * Copyright (C) 2010 Julien Chaffraix <jchaffraix@webkit.org>  All right
 * reserved.
 * Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "core/xmlhttprequest/XMLHttpRequestProgressEventThrottle.h"

#include "core/EventTypeNames.h"
#include "core/dom/TaskRunnerHelper.h"
#include "core/events/ProgressEvent.h"
#include "core/inspector/InspectorInstrumentation.h"
#include "core/inspector/InspectorTraceEvents.h"
#include "core/xmlhttprequest/XMLHttpRequest.h"
#include "public/platform/Platform.h"
#include "public/platform/WebScheduler.h"
#include "public/platform/WebThread.h"
#include "wtf/Assertions.h"
#include "wtf/text/AtomicString.h"

namespace blink {

static const double kMinimumProgressEventDispatchingIntervalInSeconds =
    .05;  // 50 ms per specification.

XMLHttpRequestProgressEventThrottle::DeferredEvent::DeferredEvent() {
  clear();
}

void XMLHttpRequestProgressEventThrottle::DeferredEvent::set(
    bool lengthComputable,
    unsigned long long loaded,
    unsigned long long total) {
  m_isSet = true;

  m_lengthComputable = lengthComputable;
  m_loaded = loaded;
  m_total = total;
}

void XMLHttpRequestProgressEventThrottle::DeferredEvent::clear() {
  m_isSet = false;

  m_lengthComputable = false;
  m_loaded = 0;
  m_total = 0;
}

Event* XMLHttpRequestProgressEventThrottle::DeferredEvent::take() {
  DCHECK(m_isSet);

  Event* event = ProgressEvent::create(EventTypeNames::progress,
                                       m_lengthComputable, m_loaded, m_total);
  clear();
  return event;
}

XMLHttpRequestProgressEventThrottle::XMLHttpRequestProgressEventThrottle(
    XMLHttpRequest* target)
    : TimerBase(TaskRunnerHelper::get(TaskType::Networking,
                                      target->getExecutionContext())),
      m_target(target),
      m_hasDispatchedProgressProgressEvent(false) {
  DCHECK(target);
}

XMLHttpRequestProgressEventThrottle::~XMLHttpRequestProgressEventThrottle() {}

void XMLHttpRequestProgressEventThrottle::dispatchProgressEvent(
    const AtomicString& type,
    bool lengthComputable,
    unsigned long long loaded,
    unsigned long long total) {
  // Given that ResourceDispatcher doesn't deliver an event when suspended,
  // we don't have to worry about event dispatching while suspended.
  if (type != EventTypeNames::progress) {
    m_target->dispatchEvent(
        ProgressEvent::create(type, lengthComputable, loaded, total));
    return;
  }

  if (isActive()) {
    m_deferred.set(lengthComputable, loaded, total);
  } else {
    dispatchProgressProgressEvent(ProgressEvent::create(
        EventTypeNames::progress, lengthComputable, loaded, total));
    startOneShot(kMinimumProgressEventDispatchingIntervalInSeconds,
                 BLINK_FROM_HERE);
  }
}

void XMLHttpRequestProgressEventThrottle::dispatchReadyStateChangeEvent(
    Event* event,
    DeferredEventAction action) {
  XMLHttpRequest::State state = m_target->readyState();
  // Given that ResourceDispatcher doesn't deliver an event when suspended,
  // we don't have to worry about event dispatching while suspended.
  if (action == Flush) {
    if (m_deferred.isSet())
      dispatchProgressProgressEvent(m_deferred.take());

    stop();
  } else if (action == Clear) {
    m_deferred.clear();
    stop();
  }

  m_hasDispatchedProgressProgressEvent = false;
  if (state == m_target->readyState()) {
    // We don't dispatch the event when an event handler associated with
    // the previously dispatched event changes the readyState (e.g. when
    // the event handler calls xhr.abort()). In such cases a
    // readystatechange should have been already dispatched if necessary.
    InspectorInstrumentation::AsyncTask asyncTask(
        m_target->getExecutionContext(), m_target, m_target->isAsync());
    m_target->dispatchEvent(event);
  }
}

void XMLHttpRequestProgressEventThrottle::dispatchProgressProgressEvent(
    Event* progressEvent) {
  XMLHttpRequest::State state = m_target->readyState();
  if (m_target->readyState() == XMLHttpRequest::kLoading &&
      m_hasDispatchedProgressProgressEvent) {
    TRACE_EVENT1("devtools.timeline", "XHRReadyStateChange", "data",
                 InspectorXhrReadyStateChangeEvent::data(
                     m_target->getExecutionContext(), m_target));
    InspectorInstrumentation::AsyncTask asyncTask(
        m_target->getExecutionContext(), m_target, m_target->isAsync());
    m_target->dispatchEvent(Event::create(EventTypeNames::readystatechange));
    TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"),
                         "UpdateCounters", TRACE_EVENT_SCOPE_THREAD, "data",
                         InspectorUpdateCountersEvent::data());
  }

  if (m_target->readyState() != state)
    return;

  m_hasDispatchedProgressProgressEvent = true;
  InspectorInstrumentation::AsyncTask asyncTask(m_target->getExecutionContext(),
                                                m_target, m_target->isAsync());
  m_target->dispatchEvent(progressEvent);
}

void XMLHttpRequestProgressEventThrottle::fired() {
  if (!m_deferred.isSet()) {
    // No "progress" event was queued since the previous dispatch, we can
    // safely stop the timer.
    return;
  }

  dispatchProgressProgressEvent(m_deferred.take());

  // Watch if another "progress" ProgressEvent arrives in the next 50ms.
  startOneShot(kMinimumProgressEventDispatchingIntervalInSeconds,
               BLINK_FROM_HERE);
}

void XMLHttpRequestProgressEventThrottle::suspend() {
  stop();
}

void XMLHttpRequestProgressEventThrottle::resume() {
  if (!m_deferred.isSet())
    return;

  // Do not dispatch events inline here, since ExecutionContext is iterating
  // over the list of active DOM objects to resume them, and any activated JS
  // event-handler could insert new active DOM objects to the list.
  startOneShot(0, BLINK_FROM_HERE);
}

DEFINE_TRACE(XMLHttpRequestProgressEventThrottle) {
  visitor->trace(m_target);
}

}  // namespace blink