dom/html/HTMLFormControlsCollection.cpp
author Nicholas Nethercote <nnethercote@mozilla.com>
Fri, 03 Mar 2017 15:32:11 +1100
changeset 374836 4e196d802c7be7f3a3c147cc6c5b6406656584b1
parent 356201 748010a48c9e4865a58396bf2c16c50871fa824b
permissions -rw-r--r--
Bug 1344118 - Fix the profiler's sleeping threads optimization. r=jseward. When ProfilerBuffer::reset() is called, DuplicateLastSample() will start failing for all sleeping threads because there will be no prior thread data in the buffer to duplicate. But the sampling loop doesn't detect such failure. This causes two problems: - Missing samples. - CPU usage goes through the roof, because each time around the sampling loop the length of the failing search increases. The fix is simple: detect failure in the sampling loop and do a normal sample in that case. The patch also removes ThreadInfo::DuplicateLastSample(), because it just calls onto ProfileBuffer::DuplicateLastSample().

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/dom/HTMLFormControlsCollection.h"

#include "mozilla/FlushType.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/HTMLFormControlsCollectionBinding.h"
#include "mozilla/dom/HTMLFormElement.h"
#include "nsGenericHTMLElement.h" // nsGenericHTMLFormElement
#include "nsIDocument.h"
#include "nsIDOMNode.h"
#include "nsIDOMNodeList.h"
#include "nsIFormControl.h"
#include "RadioNodeList.h"
#include "jsfriendapi.h"

namespace mozilla {
namespace dom {

/* static */ bool
HTMLFormControlsCollection::ShouldBeInElements(nsIFormControl* aFormControl)
{
  // For backwards compatibility (with 4.x and IE) we must not add
  // <input type=image> elements to the list of form controls in a
  // form.

  switch (aFormControl->GetType()) {
  case NS_FORM_BUTTON_BUTTON :
  case NS_FORM_BUTTON_RESET :
  case NS_FORM_BUTTON_SUBMIT :
  case NS_FORM_INPUT_BUTTON :
  case NS_FORM_INPUT_CHECKBOX :
  case NS_FORM_INPUT_COLOR :
  case NS_FORM_INPUT_EMAIL :
  case NS_FORM_INPUT_FILE :
  case NS_FORM_INPUT_HIDDEN :
  case NS_FORM_INPUT_RESET :
  case NS_FORM_INPUT_PASSWORD :
  case NS_FORM_INPUT_RADIO :
  case NS_FORM_INPUT_SEARCH :
  case NS_FORM_INPUT_SUBMIT :
  case NS_FORM_INPUT_TEXT :
  case NS_FORM_INPUT_TEL :
  case NS_FORM_INPUT_URL :
  case NS_FORM_INPUT_NUMBER :
  case NS_FORM_INPUT_RANGE :
  case NS_FORM_INPUT_DATE :
  case NS_FORM_INPUT_TIME :
  case NS_FORM_INPUT_MONTH :
  case NS_FORM_INPUT_WEEK :
  case NS_FORM_INPUT_DATETIME_LOCAL :
  case NS_FORM_SELECT :
  case NS_FORM_TEXTAREA :
  case NS_FORM_FIELDSET :
  case NS_FORM_OBJECT :
  case NS_FORM_OUTPUT :
    return true;
  }

  // These form control types are not supposed to end up in the
  // form.elements array
  //
  // NS_FORM_INPUT_IMAGE
  //
  // XXXbz maybe we should just check for that type here instead of the big
  // switch?

  return false;
}

HTMLFormControlsCollection::HTMLFormControlsCollection(HTMLFormElement* aForm)
  : mForm(aForm)
  // Initialize the elements list to have an initial capacity
  // of 8 to reduce allocations on small forms.
  , mElements(8)
  , mNameLookupTable(HTMLFormElement::FORM_CONTROL_LIST_HASHTABLE_LENGTH)
{
}

HTMLFormControlsCollection::~HTMLFormControlsCollection()
{
  mForm = nullptr;
  Clear();
}

void
HTMLFormControlsCollection::DropFormReference()
{
  mForm = nullptr;
  Clear();
}

void
HTMLFormControlsCollection::Clear()
{
  // Null out childrens' pointer to me.  No refcounting here
  for (int32_t i = mElements.Length() - 1; i >= 0; i--) {
    mElements[i]->ClearForm(false);
  }
  mElements.Clear();

  for (int32_t i = mNotInElements.Length() - 1; i >= 0; i--) {
    mNotInElements[i]->ClearForm(false);
  }
  mNotInElements.Clear();

  mNameLookupTable.Clear();
}

void
HTMLFormControlsCollection::FlushPendingNotifications()
{
  if (mForm) {
    nsIDocument* doc = mForm->GetUncomposedDoc();
    if (doc) {
      doc->FlushPendingNotifications(FlushType::Content);
    }
  }
}

NS_IMPL_CYCLE_COLLECTION_CLASS(HTMLFormControlsCollection)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(HTMLFormControlsCollection)
  // Note: We intentionally don't set tmp->mForm to nullptr here, since doing
  // so may result in crashes because of inconsistent null-checking after the
  // object gets unlinked.
  tmp->Clear();
  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(HTMLFormControlsCollection)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mNameLookupTable)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(HTMLFormControlsCollection)
  NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_TRACE_END

// XPConnect interface list for HTMLFormControlsCollection
NS_INTERFACE_TABLE_HEAD(HTMLFormControlsCollection)
  NS_WRAPPERCACHE_INTERFACE_TABLE_ENTRY
  NS_INTERFACE_TABLE(HTMLFormControlsCollection,
                     nsIHTMLCollection,
                     nsIDOMHTMLCollection)
  NS_INTERFACE_TABLE_TO_MAP_SEGUE_CYCLE_COLLECTION(HTMLFormControlsCollection)
NS_INTERFACE_MAP_END


NS_IMPL_CYCLE_COLLECTING_ADDREF(HTMLFormControlsCollection)
NS_IMPL_CYCLE_COLLECTING_RELEASE(HTMLFormControlsCollection)


// nsIDOMHTMLCollection interface

NS_IMETHODIMP
HTMLFormControlsCollection::GetLength(uint32_t* aLength)
{
  FlushPendingNotifications();
  *aLength = mElements.Length();
  return NS_OK;
}

NS_IMETHODIMP
HTMLFormControlsCollection::Item(uint32_t aIndex, nsIDOMNode** aReturn)
{
  nsISupports* item = GetElementAt(aIndex);
  if (!item) {
    *aReturn = nullptr;

    return NS_OK;
  }

  return CallQueryInterface(item, aReturn);
}

NS_IMETHODIMP 
HTMLFormControlsCollection::NamedItem(const nsAString& aName,
                                      nsIDOMNode** aReturn)
{
  FlushPendingNotifications();

  *aReturn = nullptr;

  nsCOMPtr<nsISupports> supports;

  if (!mNameLookupTable.Get(aName, getter_AddRefs(supports))) {
    // key not found
    return NS_OK;
  }

  if (!supports) {
    return NS_OK;
  }

  // We found something, check if it's a node
  CallQueryInterface(supports, aReturn);
  if (*aReturn) {
    return NS_OK;
  }

  // If not, we check if it's a node list.
  nsCOMPtr<nsIDOMNodeList> nodeList = do_QueryInterface(supports);
  NS_ASSERTION(nodeList, "Huh, what's going one here?");
  if (!nodeList) {
    return NS_OK;
  }

  // And since we're only asking for one node here, we return the first
  // one from the list.
  return nodeList->Item(0, aReturn);
}

nsISupports*
HTMLFormControlsCollection::NamedItemInternal(const nsAString& aName,
                                              bool aFlushContent)
{
  if (aFlushContent) {
    FlushPendingNotifications();
  }

  return mNameLookupTable.GetWeak(aName);
}

nsresult
HTMLFormControlsCollection::AddElementToTable(nsGenericHTMLFormElement* aChild,
                                              const nsAString& aName)
{
  if (!ShouldBeInElements(aChild)) {
    return NS_OK;
  }

  return mForm->AddElementToTableInternal(mNameLookupTable, aChild, aName);
}

nsresult
HTMLFormControlsCollection::IndexOfControl(nsIFormControl* aControl,
                                           int32_t* aIndex)
{
  // Note -- not a DOM method; callers should handle flushing themselves
  
  NS_ENSURE_ARG_POINTER(aIndex);

  *aIndex = mElements.IndexOf(aControl);

  return NS_OK;
}

nsresult
HTMLFormControlsCollection::RemoveElementFromTable(
  nsGenericHTMLFormElement* aChild, const nsAString& aName)
{
  if (!ShouldBeInElements(aChild)) {
    return NS_OK;
  }

  return mForm->RemoveElementFromTableInternal(mNameLookupTable, aChild, aName);
}

nsresult
HTMLFormControlsCollection::GetSortedControls(
  nsTArray<nsGenericHTMLFormElement*>& aControls) const
{
#ifdef DEBUG
  HTMLFormElement::AssertDocumentOrder(mElements, mForm);
  HTMLFormElement::AssertDocumentOrder(mNotInElements, mForm);
#endif

  aControls.Clear();

  // Merge the elements list and the not in elements list. Both lists are
  // already sorted.
  uint32_t elementsLen = mElements.Length();
  uint32_t notInElementsLen = mNotInElements.Length();
  aControls.SetCapacity(elementsLen + notInElementsLen);

  uint32_t elementsIdx = 0;
  uint32_t notInElementsIdx = 0;

  while (elementsIdx < elementsLen || notInElementsIdx < notInElementsLen) {
    // Check whether we're done with mElements
    if (elementsIdx == elementsLen) {
      NS_ASSERTION(notInElementsIdx < notInElementsLen,
                   "Should have remaining not-in-elements");
      // Append the remaining mNotInElements elements
      if (!aControls.AppendElements(mNotInElements.Elements() +
                                      notInElementsIdx,
                                    notInElementsLen -
                                      notInElementsIdx)) {
        return NS_ERROR_OUT_OF_MEMORY;
      }
      break;
    }
    // Check whether we're done with mNotInElements
    if (notInElementsIdx == notInElementsLen) {
      NS_ASSERTION(elementsIdx < elementsLen,
                   "Should have remaining in-elements");
      // Append the remaining mElements elements
      if (!aControls.AppendElements(mElements.Elements() +
                                      elementsIdx,
                                    elementsLen -
                                      elementsIdx)) {
        return NS_ERROR_OUT_OF_MEMORY;
      }
      break;
    }
    // Both lists have elements left.
    NS_ASSERTION(mElements[elementsIdx] &&
                 mNotInElements[notInElementsIdx],
                 "Should have remaining elements");
    // Determine which of the two elements should be ordered
    // first and add it to the end of the list.
    nsGenericHTMLFormElement* elementToAdd;
    if (HTMLFormElement::CompareFormControlPosition(
          mElements[elementsIdx], mNotInElements[notInElementsIdx], mForm) < 0) {
      elementToAdd = mElements[elementsIdx];
      ++elementsIdx;
    } else {
      elementToAdd = mNotInElements[notInElementsIdx];
      ++notInElementsIdx;
    }
    // Add the first element to the list.
    if (!aControls.AppendElement(elementToAdd)) {
      return NS_ERROR_OUT_OF_MEMORY;
    }
  }

  NS_ASSERTION(aControls.Length() == elementsLen + notInElementsLen,
               "Not all form controls were added to the sorted list");
#ifdef DEBUG
  HTMLFormElement::AssertDocumentOrder(aControls, mForm);
#endif

  return NS_OK;
}

Element*
HTMLFormControlsCollection::GetElementAt(uint32_t aIndex)
{
  FlushPendingNotifications();

  return mElements.SafeElementAt(aIndex, nullptr);
}

/* virtual */ nsINode*
HTMLFormControlsCollection::GetParentObject()
{
  return mForm;
}

/* virtual */ Element*
HTMLFormControlsCollection::GetFirstNamedElement(const nsAString& aName, bool& aFound)
{
  Nullable<OwningRadioNodeListOrElement> maybeResult;
  NamedGetter(aName, aFound, maybeResult);
  if (!aFound) {
    return nullptr;
  }
  MOZ_ASSERT(!maybeResult.IsNull());
  const OwningRadioNodeListOrElement& result = maybeResult.Value();
  if (result.IsElement()) {
    return result.GetAsElement().get();
  }
  if (result.IsRadioNodeList()) {
    RadioNodeList& nodelist = result.GetAsRadioNodeList();
    return nodelist.Item(0)->AsElement();
  }
  MOZ_ASSERT_UNREACHABLE("Should only have Elements and NodeLists here.");
  return nullptr;
}

void
HTMLFormControlsCollection::NamedGetter(const nsAString& aName,
                                        bool& aFound,
                                        Nullable<OwningRadioNodeListOrElement>& aResult)
{
  nsISupports* item = NamedItemInternal(aName, true);
  if (!item) {
    aFound = false;
    return;
  }
  aFound = true;
  if (nsCOMPtr<Element> element = do_QueryInterface(item)) {
    aResult.SetValue().SetAsElement() = element;
    return;
  }
  if (nsCOMPtr<RadioNodeList> nodelist = do_QueryInterface(item)) {
    aResult.SetValue().SetAsRadioNodeList() = nodelist;
    return;
  }
  MOZ_ASSERT_UNREACHABLE("Should only have Elements and NodeLists here.");
}

void
HTMLFormControlsCollection::GetSupportedNames(nsTArray<nsString>& aNames)
{
  FlushPendingNotifications();
  // Just enumerate mNameLookupTable.  This won't guarantee order, but
  // that's OK, because the HTML5 spec doesn't define an order for
  // this enumeration.
  for (auto iter = mNameLookupTable.Iter(); !iter.Done(); iter.Next()) {
    aNames.AppendElement(iter.Key());
  }
}

/* virtual */ JSObject*
HTMLFormControlsCollection::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
  return HTMLFormControlsCollectionBinding::Wrap(aCx, this, aGivenProto);
}

} // namespace dom
} // namespace mozilla