gecko-dev/dom/base/NodeInfo.cpp

/* -*- 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/. */

/*
 * Class that represents a prefix/namespace/localName triple; a single
 * nodeinfo is shared by all elements in a document that have that
 * prefix, namespace, and localName.
 */

#include "mozilla/dom/NodeInfo.h"
#include "mozilla/dom/NodeInfoInlines.h"

#include "mozilla/ArrayUtils.h"
#include "mozilla/Likely.h"

#include "nsNodeInfoManager.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "nsAtom.h"
#include "nsDOMString.h"
#include "nsCRT.h"
#include "nsContentUtils.h"
#include "nsReadableUtils.h"
#include "mozilla/Sprintf.h"
#include "nsIDocument.h"
#include "nsGkAtoms.h"
#include "nsCCUncollectableMarker.h"
#include "nsNameSpaceManager.h"

using namespace mozilla;
using mozilla::dom::NodeInfo;

NodeInfo::~NodeInfo()
{
  mOwnerManager->RemoveNodeInfo(this);

  // We can't use NS_IF_RELEASE because mName is const.
  if (mInner.mName) {
    mInner.mName->Release();
  }
  NS_IF_RELEASE(mInner.mPrefix);
  NS_IF_RELEASE(mInner.mExtraName);
}

NodeInfo::NodeInfo(nsAtom *aName, nsAtom *aPrefix, int32_t aNamespaceID,
                   uint16_t aNodeType, nsAtom* aExtraName,
                   nsNodeInfoManager *aOwnerManager)
  : mDocument(aOwnerManager->GetDocument()),
    mInner(aName, aPrefix, aNamespaceID, aNodeType, aExtraName),
    mOwnerManager(aOwnerManager)
{
  CheckValidNodeInfo(aNodeType, aName, aNamespaceID, aExtraName);

  NS_IF_ADDREF(mInner.mName);
  NS_IF_ADDREF(mInner.mPrefix);
  NS_IF_ADDREF(mInner.mExtraName);

  // Now compute our cached members.

  // Qualified name.  If we have no prefix, use ToString on
  // mInner.mName so that we get to share its buffer.
  if (aPrefix) {
    mQualifiedName = nsDependentAtomString(mInner.mPrefix) +
                     NS_LITERAL_STRING(":") +
                     nsDependentAtomString(mInner.mName);
  } else {
    mInner.mName->ToString(mQualifiedName);
  }

  MOZ_ASSERT_IF(aNodeType != nsIDOMNode::ELEMENT_NODE &&
                aNodeType != nsIDOMNode::ATTRIBUTE_NODE &&
                aNodeType != UINT16_MAX,
                aNamespaceID == kNameSpaceID_None && !aPrefix);

  switch (aNodeType) {
    case nsIDOMNode::ELEMENT_NODE:
    case nsIDOMNode::ATTRIBUTE_NODE:
      // Correct the case for HTML
      if (aNodeType == nsIDOMNode::ELEMENT_NODE &&
          aNamespaceID == kNameSpaceID_XHTML && GetDocument() &&
          GetDocument()->IsHTMLDocument()) {
        nsContentUtils::ASCIIToUpper(mQualifiedName, mNodeName);
      } else {
        mNodeName = mQualifiedName;
      }
      mInner.mName->ToString(mLocalName);
      break;
    case nsIDOMNode::TEXT_NODE:
    case nsIDOMNode::CDATA_SECTION_NODE:
    case nsIDOMNode::COMMENT_NODE:
    case nsIDOMNode::DOCUMENT_NODE:
    case nsIDOMNode::DOCUMENT_FRAGMENT_NODE:
      mInner.mName->ToString(mNodeName);
      SetDOMStringToNull(mLocalName);
      break;
    case nsIDOMNode::PROCESSING_INSTRUCTION_NODE:
    case nsIDOMNode::DOCUMENT_TYPE_NODE:
      mInner.mExtraName->ToString(mNodeName);
      SetDOMStringToNull(mLocalName);
      break;
    default:
      MOZ_ASSERT(aNodeType == UINT16_MAX, "Unknown node type");
  }
}


// nsISupports

NS_IMPL_CYCLE_COLLECTION_CLASS(NodeInfo)

NS_IMPL_CYCLE_COLLECTION_UNLINK_0(NodeInfo)

static const char* kNodeInfoNSURIs[] = {
  " ([none])",
  " (xmlns)",
  " (xml)",
  " (xhtml)",
  " (XLink)",
  " (XSLT)",
  " (XBL)",
  " (MathML)",
  " (RDF)",
  " (XUL)"
};

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(NodeInfo)
  if (MOZ_UNLIKELY(cb.WantDebugInfo())) {
    char name[72];
    uint32_t nsid = tmp->NamespaceID();
    nsAtomCString localName(tmp->NameAtom());
    if (nsid < ArrayLength(kNodeInfoNSURIs)) {
      SprintfLiteral(name, "NodeInfo%s %s", kNodeInfoNSURIs[nsid],
                     localName.get());
    }
    else {
      SprintfLiteral(name, "NodeInfo %s", localName.get());
    }

    cb.DescribeRefCountedNode(tmp->mRefCnt.get(), name);
  }
  else {
    NS_IMPL_CYCLE_COLLECTION_DESCRIBE(NodeInfo, tmp->mRefCnt.get())
  }

  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOwnerManager)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(NodeInfo)
  return nsCCUncollectableMarker::sGeneration && tmp->CanSkip();
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(NodeInfo)
  return nsCCUncollectableMarker::sGeneration && tmp->CanSkip();
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(NodeInfo)
  return nsCCUncollectableMarker::sGeneration && tmp->CanSkip();
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END


NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(NodeInfo, AddRef)
NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(NodeInfo, Release)

void
NodeInfo::GetName(nsAString& aName) const
{
  mInner.mName->ToString(aName);
}

void
NodeInfo::GetPrefix(nsAString& aPrefix) const
{
  if (mInner.mPrefix) {
    mInner.mPrefix->ToString(aPrefix);
  } else {
    SetDOMStringToNull(aPrefix);
  }
}

void
NodeInfo::GetNamespaceURI(nsAString& aNameSpaceURI) const
{
  if (mInner.mNamespaceID > 0) {
    nsresult rv =
      nsContentUtils::NameSpaceManager()->GetNameSpaceURI(mInner.mNamespaceID,
                                                          aNameSpaceURI);
    // How can we possibly end up with a bogus namespace ID here?
    if (NS_FAILED(rv)) {
      MOZ_CRASH();
    }
  } else {
    SetDOMStringToNull(aNameSpaceURI);
  }
}

bool
NodeInfo::NamespaceEquals(const nsAString& aNamespaceURI) const
{
  int32_t nsid =
    nsContentUtils::NameSpaceManager()->GetNameSpaceID(aNamespaceURI,
      nsContentUtils::IsChromeDoc(mOwnerManager->GetDocument()));

  return mozilla::dom::NodeInfo::NamespaceEquals(nsid);
}

void
NodeInfo::DeleteCycleCollectable()
{
  RefPtr<nsNodeInfoManager> kungFuDeathGrip = mOwnerManager;
  mozilla::Unused << kungFuDeathGrip; // Just keeping value alive for longer than this
  delete this;
}

bool
NodeInfo::CanSkip()
{
  return mDocument &&
    nsCCUncollectableMarker::InGeneration(mDocument->GetMarkedCCGeneration());
}