/* -*- 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 the name (nodeinfo or atom) of an attribute;

 * using nodeinfos all the time is too slow, so we use atoms when we

 * can.

 */

#ifndef nsAttrName_h___

#define nsAttrName_h___

#include "mozilla/dom/NodeInfo.h"

#include "nsAtom.h"

#include "nsDOMString.h"

#define NS_ATTRNAME_NODEINFO_BIT 1

class nsAttrName

{

public:

  nsAttrName(const nsAttrName& aOther)

    : mBits(aOther.mBits)

  {

    AddRefInternalName();

  }

  explicit nsAttrName(nsAtom* aAtom)

    : mBits(reinterpret_cast<uintptr_t>(aAtom))

  {

    NS_ASSERTION(aAtom, "null atom-name in nsAttrName");

    NS_ADDREF(aAtom);

  }

  explicit nsAttrName(mozilla::dom::NodeInfo* aNodeInfo)

  {

    NS_ASSERTION(aNodeInfo, "null nodeinfo-name in nsAttrName");

    if (aNodeInfo->NamespaceEquals(kNameSpaceID_None)) {

      mBits = reinterpret_cast<uintptr_t>(aNodeInfo->NameAtom());

      NS_ADDREF(aNodeInfo->NameAtom());

    }

    else {

      mBits = reinterpret_cast<uintptr_t>(aNodeInfo) |

              NS_ATTRNAME_NODEINFO_BIT;

      NS_ADDREF(aNodeInfo);

    }

  }

  ~nsAttrName()

  {

    ReleaseInternalName();

  }

  void SetTo(mozilla::dom::NodeInfo* aNodeInfo)

  {

    NS_ASSERTION(aNodeInfo, "null nodeinfo-name in nsAttrName");

    ReleaseInternalName();

    if (aNodeInfo->NamespaceEquals(kNameSpaceID_None)) {

      mBits = reinterpret_cast<uintptr_t>(aNodeInfo->NameAtom());

      NS_ADDREF(aNodeInfo->NameAtom());

    }

    else {

      mBits = reinterpret_cast<uintptr_t>(aNodeInfo) |

              NS_ATTRNAME_NODEINFO_BIT;

      NS_ADDREF(aNodeInfo);

    }

  }

  void SetTo(nsAtom* aAtom)

  {

    NS_ASSERTION(aAtom, "null atom-name in nsAttrName");

    ReleaseInternalName();

    mBits = reinterpret_cast<uintptr_t>(aAtom);

    NS_ADDREF(aAtom);

  }

  bool IsAtom() const

  {

    return !(mBits & NS_ATTRNAME_NODEINFO_BIT);

  }

  mozilla::dom::NodeInfo* NodeInfo() const

  {

    NS_ASSERTION(!IsAtom(), "getting nodeinfo-value of atom-name");

    return reinterpret_cast<mozilla::dom::NodeInfo*>(mBits & ~NS_ATTRNAME_NODEINFO_BIT);

  }

  nsAtom* Atom() const

  {

    NS_ASSERTION(IsAtom(), "getting atom-value of nodeinfo-name");

    return reinterpret_cast<nsAtom*>(mBits);

  }

  bool Equals(const nsAttrName& aOther) const

  {

    return mBits == aOther.mBits;

  }

  // Faster comparison in the case we know the namespace is null

  // Note that some callers such as AttrArray::IndexOfAttr() will

  // call this function on nsAttrName structs with 0 mBits, so no attempt

  // must be made to do anything with mBits besides comparing it with the

  // incoming aAtom argument.

  bool Equals(nsAtom* aAtom) const

  {

    return reinterpret_cast<uintptr_t>(aAtom) == mBits;

  }

  // And the same but without forcing callers to atomize

  bool Equals(const nsAString& aLocalName) const

  {

    return IsAtom() && Atom()->Equals(aLocalName);

  }

  bool Equals(nsAtom* aLocalName, int32_t aNamespaceID) const

  {

    if (aNamespaceID == kNameSpaceID_None) {

      return Equals(aLocalName);

    }

    return !IsAtom() && NodeInfo()->Equals(aLocalName, aNamespaceID);

  }

  bool Equals(mozilla::dom::NodeInfo* aNodeInfo) const

  {

    return Equals(aNodeInfo->NameAtom(), aNodeInfo->NamespaceID());

  }

  int32_t NamespaceID() const

  {

    return IsAtom() ? kNameSpaceID_None : NodeInfo()->NamespaceID();

  }

  int32_t NamespaceEquals(int32_t aNamespaceID) const

  {

    return aNamespaceID == kNameSpaceID_None ?

           IsAtom() :

           (!IsAtom() && NodeInfo()->NamespaceEquals(aNamespaceID));

  }

  nsAtom* LocalName() const

  {

    return IsAtom() ? Atom() : NodeInfo()->NameAtom();

  }

  nsAtom* GetPrefix() const

  {

    return IsAtom() ? nullptr : NodeInfo()->GetPrefixAtom();

  }

  bool QualifiedNameEquals(const nsAString& aName) const

  {

    return IsAtom() ? Atom()->Equals(aName) :

                      NodeInfo()->QualifiedNameEquals(aName);

  }

  void GetQualifiedName(nsAString& aStr) const

  {

    if (IsAtom()) {

      Atom()->ToString(aStr);

    }

    else {

      aStr = NodeInfo()->QualifiedName();

    }

  }

#ifdef MOZILLA_INTERNAL_API

  void GetPrefix(nsAString& aStr) const

  {

    if (IsAtom()) {

      SetDOMStringToNull(aStr);

    }

    else {

      NodeInfo()->GetPrefix(aStr);

    }

  }

#endif

  uint32_t HashValue() const

  {

    // mBits and uint32_t might have different size. This should silence

    // any warnings or compile-errors. This is what the implementation of

    // NS_PTR_TO_INT32 does to take care of the same problem.

    return mBits - 0;

  }

  bool IsSmaller(nsAtom* aOther) const

  {

    return mBits < reinterpret_cast<uintptr_t>(aOther);

  }

private:

  void AddRefInternalName()

  {

    if (IsAtom()) {

      NS_ADDREF(Atom());

    } else {

      NS_ADDREF(NodeInfo());

    }

  }

  void ReleaseInternalName()

  {

    if (IsAtom()) {

      Atom()->Release();

    } else {

      NodeInfo()->Release();

    }

  }

  uintptr_t mBits;

};

#endif