michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * Class that represents the name (nodeinfo or atom) of an attribute;
michael@0:  * using nodeinfos all the time is too slow, so we use atoms when we
michael@0:  * can.
michael@0:  */
michael@0: 
michael@0: #ifndef nsAttrName_h___
michael@0: #define nsAttrName_h___
michael@0: 
michael@0: #include "nsINodeInfo.h"
michael@0: #include "nsIAtom.h"
michael@0: #include "nsDOMString.h"
michael@0: 
michael@0: #define NS_ATTRNAME_NODEINFO_BIT 1
michael@0: class nsAttrName
michael@0: {
michael@0: public:
michael@0:   nsAttrName(const nsAttrName& aOther)
michael@0:     : mBits(aOther.mBits)
michael@0:   {
michael@0:     AddRefInternalName();
michael@0:   }
michael@0: 
michael@0:   explicit nsAttrName(nsIAtom* aAtom)
michael@0:     : mBits(reinterpret_cast<uintptr_t>(aAtom))
michael@0:   {
michael@0:     NS_ASSERTION(aAtom, "null atom-name in nsAttrName");
michael@0:     NS_ADDREF(aAtom);
michael@0:   }
michael@0: 
michael@0:   explicit nsAttrName(nsINodeInfo* aNodeInfo)
michael@0:   {
michael@0:     NS_ASSERTION(aNodeInfo, "null nodeinfo-name in nsAttrName");
michael@0:     if (aNodeInfo->NamespaceEquals(kNameSpaceID_None)) {
michael@0:       mBits = reinterpret_cast<uintptr_t>(aNodeInfo->NameAtom());
michael@0:       NS_ADDREF(aNodeInfo->NameAtom());
michael@0:     }
michael@0:     else {
michael@0:       mBits = reinterpret_cast<uintptr_t>(aNodeInfo) |
michael@0:               NS_ATTRNAME_NODEINFO_BIT;
michael@0:       NS_ADDREF(aNodeInfo);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   ~nsAttrName()
michael@0:   {
michael@0:     ReleaseInternalName();
michael@0:   }
michael@0: 
michael@0:   void SetTo(nsINodeInfo* aNodeInfo)
michael@0:   {
michael@0:     NS_ASSERTION(aNodeInfo, "null nodeinfo-name in nsAttrName");
michael@0: 
michael@0:     ReleaseInternalName();
michael@0:     if (aNodeInfo->NamespaceEquals(kNameSpaceID_None)) {
michael@0:       mBits = reinterpret_cast<uintptr_t>(aNodeInfo->NameAtom());
michael@0:       NS_ADDREF(aNodeInfo->NameAtom());
michael@0:     }
michael@0:     else {
michael@0:       mBits = reinterpret_cast<uintptr_t>(aNodeInfo) |
michael@0:               NS_ATTRNAME_NODEINFO_BIT;
michael@0:       NS_ADDREF(aNodeInfo);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   void SetTo(nsIAtom* aAtom)
michael@0:   {
michael@0:     NS_ASSERTION(aAtom, "null atom-name in nsAttrName");
michael@0: 
michael@0:     ReleaseInternalName();
michael@0:     mBits = reinterpret_cast<uintptr_t>(aAtom);
michael@0:     NS_ADDREF(aAtom);
michael@0:   }
michael@0: 
michael@0:   bool IsAtom() const
michael@0:   {
michael@0:     return !(mBits & NS_ATTRNAME_NODEINFO_BIT);
michael@0:   }
michael@0: 
michael@0:   nsINodeInfo* NodeInfo() const
michael@0:   {
michael@0:     NS_ASSERTION(!IsAtom(), "getting nodeinfo-value of atom-name");
michael@0:     return reinterpret_cast<nsINodeInfo*>(mBits & ~NS_ATTRNAME_NODEINFO_BIT);
michael@0:   }
michael@0: 
michael@0:   nsIAtom* Atom() const
michael@0:   {
michael@0:     NS_ASSERTION(IsAtom(), "getting atom-value of nodeinfo-name");
michael@0:     return reinterpret_cast<nsIAtom*>(mBits);
michael@0:   }
michael@0: 
michael@0:   bool Equals(const nsAttrName& aOther) const
michael@0:   {
michael@0:     return mBits == aOther.mBits;
michael@0:   }
michael@0: 
michael@0:   // Faster comparison in the case we know the namespace is null
michael@0:   bool Equals(nsIAtom* aAtom) const
michael@0:   {
michael@0:     return reinterpret_cast<uintptr_t>(aAtom) == mBits;
michael@0:   }
michael@0: 
michael@0:   // And the same but without forcing callers to atomize
michael@0:   bool Equals(const nsAString& aLocalName) const
michael@0:   {
michael@0:     return IsAtom() && Atom()->Equals(aLocalName);
michael@0:   }
michael@0: 
michael@0:   bool Equals(nsIAtom* aLocalName, int32_t aNamespaceID) const
michael@0:   {
michael@0:     if (aNamespaceID == kNameSpaceID_None) {
michael@0:       return Equals(aLocalName);
michael@0:     }
michael@0:     return !IsAtom() && NodeInfo()->Equals(aLocalName, aNamespaceID);
michael@0:   }
michael@0: 
michael@0:   bool Equals(nsINodeInfo* aNodeInfo) const
michael@0:   {
michael@0:     return Equals(aNodeInfo->NameAtom(), aNodeInfo->NamespaceID());
michael@0:   }
michael@0: 
michael@0:   int32_t NamespaceID() const
michael@0:   {
michael@0:     return IsAtom() ? kNameSpaceID_None : NodeInfo()->NamespaceID();
michael@0:   }
michael@0: 
michael@0:   int32_t NamespaceEquals(int32_t aNamespaceID) const
michael@0:   {
michael@0:     return aNamespaceID == kNameSpaceID_None ?
michael@0:            IsAtom() :
michael@0:            (!IsAtom() && NodeInfo()->NamespaceEquals(aNamespaceID));
michael@0:   }
michael@0: 
michael@0:   nsIAtom* LocalName() const
michael@0:   {
michael@0:     return IsAtom() ? Atom() : NodeInfo()->NameAtom();
michael@0:   }
michael@0: 
michael@0:   nsIAtom* GetPrefix() const
michael@0:   {
michael@0:     return IsAtom() ? nullptr : NodeInfo()->GetPrefixAtom();
michael@0:   }
michael@0: 
michael@0:   bool QualifiedNameEquals(const nsAString& aName) const
michael@0:   {
michael@0:     return IsAtom() ? Atom()->Equals(aName) :
michael@0:                       NodeInfo()->QualifiedNameEquals(aName);
michael@0:   }
michael@0: 
michael@0:   void GetQualifiedName(nsAString& aStr) const
michael@0:   {
michael@0:     if (IsAtom()) {
michael@0:       Atom()->ToString(aStr);
michael@0:     }
michael@0:     else {
michael@0:       aStr = NodeInfo()->QualifiedName();
michael@0:     }
michael@0:   }
michael@0: 
michael@0: #ifdef MOZILLA_INTERNAL_API
michael@0:   void GetPrefix(nsAString& aStr) const
michael@0:   {
michael@0:     if (IsAtom()) {
michael@0:       SetDOMStringToNull(aStr);
michael@0:     }
michael@0:     else {
michael@0:       NodeInfo()->GetPrefix(aStr);
michael@0:     }
michael@0:   }
michael@0: #endif
michael@0: 
michael@0:   uint32_t HashValue() const
michael@0:   {
michael@0:     // mBits and uint32_t might have different size. This should silence
michael@0:     // any warnings or compile-errors. This is what the implementation of
michael@0:     // NS_PTR_TO_INT32 does to take care of the same problem.
michael@0:     return mBits - 0;
michael@0:   }
michael@0: 
michael@0:   bool IsSmaller(nsIAtom* aOther) const
michael@0:   {
michael@0:     return mBits < reinterpret_cast<uintptr_t>(aOther);
michael@0:   }
michael@0: 
michael@0: private:
michael@0: 
michael@0:   void AddRefInternalName()
michael@0:   {
michael@0:     // Since both nsINodeInfo and nsIAtom inherit nsISupports as its first
michael@0:     // interface we can safely assume that it's first in the vtable
michael@0:     nsISupports* name = reinterpret_cast<nsISupports *>
michael@0:                                         (mBits & ~NS_ATTRNAME_NODEINFO_BIT);
michael@0: 
michael@0:     NS_ADDREF(name);
michael@0:   }
michael@0: 
michael@0:   void ReleaseInternalName()
michael@0:   {
michael@0:     // Since both nsINodeInfo and nsIAtom inherit nsISupports as its first
michael@0:     // interface we can safely assume that it's first in the vtable
michael@0:     nsISupports* name = reinterpret_cast<nsISupports *>
michael@0:                                         (mBits & ~NS_ATTRNAME_NODEINFO_BIT);
michael@0: 
michael@0:     NS_RELEASE(name);
michael@0:   }
michael@0: 
michael@0:   uintptr_t mBits;
michael@0: };
michael@0: 
michael@0: #endif