gecko-dev/xpcom/ds/nsIAtom.idl

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
* The contents of this file are subject to the Netscape Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is Mozilla Communicator client code,
* released March 31, 1998.
*
* The Initial Developer of the Original Code is Netscape Communications
* Corporation. Portions created by Netscape are
* Copyright (C) 1998-1999 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*
*/
#include "nsISupports.idl"
interface nsISizeOfHandler;
%{C++
#include "nsAString.h"
#include "nsCOMPtr.h"
%}
/*
* Should this really be scriptable? Using atoms from script or proxies
* could be dangerous since double-wrapping could lead to loss of
* pointer identity.
*/
[scriptable, uuid(3d1b15b0-93b4-11d1-895b-006008911b81)]
interface nsIAtom : nsISupports
{
/**
* Translate the unicode string into the stringbuf.
*/
[noscript] AString toString();
/**
* Return a pointer to a zero terminated unicode string.
*/
void GetUnicode([shared, retval] out wstring aResult);
/**
* Get the size, in bytes, of the atom.
*/
PRUint32 SizeOf(in nsISizeOfHandler aHandler);
};
%{C++
/*
* The three forms of NS_NewAtom and do_GetAtom (for use with
* |nsCOMPtr<nsIAtom>|) return the atom for the string given. At any
* given time there will always be one atom representing a given string.
* Atoms are intended to make string comparison cheaper by simplifying
* it to pointer equality. A pointer to the atom that does not own a
* reference is not guaranteed to be valid.
*
* The three forms of NS_NewPermanentAtom and do_GetPermanentAtom return
* the atom for the given string and ensure that the atom is permanent.
* An atom that is permanent will exist (occupy space at a specific
* location in memory) until XPCOM is shut down. The advantage of
* permanent atoms is that they do not need to maintain a reference
* count, which requires locking and hurts performance.
*/
/**
* Find an atom that matches the given ISO-Latin1 C string. The
* C string is translated into its unicode equivalent.
*/
extern NS_COM nsIAtom* NS_NewAtom(const char* isolatin1);
extern NS_COM nsIAtom* NS_NewPermanentAtom(const char* isolatin1);
inline already_AddRefed<nsIAtom> do_GetAtom(const char* isolatin1)
{ return NS_NewAtom(isolatin1); }
inline already_AddRefed<nsIAtom> do_GetPermanentAtom(const char* isolatin1)
{ return NS_NewPermanentAtom(isolatin1); }
/**
* Find an atom that matches the given unicode string. The string is assumed
* to be zero terminated.
*/
extern NS_COM nsIAtom* NS_NewAtom(const PRUnichar* unicode);
extern NS_COM nsIAtom* NS_NewPermanentAtom(const PRUnichar* unicode);
inline already_AddRefed<nsIAtom> do_GetAtom(const PRUnichar* unicode)
{ return NS_NewAtom(unicode); }
inline already_AddRefed<nsIAtom> do_GetPermanentAtom(const PRUnichar* unicode)
{ return NS_NewPermanentAtom(unicode); }
/**
* Find an atom that matches the given string.
*/
extern NS_COM nsIAtom* NS_NewAtom(const nsAString& aString);
extern NS_COM nsIAtom* NS_NewPermanentAtom(const nsAString& aString);
inline already_AddRefed<nsIAtom> do_GetAtom(const nsAString& aString)
{ return NS_NewAtom(aString); }
inline already_AddRefed<nsIAtom> do_GetPermanentAtom(const nsAString& aString)
{ return NS_NewPermanentAtom(aString); }
/**
* Return a count of the total number of atoms currently
* alive in the system.
*/
extern NS_COM nsrefcnt NS_GetNumberOfAtoms(void);
%}