/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla 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/MPL/
 *
 * 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 the Initial Developer are Copyright (C) 2001
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Mike Shaver <shaver@mozilla.org>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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/*
 * Infrastructure for sharing DOMString data with JSStrings.
 *
 * Importing an nsAString into JS:
 * If possible (GetSharedBufferHandle works) use the external string support in
 * JS to create a JSString that points to the readable's buffer.  We keep a
 * reference to the buffer handle until the JSString is finalized.
 *
 * Exporting a JSString as an nsAReadable:
 * Wrap the JSString with a root-holding XPCJSReadableStringWrapper, which roots
 * the string and exposes its buffer via the nsAString interface, as
 * well as providing refcounting support.
 */

#include "xpcprivate.h"


// convert a readable to a JSString, copying string data
// static
JSString *
XPCStringConvert::ReadableToJSString(JSContext *cx,
                                     const nsAString &readable)
{
    JSString *str;

    // blech, have to copy.

    PRUint32 length = readable.Length();
    jschar *chars = NS_REINTERPRET_CAST(jschar *,
                                        JS_malloc(cx, (length + 1) *
                                                  sizeof(jschar)));
    if (!chars)
        return NULL;

    if (length && !CopyUnicodeTo(readable, 0,
                                 NS_REINTERPRET_CAST(PRUnichar *, chars),
                                 length))
    {
        JS_free(cx, chars);
        return NULL;
    }

    chars[length] = 0;

    str = JS_NewUCString(cx, chars, length);
    if (!str)
        JS_free(cx, chars);

    return str;
}

// static
XPCReadableJSStringWrapper *
XPCStringConvert::JSStringToReadable(JSString *str)
{
    return new
        XPCReadableJSStringWrapper(NS_REINTERPRET_CAST(PRUnichar *,
                                                       JS_GetStringChars(str)),
                                   JS_GetStringLength(str));
}