/*

* Copyright (c) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

package com.nokia.mj.impl.utils;

import java.io.InputStream;

import java.io.IOException;

import java.util.Enumeration;

import java.util.Hashtable;

/**

 * ManifestReader is used to parse Manifest files inside .jar file.

 *

 * BNF for parsing manifests is the default

 * BNF from MIDP 2.1 spec

 * + ignoring lines containing only CTLs and WSP

 * + ignore WSP after attrname

 * + ignore WSP before and after attribute value

 * + max attribute name is 512 characters

 * + no maximum line length

 * + max manifest length is 1MB

 *

 * Max attribute value length is AttributeReader.MAX_ATTR_VALUE_LEN,

 * currently 65536 characters

 *

 * manifest: *attrline

 * attrline: attrname [WSP] ":" [WSP] *otherchar newline *continuation

 * attrname: alphanum *headerchar

 * continuation: SP *otherchar newline

 *

 * alphanum: {A-Z} | {a-z} | {0-9}

 * headerchar: alphanum | - | _

 * valuechar: <any UTF-8 character, excluding NUL, CR and LF>

 * newline: CR LF | LF | CR

 * CR = <UTF-8 carriage return (U+000D)>

 * LF = <UTF-8 linefeed (U+000A)>

 * WSP: 1*( SP | HT )

 * SP = <UTF-8 space (U+0020)>

 * HT = <UTF-8 horizontal-tab (U+0009)>

 *

 */

public class ManifestReader extends AttributeReader

{

    /**

     * Reads Manifest attributes from given InputStream.

     * If duplicate attributes are found,

     * the last value of the attribute is used.

     *

     * @param aInputStream InputStream from where the attributes are parsed

     * @return hashtable that contains all the attributes

     * @throws IOException if the attributes cannot be read

     */

    public static Hashtable getAttributes(InputStream aInputStream)

    throws IOException

    {

        return (new ManifestReader()).readAttributes(

                   aInputStream, null, MAX_ATTR_VALUE_LEN);

    }

    /*** ---------------------------- PROTECTED --------------------------- */

    /**

     * Default constructor.

     */

    protected ManifestReader()

    {

        super();

        iFileType = "Manifest";

    }

    protected boolean isNameChar(int ch)

    {

        // First character of name must be alphanum.

        if (iNextParseFirstNameChar)

        {

            iNextParseFirstNameChar = false;

            return isAlphanum(ch);

        }

        // Following characters can be header chars.

        return isHeaderChar(ch);

    }

    protected boolean isValueChar(int ch)

    {

        if ((ch > 0) && (ch != 0x0D) && (ch != 0x0A))

        {

            return true;

        }

        return false;

    }

    /*** ----------------------------- PRIVATE ---------------------------- */

    private static boolean isAlphanum(int ch)

    {

        // alphanum: {A-Z} | {a-z} | {0-9}

        if (((ch > 0x40) && (ch < 0x5B)) ||

                ((ch > 0x60) && (ch < 0x7B)) ||

                ((ch > 0x2F) && (ch < 0x3A)))

        {

            return true;

        }

        return false;

    }

    private static boolean isHeaderChar(int ch)

    {

        // '-' or '_' or alphanum

        if ((ch == 0x2D) || (ch == 0x5F) || isAlphanum(ch))

        {

            return true;

        }

        return false;

    }

}