/*
 * Copyright (c) 2005, 2009, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
/*
 *******************************************************************************
 * (C) Copyright IBM Corp. and others, 1996-2009 - All Rights Reserved         *
 *                                                                             *
 * The original version of this source code and documentation is copyrighted   *
 * and owned by IBM, These materials are provided under terms of a License     *
 * Agreement between IBM and Sun. This technology is protected by multiple     *
 * US and International patents. This notice and attribution to IBM may not    *
 * to removed.                                                                 *
 *******************************************************************************
*   file name:  UBiDiProps.java
*   encoding:   US-ASCII
*   tab size:   8 (not used)
*   indentation:4
*
*   created on: 2005jan16
*   created by: Markus W. Scherer
*
*   Low-level Unicode bidi/shaping properties access.
*   Java port of ubidi_props.h/.c.
*/

package sun.text.normalizer;

import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.InputStream;
import java.io.IOException;

public final class UBiDiProps {
    // constructors etc. --------------------------------------------------- ***

    // port of ubidi_openProps()
    public UBiDiProps() throws IOException{
        InputStream is=ICUData.getStream(DATA_FILE_NAME);
        BufferedInputStream b=new BufferedInputStream(is, 4096 /* data buffer size */);
        readData(b);
        b.close();
        is.close();

    }

    private void readData(InputStream is) throws IOException {
        DataInputStream inputStream=new DataInputStream(is);

        // read the header
        ICUBinary.readHeader(inputStream, FMT, new IsAcceptable());

        // read indexes[]
        int i, count;
        count=inputStream.readInt();
        if(count<IX_INDEX_TOP) {
            throw new IOException("indexes[0] too small in "+DATA_FILE_NAME);
        }
        indexes=new int[count];

        indexes[0]=count;
        for(i=1; i<count; ++i) {
            indexes[i]=inputStream.readInt();
        }

        // read the trie
        trie=new CharTrie(inputStream, null);

        // read mirrors[]
        count=indexes[IX_MIRROR_LENGTH];
        if(count>0) {
            mirrors=new int[count];
            for(i=0; i<count; ++i) {
                mirrors[i]=inputStream.readInt();
            }
        }

        // read jgArray[]
        count=indexes[IX_JG_LIMIT]-indexes[IX_JG_START];
        jgArray=new byte[count];
        for(i=0; i<count; ++i) {
            jgArray[i]=inputStream.readByte();
        }
    }

    // implement ICUBinary.Authenticate
    private final class IsAcceptable implements ICUBinary.Authenticate {
        public boolean isDataVersionAcceptable(byte version[]) {
            return version[0]==1 &&
                   version[2]==Trie.INDEX_STAGE_1_SHIFT_ && version[3]==Trie.INDEX_STAGE_2_SHIFT_;
        }
    }

    // UBiDiProps singleton
    private static UBiDiProps gBdp=null;

    // port of ubidi_getSingleton()
    public static final synchronized UBiDiProps getSingleton() throws IOException {
        if(gBdp==null) {
            gBdp=new UBiDiProps();
        }
        return gBdp;
    }

    // UBiDiProps dummy singleton
    private static UBiDiProps gBdpDummy=null;

    private UBiDiProps(boolean makeDummy) { // ignore makeDummy, only creates a unique signature
        indexes=new int[IX_TOP];
        indexes[0]=IX_TOP;
        trie=new CharTrie(0, 0, null); // dummy trie, always returns 0
    }

    
Get a singleton dummy object, one that works with no real data.
This can be used when the real data is not available.
Using the dummy can reduce checks for available data after an initial failure.
Port of ucase_getDummy().
/**
     * Get a singleton dummy object, one that works with no real data.
     * This can be used when the real data is not available.
     * Using the dummy can reduce checks for available data after an initial failure.
     * Port of ucase_getDummy().
     */
    public static final synchronized UBiDiProps getDummy() {
        if(gBdpDummy==null) {
            gBdpDummy=new UBiDiProps(true);
        }
        return gBdpDummy;
    }

    public final int getClass(int c) {
        return getClassFromProps(trie.getCodePointValue(c));
    }

    // data members -------------------------------------------------------- ***
    private int indexes[];
    private int mirrors[];
    private byte jgArray[];

    private CharTrie trie;

    // data format constants ----------------------------------------------- ***
    private static final String DATA_FILE_NAME = "/sun/text/resources/ubidi.icu";

    /* format "BiDi" */
    private static final byte FMT[]={ 0x42, 0x69, 0x44, 0x69 };

    /* indexes into indexes[] */
    private static final int IX_INDEX_TOP=0;
    private static final int IX_MIRROR_LENGTH=3;

    private static final int IX_JG_START=4;
    private static final int IX_JG_LIMIT=5;

    private static final int IX_TOP=16;

    private static final int CLASS_MASK=    0x0000001f;

    private static final int getClassFromProps(int props) {
        return props&CLASS_MASK;
    }

}