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/*
 *******************************************************************************
 * Copyright (C) 1996-2014, International Business Machines Corporation and
 * others. All Rights Reserved.
 *******************************************************************************
 */

package jdk.internal.icu.impl;

import java.io.DataInputStream;
import java.io.InputStream;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.Arrays;
import java.security.AccessController;
import java.security.PrivilegedAction;

import jdk.internal.icu.util.VersionInfo;

public final class ICUBinary {

    private static final class IsAcceptable implements Authenticate {
        @Override
        public boolean isDataVersionAcceptable(byte version[]) {
            return version[0] == 1;
        }
    }

    // public inner interface ------------------------------------------------

    
Special interface for data authentication
/** * Special interface for data authentication */
public static interface Authenticate {
Method used in ICUBinary.readHeader() to provide data format authentication.
Params:
  • version – version of the current data
Returns:true if dataformat is an acceptable version, false otherwise
/** * Method used in ICUBinary.readHeader() to provide data format * authentication. * @param version version of the current data * @return true if dataformat is an acceptable version, false otherwise */
public boolean isDataVersionAcceptable(byte version[]); } // public methods --------------------------------------------------------
Loads an ICU binary data file and returns it as a ByteBuffer. The buffer contents is normally read-only, but its position etc. can be modified.
Params:
  • itemPath – Relative ICU data item path, for example "root.res" or "coll/ucadata.icu".
Returns:The data as a read-only ByteBuffer.
/** * Loads an ICU binary data file and returns it as a ByteBuffer. * The buffer contents is normally read-only, but its position etc. can be modified. * * @param itemPath Relative ICU data item path, for example "root.res" or "coll/ucadata.icu". * @return The data as a read-only ByteBuffer. */
public static ByteBuffer getRequiredData(String itemPath) { final Class<ICUBinary> root = ICUBinary.class; try (InputStream is = AccessController.doPrivileged(new PrivilegedAction<InputStream>() { public InputStream run() { return root.getResourceAsStream(itemPath); } })) { // is.available() may return 0, or 1, or the total number of bytes in the stream, // or some other number. // Do not try to use is.available() == 0 to find the end of the stream! byte[] bytes; int avail = is.available(); if (avail > 32) { // There are more bytes available than just the ICU data header length. // With luck, it is the total number of bytes. bytes = new byte[avail]; } else { bytes = new byte[128]; // empty .res files are even smaller } // Call is.read(...) until one returns a negative value. int length = 0; for(;;) { if (length < bytes.length) { int numRead = is.read(bytes, length, bytes.length - length); if (numRead < 0) { break; // end of stream } length += numRead; } else { // See if we are at the end of the stream before we grow the array. int nextByte = is.read(); if (nextByte < 0) { break; } int capacity = 2 * bytes.length; if (capacity < 128) { capacity = 128; } else if (capacity < 0x4000) { capacity *= 2; // Grow faster until we reach 16kB. } bytes = Arrays.copyOf(bytes, capacity); bytes[length++] = (byte) nextByte; } } return ByteBuffer.wrap(bytes, 0, length); } catch (IOException e) { throw new UncheckedIOException(e); } }
Same as readHeader(), but returns a VersionInfo rather than a compact int.
/** * Same as readHeader(), but returns a VersionInfo rather than a compact int. */
public static VersionInfo readHeaderAndDataVersion(ByteBuffer bytes, int dataFormat, Authenticate authenticate) throws IOException { return getVersionInfoFromCompactInt(readHeader(bytes, dataFormat, authenticate)); } private static final byte BIG_ENDIAN_ = 1; public static final byte[] readHeader(InputStream inputStream, byte dataFormatIDExpected[], Authenticate authenticate) throws IOException { DataInputStream input = new DataInputStream(inputStream); char headersize = input.readChar(); int readcount = 2; //reading the header format byte magic1 = input.readByte(); readcount ++; byte magic2 = input.readByte(); readcount ++; if (magic1 != MAGIC1 || magic2 != MAGIC2) { throw new IOException(MAGIC_NUMBER_AUTHENTICATION_FAILED_); } input.readChar(); // reading size readcount += 2; input.readChar(); // reading reserved word readcount += 2; byte bigendian = input.readByte(); readcount ++; byte charset = input.readByte(); readcount ++; byte charsize = input.readByte(); readcount ++; input.readByte(); // reading reserved byte readcount ++; byte dataFormatID[] = new byte[4]; input.readFully(dataFormatID); readcount += 4; byte dataVersion[] = new byte[4]; input.readFully(dataVersion); readcount += 4; byte unicodeVersion[] = new byte[4]; input.readFully(unicodeVersion); readcount += 4; if (headersize < readcount) { throw new IOException("Internal Error: Header size error"); } input.skipBytes(headersize - readcount); if (bigendian != BIG_ENDIAN_ || charset != CHAR_SET_ || charsize != CHAR_SIZE_ || !Arrays.equals(dataFormatIDExpected, dataFormatID) || (authenticate != null && !authenticate.isDataVersionAcceptable(dataVersion))) { throw new IOException(HEADER_AUTHENTICATION_FAILED_); } return unicodeVersion; }
Reads an ICU data header, checks the data format, and returns the data version.

Assumes that the ByteBuffer position is 0 on input. The buffer byte order is set according to the data. The buffer position is advanced past the header (including UDataInfo and comment).

See C++ ucmndata.h and unicode/udata.h.

Throws:
  • IOException – if this is not a valid ICU data item of the expected dataFormat
Returns:dataVersion
/** * Reads an ICU data header, checks the data format, and returns the data version. * * <p>Assumes that the ByteBuffer position is 0 on input. * The buffer byte order is set according to the data. * The buffer position is advanced past the header (including UDataInfo and comment). * * <p>See C++ ucmndata.h and unicode/udata.h. * * @return dataVersion * @throws IOException if this is not a valid ICU data item of the expected dataFormat */
public static int readHeader(ByteBuffer bytes, int dataFormat, Authenticate authenticate) throws IOException { assert bytes.position() == 0; byte magic1 = bytes.get(2); byte magic2 = bytes.get(3); if (magic1 != MAGIC1 || magic2 != MAGIC2) { throw new IOException(MAGIC_NUMBER_AUTHENTICATION_FAILED_); } byte isBigEndian = bytes.get(8); byte charsetFamily = bytes.get(9); byte sizeofUChar = bytes.get(10); if (isBigEndian < 0 || 1 < isBigEndian || charsetFamily != CHAR_SET_ || sizeofUChar != CHAR_SIZE_) { throw new IOException(HEADER_AUTHENTICATION_FAILED_); } bytes.order(isBigEndian != 0 ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN); int headerSize = bytes.getChar(0); int sizeofUDataInfo = bytes.getChar(4); if (sizeofUDataInfo < 20 || headerSize < (sizeofUDataInfo + 4)) { throw new IOException("Internal Error: Header size error"); } // TODO: Change Authenticate to take int major, int minor, int milli, int micro // to avoid array allocation. byte[] formatVersion = new byte[] { bytes.get(16), bytes.get(17), bytes.get(18), bytes.get(19) }; if (bytes.get(12) != (byte)(dataFormat >> 24) || bytes.get(13) != (byte)(dataFormat >> 16) || bytes.get(14) != (byte)(dataFormat >> 8) || bytes.get(15) != (byte)dataFormat || (authenticate != null && !authenticate.isDataVersionAcceptable(formatVersion))) { throw new IOException(HEADER_AUTHENTICATION_FAILED_ + String.format("; data format %02x%02x%02x%02x, format version %d.%d.%d.%d", bytes.get(12), bytes.get(13), bytes.get(14), bytes.get(15), formatVersion[0] & 0xff, formatVersion[1] & 0xff, formatVersion[2] & 0xff, formatVersion[3] & 0xff)); } bytes.position(headerSize); return // dataVersion ((int)bytes.get(20) << 24) | ((bytes.get(21) & 0xff) << 16) | ((bytes.get(22) & 0xff) << 8) | (bytes.get(23) & 0xff); } public static void skipBytes(ByteBuffer bytes, int skipLength) { if (skipLength > 0) { bytes.position(bytes.position() + skipLength); } } public static byte[] getBytes(ByteBuffer bytes, int length, int additionalSkipLength) { byte[] dest = new byte[length]; bytes.get(dest); if (additionalSkipLength > 0) { skipBytes(bytes, additionalSkipLength); } return dest; } public static String getString(ByteBuffer bytes, int length, int additionalSkipLength) { CharSequence cs = bytes.asCharBuffer(); String s = cs.subSequence(0, length).toString(); skipBytes(bytes, length * 2 + additionalSkipLength); return s; } public static char[] getChars(ByteBuffer bytes, int length, int additionalSkipLength) { char[] dest = new char[length]; bytes.asCharBuffer().get(dest); skipBytes(bytes, length * 2 + additionalSkipLength); return dest; } public static int[] getInts(ByteBuffer bytes, int length, int additionalSkipLength) { int[] dest = new int[length]; bytes.asIntBuffer().get(dest); skipBytes(bytes, length * 4 + additionalSkipLength); return dest; }
Returns a VersionInfo for the bytes in the compact version integer.
/** * Returns a VersionInfo for the bytes in the compact version integer. */
public static VersionInfo getVersionInfoFromCompactInt(int version) { return VersionInfo.getInstance( version >>> 24, (version >> 16) & 0xff, (version >> 8) & 0xff, version & 0xff); } // private variables -------------------------------------------------
Magic numbers to authenticate the data file
/** * Magic numbers to authenticate the data file */
private static final byte MAGIC1 = (byte)0xda; private static final byte MAGIC2 = (byte)0x27;
File format authentication values
/** * File format authentication values */
private static final byte CHAR_SET_ = 0; private static final byte CHAR_SIZE_ = 2;
Error messages
/** * Error messages */
private static final String MAGIC_NUMBER_AUTHENTICATION_FAILED_ = "ICUBinary data file error: Magic number authentication failed"; private static final String HEADER_AUTHENTICATION_FAILED_ = "ICUBinary data file error: Header authentication failed"; }