src/main/java/org/eclipse/mdm/openatfx/mdf/mdf4/FHBLOCK.java - mdmbl/org.eclipse.mdm.openatfx.mdf - Git at Google

 /********************************************************************************
  * Copyright (c) 2015-2018 Contributors to the Eclipse Foundation
  *
  * See the NOTICE file(s) distributed with this work for additional
  * information regarding copyright ownership.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
  * http://www.eclipse.org/legal/epl-2.0.
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  ********************************************************************************/


 package org.eclipse.mdm.openatfx.mdf.mdf4;

 import java.io.IOException;
 import java.math.BigInteger;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.nio.channels.SeekableByteChannel;

 /**
  * <p>
  * THE FILE HISTORY BLOCK <code>FHBLOCK<code>
  * </p>
  * The FHBLOCK describes who/which tool generated or changed the MDF file. Each
  * FHBLOCK contains a change log entry for the MDF file. The first FHBLOCK
  * referenced by the HDBLOCK must contain information about the tool which
  * created the MDF file. Starting from this FHBLOCK then a linked list of
  * FHBLOCKs can be maintained with a chronological change history, i.e. any
  * other application that changes the file must append a new FHBLOCK to the
  * list. A zero-based index value is used to reference blocks within this linked
  * list, thus the ordering of the blocks must not be changed.
  *
  * @author Christian Rechner
  */
 class FHBLOCK extends BLOCK {

 	public static String BLOCK_ID = "##FH";

 	/** Link section */

 	// Link to next FHBLOCK (can be NIL if list finished)
 	// LINK
 	private long lnkFhNext;

 	// Link to MDBLOCK containing comment about the creation or modification of
 	// the MDF file.
 	// LINK
 	private long lnkMdComment;

 	/** Data section */

 	// Time stamp at which the file has been changed/created (first entry) in
 	// nanoseconds elapsed since 00:00:00
 	// 01.01.1970 (UTC time or local time, depending on "local time" flag).
 	// UINT64
 	private long startTimeNs;

 	// Time zone offset in minutes.
 	// The value is not necessarily a multiple of 60 and can be negative! For
 	// the current time zone definitions, it is
 	// expected to be in the range [-840,840] min.
 	// For example a value of 60 (min) means UTC+1 time zone = Central European
 	// Time
 	// Only valid if "time offsets valid" flag is set in time flags.
 	// INT16
 	private short tzOffsetMin;

 	// Daylight saving time (DST) offset in minutes for start time stamp. During
 	// the summer months, most regions observe
 	// a DST offset of 60 min (1 hour).
 	// Only valid if "time offsets valid" flag is set in time flags.
 	// INT16
 	private short dstOffsetMin;

 	// Time flags
 	// The value contains the following bit flags (Bit 0 = LSB):
 	// Bit 0: Local time flag
 	// If set, the start time stamp in nanoseconds represents the local time
 	// instead of the UTC time, In this case, time
 	// zone and DST offset must not be considered (time offsets flag must not be
 	// set). Should only be used if UTC time
 	// is unknown.
 	// If the bit is not set (default), the start time stamp represents the UTC
 	// time.
 	// Bit 1: Time offsets valid flag
 	// If set, the time zone and DST offsets are valid. Must not be set together
 	// with "local time" flag (mutually
 	// exclusive).
 	// If the offsets are valid, the locally displayed time at start of
 	// recording can be determined
 	// (after conversion of offsets to ns) by
 	// Local time = UTC time + time zone offset + DST offset.
 	// UINT8
 	private byte timeFlags;

 	/**
 	 * Constructor.
 	 *
 	 * @param sbc
 	 *            The byte channel pointing to the MDF file.
 	 * @param pos
 	 *            The position of the block within the MDF file.
 	 */
 	private FHBLOCK(SeekableByteChannel sbc, long pos) {
 		super(sbc, pos);
 	}

 	private void setLnkFhNext(long lnkFhNext) {
 		this.lnkFhNext = lnkFhNext;
 	}

 	private void setLnkMdComment(long lnkMdComment) {
 		this.lnkMdComment = lnkMdComment;
 	}

 	private void setStartTimeNs(long startTimeNs) {
 		this.startTimeNs = startTimeNs;
 	}

 	private void setTzOffsetMin(short tzOffsetMin) {
 		this.tzOffsetMin = tzOffsetMin;
 	}

 	private void setDstOffsetMin(short dstOffsetMin) {
 		this.dstOffsetMin = dstOffsetMin;
 	}

 	private void setTimeFlags(byte timeFlags) {
 		this.timeFlags = timeFlags;
 	}

 	public long getLnkFhNext() {
 		return lnkFhNext;
 	}

 	public long getLnkMdComment() {
 		return lnkMdComment;
 	}

 	public long getStartTimeNs() {
 		return startTimeNs;
 	}

 	public short getTzOffsetMin() {
 		return tzOffsetMin;
 	}

 	public short getDstOffsetMin() {
 		return dstOffsetMin;
 	}

 	public byte getTimeFlags() {
 		return timeFlags;
 	}

 	public boolean isLocalTime() {
 		return BigInteger.valueOf(timeFlags).testBit(0);
 	}

 	public boolean isTimeFlagsValid() {
 		return BigInteger.valueOf(timeFlags).testBit(1);
 	}

 	public FHBLOCK getFhNextBlock() throws IOException {
 		if (lnkFhNext > 0) {
 			return FHBLOCK.read(sbc, lnkFhNext);
 		}
 		return null;
 	}

 	public MDBLOCK getMdCommentBlock() throws IOException {
 		if (lnkMdComment > 0) {
 			return MDBLOCK.read(sbc, lnkMdComment);
 		}
 		return null;
 	}

 	@Override
 	public String toString() {
 		return "FHBLOCK [lnkFhNext=" + lnkFhNext + ", lnkMdComment=" + lnkMdComment + ", startTimeNs=" + startTimeNs
 				+ ", tzOffsetMin=" + tzOffsetMin + ", dstOffsetMin=" + dstOffsetMin + ", timeFlags=" + timeFlags + "]";
 	}

 	/**
 	 * Reads a FHBLOCK from the channel starting at current channel position.
 	 *
 	 * @param channel
 	 *            The channel to read from.
 	 * @param pos
 	 *            The position within the channel.
 	 * @return The block data.
 	 * @throws IOException
 	 *             The exception.
 	 */
 	public static FHBLOCK read(SeekableByteChannel channel, long pos) throws IOException {
 		FHBLOCK block = new FHBLOCK(channel, pos);

 		// read block header
 		ByteBuffer bb = ByteBuffer.allocate(56);
 		bb.order(ByteOrder.LITTLE_ENDIAN);
 		channel.position(pos);
 		channel.read(bb);
 		bb.rewind();

 		// CHAR 4: Block type identifier
 		block.setId(MDF4Util.readCharsISO8859(bb, 4));
 		if (!block.getId().equals(BLOCK_ID)) {
 			throw new IOException("Wrong block type - expected '" + BLOCK_ID + "', found '" + block.getId() + "'");
 		}

 		// BYTE 4: Reserved used for 8-Byte alignment
 		bb.get(new byte[4]);

 		// UINT64: Length of block
 		block.setLength(MDF4Util.readUInt64(bb));

 		// UINT64: Number of links
 		block.setLinkCount(MDF4Util.readUInt64(bb));

 		// LINK: Link to next FHBLOCK (can be NIL if list finished)
 		block.setLnkFhNext(MDF4Util.readLink(bb));

 		// LINK: Link to MDBLOCK containing comment about the creation or
 		// modification of the MDF file.
 		block.setLnkMdComment(MDF4Util.readLink(bb));

 		// UINT64: Time stamp at which the file has been changed/created (first
 		// entry)
 		block.setStartTimeNs(MDF4Util.readUInt64(bb));

 		// INT16: Time zone offset in minutes.
 		block.setTzOffsetMin(MDF4Util.readInt16(bb));

 		// INT16: Daylight saving time (DST) offset in minutes for start time
 		// stamp.
 		block.setDstOffsetMin(MDF4Util.readInt16(bb));

 		// UINT8: Time flags
 		block.setTimeFlags(MDF4Util.readUInt8(bb));

 		return block;
 	}

 }
	/********************************************************************************
	* Copyright (c) 2015-2018 Contributors to the Eclipse Foundation
	*
	* See the NOTICE file(s) distributed with this work for additional
	* information regarding copyright ownership.
	*
	* This program and the accompanying materials are made available under the
	* terms of the Eclipse Public License v. 2.0 which is available at
	* http://www.eclipse.org/legal/epl-2.0.
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	********************************************************************************/


	package org.eclipse.mdm.openatfx.mdf.mdf4;

	import java.io.IOException;
	import java.math.BigInteger;
	import java.nio.ByteBuffer;
	import java.nio.ByteOrder;
	import java.nio.channels.SeekableByteChannel;

	/**
	* <p>
	* THE FILE HISTORY BLOCK <code>FHBLOCK<code>
	* </p>
	* The FHBLOCK describes who/which tool generated or changed the MDF file. Each
	* FHBLOCK contains a change log entry for the MDF file. The first FHBLOCK
	* referenced by the HDBLOCK must contain information about the tool which
	* created the MDF file. Starting from this FHBLOCK then a linked list of
	* FHBLOCKs can be maintained with a chronological change history, i.e. any
	* other application that changes the file must append a new FHBLOCK to the
	* list. A zero-based index value is used to reference blocks within this linked
	* list, thus the ordering of the blocks must not be changed.
	*
	* @author Christian Rechner
	*/
	class FHBLOCK extends BLOCK {

	public static String BLOCK_ID = "##FH";

	/** Link section */

	// Link to next FHBLOCK (can be NIL if list finished)
	// LINK
	private long lnkFhNext;

	// Link to MDBLOCK containing comment about the creation or modification of
	// the MDF file.
	// LINK
	private long lnkMdComment;

	/** Data section */

	// Time stamp at which the file has been changed/created (first entry) in
	// nanoseconds elapsed since 00:00:00
	// 01.01.1970 (UTC time or local time, depending on "local time" flag).
	// UINT64
	private long startTimeNs;

	// Time zone offset in minutes.
	// The value is not necessarily a multiple of 60 and can be negative! For
	// the current time zone definitions, it is
	// expected to be in the range [-840,840] min.
	// For example a value of 60 (min) means UTC+1 time zone = Central European
	// Time
	// Only valid if "time offsets valid" flag is set in time flags.
	// INT16
	private short tzOffsetMin;

	// Daylight saving time (DST) offset in minutes for start time stamp. During
	// the summer months, most regions observe
	// a DST offset of 60 min (1 hour).
	// Only valid if "time offsets valid" flag is set in time flags.
	// INT16
	private short dstOffsetMin;

	// Time flags
	// The value contains the following bit flags (Bit 0 = LSB):
	// Bit 0: Local time flag
	// If set, the start time stamp in nanoseconds represents the local time
	// instead of the UTC time, In this case, time
	// zone and DST offset must not be considered (time offsets flag must not be
	// set). Should only be used if UTC time
	// is unknown.
	// If the bit is not set (default), the start time stamp represents the UTC
	// time.
	// Bit 1: Time offsets valid flag
	// If set, the time zone and DST offsets are valid. Must not be set together
	// with "local time" flag (mutually
	// exclusive).
	// If the offsets are valid, the locally displayed time at start of
	// recording can be determined
	// (after conversion of offsets to ns) by
	// Local time = UTC time + time zone offset + DST offset.
	// UINT8
	private byte timeFlags;

	/**
	* Constructor.
	*
	* @param sbc
	* The byte channel pointing to the MDF file.
	* @param pos
	* The position of the block within the MDF file.
	*/
	private FHBLOCK(SeekableByteChannel sbc, long pos) {
	super(sbc, pos);
	}

	private void setLnkFhNext(long lnkFhNext) {
	this.lnkFhNext = lnkFhNext;
	}

	private void setLnkMdComment(long lnkMdComment) {
	this.lnkMdComment = lnkMdComment;
	}

	private void setStartTimeNs(long startTimeNs) {
	this.startTimeNs = startTimeNs;
	}

	private void setTzOffsetMin(short tzOffsetMin) {
	this.tzOffsetMin = tzOffsetMin;
	}

	private void setDstOffsetMin(short dstOffsetMin) {
	this.dstOffsetMin = dstOffsetMin;
	}

	private void setTimeFlags(byte timeFlags) {
	this.timeFlags = timeFlags;
	}

	public long getLnkFhNext() {
	return lnkFhNext;
	}

	public long getLnkMdComment() {
	return lnkMdComment;
	}

	public long getStartTimeNs() {
	return startTimeNs;
	}

	public short getTzOffsetMin() {
	return tzOffsetMin;
	}

	public short getDstOffsetMin() {
	return dstOffsetMin;
	}

	public byte getTimeFlags() {
	return timeFlags;
	}

	public boolean isLocalTime() {
	return BigInteger.valueOf(timeFlags).testBit(0);
	}

	public boolean isTimeFlagsValid() {
	return BigInteger.valueOf(timeFlags).testBit(1);
	}

	public FHBLOCK getFhNextBlock() throws IOException {
	if (lnkFhNext > 0) {
	return FHBLOCK.read(sbc, lnkFhNext);
	}
	return null;
	}

	public MDBLOCK getMdCommentBlock() throws IOException {
	if (lnkMdComment > 0) {
	return MDBLOCK.read(sbc, lnkMdComment);
	}
	return null;
	}

	@Override
	public String toString() {
	return "FHBLOCK [lnkFhNext=" + lnkFhNext + ", lnkMdComment=" + lnkMdComment + ", startTimeNs=" + startTimeNs
	+ ", tzOffsetMin=" + tzOffsetMin + ", dstOffsetMin=" + dstOffsetMin + ", timeFlags=" + timeFlags + "]";
	}

	/**
	* Reads a FHBLOCK from the channel starting at current channel position.
	*
	* @param channel
	* The channel to read from.
	* @param pos
	* The position within the channel.
	* @return The block data.
	* @throws IOException
	* The exception.
	*/
	public static FHBLOCK read(SeekableByteChannel channel, long pos) throws IOException {
	FHBLOCK block = new FHBLOCK(channel, pos);

	// read block header
	ByteBuffer bb = ByteBuffer.allocate(56);
	bb.order(ByteOrder.LITTLE_ENDIAN);
	channel.position(pos);
	channel.read(bb);
	bb.rewind();

	// CHAR 4: Block type identifier
	block.setId(MDF4Util.readCharsISO8859(bb, 4));
	if (!block.getId().equals(BLOCK_ID)) {
	throw new IOException("Wrong block type - expected '" + BLOCK_ID + "', found '" + block.getId() + "'");
	}

	// BYTE 4: Reserved used for 8-Byte alignment
	bb.get(new byte[4]);

	// UINT64: Length of block
	block.setLength(MDF4Util.readUInt64(bb));

	// UINT64: Number of links
	block.setLinkCount(MDF4Util.readUInt64(bb));

	// LINK: Link to next FHBLOCK (can be NIL if list finished)
	block.setLnkFhNext(MDF4Util.readLink(bb));

	// LINK: Link to MDBLOCK containing comment about the creation or
	// modification of the MDF file.
	block.setLnkMdComment(MDF4Util.readLink(bb));

	// UINT64: Time stamp at which the file has been changed/created (first
	// entry)
	block.setStartTimeNs(MDF4Util.readUInt64(bb));

	// INT16: Time zone offset in minutes.
	block.setTzOffsetMin(MDF4Util.readInt16(bb));

	// INT16: Daylight saving time (DST) offset in minutes for start time
	// stamp.
	block.setDstOffsetMin(MDF4Util.readInt16(bb));

	// UINT8: Time flags
	block.setTimeFlags(MDF4Util.readUInt8(bb));

	return block;
	}

	}