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From kmars...@apache.org
Subject svn commit: r159659 - incubator/derby/code/trunk/java/engine/org/apache/derby/impl/store/raw/log/ChecksumOperation.java
Date Fri, 01 Apr 2005 03:25:46 GMT
Author: kmarsden
Date: Thu Mar 31 19:25:45 2005
New Revision: 159659

URL: http://svn.apache.org/viewcvs?view=rev&rev=159659
Log:
Missing file from suresh's checksum checkin


Added:
    incubator/derby/code/trunk/java/engine/org/apache/derby/impl/store/raw/log/ChecksumOperation.java
  (with props)

Added: incubator/derby/code/trunk/java/engine/org/apache/derby/impl/store/raw/log/ChecksumOperation.java
URL: http://svn.apache.org/viewcvs/incubator/derby/code/trunk/java/engine/org/apache/derby/impl/store/raw/log/ChecksumOperation.java?view=auto&rev=159659
==============================================================================
--- incubator/derby/code/trunk/java/engine/org/apache/derby/impl/store/raw/log/ChecksumOperation.java
(added)
+++ incubator/derby/code/trunk/java/engine/org/apache/derby/impl/store/raw/log/ChecksumOperation.java
Thu Mar 31 19:25:45 2005
@@ -0,0 +1,266 @@
+/*
+
+   Derby - Class org.apache.derby.impl.store.raw.log.ChecksumOperation
+
+   Copyright 1997, 2004 The Apache Software Foundation or its licensors, as applicable.
+
+   Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+ */
+
+package org.apache.derby.impl.store.raw.log;
+
+import org.apache.derby.iapi.services.sanity.SanityManager;
+import org.apache.derby.iapi.services.io.Formatable;
+import org.apache.derby.iapi.services.io.FormatIdUtil;
+import org.apache.derby.iapi.services.io.StoredFormatIds;
+import org.apache.derby.catalog.UUID;
+
+import org.apache.derby.iapi.store.raw.Transaction;
+import org.apache.derby.iapi.store.raw.Loggable;
+import org.apache.derby.iapi.store.raw.log.LogInstant;
+import org.apache.derby.iapi.store.raw.log.LogFactory;
+import org.apache.derby.iapi.store.raw.xact.RawTransaction;
+
+import org.apache.derby.iapi.error.StandardException;
+
+import org.apache.derby.iapi.services.io.CompressedNumber;
+import org.apache.derby.iapi.util.ByteArray;
+
+import java.io.Externalizable;
+import java.io.OutputStream;
+import java.io.InputStream;
+import java.io.ObjectInput;
+import java.io.ObjectOutput;
+import java.io.IOException;
+import org.apache.derby.iapi.services.io.LimitObjectInput;
+
+import java.util.zip.Checksum;
+import java.util.zip.CRC32;
+
+
+/**
+	A Log Operation that represents a checksum for a group of log records
+	that are written to the tranaction log file.
+
+	<PRE>
+	@format_id	LOGOP_CHECKSUM
+		the formatId is written by FormatIdOutputStream when this object is
+		written out by writeObject
+	@purpose  checksum one or more log records while writing to disk
+	@upgrade
+	@disk_layout
+		checksumAlgo(byte)  	the checksum algorithm 
+		checksumValue(long)     the checksum value 
+		dataLength(int)			number of bytes that the checksum is calculated
+	@end_format
+	</PRE>
+
+	@author  Suresh Thalamati
+	@see Loggable
+*/
+
+public class ChecksumOperation implements Loggable 
+{
+
+	private  byte   checksumAlgo;
+	private  long   checksumValue;   
+	private  int	dataLength; 
+	private Checksum checksum; 
+
+	/*
+	 * constant values for algorithm that are used to perform the checksum.
+	 */
+    public static final byte CRC32_ALGORITHM  = (byte) 0x1; //java.util.zip.CRC32
+	
+	private static final int formatLength = FormatIdUtil.getFormatIdByteLength(StoredFormatIds.LOGOP_CHECKSUM);
+	
+	public void init()
+	{
+		this.checksumAlgo = CRC32_ALGORITHM;
+		initializeChecksumAlgo();
+		dataLength = 0;
+	}
+
+	
+	// update the checksum
+	protected void update(byte[] buf, int off, int len)
+	{
+		checksum.update(buf, off , len);
+		dataLength += len;
+	}
+
+	
+	// reset the checksum 
+	protected void reset()
+	{
+		checksum.reset();
+		dataLength = 0;
+	}
+
+
+	private void initializeChecksumAlgo()
+	{
+		if(checksumAlgo == CRC32_ALGORITHM)
+			this.checksum = new CRC32();
+	}
+
+
+	/*
+	 * Formatable methods
+	 */
+
+	// no-arg constructor, required by Formatable 
+	public ChecksumOperation() { super();}
+
+	public void writeExternal(ObjectOutput out) throws IOException 
+	{	
+		checksumValue = checksum.getValue();
+		out.writeByte(checksumAlgo);
+		out.writeInt(dataLength);
+		out.writeLong(checksumValue);
+	}
+
+	public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException
+	{
+		checksumAlgo = (byte) in.readUnsignedByte();
+		dataLength = in.readInt();
+		checksumValue = in.readLong();
+		initializeChecksumAlgo();
+	}
+
+
+	public int getStoredSize()
+	{
+		return formatLength + 1 + 4 + 8;
+	}	
+
+
+
+	/**
+		Return my format identifier.
+	*/
+	public int getTypeFormatId() {
+		return StoredFormatIds.LOGOP_CHECKSUM;
+	}
+
+
+
+
+
+	/**
+		Loggable methods
+	*/
+
+	/**
+	 *	Nothing to do for the checksum log record because it does need to be
+	 *  applied during redo. 
+	 */
+	public void doMe(Transaction xact, LogInstant instant, LimitObjectInput in) throws StandardException
+	{
+	}
+
+	/**
+		the default for prepared log is always null for all the operations
+		that don't have optionalData.  If an operation has optional data,
+		the operation need to prepare the optional data for this method.
+
+		Checksum has no optional data to write out
+
+		@param out Where and how to write to optional data.
+		
+	*/
+	public ByteArray getPreparedLog()
+	{
+		return (ByteArray) null;
+	}
+
+	/**
+		Checksum does not need to be redone, it is used to just verify that
+		log records are written completely.
+	*/
+	public boolean needsRedo(Transaction xact)
+	{
+		return false;
+	}
+
+
+	/**
+	  Checksum has no resources to release
+	*/
+	public void releaseResource(Transaction xact)
+	{}
+
+	/**
+		Checksum is a raw store operation
+	*/
+	public int group()
+	{
+		return Loggable.RAWSTORE | Loggable.CHECKSUM;
+	}
+
+	
+
+
+	/**
+	 * Access attributes of the checksum log record
+	 */
+
+	protected int getDataLength() 
+	{
+		return dataLength;
+	}
+
+
+	protected boolean isChecksumValid(byte[] data, int off , int length)
+	{
+		checksum.reset();
+		checksum.update(data , off , length);
+		return checksum.getValue()== checksumValue;
+
+	}
+
+
+	/**
+	  DEBUG: Print self.
+	*/
+	public String toString()
+	{
+		if (SanityManager.DEBUG)
+		{
+			StringBuffer str = new StringBuffer(200)
+				.append("Checksum Operation ")
+				.append(" algorithm = ")
+				.append(checksumAlgo)
+				.append(" value = ")
+				.append(checksumValue)
+				.append(" data length= ").append(dataLength);
+
+				return str.toString();
+		}
+		else
+			return null;
+	}
+}
+
+
+
+
+
+
+
+
+
+
+
+

Propchange: incubator/derby/code/trunk/java/engine/org/apache/derby/impl/store/raw/log/ChecksumOperation.java
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    svn:eol-style = native



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