/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.cassandra.db.commitlog;
import java.io.File;
import java.io.IOError;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.zip.CRC32;
import java.util.zip.Checksum;
import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.net.MessagingService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.db.RowMutation;
import org.apache.cassandra.io.util.BufferedRandomAccessFile;
public class CommitLogSegment
{
private static final Logger logger = LoggerFactory.getLogger(CommitLogSegment.class);
private static Pattern COMMIT_LOG_FILE_PATTERN = Pattern.compile("CommitLog-(\\d+).log");
public final long id;
private final BufferedRandomAccessFile logWriter;
// cache which cf is dirty in this segment to avoid having to lookup all ReplayPositions to decide if we could delete this segment
private Set<Integer> cfDirty = new HashSet<Integer>();
public CommitLogSegment()
{
id = System.currentTimeMillis();
String logFile = DatabaseDescriptor.getCommitLogLocation() + File.separator + "CommitLog-" + id + ".log";
logger.info("Creating new commitlog segment " + logFile);
try
{
logWriter = createWriter(logFile);
}
catch (IOException e)
{
throw new IOError(e);
}
}
// assume filename is a 'possibleCommitLogFile()'
public static long idFromFilename(String filename)
{
Matcher matcher = COMMIT_LOG_FILE_PATTERN.matcher(filename);
try
{
if (matcher.matches())
return Long.valueOf(matcher.group(1));
else
return -1L;
}
catch (NumberFormatException e)
{
return -1L;
}
}
public static boolean possibleCommitLogFile(String filename)
{
return COMMIT_LOG_FILE_PATTERN.matcher(filename).matches();
}
private static BufferedRandomAccessFile createWriter(String file) throws IOException
{
return new BufferedRandomAccessFile(new File(file), "rw", 128 * 1024, true);
}
public ReplayPosition write(RowMutation rowMutation) throws IOException
{
long currentPosition = -1L;
try
{
currentPosition = logWriter.getFilePointer();
assert currentPosition <= Integer.MAX_VALUE;
ReplayPosition cLogCtx = new ReplayPosition(id, (int) currentPosition);
// write mutation, w/ checksum on the size and data
Checksum checksum = new CRC32();
byte[] serializedRow = rowMutation.getSerializedBuffer(MessagingService.version_);
checksum.update(serializedRow.length);
logWriter.writeInt(serializedRow.length);
logWriter.writeLong(checksum.getValue());
logWriter.write(serializedRow);
checksum.update(serializedRow, 0, serializedRow.length);
logWriter.writeLong(checksum.getValue());
return cLogCtx;
}
catch (IOException e)
{
if (currentPosition != -1)
logWriter.seek(currentPosition);
throw e;
}
}
public void sync() throws IOException
{
logWriter.sync();
}
public ReplayPosition getContext()
{
long position = logWriter.getFilePointer();
assert position <= Integer.MAX_VALUE;
return new ReplayPosition(id, (int) position);
}
public String getPath()
{
return logWriter.getPath();
}
public String getName()
{
return logWriter.getPath().substring(logWriter.getPath().lastIndexOf(File.separator) + 1);
}
public long length()
{
try
{
return logWriter.length();
}
catch (IOException e)
{
throw new IOError(e);
}
}
public void close()
{
try
{
logWriter.close();
}
catch (IOException e)
{
throw new IOError(e);
}
}
void turnOn(Integer cfId)
{
cfDirty.add(cfId);
}
void turnOff(Integer cfId)
{
cfDirty.remove(cfId);
}
// For debugging, not fast
String dirtyString()
{
StringBuilder sb = new StringBuilder();
for (Integer cfId : cfDirty)
{
CFMetaData m = DatabaseDescriptor.getCFMetaData(cfId);
sb.append(m == null ? m.cfName : "<deleted>").append(" (").append(cfId).append("), ");
}
return sb.toString();
}
boolean isSafeToDelete()
{
return cfDirty.isEmpty();
}
@Override
public String toString()
{
return "CommitLogSegment(" + logWriter.getPath() + ')';
}
}