/**
* 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;
import java.io.IOException;
import java.util.Iterator;
import org.apache.cassandra.io.DataInputBuffer;
import org.apache.cassandra.io.DataOutputBuffer;
import org.apache.cassandra.io.IFileReader;
import org.apache.cassandra.io.SSTable;
import org.apache.cassandra.io.Coordinate;
import org.apache.cassandra.dht.IPartitioner;
import org.apache.log4j.Logger;
public class FileStruct implements Comparable<FileStruct>, Iterator<String>
{
private static Logger logger = Logger.getLogger(FileStruct.class);
private String key = null; // decorated!
private boolean exhausted = false;
private IFileReader reader;
private DataInputBuffer bufIn;
private DataOutputBuffer bufOut;
private IPartitioner partitioner;
private FileStructIterator iterator;
public FileStruct(IFileReader reader, IPartitioner partitioner)
{
this.reader = reader;
this.partitioner = partitioner;
bufIn = new DataInputBuffer();
bufOut = new DataOutputBuffer();
}
public String getFileName()
{
return reader.getFileName();
}
public void close() throws IOException
{
reader.close();
}
public boolean isExhausted()
{
return exhausted;
}
public DataInputBuffer getBufIn()
{
return bufIn;
}
public String getKey()
{
return key;
}
public int compareTo(FileStruct f)
{
return partitioner.getDecoratedKeyComparator().compare(key, f.key);
}
public void seekTo(String seekKey)
{
try
{
Coordinate range = SSTable.getCoordinates(seekKey, reader, partitioner);
reader.seek(range.end_);
long position = reader.getPositionFromBlockIndex(seekKey);
if (position == -1)
{
reader.seek(range.start_);
}
else
{
reader.seek(position);
}
while (!exhausted)
{
advance();
if (key.compareTo(seekKey) >= 0)
{
break;
}
}
}
catch (IOException e)
{
throw new RuntimeException("corrupt sstable", e);
}
}
/*
* Read the next key from the data file, skipping block indexes.
* Caller must check isExhausted after each call to see if further
* reads are valid.
* Do not mix with calls to the iterator interface (next/hasnext).
* @deprecated -- prefer the iterator interface.
*/
public void advance() throws IOException
{
if (exhausted)
{
throw new IndexOutOfBoundsException();
}
bufOut.reset();
if (reader.isEOF())
{
reader.close();
exhausted = true;
return;
}
long bytesread = reader.next(bufOut);
if (bytesread == -1)
{
reader.close();
exhausted = true;
return;
}
bufIn.reset(bufOut.getData(), bufOut.getLength());
key = bufIn.readUTF();
/* If the key we read is the Block Index Key then omit and read the next key. */
if (key.equals(SSTable.blockIndexKey_))
{
reader.close();
exhausted = true;
}
}
public boolean hasNext()
{
if (iterator == null)
iterator = new FileStructIterator();
return iterator.hasNext();
}
/** do not mix with manual calls to advance(). */
public String next()
{
if (iterator == null)
iterator = new FileStructIterator();
return iterator.next();
}
public void remove()
{
throw new UnsupportedOperationException();
}
private class FileStructIterator
{
String saved;
public FileStructIterator()
{
if (key == null)
{
if (!isExhausted())
{
forward();
}
}
if (key.equals(SSTable.blockIndexKey_))
{
saved = null;
}
else
{
saved = key;
}
}
private void forward()
{
try
{
advance();
}
catch (IOException e)
{
throw new RuntimeException(e);
}
saved = isExhausted() ? null : key;
}
public boolean hasNext()
{
return saved != null;
}
public String next()
{
if (saved == null)
{
throw new IndexOutOfBoundsException();
}
String key = saved;
forward();
return key;
}
}
}