package org.apache.cassandra.io;
/*
*
* 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.
*
*/
import java.io.DataOutput;
import java.io.IOException;
import java.security.MessageDigest;
import org.apache.cassandra.db.DecoratedKey;
/**
* a CompactedRow is an object that takes a bunch of rows (keys + columnfamilies)
* and can write a compacted version of those rows to an output stream. It does
* NOT necessarily require creating a merged CF object in memory.
*/
public abstract class AbstractCompactedRow
{
public final DecoratedKey key;
public AbstractCompactedRow(DecoratedKey key)
{
this.key = key;
}
/**
* write the row (size + column index + filter + column data, but NOT row key) to @param out
*/
public abstract void write(DataOutput out) throws IOException;
/**
* update @param digest with the data bytes of the row (not including row key or row size)
*/
public abstract void update(MessageDigest digest);
/**
* @return true if there are no columns in the row AND there are no row-level tombstones to be preserved
*/
public abstract boolean isEmpty();
/**
* @return the number of columns in the row
*/
public abstract int columnCount();
}