/*
* 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.mina.filter.codec.statemachine;
import org.apache.mina.common.IoBuffer;
import org.apache.mina.filter.codec.ProtocolDecoderOutput;
/**
* A {@link DecodingState} which consumes all received bytes until a configured
* number of read bytes has been reached. Please note that this state can
* produce the buffer with less data if the associated session has been
* closed unexpectedly.
*
* @author The Apache MINA Project (dev@mina.apache.org)
* @version $Rev: 601994 $, $Date: 2007-12-07 13:58:00 +0900 (금, 07 12월 2007) $
*/
public abstract class FixedLengthDecodingState implements DecodingState {
private final int length;
private IoBuffer buffer;
/**
* Constructs with a known decode length.
*
* @param length The decode length
*/
public FixedLengthDecodingState(int length) {
this.length = length;
}
public DecodingState decode(IoBuffer in, ProtocolDecoderOutput out)
throws Exception {
if (buffer == null) {
if (in.remaining() >= length) {
int limit = in.limit();
in.limit(in.position() + length);
IoBuffer product = in.slice();
in.position(in.position() + length);
in.limit(limit);
return finishDecode(product, out);
} else {
buffer = IoBuffer.allocate(length);
buffer.put(in);
return this;
}
} else {
if (in.remaining() >= length - buffer.position()) {
int limit = in.limit();
in.limit(in.position() + length - buffer.position());
buffer.put(in);
in.limit(limit);
IoBuffer product = this.buffer;
this.buffer = null;
return finishDecode(product.flip(), out);
} else {
buffer.put(in);
return this;
}
}
}
public DecodingState finishDecode(ProtocolDecoderOutput out)
throws Exception {
IoBuffer readData;
if (buffer == null) {
readData = IoBuffer.allocate(0);
} else {
readData = buffer.flip();
buffer = null;
}
return finishDecode(readData ,out);
}
protected abstract DecodingState finishDecode(IoBuffer readData,
ProtocolDecoderOutput out) throws Exception;
}