info.zhoumin.dat.analyzer.StringAnalyzer.java Source code

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Here is the source code for info.zhoumin.dat.analyzer.StringAnalyzer.java

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/*
 * 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 info.zhoumin.dat.analyzer;

import java.nio.ByteOrder;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.PooledByteBufAllocator;
import io.netty.buffer.Unpooled;

/**
 * @author Min Zhou (coderplay AT gmail.com)
 */
public class StringAnalyzer extends AbstractAnalyzer<String> {

    public static final StringAnalyzer INSTANCE = new StringAnalyzer();

    @Override
    public boolean hasNext() {
        return (index + 1) < (value.length() << 1);
    }

    @Override
    public byte next() {
        ++index;
        char ch = value.charAt(index >> 1);
        return (byte) ((index & 1) == 0 ? (ch & 0xff) : (ch >> Byte.SIZE & 0xff));
    }

    @Override
    public ByteBuf rest() {
        int len = (value.length() << 1) - (index + 1);
        ByteBuf bb = PooledByteBufAllocator.DEFAULT.directBuffer(len).order(ByteOrder.nativeOrder());
        for (int i = len; i > 0; i--) {
            int idx = (value.length() << 1) - i;
            char ch = value.charAt(idx >> 1);
            byte b = (byte) ((idx & 1) == 0 ? (ch & 0xff) : (ch >> Byte.SIZE & 0xff));
            bb.writeByte(b);
        }
        return bb;
    }

}