org.elasticsearch.common.io.stream.HandlesStreamInput Maven / Gradle / Ivy

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There is a newer version: 8.15.1
/*
 * Licensed to Elastic Search and Shay Banon under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Elastic Search 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.elasticsearch.common.io.stream;

import org.elasticsearch.common.trove.TIntObjectHashMap;

import java.io.IOException;

/**
 * @author kimchy (shay.banon)
 */
public class HandlesStreamInput extends StreamInput {

    private StreamInput in;

    private final TIntObjectHashMap handles = new TIntObjectHashMap();

    private final TIntObjectHashMap identityHandles = new TIntObjectHashMap();

    HandlesStreamInput() {
    }

    public HandlesStreamInput(StreamInput in) {
        this.in = in;
    }

    @Override public String readUTF() throws IOException {
        byte b = in.readByte();
        if (b == 0) {
            // full string with handle
            int handle = in.readVInt();
            String s = in.readUTF();
            handles.put(handle, s);
            return s;
        } else if (b == 1) {
            return handles.get(in.readVInt());
        } else if (b == 2) {
            // full string with handle
            int handle = in.readVInt();
            String s = in.readUTF();
            identityHandles.put(handle, s);
            return s;
        } else if (b == 3) {
            return identityHandles.get(in.readVInt());
        } else {
            throw new IOException("Expected handle header, got [" + b + "]");
        }
    }

    @Override public int read() throws IOException {
        return in.read();
    }

    @Override public int read(byte[] b) throws IOException {
        return in.read(b);
    }

    @Override public int read(byte[] b, int off, int len) throws IOException {
        return in.read(b, off, len);
    }

    @Override public byte readByte() throws IOException {
        return in.readByte();
    }

    @Override public void readBytes(byte[] b, int offset, int len) throws IOException {
        in.readBytes(b, offset, len);
    }

    public void cleanHandles() {
        handles.clear();
    }

    @Override public void reset() throws IOException {
        in.reset();
        handles.clear();
    }

    public void reset(StreamInput in) {
        this.in = in;
        handles.clear();
        identityHandles.clear();
    }

    @Override public void close() throws IOException {
        in.close();
    }
}