org.apache.giraph.utils.DynamicChannelBufferOutputStream.java Source code

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Here is the source code for org.apache.giraph.utils.DynamicChannelBufferOutputStream.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 org.apache.giraph.utils;

import java.io.DataOutput;
import java.io.IOException;
import java.nio.ByteOrder;

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

/**
 * Special output stream that can grow as needed and dumps to a
 * DynamicChannelBuffer.
 */
public class DynamicChannelBufferOutputStream implements DataOutput {
    /** Internal dynamic channel buffer */
    private ByteBuf buffer;

    /**
     * Constructor
     *
     * @param estimatedLength Estimated length of the buffer
     */
    public DynamicChannelBufferOutputStream(int estimatedLength) {
        buffer = Unpooled.unreleasableBuffer(Unpooled.buffer(estimatedLength)).order(ByteOrder.LITTLE_ENDIAN);
        // -- TODO unresolved what are benefits of using releasable?
        // currently nit because it is just used in 1 test file
    }

    /**
     * Constructor with the buffer to use
     *
     * @param buffer Buffer to be written to (cleared before use)
     */
    public DynamicChannelBufferOutputStream(ByteBuf buffer) {
        this.buffer = buffer;
        buffer.clear();
    }

    /**
     * Get the dynamic channel buffer
     *
     * @return dynamic channel buffer (not a copy)
     */
    public ByteBuf getDynamicChannelBuffer() {
        return buffer;
    }

    @Override
    public void write(int b) throws IOException {
        buffer.writeByte(b);
    }

    @Override
    public void write(byte[] b) throws IOException {
        buffer.writeBytes(b);
    }

    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        buffer.writeBytes(b, off, len);
    }

    @Override
    public void writeBoolean(boolean v) throws IOException {
        buffer.writeByte(v ? 1 : 0);
    }

    @Override
    public void writeByte(int v) throws IOException {
        buffer.writeByte(v);
    }

    @Override
    public void writeShort(int v) throws IOException {
        buffer.writeShort(v);
    }

    @Override
    public void writeChar(int v) throws IOException {
        buffer.writeChar(v);
    }

    @Override
    public void writeInt(int v) throws IOException {
        buffer.writeInt(v);
    }

    @Override
    public void writeLong(long v) throws IOException {
        buffer.writeLong(v);
    }

    @Override
    public void writeFloat(float v) throws IOException {
        buffer.writeFloat(v);
    }

    @Override
    public void writeDouble(double v) throws IOException {
        buffer.writeDouble(v);
    }

    @Override
    public void writeBytes(String s) throws IOException {
        // Note that this code is mostly copied from DataOutputStream
        int len = s.length();
        for (int i = 0; i < len; i++) {
            buffer.writeByte((byte) s.charAt(i));
        }
    }

    @Override
    public void writeChars(String s) throws IOException {
        // Note that this code is mostly copied from DataOutputStream
        int len = s.length();
        for (int i = 0; i < len; i++) {
            int v = s.charAt(i);
            buffer.writeByte((v >>> 8) & 0xFF);
            buffer.writeByte((v >>> 0) & 0xFF);
        }
    }

    @Override
    public void writeUTF(String s) throws IOException {
        // Note that this code is mostly copied from DataOutputStream
        int strlen = s.length();
        int utflen = 0;
        int c;

        /* use charAt instead of copying String to char array */
        for (int i = 0; i < strlen; i++) {
            c = s.charAt(i);
            if ((c >= 0x0001) && (c <= 0x007F)) {
                utflen++;
            } else if (c > 0x07FF) {
                utflen += 3;
            } else {
                utflen += 2;
            }
        }

        buffer.writeByte((byte) ((utflen >>> 8) & 0xFF));
        buffer.writeByte((byte) ((utflen >>> 0) & 0xFF));

        int i = 0;
        for (i = 0; i < strlen; i++) {
            c = s.charAt(i);
            if (!((c >= 0x0001) && (c <= 0x007F))) {
                break;
            }
            buffer.writeByte((byte) c);
        }

        for (; i < strlen; i++) {
            c = s.charAt(i);
            if ((c >= 0x0001) && (c <= 0x007F)) {
                buffer.writeByte((byte) c);

            } else if (c > 0x07FF) {
                buffer.writeByte((byte) (0xE0 | ((c >> 12) & 0x0F)));
                buffer.writeByte((byte) (0x80 | ((c >> 6) & 0x3F)));
                buffer.writeByte((byte) (0x80 | ((c >> 0) & 0x3F)));
            } else {
                buffer.writeByte((byte) (0xC0 | ((c >> 6) & 0x1F)));
                buffer.writeByte((byte) (0x80 | ((c >> 0) & 0x3F)));
            }
        }
    }
}