com.moilioncircle.redis.replicator.util.ByteBuilder Maven / Gradle / Ivy

Go to download
/*
 * Copyright 2016-2018 Leon Chen
 *
 * Licensed 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 com.moilioncircle.redis.replicator.util;

import static com.moilioncircle.redis.replicator.util.Buffers.flip;
import static java.nio.ByteBuffer.wrap;

import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;

/**
 * @author Leon Chen
 * @since 2.1.0
 */
//@NonThreadSafe
public class ByteBuilder {
    
    private int total = 0;
    private final ByteBuffer buffer;
    private final List list = new ArrayList<>();

    private ByteBuilder(int cap) {
        this.buffer = ByteBuffer.allocate(cap);
    }

    public static ByteBuilder allocate(int cap) {
        return new ByteBuilder(cap);
    }

    public void put(byte b) {
        total++;
        if (buffer.hasRemaining()) {
            buffer.put(b);
        } else {
            byte[] temp = new byte[buffer.capacity()];
            System.arraycopy(buffer.array(), 0, temp, 0, buffer.capacity());
            list.add(wrap(temp));
            Buffers.clear(buffer);
            buffer.put(b);
        }
    }
    
    /**
     * @param bytes bytes
     * @since 3.5.5
     */
    public void put(byte[] bytes) {
        put(bytes, 0, bytes.length);
    }
    
    /**
     * @since 3.5.5
     * @param bytes bytes
     * @param offset offset
     * @param length length
     */
    public void put(byte[] bytes, int offset, int length) {
        for (int i = offset; i < length; i++) {
            put(bytes[i]);
        }
    }
    
    /**
     * @param buf buf
     * @since 3.5.5
     */
    public void put(ByteBuffer buf) {
        put(buf.array(), buf.position(), buf.limit());
    }
    
    public int length() {
        return total;
    }
    
    public byte[] array() {
        int len = total, offset = 0;
        byte[] ary = new byte[len];
        if (len < buffer.capacity()) {
            System.arraycopy(buffer.array(), 0, ary, offset, len);
            return ary;
        }
        for (ByteBuffer buf : list) {
            int length = buf.remaining();
            System.arraycopy(buf.array(), 0, ary, offset, length);
            offset += length;
            len -= length;
        }
        if (len > 0) System.arraycopy(buffer.array(), 0, ary, offset, len);
        return ary;
    }
    
    /**
     * @since 3.5.5
     * @return list buffers
     */
    public List buffers() {
        List r = new ArrayList<>(list.size() + 1);
        for (ByteBuffer buf : list) r.add(buf.duplicate());
        r.add(flip(this.buffer.duplicate()));
        return r;
    }
    
    public void clear() {
        total = 0;
        list.clear();
        Buffers.clear(buffer);
    }

    @Override
    public String toString() {
        return Strings.toString(array());
    }
}