org.leveldb.util.ByteArrayBuilder.java Source code

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Here is the source code for org.leveldb.util.ByteArrayBuilder.java

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/*
 * Copyright 2012 Andrey Vityuk
 *
 * 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 org.leveldb.util;

import com.google.common.primitives.Ints;
import com.google.common.primitives.Longs;
import com.google.common.primitives.Shorts;
import it.unimi.dsi.fastutil.bytes.ByteArrays;

import java.nio.ByteBuffer;
import java.util.Arrays;

public final class ByteArrayBuilder {
    private static final int DEFAULT_INITIAL_CAPACITY = 10;
    private static final ByteEncoder DEFAULT_BYTE_ENCODER = ByteEncoder.bigEndian();

    private final ByteEncoder encoder;
    private byte[] data;
    private int size;

    public ByteArrayBuilder(ByteEncoder encoder, int initialCapacity) {
        this.encoder = encoder;
        data = new byte[initialCapacity];
    }

    public ByteArrayBuilder(ByteEncoder encoder) {
        this(encoder, DEFAULT_INITIAL_CAPACITY);
    }

    public ByteArrayBuilder(int initialCapacity) {
        this(DEFAULT_BYTE_ENCODER, initialCapacity);
    }

    public ByteArrayBuilder() {
        this(DEFAULT_BYTE_ENCODER, DEFAULT_INITIAL_CAPACITY);
    }

    public void ensureCapacity(int capacity) {
        data = ByteArrays.grow(data, capacity);
    }

    public void ensureAdditionalCapacity(int capacity) {
        ensureCapacity(size + capacity);
    }

    public void extendToSize(int size) {
        if (this.size < size) {
            this.size = size;
            ensureCapacity(size);
        }
    }

    public int size() {
        return size;
    }

    public void trimToSize() {
        data = ByteArrays.trim(data, size);
    }

    public void clear() {
        Arrays.fill(data, (byte) 0);
        size = 0;
    }

    public void setByte(int offset, byte value) {
        data[offset] = value;
    }

    public byte getByte(int offset) {
        return data[offset];
    }

    public void setShort(int offset, short value) {
        encoder.encodeShort(data, offset, value);
    }

    public short getShort(int offset) {
        return encoder.decodeShort(data, offset);
    }

    public void setInt(int offset, int value) {
        encoder.encodeInt(data, offset, value);
    }

    public int getInt(int offset) {
        return encoder.decodeInt(data, offset);
    }

    public void setLong(int offset, long value) {
        encoder.encodeLong(data, offset, value);
    }

    public long getLong(int offset) {
        return encoder.decodeLong(data, offset);
    }

    public void setBytes(int offset, byte[] value) {
        System.arraycopy(value, offset, data, size, value.length);
    }

    public void appendByte(byte value) {
        ensureAdditionalCapacity(1);
        setByte(size, value);
        size += 1;
    }

    public void appendShort(short value) {
        ensureAdditionalCapacity(Shorts.BYTES);
        setShort(size, value);
        size += Shorts.BYTES;
    }

    public void appendInt(int value) {
        ensureAdditionalCapacity(Ints.BYTES);
        setInt(size, value);
        size += Ints.BYTES;
    }

    public void appendLong(long value) {
        ensureAdditionalCapacity(Longs.BYTES);
        setLong(size, value);
        size += Longs.BYTES;
    }

    public void appendBytes(byte[] value) {
        ensureAdditionalCapacity(value.length);
        setBytes(size, value);
        size += value.length;
    }

    public byte[] toArray() {
        return Arrays.copyOf(data, size);
    }

    public ByteBuffer asByteBuffer() {
        return ByteBuffer.wrap(data, 0, size).order(encoder.getByteOrder()).asReadOnlyBuffer();
    }
}