org.hbase.async.BitComparator Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of asynchbase Show documentation
An alternative HBase client library for applications requiring fully asynchronous, non-blocking and thread-safe HBase connectivity.
There is a newer version: 1.8.2
Show newest version
/*
 * Copyright (C) 2014  The Async HBase Authors.  All rights reserved.
 * This file is part of Async HBase.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *   - Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   - Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *   - Neither the name of the StumbleUpon nor the names of its contributors
 *     may be used to endorse or promote products derived from this software
 *     without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package org.hbase.async;

import com.google.protobuf.ByteString;
import org.jboss.netty.buffer.ChannelBuffer;

import org.hbase.async.generated.ComparatorPB;

/**
 * A bitwise comparator used in comparison filters. Performs the specified
 * bitwise operation on each of the bytes with the specified byte array.
 * Returns whether the result is non-zero.
 * 
 * Only EQUAL and NOT_EQUAL comparisons are valid with this comparator.
 * @since 1.6
 */
public final class BitComparator extends FilterComparator {

  /** Bit operators. */
  public enum BitwiseOp {
    /** Logical 'and'. */
    AND,
    /** Logical 'or'.  */
    OR,
    /** Logical 'xor'. */
    XOR,
  }

  private static final byte[] NAME =
      Bytes.UTF8("org.apache.hadoop.hbase.filter.BitComparator");
  private static final byte CODE = 48;

  private final byte[] value;
  private final BitwiseOp bit_operator;

  public BitComparator(byte[] value, BitwiseOp bitOperator) {
    this.value = value;
    this.bit_operator = bitOperator;
  }

  public byte[] value() {
    return value.clone();
  }

  public BitwiseOp bitwiseOperator() {
    return bit_operator;
  }

  @Override
  byte[] name() {
    return NAME;
  }

  @Override
  ComparatorPB.Comparator toProtobuf() {
    ByteString byte_string = ComparatorPB
        .BitComparator
        .newBuilder()
        .setComparable(
            ComparatorPB
                .ByteArrayComparable
                .newBuilder()
                .setValue(Bytes.wrap(value)))
        .setBitwiseOp(ComparatorPB
            .BitComparator.BitwiseOp.valueOf(bit_operator.name()))
        .build()
        .toByteString();
    return super.toProtobuf(byte_string);
  }

  @Override
  void serializeOld(ChannelBuffer buf) {
    super.serializeOld(buf);              // super.predictSerializedSize()
    // Write class code
    buf.writeByte(CODE);                  // 1
    // Write value
    HBaseRpc.writeByteArray(buf, value);  // 3 + value.length
    // Write op
    final byte[] op_name = Bytes.UTF8(bit_operator.name());
    buf.writeShort(op_name.length);       // 2
    buf.writeBytes(op_name);              // op_name.length
  }

  @Override
  int predictSerializedSize() {
    return 1 + 3 + value.length + 2 + Bytes.UTF8(bit_operator.name()).length;
  }

  @Override
  public String toString() {
    return String.format("%s(%s)",
        getClass().getSimpleName(),
        Bytes.pretty(value));
  }
}