/*
*
* 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.hadoop.hbase.filter;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import org.apache.hadoop.hbase.ByteBufferCell;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.exceptions.DeserializationException;
import org.apache.hadoop.hbase.shaded.protobuf.generated.FilterProtos;
import org.apache.hadoop.hbase.util.Bytes;
import com.google.common.base.Preconditions;
import org.apache.hadoop.hbase.shaded.com.google.protobuf.InvalidProtocolBufferException;
/**
* A filter that will only return the key component of each KV (the value will
* be rewritten as empty).
* <p>
* This filter can be used to grab all of the keys without having to also grab
* the values.
*/
@InterfaceAudience.Public
public class KeyOnlyFilter extends FilterBase {
boolean lenAsVal;
public KeyOnlyFilter() { this(false); }
public KeyOnlyFilter(boolean lenAsVal) { this.lenAsVal = lenAsVal; }
@Override
public boolean filterRowKey(Cell cell) throws IOException {
// Impl in FilterBase might do unnecessary copy for Off heap backed Cells.
return false;
}
@Override
public Cell transformCell(Cell cell) {
return createKeyOnlyCell(cell);
}
private Cell createKeyOnlyCell(Cell c) {
if (c instanceof ByteBufferCell) {
return new KeyOnlyByteBufferCell((ByteBufferCell) c, lenAsVal);
} else {
return new KeyOnlyCell(c, lenAsVal);
}
}
@Override
public ReturnCode filterKeyValue(Cell ignored) throws IOException {
return ReturnCode.INCLUDE;
}
public static Filter createFilterFromArguments(ArrayList<byte []> filterArguments) {
Preconditions.checkArgument((filterArguments.isEmpty() || filterArguments.size() == 1),
"Expected: 0 or 1 but got: %s", filterArguments.size());
KeyOnlyFilter filter = new KeyOnlyFilter();
if (filterArguments.size() == 1) {
filter.lenAsVal = ParseFilter.convertByteArrayToBoolean(filterArguments.get(0));
}
return filter;
}
/**
* @return The filter serialized using pb
*/
public byte [] toByteArray() {
FilterProtos.KeyOnlyFilter.Builder builder =
FilterProtos.KeyOnlyFilter.newBuilder();
builder.setLenAsVal(this.lenAsVal);
return builder.build().toByteArray();
}
/**
* @param pbBytes A pb serialized {@link KeyOnlyFilter} instance
* @return An instance of {@link KeyOnlyFilter} made from <code>bytes</code>
* @throws DeserializationException
* @see #toByteArray
*/
public static KeyOnlyFilter parseFrom(final byte [] pbBytes)
throws DeserializationException {
FilterProtos.KeyOnlyFilter proto;
try {
proto = FilterProtos.KeyOnlyFilter.parseFrom(pbBytes);
} catch (InvalidProtocolBufferException e) {
throw new DeserializationException(e);
}
return new KeyOnlyFilter(proto.getLenAsVal());
}
/**
* @param other
* @return true if and only if the fields of the filter that are serialized
* are equal to the corresponding fields in other. Used for testing.
*/
boolean areSerializedFieldsEqual(Filter o) {
if (o == this) return true;
if (!(o instanceof KeyOnlyFilter)) return false;
KeyOnlyFilter other = (KeyOnlyFilter)o;
return this.lenAsVal == other.lenAsVal;
}
static class KeyOnlyCell implements Cell {
private Cell cell;
private boolean lenAsVal;
public KeyOnlyCell(Cell c, boolean lenAsVal) {
this.cell = c;
this.lenAsVal = lenAsVal;
}
@Override
public byte[] getRowArray() {
return cell.getRowArray();
}
@Override
public int getRowOffset() {
return cell.getRowOffset();
}
@Override
public short getRowLength() {
return cell.getRowLength();
}
@Override
public byte[] getFamilyArray() {
return cell.getFamilyArray();
}
@Override
public int getFamilyOffset() {
return cell.getFamilyOffset();
}
@Override
public byte getFamilyLength() {
return cell.getFamilyLength();
}
@Override
public byte[] getQualifierArray() {
return cell.getQualifierArray();
}
@Override
public int getQualifierOffset() {
return cell.getQualifierOffset();
}
@Override
public int getQualifierLength() {
return cell.getQualifierLength();
}
@Override
public long getTimestamp() {
return cell.getTimestamp();
}
@Override
public byte getTypeByte() {
return cell.getTypeByte();
}
@Override
public long getSequenceId() {
return 0;
}
@Override
public byte[] getValueArray() {
if (lenAsVal) {
return Bytes.toBytes(cell.getValueLength());
} else {
return HConstants.EMPTY_BYTE_ARRAY;
}
}
@Override
public int getValueOffset() {
return 0;
}
@Override
public int getValueLength() {
if (lenAsVal) {
return Bytes.SIZEOF_INT;
} else {
return 0;
}
}
@Override
public byte[] getTagsArray() {
return HConstants.EMPTY_BYTE_ARRAY;
}
@Override
public int getTagsOffset() {
return 0;
}
@Override
public int getTagsLength() {
return 0;
}
}
static class KeyOnlyByteBufferCell extends ByteBufferCell {
private ByteBufferCell cell;
private boolean lenAsVal;
public KeyOnlyByteBufferCell(ByteBufferCell c, boolean lenAsVal) {
this.cell = c;
this.lenAsVal = lenAsVal;
}
@Override
public byte[] getRowArray() {
return cell.getRowArray();
}
@Override
public int getRowOffset() {
return cell.getRowOffset();
}
@Override
public short getRowLength() {
return cell.getRowLength();
}
@Override
public byte[] getFamilyArray() {
return cell.getFamilyArray();
}
@Override
public int getFamilyOffset() {
return cell.getFamilyOffset();
}
@Override
public byte getFamilyLength() {
return cell.getFamilyLength();
}
@Override
public byte[] getQualifierArray() {
return cell.getQualifierArray();
}
@Override
public int getQualifierOffset() {
return cell.getQualifierOffset();
}
@Override
public int getQualifierLength() {
return cell.getQualifierLength();
}
@Override
public long getTimestamp() {
return cell.getTimestamp();
}
@Override
public byte getTypeByte() {
return cell.getTypeByte();
}
@Override
public long getSequenceId() {
return 0;
}
@Override
public byte[] getValueArray() {
if (lenAsVal) {
return Bytes.toBytes(cell.getValueLength());
} else {
return HConstants.EMPTY_BYTE_ARRAY;
}
}
@Override
public int getValueOffset() {
return 0;
}
@Override
public int getValueLength() {
if (lenAsVal) {
return Bytes.SIZEOF_INT;
} else {
return 0;
}
}
@Override
public byte[] getTagsArray() {
return HConstants.EMPTY_BYTE_ARRAY;
}
@Override
public int getTagsOffset() {
return 0;
}
@Override
public int getTagsLength() {
return 0;
}
@Override
public ByteBuffer getRowByteBuffer() {
return cell.getRowByteBuffer();
}
@Override
public int getRowPosition() {
return cell.getRowPosition();
}
@Override
public ByteBuffer getFamilyByteBuffer() {
return cell.getFamilyByteBuffer();
}
@Override
public int getFamilyPosition() {
return cell.getFamilyPosition();
}
@Override
public ByteBuffer getQualifierByteBuffer() {
return cell.getQualifierByteBuffer();
}
@Override
public int getQualifierPosition() {
return cell.getQualifierPosition();
}
@Override
public ByteBuffer getValueByteBuffer() {
if (lenAsVal) {
return ByteBuffer.wrap(Bytes.toBytes(cell.getValueLength()));
} else {
return HConstants.EMPTY_BYTE_BUFFER;
}
}
@Override
public int getValuePosition() {
return 0;
}
@Override
public ByteBuffer getTagsByteBuffer() {
return HConstants.EMPTY_BYTE_BUFFER;
}
@Override
public int getTagsPosition() {
return 0;
}
}
}