| /* |
| * 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.druid.segment.column; |
| |
| import org.apache.druid.segment.data.ObjectStrategy; |
| |
| import javax.annotation.Nullable; |
| import java.nio.ByteBuffer; |
| |
| /** |
| * Default implementation of {@link TypeStrategy} for all {@link org.apache.druid.segment.serde.ComplexMetricSerde} |
| * implementations that just wraps the {@link ObjectStrategy} they are required to implement. |
| * |
| * This is not likely to be the most efficient way to do things, especially since writing must first produce a byte |
| * array before it can be written to the buffer, but it is cheap and should work correctly, which is important. |
| */ |
| public class ObjectStrategyComplexTypeStrategy<T> implements TypeStrategy<T> |
| { |
| private final ObjectStrategy<T> objectStrategy; |
| private final TypeSignature<?> typeSignature; |
| |
| public ObjectStrategyComplexTypeStrategy(ObjectStrategy<T> objectStrategy, TypeSignature<?> signature) |
| { |
| this.objectStrategy = objectStrategy; |
| this.typeSignature = signature; |
| } |
| |
| @Override |
| public int estimateSizeBytes(@Nullable T value) |
| { |
| byte[] bytes = objectStrategy.toBytes(value); |
| return bytes == null ? 0 : bytes.length; |
| } |
| |
| @Override |
| public T read(ByteBuffer buffer) |
| { |
| final int complexLength = buffer.getInt(); |
| ByteBuffer dupe = buffer.duplicate(); |
| dupe.limit(dupe.position() + complexLength); |
| return objectStrategy.fromByteBuffer(dupe, complexLength); |
| } |
| |
| @Override |
| public boolean readRetainsBufferReference() |
| { |
| // Can't guarantee that ObjectStrategy *doesn't* retain a reference. |
| return true; |
| } |
| |
| @Override |
| public int write(ByteBuffer buffer, T value, int maxSizeBytes) |
| { |
| TypeStrategies.checkMaxSize(buffer.remaining(), maxSizeBytes, typeSignature); |
| byte[] bytes = objectStrategy.toBytes(value); |
| final int sizeBytes = Integer.BYTES + bytes.length; |
| final int remaining = maxSizeBytes - sizeBytes; |
| if (remaining >= 0) { |
| buffer.putInt(bytes.length); |
| buffer.put(bytes, 0, bytes.length); |
| return sizeBytes; |
| } |
| return remaining; |
| } |
| |
| @Override |
| public int compare(T o1, T o2) |
| { |
| return objectStrategy.compare(o1, o2); |
| } |
| } |