| /** |
| * 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.crunch; |
| |
| import com.google.common.base.Preconditions; |
| |
| /** |
| * Options for controlling how a {@code PCollection<T>} is cached for subsequent processing. Different pipeline |
| * execution frameworks may use some or all of these options when deciding how to cache a given {@code PCollection} |
| * depending on the implementation details of the framework. |
| */ |
| public class CachingOptions { |
| |
| private final boolean useDisk; |
| private final boolean useMemory; |
| private final boolean deserialized; |
| private final int replicas; |
| |
| private CachingOptions( |
| boolean useDisk, |
| boolean useMemory, |
| boolean deserialized, |
| int replicas) { |
| this.useDisk = useDisk; |
| this.useMemory = useMemory; |
| this.deserialized = deserialized; |
| this.replicas = replicas; |
| } |
| |
| /** |
| * Whether the framework may cache data on disk. |
| */ |
| public boolean useDisk() { |
| return useDisk; |
| } |
| |
| /** |
| * Whether the framework may cache data in memory without writing it to disk. |
| */ |
| public boolean useMemory() { |
| return useMemory; |
| } |
| |
| /** |
| * Whether the data should remain deserialized in the cache, which trades off CPU processing time |
| * for additional storage overhead. |
| */ |
| public boolean deserialized() { |
| return deserialized; |
| } |
| |
| /** |
| * Returns the number of replicas of the data that should be maintained in the cache. |
| */ |
| public int replicas() { |
| return replicas; |
| } |
| |
| /** |
| * Creates a new {@link Builder} instance to use for specifying the caching options for a particular |
| * {@code PCollection<T>}. |
| * @return |
| */ |
| public static Builder builder() { |
| return new CachingOptions.Builder(); |
| } |
| |
| /** |
| * An instance of {@code CachingOptions} with the default caching settings. |
| */ |
| public static final CachingOptions DEFAULT = CachingOptions.builder().build(); |
| |
| /** |
| * A Builder class to use for setting the {@code CachingOptions} for a {@link PCollection}. The default |
| * settings are to keep a single replica of the data deserialized in memory, without writing to disk |
| * unless it is required due to resource limitations. |
| */ |
| public static class Builder { |
| private boolean useDisk = false; |
| private boolean useMemory = true; |
| private boolean deserialized = true; |
| private int replicas = 1; |
| |
| public Builder() {} |
| |
| public Builder useMemory(boolean useMemory) { |
| this.useMemory = useMemory; |
| return this; |
| } |
| |
| public Builder useDisk(boolean useDisk) { |
| this.useDisk = useDisk; |
| return this; |
| } |
| |
| public Builder deserialized(boolean deserialized) { |
| this.deserialized = deserialized; |
| return this; |
| } |
| |
| public Builder replicas(int replicas) { |
| Preconditions.checkArgument(replicas > 0); |
| this.replicas = replicas; |
| return this; |
| } |
| |
| public CachingOptions build() { |
| return new CachingOptions(useDisk, useMemory, deserialized, replicas); |
| } |
| } |
| } |