| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| BlockFactory |
|
| 1.0;1 |
| 1 | /* | |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one | |
| 3 | * or more contributor license agreements. See the NOTICE file | |
| 4 | * distributed with this work for additional information | |
| 5 | * regarding copyright ownership. The ASF licenses this file | |
| 6 | * to you under the Apache License, Version 2.0 (the | |
| 7 | * "License"); you may not use this file except in compliance | |
| 8 | * with the License. You may obtain a copy of the License at | |
| 9 | * | |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 11 | * | |
| 12 | * Unless required by applicable law or agreed to in writing, software | |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, | |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 15 | * See the License for the specific language governing permissions and | |
| 16 | * limitations under the License. | |
| 17 | */ | |
| 18 | package org.apache.giraph.block_app.framework; | |
| 19 | ||
| 20 | import java.util.List; | |
| 21 | ||
| 22 | import org.apache.giraph.block_app.framework.block.Block; | |
| 23 | import org.apache.giraph.conf.GiraphConfiguration; | |
| 24 | import org.apache.hadoop.conf.Configuration; | |
| 25 | ||
| 26 | /** | |
| 27 | * Class describing a particular application. | |
| 28 | * Everything except input and output should be fully encapsulated within | |
| 29 | * this class. For any application, it should be enough to only specify | |
| 30 | * particular BlockFactory. | |
| 31 | * | |
| 32 | * Given configuration, it creates a block that represents a full Giraph job. | |
| 33 | * | |
| 34 | * Recommended is to extend AbstractBlockFactory directly for most cases. | |
| 35 | * | |
| 36 | * @param <S> Execution stage type | |
| 37 | */ | |
| 38 | public interface BlockFactory<S> { | |
| 39 | /** | |
| 40 | * Based on provided configuration, updates it, such that all necessary | |
| 41 | * properties are initialized. | |
| 42 | */ | |
| 43 | void initConfig(GiraphConfiguration conf); | |
| 44 | ||
| 45 | /** | |
| 46 | * Create a block (representing a full Giraph job), based on the given | |
| 47 | * configuration. Configuration should be treated as immutable at this point. | |
| 48 | * | |
| 49 | * If there are issues in configuration, it is very cheap to throw | |
| 50 | * from this method - as Giraph job will not even start. | |
| 51 | * This function will be called two times - once before starting | |
| 52 | * of the Giraph job, to fail early if anything is incorrectly configured. | |
| 53 | * Second time will be on Master, which will return Block instance | |
| 54 | * on which createIterator will be called once, which should return | |
| 55 | * current application run. | |
| 56 | * initConfig will be called only once, before starting Giraph job itself. | |
| 57 | * Master will contain configuration already modified by initConfig. | |
| 58 | */ | |
| 59 | Block createBlock(GiraphConfiguration conf); | |
| 60 | ||
| 61 | /** | |
| 62 | * Create an empty instance of execution stage object. | |
| 63 | * | |
| 64 | * Can be used by application to be aware of what was executed before. | |
| 65 | * Most common example is counting iterations, or for having a boolean whether | |
| 66 | * some important event happened. | |
| 67 | * | |
| 68 | * Execution stage should be immutable object, with creating a new | |
| 69 | * object when different value is needed. | |
| 70 | */ | |
| 71 | S createExecutionStage(GiraphConfiguration conf); | |
| 72 | ||
| 73 | /** | |
| 74 | * Get special GC Java options. If returns null, default options are used. | |
| 75 | */ | |
| 76 | List<String> getGcJavaOpts(Configuration conf); | |
| 77 | ||
| 78 | /** | |
| 79 | * Register outputs to use during the application (vs output at the end of | |
| 80 | * the application), based on provided configuration. | |
| 81 | */ | |
| 82 | void registerOutputs(GiraphConfiguration conf); | |
| 83 | } |