001/* 002 * (C) Copyright 2017 Nuxeo SA (http://nuxeo.com/) and others. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 * 016 * Contributors: 017 * bdelbosc 018 */ 019package org.nuxeo.lib.stream.computation; 020 021import java.util.stream.Collectors; 022import java.util.stream.IntStream; 023 024import org.apache.commons.logging.Log; 025import org.apache.commons.logging.LogFactory; 026 027/** 028 * An abstract {@link Computation} that manages the metadata init. 029 * <p> 030 * By convention the inputs streams are named internally: i1, i2 ... 031 * <p> 032 * and the output streams are named: o1, o2 ... 033 * 034 * @since 9.3 035 */ 036public abstract class AbstractComputation implements Computation { 037 private static final Log log = LogFactory.getLog(AbstractComputation.class); 038 039 protected final ComputationMetadata metadata; 040 041 public static final String INPUT_1 = "i1"; 042 043 public static final String INPUT_2 = "i2"; 044 045 public static final String INPUT_3 = "i3"; 046 047 public static final String OUTPUT_1 = "o1"; 048 049 public static final String OUTPUT_2 = "o2"; 050 051 public static final String OUTPUT_3 = "o3"; 052 053 public static final String OUTPUT_4 = "o4"; 054 055 // @since 11.1 can be used as input for single producer pattern 056 public static final String INPUT_NULL = "input/null"; 057 058 /** 059 * Creates a computation with the requested number of input and output streams. 060 * 061 * @since 10.3 062 */ 063 public AbstractComputation(String name, int nbInputStreams, int nbOutputStreams) { 064 this.metadata = new ComputationMetadata(name, 065 IntStream.range(1, nbInputStreams + 1).boxed().map(i -> "i" + i).collect(Collectors.toSet()), 066 IntStream.range(1, nbOutputStreams + 1).boxed().map(i -> "o" + i).collect(Collectors.toSet())); 067 } 068 069 @Override 070 public void init(ComputationContext context) { 071 072 } 073 074 @Override 075 public void processTimer(ComputationContext context, String key, long timestamp) { 076 077 } 078 079 @Override 080 public ComputationMetadata metadata() { 081 return metadata; 082 } 083 084 @Override 085 public void processRetry(ComputationContext context, Throwable failure) { 086 log.warn(String.format("Computation: %s fails last record: %s, retrying ...", metadata.name(), 087 context.getLastOffset()), failure); 088 } 089 090 @Override 091 public void processFailure(ComputationContext context, Throwable failure) { 092 log.error(String.format("Computation: %s fails last record: %s, after retries.", metadata.name(), 093 context.getLastOffset()), failure); 094 } 095}