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.time.Duration; 022 023import org.nuxeo.lib.stream.log.Latency; 024 025/** 026 * Run a topology of computations according to some settings. 027 * 028 * @since 9.3 029 */ 030public interface StreamProcessor { 031 032 /** 033 * Initialize streams, but don't run the computations 034 */ 035 StreamProcessor init(Topology topology, Settings settings); 036 037 /** 038 * Run the initialized computations. 039 */ 040 void start(); 041 042 /** 043 * Try to stop computations gracefully after processing a record or a timer within the timeout duration. If this can 044 * not be done within the timeout, shutdown and returns false. 045 */ 046 boolean stop(Duration timeout); 047 048 /** 049 * Stop computations when input streams are empty. The timeout is applied for each computation, the total duration 050 * can be up to nb computations * timeout 051 * <p/> 052 * Returns {@code true} if computations are stopped during the timeout delay. 053 */ 054 boolean drainAndStop(Duration timeout); 055 056 /** 057 * Shutdown immediately. 058 */ 059 void shutdown(); 060 061 /** 062 * Returns the low watermark for the computation. Any message with an offset below the low watermark has been 063 * processed by this computation and its ancestors. The returned watermark is local to this processing node, if the 064 * computation is distributed the global low watermark is the minimum of all nodes low watermark. 065 */ 066 long getLowWatermark(String computationName); 067 068 /** 069 * Returns the low watermark for all the computations of the topology. Any message with an offset below the low 070 * watermark has been processed. The returned watermark is local to this processing node. 071 */ 072 long getLowWatermark(); 073 074 /** 075 * Returns the latency for a computation. This works also for distributed computations. 076 * 077 * @since 10.1 078 */ 079 Latency getLatency(String computationName); 080 081 /** 082 * Returns true if all messages with a lower timestamp has been processed by the topology. 083 */ 084 boolean isDone(long timestamp); 085 086 /** 087 * Wait for the computations to have assigned partitions ready to process records. The processor must be started. 088 * This is useful for writing unit test. 089 * <p/> 090 * Returns {@code true} if all computations have assigned partitions during the timeout delay. 091 */ 092 boolean waitForAssignments(Duration timeout) throws InterruptedException; 093 094 /** 095 * True if there is no active processing threads. 096 * 097 * @since 10.1 098 */ 099 boolean isTerminated(); 100}