/* * 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 hivemall.tools.datetime; import java.util.UUID; import javax.annotation.Nonnull; import javax.annotation.Nullable; import org.apache.hadoop.hive.ql.exec.Description; import org.apache.hadoop.hive.ql.exec.UDF; import org.apache.hadoop.hive.ql.udf.UDFType; import org.apache.hadoop.io.LongWritable; import org.apache.hadoop.io.Text; //@formatter:off @Description(name = "sessionize", value = "_FUNC_(long timeInSec, long thresholdInSec [, String subject])" + "- Returns a UUID string of a session.", extended = "SELECT \n" + " sessionize(time, 3600, ip_addr) as session_id, \n" + " time, ip_addr\n" + "FROM (\n" + " SELECT time, ipaddr \n" + " FROM weblog \n" + " DISTRIBUTE BY ip_addr, time SORT BY ip_addr, time DESC\n" + ") t1") //@formatter:on @UDFType(deterministic = false, stateful = true) public final class SessionizeUDF extends UDF { private long lastTime; @Nullable private Text lastSubject; @Nonnull private final Text sessionId = new Text(); @Nullable public Text evaluate(@Nullable LongWritable time, @Nullable LongWritable threshold) { if (time == null || threshold == null) { return null; } final long thisTime = time.get(); final long diff = thisTime - lastTime; if (diff < threshold.get()) { this.lastTime = thisTime; return sessionId; } sessionId.set(UUID.randomUUID().toString()); this.lastTime = time.get(); return sessionId; } @Nullable public Text evaluate(@Nullable LongWritable time, @Nullable LongWritable threshold, @Nullable Text subject) { if (time == null || threshold == null || subject == null) { return null; } if (subject.equals(lastSubject)) { final long thisTime = time.get(); final long diff = thisTime - lastTime; if (diff < threshold.get()) { this.lastTime = thisTime; return sessionId; } } else { if (lastSubject == null) { lastSubject = new Text(subject); } else { lastSubject.set(subject); } } sessionId.set(UUID.randomUUID().toString()); this.lastTime = time.get(); return sessionId; } }