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ASF GitHub Bot commented on DRILL-4134: --------------------------------------- Github user adeneche commented on a diff in the pull request: https://github.com/apache/drill/pull/283#discussion_r46585304 --- Diff: common/src/main/java/org/apache/drill/common/HistoricalLog.java --- @@ -0,0 +1,179 @@ +/** + * 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.drill.common; + +import java.util.Arrays; +import java.util.LinkedList; + +import org.slf4j.Logger; + +/** + * Utility class that can be used to log activity within a class + * for later logging and debugging. Supports recording events and + * recording the stack at the time they occur. + */ +public class HistoricalLog { + private static class Event { + private final String note; // the event text + private final StackTrace stackTrace; // where the event occurred + + public Event(final String note) { + this.note = note; + stackTrace = new StackTrace(); + } + } + + private final LinkedList<Event> history = new LinkedList<>(); + private final String idString; // the formatted id string + private Event firstEvent; // the first stack trace recorded + private final int limit; // the limit on the number of events kept + + /** + * Constructor. The format string will be formatted and have its arguments + * substituted at the time this is called. + * + * @param idStringFormat {@link String#format} format string that can be used + * to identify this object in a log. Including some kind of unique identifier + * that can be associated with the object instance is best. + * @param args for the format string, or nothing if none are required + */ + public HistoricalLog(final String idStringFormat, Object... args) { + this(Integer.MAX_VALUE, idStringFormat, args); + } + + /** + * Constructor. The format string will be formatted and have its arguments + * substituted at the time this is called. + * + * <p>This form supports the specification of a limit that will limit the + * number of historical entries kept (which keeps down the amount of memory + * used). With the limit, the first entry made is always kept (under the + * assumption that this is the creation site of the object, which is usually + * interesting), and then up to the limit number of entries are kept after that. + * Each time a new entry is made, the oldest that is not the first is dropped. + * </p> + * + * @param limit the maximum number of historical entries that will be kept, + * not including the first entry made + * @param idStringFormat {@link String#format} format string that can be used + * to identify this object in a log. Including some kind of unique identifier + * that can be associated with the object instance is best. + * @param args for the format string, or nothing if none are required + */ + public HistoricalLog(final int limit, final String idStringFormat, Object... args) { + this.limit = limit; + this.idString = String.format(idStringFormat, args); + } + + /** + * Record an event. Automatically captures the stack trace at the time this is + * called. The format string will be formatted and have its arguments substituted + * at the time this is called. + * + * @param noteFormat {@link String#format} format string that describes the event + * @param args for the format string, or nothing if none are required + */ + public synchronized void recordEvent(final String noteFormat, Object... args) { --- End diff -- would it make sense to also store a timestamp for each event ? This would help debugging sliced buffers > Incorporate remaining patches from DRILL-1942 Allocator refactor > ---------------------------------------------------------------- > > Key: DRILL-4134 > URL: https://issues.apache.org/jira/browse/DRILL-4134 > Project: Apache Drill > Issue Type: Sub-task > Components: Execution - Flow > Reporter: Jacques Nadeau > Assignee: Jacques Nadeau > Fix For: 1.4.0 > > -- This message was sent by Atlassian JIRA (v6.3.4#6332)