| /* |
| * 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.jackrabbit.oak.segment.file; |
| |
| import static java.lang.String.format; |
| import static org.apache.jackrabbit.oak.segment.file.PrintableBytes.newPrintableBytes; |
| |
| class TailSizeDeltaEstimationStrategy implements EstimationStrategy { |
| |
| @Override |
| public EstimationResult estimate(Context context) { |
| if (context.getSizeDelta() == 0) { |
| return new EstimationResult(true, "Estimation skipped because the size delta value equals 0"); |
| } |
| |
| long previousSize = readPreviousSize(context); |
| |
| if (previousSize < 0) { |
| return new EstimationResult(true, "Estimation skipped because of missing gc journal data (expected on first run)"); |
| } |
| |
| long gain = context.getCurrentSize() - previousSize; |
| boolean gcNeeded = gain > context.getSizeDelta(); |
| String gcInfo = format( |
| "Segmentstore size has increased since the last tail garbage collection from %s to %s, an increase of %s or %s%%. ", |
| newPrintableBytes(previousSize), |
| newPrintableBytes(context.getCurrentSize()), |
| newPrintableBytes(gain), |
| 100 * gain / previousSize |
| ); |
| if (gcNeeded) { |
| gcInfo = gcInfo + format( |
| "This is greater than sizeDeltaEstimation=%s, so running garbage collection", |
| newPrintableBytes(context.getSizeDelta()) |
| ); |
| } else { |
| gcInfo = gcInfo + format( |
| "This is less than sizeDeltaEstimation=%s, so skipping garbage collection", |
| newPrintableBytes(context.getSizeDelta()) |
| ); |
| } |
| return new EstimationResult(gcNeeded, gcInfo); |
| } |
| |
| private long readPreviousSize(Context context) { |
| return context.getGCJournal().read().getRepoSize(); |
| } |
| |
| } |