| /** |
| * 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.hadoop.hdfs.tools.offlineImageViewer; |
| |
| import java.io.IOException; |
| import java.util.HashMap; |
| import java.util.Map.Entry; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| |
| /** |
| * File name distribution visitor. |
| * <p> |
| * It analyzes file names in fsimage and prints the following information: |
| * <li>Number of unique file names</li> |
| * <li>Number file names and the corresponding number range of files that use |
| * these same names</li> |
| * <li>Heap saved if the file name objects are reused</li> |
| */ |
| @InterfaceAudience.Private |
| public class NameDistributionVisitor extends TextWriterImageVisitor { |
| HashMap<String, Integer> counts = new HashMap<String, Integer>(); |
| |
| public NameDistributionVisitor(String filename, boolean printToScreen) |
| throws IOException { |
| super(filename, printToScreen); |
| } |
| |
| @Override |
| void finish() throws IOException { |
| final int BYTEARRAY_OVERHEAD = 24; |
| |
| write("Total unique file names " + counts.size()); |
| // Columns: Frequency of file occurrence, savings in heap, total files using |
| // the name and number of file names |
| final long stats[][] = { { 100000, 0, 0, 0 }, |
| { 10000, 0, 0, 0 }, |
| { 1000, 0, 0, 0 }, |
| { 100, 0, 0, 0 }, |
| { 10, 0, 0, 0 }, |
| { 5, 0, 0, 0 }, |
| { 4, 0, 0, 0 }, |
| { 3, 0, 0, 0 }, |
| { 2, 0, 0, 0 }}; |
| |
| int highbound = Integer.MIN_VALUE; |
| for (Entry<String, Integer> entry : counts.entrySet()) { |
| highbound = Math.max(highbound, entry.getValue()); |
| for (int i = 0; i < stats.length; i++) { |
| if (entry.getValue() >= stats[i][0]) { |
| stats[i][1] += (BYTEARRAY_OVERHEAD + entry.getKey().length()) |
| * (entry.getValue() - 1); |
| stats[i][2] += entry.getValue(); |
| stats[i][3]++; |
| break; |
| } |
| } |
| } |
| |
| long lowbound = 0; |
| long totalsavings = 0; |
| for (long[] stat : stats) { |
| lowbound = stat[0]; |
| totalsavings += stat[1]; |
| String range = lowbound == highbound ? " " + lowbound : |
| " between " + lowbound + "-" + highbound; |
| write("\n" + stat[3] + " names are used by " + stat[2] + " files" |
| + range + " times. Heap savings ~" + stat[1] + " bytes."); |
| highbound = (int) stat[0] - 1; |
| } |
| write("\n\nTotal saved heap ~" + totalsavings + "bytes.\n"); |
| super.finish(); |
| } |
| |
| @Override |
| void visit(ImageElement element, String value) throws IOException { |
| if (element == ImageElement.INODE_PATH) { |
| String filename = value.substring(value.lastIndexOf("/") + 1); |
| if (counts.containsKey(filename)) { |
| counts.put(filename, counts.get(filename) + 1); |
| } else { |
| counts.put(filename, 1); |
| } |
| } |
| } |
| |
| @Override |
| void leaveEnclosingElement() throws IOException { |
| } |
| |
| @Override |
| void start() throws IOException { |
| } |
| |
| @Override |
| void visitEnclosingElement(ImageElement element) throws IOException { |
| } |
| |
| @Override |
| void visitEnclosingElement(ImageElement element, ImageElement key, |
| String value) throws IOException { |
| } |
| } |