| /** |
| * |
| * 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.hbase.regionserver; |
| |
| import java.io.IOException; |
| import java.util.Collection; |
| |
| import org.apache.hadoop.hbase.classification.InterfaceAudience; |
| |
| /** |
| * Utility functions for region server storage layer. |
| */ |
| @InterfaceAudience.Private |
| public class StoreUtils { |
| /** |
| * Creates a deterministic hash code for store file collection. |
| */ |
| public static Integer getDeterministicRandomSeed(final Collection<StoreFile> files) { |
| if (files != null && !files.isEmpty()) { |
| return files.iterator().next().getPath().getName().hashCode(); |
| } |
| return null; |
| } |
| |
| /** |
| * Determines whether any files in the collection are references. |
| * @param files The files. |
| */ |
| public static boolean hasReferences(final Collection<StoreFile> files) { |
| if (files != null) { |
| for (StoreFile hsf: files) { |
| if (hsf.isReference()) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Gets lowest timestamp from candidate StoreFiles |
| */ |
| public static long getLowestTimestamp(final Collection<StoreFile> candidates) |
| throws IOException { |
| long minTs = Long.MAX_VALUE; |
| for (StoreFile storeFile : candidates) { |
| minTs = Math.min(minTs, storeFile.getModificationTimeStamp()); |
| } |
| return minTs; |
| } |
| |
| /** |
| * Gets the largest file (with reader) out of the list of files. |
| * @param candidates The files to choose from. |
| * @return The largest file; null if no file has a reader. |
| */ |
| static StoreFile getLargestFile(final Collection<StoreFile> candidates) { |
| long maxSize = -1L; |
| StoreFile largestSf = null; |
| for (StoreFile sf : candidates) { |
| StoreFileReader r = sf.getReader(); |
| if (r == null) continue; |
| long size = r.length(); |
| if (size > maxSize) { |
| maxSize = size; |
| largestSf = sf; |
| } |
| } |
| return largestSf; |
| } |
| } |