Java tutorial
/** * * 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.util; import java.io.IOException; import java.util.NavigableSet; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.fs.FileStatus; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.fs.PathFilter; import org.apache.hadoop.hbase.HConstants; import org.apache.hadoop.hbase.regionserver.wal.HLogUtil; /** * Utility methods for interacting with the hbase.root file system. */ @InterfaceAudience.Private public final class FSVisitor { private static final Log LOG = LogFactory.getLog(FSVisitor.class); public interface RegionVisitor { void region(final String region) throws IOException; } public interface StoreFileVisitor { void storeFile(final String region, final String family, final String hfileName) throws IOException; } public interface RecoveredEditsVisitor { void recoveredEdits(final String region, final String logfile) throws IOException; } public interface LogFileVisitor { void logFile(final String server, final String logfile) throws IOException; } private FSVisitor() { // private constructor for utility class } /** * Iterate over the table store files * * @param fs {@link FileSystem} * @param tableDir {@link Path} to the table directory * @param visitor callback object to get the store files * @throws IOException if an error occurred while scanning the directory */ public static void visitRegions(final FileSystem fs, final Path tableDir, final RegionVisitor visitor) throws IOException { FileStatus[] regions = FSUtils.listStatus(fs, tableDir, new FSUtils.RegionDirFilter(fs)); if (regions == null) { LOG.info("No regions under directory:" + tableDir); return; } for (FileStatus region : regions) { visitor.region(region.getPath().getName()); } } /** * Iterate over the table store files * * @param fs {@link FileSystem} * @param tableDir {@link Path} to the table directory * @param visitor callback object to get the store files * @throws IOException if an error occurred while scanning the directory */ public static void visitTableStoreFiles(final FileSystem fs, final Path tableDir, final StoreFileVisitor visitor) throws IOException { FileStatus[] regions = FSUtils.listStatus(fs, tableDir, new FSUtils.RegionDirFilter(fs)); if (regions == null) { LOG.info("No regions under directory:" + tableDir); return; } for (FileStatus region : regions) { visitRegionStoreFiles(fs, region.getPath(), visitor); } } /** * Iterate over the region store files * * @param fs {@link FileSystem} * @param regionDir {@link Path} to the region directory * @param visitor callback object to get the store files * @throws IOException if an error occurred while scanning the directory */ public static void visitRegionStoreFiles(final FileSystem fs, final Path regionDir, final StoreFileVisitor visitor) throws IOException { FileStatus[] families = FSUtils.listStatus(fs, regionDir, new FSUtils.FamilyDirFilter(fs)); if (families == null) { LOG.info("No families under region directory:" + regionDir); return; } PathFilter fileFilter = new FSUtils.FileFilter(fs); for (FileStatus family : families) { Path familyDir = family.getPath(); String familyName = familyDir.getName(); // get all the storeFiles in the family FileStatus[] storeFiles = FSUtils.listStatus(fs, familyDir, fileFilter); if (storeFiles == null) { LOG.debug("No hfiles found for family: " + familyDir + ", skipping."); continue; } for (FileStatus hfile : storeFiles) { Path hfilePath = hfile.getPath(); visitor.storeFile(regionDir.getName(), familyName, hfilePath.getName()); } } } /** * Iterate over each region in the table and inform about recovered.edits * * @param fs {@link FileSystem} * @param tableDir {@link Path} to the table directory * @param visitor callback object to get the recovered.edits files * @throws IOException if an error occurred while scanning the directory */ public static void visitTableRecoveredEdits(final FileSystem fs, final Path tableDir, final FSVisitor.RecoveredEditsVisitor visitor) throws IOException { FileStatus[] regions = FSUtils.listStatus(fs, tableDir, new FSUtils.RegionDirFilter(fs)); if (regions == null) { LOG.info("No recoveredEdits regions under directory:" + tableDir); return; } for (FileStatus region : regions) { visitRegionRecoveredEdits(fs, region.getPath(), visitor); } } /** * Iterate over recovered.edits of the specified region * * @param fs {@link FileSystem} * @param regionDir {@link Path} to the Region directory * @param visitor callback object to get the recovered.edits files * @throws IOException if an error occurred while scanning the directory */ public static void visitRegionRecoveredEdits(final FileSystem fs, final Path regionDir, final FSVisitor.RecoveredEditsVisitor visitor) throws IOException { NavigableSet<Path> files = HLogUtil.getSplitEditFilesSorted(fs, regionDir); if (files == null || files.size() == 0) return; for (Path source : files) { // check to see if the file is zero length, in which case we can skip it FileStatus stat = fs.getFileStatus(source); if (stat.getLen() <= 0) continue; visitor.recoveredEdits(regionDir.getName(), source.getName()); } } /** * Iterate over hbase log files * * @param fs {@link FileSystem} * @param rootDir {@link Path} to the HBase root folder * @param visitor callback object to get the log files * @throws IOException if an error occurred while scanning the directory */ public static void visitLogFiles(final FileSystem fs, final Path rootDir, final LogFileVisitor visitor) throws IOException { Path logsDir = new Path(rootDir, HConstants.HREGION_LOGDIR_NAME); FileStatus[] logServerDirs = FSUtils.listStatus(fs, logsDir); if (logServerDirs == null) { LOG.info("No logs under directory:" + logsDir); return; } for (FileStatus serverLogs : logServerDirs) { String serverName = serverLogs.getPath().getName(); FileStatus[] hlogs = FSUtils.listStatus(fs, serverLogs.getPath()); if (hlogs == null) { LOG.debug("No hfiles found for server: " + serverName + ", skipping."); continue; } for (FileStatus hlogRef : hlogs) { visitor.logFile(serverName, hlogRef.getPath().getName()); } } } }