Java tutorial
package com.bigdata.dastor.streaming; /* * * 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. * */ import java.io.*; import java.net.InetAddress; import java.util.HashMap; import java.util.HashSet; import java.util.Map; import java.util.Set; import org.apache.commons.lang.StringUtils; import org.apache.log4j.Logger; import com.bigdata.dastor.config.DatabaseDescriptor; import com.bigdata.dastor.db.ColumnFamilyStore; import com.bigdata.dastor.db.Table; import com.bigdata.dastor.net.IVerbHandler; import com.bigdata.dastor.net.Message; import com.bigdata.dastor.net.MessagingService; import com.bigdata.dastor.service.StorageService; import com.bigdata.dastor.streaming.StreamInManager; import com.bigdata.dastor.streaming.StreamInitiateMessage; import com.bigdata.dastor.utils.FBUtilities; public class StreamInitiateVerbHandler implements IVerbHandler { private static Logger logger = Logger.getLogger(StreamInitiateVerbHandler.class); /* * Here we handle the StreamInitiateMessage. Here we get the * array of StreamContexts. We get file names for the column * families associated with the files and replace them with the * file names as obtained from the column family store on the * receiving end. */ public void doVerb(Message message) { byte[] body = message.getMessageBody(); ByteArrayInputStream bufIn = new ByteArrayInputStream(body); if (logger.isDebugEnabled()) logger.debug(String.format("StreamInitiateVerbeHandler.doVerb %s %s %s", message.getVerb(), message.getMessageId(), message.getMessageType())); try { StreamInitiateMessage biMsg = StreamInitiateMessage.serializer() .deserialize(new DataInputStream(bufIn)); PendingFile[] pendingFiles = biMsg.getStreamContext(); if (pendingFiles.length == 0) { if (logger.isDebugEnabled()) logger.debug("no data needed from " + message.getFrom()); if (StorageService.instance.isBootstrapMode()) StorageService.instance.removeBootstrapSource(message.getFrom(), new String(message.getHeader(StreamOut.TABLE_NAME))); return; } Map<String, String> fileNames = getNewNames(pendingFiles); Map<String, String> pathNames = new HashMap<String, String>(); for (String ssName : fileNames.keySet()) pathNames.put(ssName, DatabaseDescriptor.getNextAvailableDataLocation()); /* * For each of stream context's in the incoming message * generate the new file names and store the new file names * in the StreamContextManager. */ for (PendingFile pendingFile : pendingFiles) { CompletedFileStatus streamStatus = new CompletedFileStatus(pendingFile.getTargetFile(), pendingFile.getExpectedBytes()); String file = getNewFileNameFromOldContextAndNames(fileNames, pathNames, pendingFile); if (logger.isDebugEnabled()) logger.debug("Received Data from : " + message.getFrom() + " " + pendingFile.getTargetFile() + " " + file); pendingFile.setTargetFile(file); addStreamContext(message.getFrom(), pendingFile, streamStatus); } StreamInManager.registerStreamCompletionHandler(message.getFrom(), new StreamCompletionHandler()); if (logger.isDebugEnabled()) logger.debug("Sending a stream initiate done message ..."); Message doneMessage = new Message(FBUtilities.getLocalAddress(), "", StorageService.Verb.STREAM_INITIATE_DONE, new byte[0]); MessagingService.instance.sendOneWay(doneMessage, message.getFrom()); } catch (IOException ex) { throw new IOError(ex); } } public String getNewFileNameFromOldContextAndNames(Map<String, String> fileNames, Map<String, String> pathNames, PendingFile pendingFile) { File sourceFile = new File(pendingFile.getTargetFile()); String[] piece = FBUtilities.strip(sourceFile.getName(), "-"); String cfName = piece[0]; String ssTableNum = piece[1]; String typeOfFile = piece[2]; String newFileNameExpanded = fileNames.get(pendingFile.getTable() + "-" + cfName + "-" + ssTableNum); String path = pathNames.get(pendingFile.getTable() + "-" + cfName + "-" + ssTableNum); //Drop type (Data.db) from new FileName String newFileName = newFileNameExpanded.replace("Data.db", typeOfFile); return path + File.separator + pendingFile.getTable() + File.separator + newFileName; } // todo: this method needs to be private, or package at the very least for easy unit testing. public Map<String, String> getNewNames(PendingFile[] pendingFiles) throws IOException { /* * Mapping for each file with unique CF-i ---> new file name. For eg. * for a file with name <CF>-<i>-Data.db there is a corresponding * <CF>-<i>-Index.db. We maintain a mapping from <CF>-<i> to a newly * generated file name. */ Map<String, String> fileNames = new HashMap<String, String>(); /* Get the distinct entries from StreamContexts i.e have one entry per Data/Index/Filter file set */ Set<String> distinctEntries = new HashSet<String>(); for (PendingFile pendingFile : pendingFiles) { String[] pieces = FBUtilities.strip(new File(pendingFile.getTargetFile()).getName(), "-"); distinctEntries.add(pendingFile.getTable() + "-" + pieces[0] + "-" + pieces[1]); } /* Generate unique file names per entry */ for (String distinctEntry : distinctEntries) { String tableName; String[] pieces = FBUtilities.strip(distinctEntry, "-"); if (pieces.length > 2) { tableName = StringUtils.join(pieces, "-", 0, pieces.length - 2); } else { tableName = pieces[0]; } Table table = Table.open(tableName); ColumnFamilyStore cfStore = table.getColumnFamilyStore(pieces[pieces.length - 2]); if (logger.isDebugEnabled()) logger.debug("Generating file name for " + distinctEntry + " ..."); fileNames.put(distinctEntry, cfStore.getTempSSTableFileName()); } return fileNames; } private void addStreamContext(InetAddress host, PendingFile pendingFile, CompletedFileStatus streamStatus) { if (logger.isDebugEnabled()) logger.debug("Adding stream context " + pendingFile + " for " + host + " ..."); StreamInManager.addStreamContext(host, pendingFile, streamStatus); } }