content: /*
   * 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.activemq.artemis.cli.commands.util;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.text.DecimalFormat;
  import java.util.Arrays;
  import java.util.concurrent.TimeUnit;
  
  import org.apache.activemq.artemis.cli.commands.ActionContext;
  import org.apache.activemq.artemis.core.io.IOCallback;
  import org.apache.activemq.artemis.core.io.SequentialFile;
  import org.apache.activemq.artemis.core.io.SequentialFileFactory;
  import org.apache.activemq.artemis.core.io.aio.AIOSequentialFileFactory;
  import org.apache.activemq.artemis.core.io.mapped.MappedSequentialFileFactory;
  import org.apache.activemq.artemis.core.io.nio.NIOSequentialFileFactory;
  import org.apache.activemq.artemis.core.server.ActiveMQMessageBundle;
  import org.apache.activemq.artemis.core.server.JournalType;
  import org.apache.activemq.artemis.nativo.jlibaio.LibaioContext;
  import org.apache.activemq.artemis.utils.ReusableLatch;
  
  /**
   * It will perform a simple test to evaluate how many syncs a disk can make per second
   */
  public class SyncCalculation {
  
     //uses nanoseconds to avoid any conversion cost: useful when performing operation on mapped journal without fsync or with RAM-like devices
     private static final long MAX_FLUSH_NANOS = TimeUnit.SECONDS.toNanos(5);
  
     /**
      * It will perform {@code tries} write tests of {@code blockSize * blocks} bytes and returning the lowest elapsed
      * time to perform a try.    *
      * <p>
      * Please configure {@code blocks >= -XX:CompileThreshold} (ie by default on most JVMs is 10000) to favour the best
      * JIT/OSR compilation (ie: Just In Time/On Stack Replacement) if the test is running on a temporary file-system (eg:
      * tmpfs on Linux) or without {@code fsync}.
      * <p>
      * NOTE: The write latencies are provided only if
      * {@code verbose && !(journalType == JournalType.ASYNCIO && !syncWrites)} (ie are used effective synchronous
      * writes).
      *
      * @param datafolder  the folder where the journal files will be stored
      * @param blockSize   the size in bytes of each write on the journal
      * @param blocks      the number of {@code blockSize} writes performed on each try
      * @param tries       the number of tests
      * @param verbose     {@code true} to make the output verbose, {@code false} otherwise
      * @param fsync       if {@code true} the test is performing full durable writes, {@code false} otherwise
      * @param syncWrites  if {@code true} each write is performed only if the previous one is completed, {@code false}
      *                    otherwise (ie each try will wait only the last write)
      * @param fileName    the name of the journal file used for the test
      * @param maxAIO      the max number of in-flight IO requests (if {@code journalType} will support it)
      * @param journalType the {@link JournalType} used for the tests
      * @return the lowest elapsed time (in {@link TimeUnit#MILLISECONDS}) to perform a try
      */
     public static long syncTest(File datafolder,
                                 int blockSize,
                                 int blocks,
                                 int tries,
                                 boolean verbose,
                                 boolean fsync,
                                 boolean syncWrites,
                                 String fileName,
                                 int maxAIO,
                                 JournalType journalType,
                                 ActionContext context) throws Exception {
        SequentialFileFactory factory = newFactory(datafolder, fsync, journalType, blockSize * blocks, maxAIO);
  
        if (factory instanceof AIOSequentialFileFactory) {
           factory.setAlignment(blockSize);
        }
        //the write latencies could be taken only when writes are effectively synchronous
  
        if (journalType == JournalType.ASYNCIO && syncWrites) {
           context.out.println();
           context.out.println("*******************************************************************************************");
           context.out.println("*** Notice: The recommendation for AsyncIO journal is to not use --sync-writes          ***");
           context.out.println("***         The measures here will be useful to understand your device                  ***");
           context.out.println("***         however the result here won't represent the best configuration option       ***");
           context.out.println("*******************************************************************************************");
           context.out.println();
        }
  
        if (verbose) {
           context.out.println("Using " + factory.getClass().getName() + " to calculate sync times, alignment=" + factory.getAlignment());
        }
        SequentialFile file = factory.createSequentialFile(fileName);
        //to be sure that a process/thread crash won't leave the dataFolder with garbage files
        file.getJavaFile().deleteOnExit();
        try {
           final ByteBuffer bufferBlock = allocateAlignedBlock(blockSize, factory);
  
           // making sure the blockSize matches the device
           blockSize = bufferBlock.remaining();
  
           file.delete();
           file.open();
  
           file.fill(blockSize * blocks);
  
           file.close();
  
           long[] result = new long[tries];
  
           final ReusableLatch latch = new ReusableLatch(0);
  
           IOCallback callback = new IOCallback() {
              @Override
              public void done() {
                 latch.countDown();
              }
  
              @Override
              public void onError(int errorCode, String errorMessage) {
  
              }
           };
  
           DecimalFormat dcformat = new DecimalFormat("###.##");
           for (int ntry = 0; ntry < tries; ntry++) {
  
              if (verbose) {
                 context.out.println("**************************************************");
                 context.out.println(ntry + " of " + tries + " calculation");
              }
              file.open();
              file.position(0);
              long start = System.currentTimeMillis();
              for (int i = 0; i < blocks; i++) {
                 bufferBlock.position(0);
                 latch.countUp();
                 file.writeDirect(bufferBlock, true, callback);
  
                 if (syncWrites) {
                    flushLatch(latch);
                 }
              }
  
              if (!syncWrites) flushLatch(latch);
  
              long end = System.currentTimeMillis();
  
              result[ntry] = (end - start);
  
              if (verbose) {
                 double writesPerMillisecond = (double) blocks / (double) result[ntry];
                 context.out.println("Time = " + result[ntry] + " milliseconds");
                 context.out.println("Writes / millisecond = " + dcformat.format(writesPerMillisecond));
                 context.out.println("bufferTimeout = " + toNanos(result[ntry], blocks, verbose, context));
                 context.out.println("**************************************************");
              }
              file.close();
  
           }
  
           factory.releaseDirectBuffer(bufferBlock);
  
           long totalTime = Long.MAX_VALUE;
           for (int i = 0; i < tries; i++) {
              if (result[i] < totalTime) {
                 totalTime = result[i];
              }
           }
  
           return totalTime;
        } finally {
           try {
              file.close();
           } catch (Exception e) {
           }
           try {
              file.delete();
           } catch (Exception e) {
           }
           try {
              factory.stop();
           } catch (Exception e) {
           }
        }
     }
  
     private static ByteBuffer allocateAlignedBlock(int blockSize, SequentialFileFactory factory) {
        final ByteBuffer bufferBlock = factory.newBuffer(blockSize);
        final byte[] block = new byte[bufferBlock.remaining()];
        Arrays.fill(block, (byte) 't');
        bufferBlock.put(block);
        bufferBlock.position(0);
        return bufferBlock;
     }
  
     private static void flushLatch(ReusableLatch latch) throws InterruptedException, IOException {
        if (!latch.await(MAX_FLUSH_NANOS, TimeUnit.NANOSECONDS)) {
           throw new IOException("Timed out on receiving IO callback");
        }
     }
  
     public static long toNanos(long time, long blocks, boolean verbose, ActionContext context) {
  
        double blocksPerMillisecond = (double) blocks / (double) (time);
  
        if (verbose) {
           context.out.println("Blocks per millisecond::" + blocksPerMillisecond);
        }
  
        long nanoSeconds = TimeUnit.NANOSECONDS.convert(1, TimeUnit.MILLISECONDS);
  
        long timeWait = (long) (nanoSeconds / blocksPerMillisecond);
  
        if (verbose) {
           context.out.println("your system could make a sync every " + timeWait + " nanoseconds, and this will be your timeout");
        }
  
        return timeWait;
     }
  
     private static SequentialFileFactory newFactory(File datafolder, boolean datasync, JournalType journalType, int fileSize, int maxAIO) {
        SequentialFileFactory factory;
  
        if (journalType == JournalType.ASYNCIO && !LibaioContext.isLoaded()) {
           journalType = JournalType.NIO;
        }
  
        switch (journalType) {
  
           case NIO:
              factory = new NIOSequentialFileFactory(datafolder, 1).setDatasync(datasync);
              ((NIOSequentialFileFactory) factory).disableBufferReuse();
              factory.start();
              return factory;
           case ASYNCIO:
              factory = new AIOSequentialFileFactory(datafolder, maxAIO).setDatasync(datasync);
              factory.start();
              ((AIOSequentialFileFactory) factory).disableBufferReuse();
              return factory;
           case MAPPED:
              factory = new MappedSequentialFileFactory(datafolder, fileSize, false, 0, 0, null)
                 .setDatasync(datasync)
                 .disableBufferReuse();
              factory.start();
              return factory;
           default:
              throw ActiveMQMessageBundle.BUNDLE.invalidJournalType2(journalType);
        }
     }
  }
  