fix delegated smoosh writer and some new facilities for segment writeout medium (#12132)

* fix delegated smoosh writer and some new facilities for segment writeout medium
changes:
* fixed issue with delegated `SmooshedWriter` when writing files that look like paths, causing `NoSuchFileException` exceptions when attempting to open a channel to the file
* `FileSmoosher.addWithSmooshedWriter` when _not_ delegating now checks that it is still open when closing, making it a no-op if already closed (allowing column serializers to add additional files and avoid delegated mode if they are finished writing out their own content and ned to add additional files)
* add `makeChildWriteOutMedium` to `SegmentWriteOutMedium` interface, which allows users of a shared medium to clean up `WriteOutBytes` if they fully control the lifecycle. there are no callers of this yet, adding for future functionality
* `OnHeapByteBufferWriteOutBytes` now can be marked as not open so it `OnHeapMemorySegmentWriteOutMedium` can now behave identically to other medium implementations

* fix to address nit - use AtomicLong

core/src/main/java/org/apache/druid/java/util/common/io/smoosh/FileSmoosher.java

@@ -21,6 +21,7 @@ package org.apache.druid.java.util.common.io.smoosh;
 
 import com.google.common.base.Joiner;
 import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.primitives.Ints;
 import org.apache.druid.java.util.common.FileUtils;
 import org.apache.druid.java.util.common.IAE;
@@ -46,9 +47,11 @@ import java.nio.charset.StandardCharsets;
 import java.nio.file.StandardOpenOption;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
+import java.util.concurrent.atomic.AtomicLong;
 
 /**
  * A class that concatenates files together into configurable sized chunks,
@@ -82,6 +85,10 @@ public class FileSmoosher implements Closeable
   private List<File> completedFiles = new ArrayList<>();
   // list of files in process writing content using delegated smooshedWriter.
   private List<File> filesInProcess = new ArrayList<>();
+  // delegated smooshedWriter creates a new temporary file per file added. we use a counter to name these temporary
+  // files, and map the file number to the file name so we don't have to escape the file names (e.g. names with '/')
+  private AtomicLong delegateFileCounter = new AtomicLong(0);
+  private Map<String, String> delegateFileNameMap;
 
   private Outer currOut = null;
   private boolean writerCurrentlyInUse = false;
@@ -100,6 +107,7 @@ public class FileSmoosher implements Closeable
   {
     this.baseDir = baseDir;
     this.maxChunkSize = maxChunkSize;
+    this.delegateFileNameMap = new HashMap<>();
 
     Preconditions.checkArgument(maxChunkSize > 0, "maxChunkSize must be a positive value.");
   }
@@ -223,6 +231,7 @@ public class FileSmoosher implements Closeable
       @Override
       public void close() throws IOException
       {
+        if (open) {
           open = false;
           internalFiles.put(name, new Metadata(currOut.getFileNum(), startOffset, currOut.getCurrOffset()));
           writerCurrentlyInUse = false;
@@ -236,6 +245,7 @@ public class FileSmoosher implements Closeable
           // Merge temporary files on to the main smoosh file.
           mergeWithSmoosher();
         }
+      }
     };
   }
 
@@ -249,9 +259,11 @@ public class FileSmoosher implements Closeable
   {
     // Get processed elements from the stack and write.
     List<File> fileToProcess = new ArrayList<>(completedFiles);
+    Map<String, String> fileNameMap = ImmutableMap.copyOf(delegateFileNameMap);
     completedFiles = new ArrayList<>();
+    delegateFileNameMap = new HashMap<>();
     for (File file : fileToProcess) {
-      add(file);
+      add(fileNameMap.get(file.getName()), file);
       if (!file.delete()) {
         LOG.warn("Unable to delete file [%s]", file);
       }
@@ -272,7 +284,8 @@ public class FileSmoosher implements Closeable
    */
   private SmooshedWriter delegateSmooshedWriter(final String name, final long size) throws IOException
   {
-    final File tmpFile = new File(baseDir, name);
+    final String delegateName = getDelegateFileName(name);
+    final File tmpFile = new File(baseDir, delegateName);
     filesInProcess.add(tmpFile);
 
     return new SmooshedWriter()
@@ -342,6 +355,13 @@ public class FileSmoosher implements Closeable
 
   }
 
+  private String getDelegateFileName(String name)
+  {
+    final String delegateName = String.valueOf(delegateFileCounter.getAndIncrement());
+    delegateFileNameMap.put(delegateName, name);
+    return delegateName;
+  }
+
   @Override
   public void close() throws IOException
   {

core/src/test/java/org/apache/druid/java/util/common/io/smoosh/SmooshedFileMapperTest.java

@@ -112,6 +112,27 @@ public class SmooshedFileMapperTest
     validateOutput(baseDir);
   }
 
+  @Test
+  public void testWhenWithPathyLookingFileNames() throws Exception
+  {
+    String prefix = "foo/bar/";
+    File baseDir = folder.newFolder("base");
+
+    try (FileSmoosher smoosher = new FileSmoosher(baseDir, 21)) {
+      final SmooshedWriter writer = smoosher.addWithSmooshedWriter(StringUtils.format("%s%d", prefix, 19), 4);
+      writer.write(ByteBuffer.wrap(Ints.toByteArray(19)));
+
+      for (int i = 0; i < 19; ++i) {
+        File tmpFile = File.createTempFile(StringUtils.format("smoosh-%s", i), ".bin");
+        Files.write(Ints.toByteArray(i), tmpFile);
+        smoosher.add(StringUtils.format("%s%d", prefix, i), tmpFile);
+        tmpFile.delete();
+      }
+      writer.close();
+    }
+    validateOutput(baseDir, prefix);
+  }
+
   @Test
   public void testBehaviorWhenReportedSizesLargeAndExceptionIgnored() throws Exception
   {
@@ -193,6 +214,11 @@ public class SmooshedFileMapperTest
   }
 
   private void validateOutput(File baseDir) throws IOException
+  {
+    validateOutput(baseDir, "");
+  }
+
+  private void validateOutput(File baseDir, String prefix) throws IOException
   {
     File[] files = baseDir.listFiles();
     Arrays.sort(files);
@@ -205,7 +231,7 @@ public class SmooshedFileMapperTest
 
     try (SmooshedFileMapper mapper = SmooshedFileMapper.load(baseDir)) {
       for (int i = 0; i < 20; ++i) {
-        ByteBuffer buf = mapper.mapFile(StringUtils.format("%d", i));
+        ByteBuffer buf = mapper.mapFile(StringUtils.format("%s%d", prefix, i));
         Assert.assertEquals(0, buf.position());
         Assert.assertEquals(4, buf.remaining());
         Assert.assertEquals(4, buf.capacity());

processing/src/main/java/org/apache/druid/segment/writeout/ByteBufferWriteOutBytes.java

@@ -47,6 +47,7 @@ public abstract class ByteBufferWriteOutBytes extends WriteOutBytes
   ByteBuffer headBuffer;
   long size;
   long capacity;
+  boolean open = true;
 
   ByteBufferWriteOutBytes()
   {
@@ -253,7 +254,17 @@ public abstract class ByteBufferWriteOutBytes extends WriteOutBytes
   @Override
   public boolean isOpen()
   {
-    return true;
+    return open;
+  }
+
+  public void free()
+  {
+    open = false;
+    buffers.clear();
+    headBufferIndex = -1;
+    headBuffer = null;
+    size = 0;
+    capacity = 0;
   }
 
   private void checkOpen()

processing/src/main/java/org/apache/druid/segment/writeout/DirectByteBufferWriteOutBytes.java

@@ -25,8 +25,6 @@ import java.nio.ByteBuffer;
 
 final class DirectByteBufferWriteOutBytes extends ByteBufferWriteOutBytes
 {
-  private boolean open = true;
-
   @Override
   protected ByteBuffer allocateBuffer()
   {
@@ -34,12 +32,7 @@ final class DirectByteBufferWriteOutBytes extends ByteBufferWriteOutBytes
   }
 
   @Override
-  public boolean isOpen()
-  {
-    return open;
-  }
-
-  void free()
+  public void free()
   {
     open = false;
     buffers.forEach(ByteBufferUtils::free);

processing/src/main/java/org/apache/druid/segment/writeout/OffHeapMemorySegmentWriteOutMedium.java

@@ -35,6 +35,14 @@ public final class OffHeapMemorySegmentWriteOutMedium implements SegmentWriteOut
     return writeOutBytes;
   }
 
+  @Override
+  public SegmentWriteOutMedium makeChildWriteOutMedium()
+  {
+    OffHeapMemorySegmentWriteOutMedium medium = new OffHeapMemorySegmentWriteOutMedium();
+    closer.register(medium);
+    return medium;
+  }
+
   @Override
   public Closer getCloser()
   {

processing/src/main/java/org/apache/druid/segment/writeout/OnHeapMemorySegmentWriteOutMedium.java

@@ -32,7 +32,17 @@ public final class OnHeapMemorySegmentWriteOutMedium implements SegmentWriteOutM
   @Override
   public WriteOutBytes makeWriteOutBytes()
   {
-    return new HeapByteBufferWriteOutBytes();
+    HeapByteBufferWriteOutBytes writeOutBytes = new HeapByteBufferWriteOutBytes();
+    closer.register(writeOutBytes::free);
+    return writeOutBytes;
+  }
+
+  @Override
+  public SegmentWriteOutMedium makeChildWriteOutMedium()
+  {
+    OnHeapMemorySegmentWriteOutMedium medium = new OnHeapMemorySegmentWriteOutMedium();
+    closer.register(medium);
+    return medium;
   }
 
   @Override

processing/src/main/java/org/apache/druid/segment/writeout/SegmentWriteOutMedium.java

@@ -39,6 +39,18 @@ public interface SegmentWriteOutMedium extends Closeable
    */
   WriteOutBytes makeWriteOutBytes() throws IOException;
 
+  /**
+   * Creates a 'child' version of the {@link SegmentWriteOutMedium}, which can be optionally closed,
+   * independent of this {@link SegmentWriteOutMedium} but otherwise shares the same configuration. This allows callers
+   * using a shared {@link SegmentWriteOutMedium} but which control the complete lifecycle of the {@link WriteOutBytes}
+   * which they require to free the backing resources when they are finished, rather than waiting until
+   * {@link #close()} is called for this medium.
+   *
+   * The 'child' medium will be closed when {@link #close()} is called, if not called explicitly prior to closing this
+   * medium.
+   */
+  SegmentWriteOutMedium makeChildWriteOutMedium() throws IOException;
+
   /**
    * Returns a closer of this SegmentWriteOutMedium, which is closed in this SegmentWriteOutMedium's close() method.
    * Could be used to "attach" some random resources to this SegmentWriteOutMedium, to be closed at the same time.

processing/src/main/java/org/apache/druid/segment/writeout/TmpFileSegmentWriteOutMedium.java

@@ -54,6 +54,14 @@ public final class TmpFileSegmentWriteOutMedium implements SegmentWriteOutMedium
     return new FileWriteOutBytes(file, ch);
   }
 
+  @Override
+  public SegmentWriteOutMedium makeChildWriteOutMedium() throws IOException
+  {
+    TmpFileSegmentWriteOutMedium tmpFileSegmentWriteOutMedium = new TmpFileSegmentWriteOutMedium(dir);
+    closer.register(tmpFileSegmentWriteOutMedium);
+    return tmpFileSegmentWriteOutMedium;
+  }
+
   @Override
   public Closer getCloser()
   {

processing/src/test/java/org/apache/druid/segment/writeout/SegmentWriteOutMediumTest.java

@@ -0,0 +1,142 @@
+/*
+ * 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.druid.segment.writeout;
+
+import com.google.common.collect.ImmutableList;
+import org.apache.druid.java.util.common.io.Closer;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.io.IOException;
+
+@RunWith(Parameterized.class)
+public class SegmentWriteOutMediumTest
+{
+
+  @Parameterized.Parameters(name = "medium = {0}")
+  public static Iterable<?> constructorFeeder()
+  {
+    return ImmutableList.of(
+        TmpFileSegmentWriteOutMediumFactory.instance(),
+        OffHeapMemorySegmentWriteOutMediumFactory.instance(),
+        OnHeapMemorySegmentWriteOutMediumFactory.instance()
+    );
+  }
+
+  @Rule
+  public TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+  private SegmentWriteOutMediumFactory factory;
+  private SegmentWriteOutMedium medium;
+
+  public SegmentWriteOutMediumTest(SegmentWriteOutMediumFactory factory)
+  {
+    this.factory = factory;
+  }
+
+  @Before
+  public void setup() throws IOException
+  {
+    this.medium = factory.makeSegmentWriteOutMedium(temporaryFolder.newFolder());
+  }
+
+  @Test
+  public void testSanity() throws IOException
+  {
+    WriteOutBytes bytes1 = medium.makeWriteOutBytes();
+    WriteOutBytes bytes2 = medium.makeWriteOutBytes();
+
+    Assert.assertTrue(bytes1.isOpen());
+    Assert.assertTrue(bytes2.isOpen());
+
+    Closer closer = medium.getCloser();
+    closer.close();
+
+    Assert.assertFalse(bytes1.isOpen());
+    Assert.assertFalse(bytes2.isOpen());
+  }
+
+  @Test
+  public void testChildCloseFreesResourcesButNotParents() throws IOException
+  {
+    WriteOutBytes bytes1 = medium.makeWriteOutBytes();
+    WriteOutBytes bytes2 = medium.makeWriteOutBytes();
+
+    Assert.assertTrue(bytes1.isOpen());
+    Assert.assertTrue(bytes2.isOpen());
+
+    SegmentWriteOutMedium childMedium = medium.makeChildWriteOutMedium();
+    Assert.assertTrue(childMedium.getClass().equals(medium.getClass()));
+
+    WriteOutBytes bytes3 = childMedium.makeWriteOutBytes();
+    WriteOutBytes bytes4 = childMedium.makeWriteOutBytes();
+
+    Assert.assertTrue(bytes3.isOpen());
+    Assert.assertTrue(bytes4.isOpen());
+
+    Closer childCloser = childMedium.getCloser();
+    childCloser.close();
+
+    Assert.assertFalse(bytes3.isOpen());
+    Assert.assertFalse(bytes4.isOpen());
+
+    Assert.assertTrue(bytes1.isOpen());
+    Assert.assertTrue(bytes2.isOpen());
+
+    Closer closer = medium.getCloser();
+    closer.close();
+
+    Assert.assertFalse(bytes1.isOpen());
+    Assert.assertFalse(bytes2.isOpen());
+  }
+
+  @Test
+  public void testChildNotClosedExplicitlyIsClosedByParent() throws IOException
+  {
+    WriteOutBytes bytes1 = medium.makeWriteOutBytes();
+    WriteOutBytes bytes2 = medium.makeWriteOutBytes();
+
+    Assert.assertTrue(bytes1.isOpen());
+    Assert.assertTrue(bytes2.isOpen());
+
+    SegmentWriteOutMedium childMedium = medium.makeChildWriteOutMedium();
+    Assert.assertTrue(childMedium.getClass().equals(medium.getClass()));
+
+    WriteOutBytes bytes3 = childMedium.makeWriteOutBytes();
+    WriteOutBytes bytes4 = childMedium.makeWriteOutBytes();
+
+    Assert.assertTrue(bytes3.isOpen());
+    Assert.assertTrue(bytes4.isOpen());
+
+    Closer closer = medium.getCloser();
+    closer.close();
+
+    Assert.assertFalse(bytes1.isOpen());
+    Assert.assertFalse(bytes2.isOpen());
+
+    Assert.assertFalse(bytes3.isOpen());
+    Assert.assertFalse(bytes4.isOpen());
+  }
+}