HDDS-2233 - Remove ByteStringHelper and refactor the code to the place where it used (#1596)

hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/XceiverClientManager.java

@@ -36,15 +36,18 @@ import org.apache.hadoop.hdds.security.x509.certificate.utils.CertificateCodec;
 import org.apache.hadoop.ozone.OzoneConfigKeys;
 import org.apache.hadoop.ozone.OzoneSecurityUtil;
 import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.ratis.thirdparty.com.google.protobuf.ByteString;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.nio.ByteBuffer;
 import java.security.cert.CertificateException;
 import java.security.cert.X509Certificate;
 import java.util.concurrent.Callable;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
 
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static org.apache.hadoop.hdds.conf.ConfigTag.OZONE;
@@ -307,6 +310,10 @@ public class XceiverClientManager implements Closeable {
     return HddsProtos.ReplicationType.STAND_ALONE;
   }
 
+  public Function<ByteBuffer, ByteString> byteBufferToByteStringConversion(){
+    return ByteStringConversion.createByteBufferConversion(conf);
+  }
+
   /**
    * Get xceiver client metric.
    */

hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/storage/BlockOutputStream.java

@@ -21,7 +21,6 @@ import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
 import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos;
-import org.apache.hadoop.hdds.scm.ByteStringHelper;
 import org.apache.hadoop.hdds.scm.XceiverClientReply;
 import org.apache.hadoop.hdds.scm.container.common.helpers.StorageContainerException;
 import org.apache.hadoop.hdds.scm.pipeline.Pipeline;
@@ -590,7 +589,7 @@ public class BlockOutputStream extends OutputStream {
    */
   private void writeChunkToContainer(ByteBuffer chunk) throws IOException {
     int effectiveChunkSize = chunk.remaining();
-    ByteString data = ByteStringHelper.getByteString(chunk);
+    ByteString data = bufferPool.byteStringConversion().apply(chunk);
     Checksum checksum = new Checksum(checksumType, bytesPerChecksum);
     ChecksumData checksumData = checksum.computeChecksum(chunk);
     ChunkInfo chunkInfo = ChunkInfo.newBuilder()

hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/storage/BufferPool.java

@@ -19,10 +19,13 @@
 package org.apache.hadoop.hdds.scm.storage;
 
 import com.google.common.base.Preconditions;
+import org.apache.hadoop.hdds.scm.ByteStringConversion;
+import org.apache.ratis.thirdparty.com.google.protobuf.ByteString;
 
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.function.Function;
 
 /**
  * This class creates and manages pool of n buffers.
@@ -33,12 +36,24 @@ public class BufferPool {
   private int currentBufferIndex;
   private final int bufferSize;
   private final int capacity;
+  private final Function<ByteBuffer, ByteString> byteStringConversion;
 
   public BufferPool(int bufferSize, int capacity) {
+    this(bufferSize, capacity,
+        ByteStringConversion.createByteBufferConversion(null));
+  }
+
+  public BufferPool(int bufferSize, int capacity,
+      Function<ByteBuffer, ByteString> byteStringConversion){
     this.capacity = capacity;
     this.bufferSize = bufferSize;
     bufferList = new ArrayList<>(capacity);
     currentBufferIndex = -1;
+    this.byteStringConversion = byteStringConversion;
+  }
+
+  public Function<ByteBuffer, ByteString> byteStringConversion(){
+    return byteStringConversion;
   }
 
   public ByteBuffer getCurrentBuffer() {

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/ByteStringConversion.java

@@ -0,0 +1,62 @@
+/*
+ * 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.hdds.scm;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.ozone.OzoneConfigKeys;
+import org.apache.ratis.thirdparty.com.google.protobuf.ByteString;
+import org.apache.ratis.thirdparty.com.google.protobuf.UnsafeByteOperations;
+
+import java.nio.ByteBuffer;
+import java.util.function.Function;
+
+/**
+ * Helper class to create a conversion function from ByteBuffer to ByteString
+ * based on the property
+ * {@link OzoneConfigKeys#OZONE_UNSAFEBYTEOPERATIONS_ENABLED} in the
+ * Ozone configuration.
+ */
+public final class ByteStringConversion {
+  private ByteStringConversion(){} // no instantiation.
+
+  /**
+   * Creates the conversion function to be used to convert ByteBuffers to
+   * ByteString instances to be used in protobuf messages.
+   *
+   * @param config the Ozone configuration
+   * @return the conversion function defined by
+   *          {@link OzoneConfigKeys#OZONE_UNSAFEBYTEOPERATIONS_ENABLED}
+   * @see <pre>ByteBuffer</pre>
+   */
+  public static Function<ByteBuffer, ByteString> createByteBufferConversion(
+      Configuration config){
+    boolean unsafeEnabled =
+        config!=null && config.getBoolean(
+            OzoneConfigKeys.OZONE_UNSAFEBYTEOPERATIONS_ENABLED,
+            OzoneConfigKeys.OZONE_UNSAFEBYTEOPERATIONS_ENABLED_DEFAULT);
+    if (unsafeEnabled) {
+      return buffer -> UnsafeByteOperations.unsafeWrap(buffer);
+    } else {
+      return buffer -> {
+        ByteString retval = ByteString.copyFrom(buffer);
+        buffer.flip();
+        return retval;
+      };
+    }
+  }
+}

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/ByteStringHelper.java

@@ -1,69 +0,0 @@
-/*
- * 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.hdds.scm;
-
-import com.google.common.base.Preconditions;
-import org.apache.ratis.thirdparty.com.google.protobuf.ByteString;
-import org.apache.ratis.thirdparty.com.google.protobuf.UnsafeByteOperations;
-
-import java.nio.ByteBuffer;
-import java.util.concurrent.atomic.AtomicBoolean;
-/**
- * Helper class to perform Unsafe ByteString conversion from byteBuffer or byte
- * array depending on the config "ozone.UnsafeByteOperations.enabled".
- */
-public final class ByteStringHelper {
-  private static final AtomicBoolean INITIALIZED = new AtomicBoolean();
-  private static volatile boolean isUnsafeByteOperationsEnabled;
-
-  /**
-   * There is no need to instantiate this class.
-   */
-  private ByteStringHelper() {
-  }
-
-  public static void init(boolean isUnsafeByteOperation) {
-    final boolean set = INITIALIZED.compareAndSet(false, true);
-    if (set) {
-      ByteStringHelper.isUnsafeByteOperationsEnabled =
-          isUnsafeByteOperation;
-    } else {
-      // already initialized, check values
-      Preconditions.checkState(isUnsafeByteOperationsEnabled
-          == isUnsafeByteOperation);
-    }
-  }
-
-  private static ByteString copyFrom(ByteBuffer buffer) {
-    final ByteString bytes = ByteString.copyFrom(buffer);
-    // flip the buffer so as to read the data starting from pos 0 again
-    buffer.flip();
-    return bytes;
-  }
-
-  public static ByteString getByteString(ByteBuffer buffer) {
-    return isUnsafeByteOperationsEnabled ?
-        UnsafeByteOperations.unsafeWrap(buffer) : copyFrom(buffer);
-  }
-
-  public static ByteString getByteString(byte[] bytes) {
-    return isUnsafeByteOperationsEnabled ?
-        UnsafeByteOperations.unsafeWrap(bytes) : ByteString.copyFrom(bytes);
-  }
-
-}

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/KeyValueHandler.java

@@ -27,6 +27,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.locks.ReentrantLock;
+import java.util.function.Function;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.conf.StorageUnit;
@@ -46,7 +47,7 @@ import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos.KeyValue;
 import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos
     .PutSmallFileRequestProto;
 import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos.Type;
-import org.apache.hadoop.hdds.scm.ByteStringHelper;
+import org.apache.hadoop.hdds.scm.ByteStringConversion;
 import org.apache.hadoop.hdds.scm.ScmConfigKeys;
 import org.apache.hadoop.hdds.scm.container.common.helpers
     .StorageContainerException;
@@ -102,6 +103,7 @@ public class KeyValueHandler extends Handler {
   private final ChunkManager chunkManager;
   private final VolumeChoosingPolicy volumeChoosingPolicy;
   private final long maxContainerSize;
+  private final Function<ByteBuffer, ByteString> byteBufferToByteString;
 
   // A lock that is held during container creation.
   private final AutoCloseableLock containerCreationLock;
@@ -125,10 +127,8 @@ public class KeyValueHandler extends Handler {
     // this handler lock is used for synchronizing createContainer Requests,
     // so using a fair lock here.
     containerCreationLock = new AutoCloseableLock(new ReentrantLock(true));
-    boolean isUnsafeByteOperationsEnabled = conf.getBoolean(
+    byteBufferToByteString =
-        OzoneConfigKeys.OZONE_UNSAFEBYTEOPERATIONS_ENABLED,
+        ByteStringConversion.createByteBufferConversion(conf);
-        OzoneConfigKeys.OZONE_UNSAFEBYTEOPERATIONS_ENABLED_DEFAULT);
-    ByteStringHelper.init(isUnsafeByteOperationsEnabled);
   }
 
   @VisibleForTesting
@@ -547,7 +547,7 @@ public class KeyValueHandler extends Handler {
     }
 
     // The container can become unhealthy after the lock is released.
-    // The operation will likely fail/timeout in that happens.
+    // The operation will likely fail/timeout if that happens.
     try {
       checkContainerIsHealthy(kvContainer);
     } catch (StorageContainerException sce) {
@@ -555,7 +555,7 @@ public class KeyValueHandler extends Handler {
     }
 
     ChunkInfo chunkInfo;
-    byte[] data;
+    ByteBuffer data;
     try {
       BlockID blockID = BlockID.getFromProtobuf(
           request.getReadChunk().getBlockID());
@@ -569,7 +569,7 @@ public class KeyValueHandler extends Handler {
 
       data = chunkManager
           .readChunk(kvContainer, blockID, chunkInfo, dispatcherContext);
-      metrics.incContainerBytesStats(Type.ReadChunk, data.length);
+      metrics.incContainerBytesStats(Type.ReadChunk, chunkInfo.getLen());
     } catch (StorageContainerException ex) {
       return ContainerUtils.logAndReturnError(LOG, ex, request);
     } catch (IOException ex) {
@@ -578,7 +578,18 @@ public class KeyValueHandler extends Handler {
           request);
     }
 
-    return ChunkUtils.getReadChunkResponse(request, data, chunkInfo);
+    Preconditions.checkNotNull(data, "Chunk data is null");
+
+    ContainerProtos.ReadChunkResponseProto.Builder response =
+        ContainerProtos.ReadChunkResponseProto.newBuilder();
+    response.setChunkData(chunkInfo.getProtoBufMessage());
+    response.setData(byteBufferToByteString.apply(data));
+    response.setBlockID(request.getReadChunk().getBlockID());
+
+    ContainerCommandResponseProto.Builder builder =
+        ContainerUtils.getSuccessResponseBuilder(request);
+    builder.setReadChunk(response);
+    return builder.build();
   }
 
   /**
@@ -800,9 +811,9 @@ public class KeyValueHandler extends Handler {
       for (ContainerProtos.ChunkInfo chunk : responseData.getChunks()) {
         // if the block is committed, all chunks must have been committed.
         // Tmp chunk files won't exist here.
-        byte[] data = chunkManager.readChunk(kvContainer, blockID,
+        ByteBuffer data = chunkManager.readChunk(kvContainer, blockID,
             ChunkInfo.getFromProtoBuf(chunk), dispatcherContext);
-        ByteString current = ByteString.copyFrom(data);
+        ByteString current = byteBufferToByteString.apply(data);
         dataBuf = dataBuf.concat(current);
         chunkInfo = chunk;
       }

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/helpers/ChunkUtils.java

@@ -24,9 +24,6 @@ import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos
     .ContainerCommandRequestProto;
 import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos
     .ContainerCommandResponseProto;
-import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos
-    .ReadChunkResponseProto;
-import org.apache.hadoop.hdds.scm.ByteStringHelper;
 import org.apache.hadoop.hdds.scm.container.common.helpers
     .StorageContainerException;
 import org.apache.hadoop.io.IOUtils;
@@ -142,8 +139,7 @@ public final class ChunkUtils {
    * @return ByteBuffer
    */
   public static ByteBuffer readData(File chunkFile, ChunkInfo data,
-      VolumeIOStats volumeIOStats) throws StorageContainerException,
+      VolumeIOStats volumeIOStats) throws StorageContainerException {
-      ExecutionException, InterruptedException {
     Logger log = LoggerFactory.getLogger(ChunkManagerImpl.class);
 
     if (!chunkFile.exists()) {
@@ -168,6 +164,7 @@ public final class ChunkUtils {
 
         try (FileLock ignored = file.lock(offset, len, true)) {
           file.read(buf, offset);
+          buf.flip();
         }
 
         // Increment volumeIO stats here.
@@ -287,33 +284,6 @@ public final class ChunkUtils {
     return ContainerUtils.getSuccessResponse(msg);
   }
 
-  /**
-   * Gets a response to the read chunk calls.
-   *
-   * @param msg - Msg
-   * @param data - Data
-   * @param info - Info
-   * @return Response.
-   */
-  public static ContainerCommandResponseProto getReadChunkResponse(
-      ContainerCommandRequestProto msg, byte[] data, ChunkInfo info) {
-    Preconditions.checkNotNull(msg);
-    Preconditions.checkNotNull(data, "Chunk data is null");
-    Preconditions.checkNotNull(info, "Chunk Info is null");
-
-    ReadChunkResponseProto.Builder response =
-        ReadChunkResponseProto.newBuilder();
-    response.setChunkData(info.getProtoBufMessage());
-    response.setData(
-        ByteStringHelper.getByteString(data));
-    response.setBlockID(msg.getReadChunk().getBlockID());
-
-    ContainerCommandResponseProto.Builder builder =
-        ContainerUtils.getSuccessResponseBuilder(msg);
-    builder.setReadChunk(response);
-    return builder.build();
-  }
-
   @VisibleForTesting
   static <T, E extends Exception> T processFileExclusively(
       Path path, CheckedSupplier<T, E> op

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/impl/ChunkManagerDummyImpl.java

@@ -120,8 +120,8 @@ public class ChunkManagerDummyImpl extends ChunkManagerImpl {
    * TODO: Explore if we need to do that for ozone.
    */
   @Override
-  public byte[] readChunk(Container container, BlockID blockID, ChunkInfo info,
+  public ByteBuffer readChunk(Container container, BlockID blockID,
-      DispatcherContext dispatcherContext) {
+      ChunkInfo info, DispatcherContext dispatcherContext) {
 
     long readStartTime = Time.monotonicNow();
 
@@ -138,7 +138,7 @@ public class ChunkManagerDummyImpl extends ChunkManagerImpl {
     volumeIOStats.incReadOpCount();
     volumeIOStats.incReadBytes(info.getLen());
 
-    return data.array();
+    return data;
   }
 
   /**

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/impl/ChunkManagerImpl.java

@@ -195,44 +195,34 @@ public class ChunkManagerImpl implements ChunkManager {
    * TODO: Right now we do not support partial reads and writes of chunks.
    * TODO: Explore if we need to do that for ozone.
    */
-  public byte[] readChunk(Container container, BlockID blockID, ChunkInfo info,
+  public ByteBuffer readChunk(Container container, BlockID blockID,
-      DispatcherContext dispatcherContext) throws StorageContainerException {
+      ChunkInfo info, DispatcherContext dispatcherContext)
-    try {
+      throws StorageContainerException {
-      KeyValueContainerData containerData = (KeyValueContainerData) container
+    KeyValueContainerData containerData = (KeyValueContainerData) container
-          .getContainerData();
+        .getContainerData();
-      ByteBuffer data;
+    ByteBuffer data;
-      HddsVolume volume = containerData.getVolume();
+    HddsVolume volume = containerData.getVolume();
-      VolumeIOStats volumeIOStats = volume.getVolumeIOStats();
+    VolumeIOStats volumeIOStats = volume.getVolumeIOStats();
 
-      // Checking here, which layout version the container is, and reading
+    // Checking here, which layout version the container is, and reading
-      // the chunk file in that format.
+    // the chunk file in that format.
-      // In version1, we verify checksum if it is available and return data
+    // In version1, we verify checksum if it is available and return data
-      // of the chunk file.
+    // of the chunk file.
-      if (containerData.getLayOutVersion() == ChunkLayOutVersion
+    if (containerData.getLayOutVersion() == ChunkLayOutVersion
-          .getLatestVersion().getVersion()) {
+        .getLatestVersion().getVersion()) {
-        File chunkFile = ChunkUtils.getChunkFile(containerData, info);
+      File chunkFile = ChunkUtils.getChunkFile(containerData, info);
 
-        // In case the chunk file does not exist but tmp chunk file exist,
+      // In case the chunk file does not exist but tmp chunk file exist,
-        // read from tmp chunk file if readFromTmpFile is set to true
+      // read from tmp chunk file if readFromTmpFile is set to true
-        if (!chunkFile.exists() && dispatcherContext != null
+      if (!chunkFile.exists() && dispatcherContext != null
-            && dispatcherContext.isReadFromTmpFile()) {
+          && dispatcherContext.isReadFromTmpFile()) {
-          chunkFile = getTmpChunkFile(chunkFile, dispatcherContext);
+        chunkFile = getTmpChunkFile(chunkFile, dispatcherContext);
-        }
-        data = ChunkUtils.readData(chunkFile, info, volumeIOStats);
-        containerData.incrReadCount();
-        long length = chunkFile.length();
-        containerData.incrReadBytes(length);
-        return data.array();
       }
-    } catch (ExecutionException ex) {
+      data = ChunkUtils.readData(chunkFile, info, volumeIOStats);
-      LOG.error("read data failed. error: {}", ex);
+      containerData.incrReadCount();
-      throw new StorageContainerException("Internal error: ",
+      long length = chunkFile.length();
-          ex, CONTAINER_INTERNAL_ERROR);
+      containerData.incrReadBytes(length);
-    } catch (InterruptedException e) {
+      return data;
-      Thread.currentThread().interrupt();
-      LOG.error("read data failed. error: {}", e);
-      throw new StorageContainerException("Internal error: ",
-          e, CONTAINER_INTERNAL_ERROR);
     }
     return null;
   }

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/interfaces/ChunkManager.java

@@ -59,7 +59,7 @@ public interface ChunkManager {
    * TODO: Right now we do not support partial reads and writes of chunks.
    * TODO: Explore if we need to do that for ozone.
    */
-  byte[] readChunk(Container container, BlockID blockID, ChunkInfo info,
+  ByteBuffer readChunk(Container container, BlockID blockID, ChunkInfo info,
       DispatcherContext dispatcherContext) throws StorageContainerException;
 
   /**

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/keyvalue/TestChunkManagerImpl.java

@@ -41,7 +41,6 @@ import org.mockito.Mockito;
 
 import java.io.File;
 import java.nio.ByteBuffer;
-import java.util.Arrays;
 import java.util.UUID;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
@@ -65,7 +64,7 @@ public class TestChunkManagerImpl {
   private BlockID blockID;
   private ChunkManagerImpl chunkManager;
   private ChunkInfo chunkInfo;
-  private byte[] data;
+  private ByteBuffer data;
 
   @Rule
   public TemporaryFolder folder = new TemporaryFolder();
@@ -92,11 +91,11 @@ public class TestChunkManagerImpl {
 
     keyValueContainer.create(volumeSet, volumeChoosingPolicy, scmId);
 
-    data = "testing write chunks".getBytes(UTF_8);
+    data = ByteBuffer.wrap("testing write chunks".getBytes(UTF_8));
     // Creating BlockData
     blockID = new BlockID(1L, 1L);
     chunkInfo = new ChunkInfo(String.format("%d.data.%d", blockID
-        .getLocalID(), 0), 0, data.length);
+        .getLocalID(), 0), 0, data.capacity());
 
     // Create a ChunkManager object.
     chunkManager = new ChunkManagerImpl(true);
@@ -118,8 +117,8 @@ public class TestChunkManagerImpl {
 
     // As no chunks are written to the volume writeBytes should be 0
     checkWriteIOStats(0, 0);
-    chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo,
+    chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo, data,
-        ByteBuffer.wrap(data), new DispatcherContext.Builder()
+        new DispatcherContext.Builder()
             .setStage(DispatcherContext.WriteChunkStage.WRITE_DATA).build());
     // Now a chunk file is being written with Stage WRITE_DATA, so it should
     // create a temporary chunk file.
@@ -137,13 +136,13 @@ public class TestChunkManagerImpl {
     // As chunk write stage is WRITE_DATA, temp chunk file will be created.
     assertTrue(tempChunkFile.exists());
 
-    checkWriteIOStats(data.length, 1);
+    checkWriteIOStats(data.capacity(), 1);
 
-    chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo,
+    chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo, data,
-        ByteBuffer.wrap(data), new DispatcherContext.Builder()
+        new DispatcherContext.Builder()
             .setStage(DispatcherContext.WriteChunkStage.COMMIT_DATA).build());
 
-    checkWriteIOStats(data.length, 1);
+    checkWriteIOStats(data.capacity(), 1);
 
     // Old temp file should have been renamed to chunk file.
     assertTrue(chunksPath.listFiles().length == 1);
@@ -160,8 +159,8 @@ public class TestChunkManagerImpl {
       long randomLength = 200L;
       chunkInfo = new ChunkInfo(String.format("%d.data.%d", blockID
           .getLocalID(), 0), 0, randomLength);
-      chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo,
+      chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo, data,
-          ByteBuffer.wrap(data), getDispatcherContext());
+          getDispatcherContext());
       fail("testWriteChunkIncorrectLength failed");
     } catch (StorageContainerException ex) {
       // As we got an exception, writeBytes should be 0.
@@ -181,35 +180,36 @@ public class TestChunkManagerImpl {
     // Initially chunks folder should be empty.
     assertTrue(chunksPath.listFiles().length == 0);
     checkWriteIOStats(0, 0);
-    chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo,
+    chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo, data,
-        ByteBuffer.wrap(data), getDispatcherContext());
+        getDispatcherContext());
     // Now a chunk file is being written with Stage COMBINED_DATA, so it should
     // create a chunk file.
     assertTrue(chunksPath.listFiles().length == 1);
     File chunkFile = ChunkUtils.getChunkFile(keyValueContainerData, chunkInfo);
     assertTrue(chunkFile.exists());
-    checkWriteIOStats(data.length, 1);
+    checkWriteIOStats(data.capacity(), 1);
   }
 
   @Test
   public void testReadChunk() throws Exception {
     checkWriteIOStats(0, 0);
-    chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo,
+    chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo, data,
-        ByteBuffer.wrap(data), getDispatcherContext());
+        getDispatcherContext());
-    checkWriteIOStats(data.length, 1);
+    checkWriteIOStats(data.capacity(), 1);
     checkReadIOStats(0, 0);
-    byte[] expectedData = chunkManager.readChunk(keyValueContainer, blockID,
+    ByteBuffer expectedData = chunkManager.readChunk(keyValueContainer, blockID,
         chunkInfo, getDispatcherContext());
-    assertEquals(expectedData.length, data.length);
+    assertEquals(expectedData.limit()-expectedData.position(),
-    assertTrue(Arrays.equals(expectedData, data));
+        chunkInfo.getLen());
-    checkReadIOStats(data.length, 1);
+    assertTrue(expectedData.rewind().equals(data.rewind()));
+    checkReadIOStats(expectedData.capacity(), 1);
   }
 
   @Test
   public void testDeleteChunk() throws Exception {
     File chunksPath = new File(keyValueContainerData.getChunksPath());
-    chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo,
+    chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo, data,
-        ByteBuffer.wrap(data), getDispatcherContext());
+        getDispatcherContext());
     assertTrue(chunksPath.listFiles().length == 1);
     chunkManager.deleteChunk(keyValueContainer, blockID, chunkInfo);
     assertTrue(chunksPath.listFiles().length == 0);
@@ -218,8 +218,8 @@ public class TestChunkManagerImpl {
   @Test
   public void testDeleteChunkUnsupportedRequest() throws Exception {
     try {
-      chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo,
+      chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo, data,
-          ByteBuffer.wrap(data), getDispatcherContext());
+          getDispatcherContext());
       long randomLength = 200L;
       chunkInfo = new ChunkInfo(String.format("%d.data.%d", blockID
           .getLocalID(), 0), 0, randomLength);
@@ -235,8 +235,8 @@ public class TestChunkManagerImpl {
   public void testReadChunkFileNotExists() throws Exception {
     try {
       // trying to read a chunk, where chunk file does not exist
-      byte[] expectedData = chunkManager.readChunk(keyValueContainer, blockID,
+      ByteBuffer expectedData = chunkManager.readChunk(keyValueContainer,
-          chunkInfo, getDispatcherContext());
+          blockID, chunkInfo, getDispatcherContext());
       fail("testReadChunkFileNotExists failed");
     } catch (StorageContainerException ex) {
       GenericTestUtils.assertExceptionContains("Unable to find the chunk " +
@@ -249,20 +249,21 @@ public class TestChunkManagerImpl {
   public void testWriteAndReadChunkMultipleTimes() throws Exception {
     for (int i=0; i<100; i++) {
       chunkInfo = new ChunkInfo(String.format("%d.data.%d", blockID
-          .getLocalID(), i), 0, data.length);
+          .getLocalID(), i), 0, data.capacity());
-      chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo,
+      chunkManager.writeChunk(keyValueContainer, blockID, chunkInfo, data,
-          ByteBuffer.wrap(data), getDispatcherContext());
+          getDispatcherContext());
+      data.rewind();
     }
-    checkWriteIOStats(data.length*100, 100);
+    checkWriteIOStats(data.capacity()*100, 100);
     assertTrue(hddsVolume.getVolumeIOStats().getWriteTime() > 0);
 
     for (int i=0; i<100; i++) {
       chunkInfo = new ChunkInfo(String.format("%d.data.%d", blockID
-          .getLocalID(), i), 0, data.length);
+          .getLocalID(), i), 0, data.capacity());
       chunkManager.readChunk(keyValueContainer, blockID, chunkInfo,
           getDispatcherContext());
     }
-    checkReadIOStats(data.length*100, 100);
+    checkReadIOStats(data.capacity()*100, 100);
     assertTrue(hddsVolume.getVolumeIOStats().getReadTime() > 0);
   }
 

hadoop-ozone/client/src/main/java/org/apache/hadoop/ozone/client/io/BlockOutputStreamEntryPool.java

@@ -18,6 +18,7 @@
  */
 package org.apache.hadoop.ozone.client.io;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos;
@@ -100,10 +101,17 @@ public class BlockOutputStreamEntryPool {
     Preconditions.checkState(streamBufferMaxSize % streamBufferFlushSize == 0);
     Preconditions.checkState(blockSize % streamBufferMaxSize == 0);
     this.bufferPool =
-        new BufferPool(chunkSize, (int) streamBufferMaxSize / chunkSize);
+        new BufferPool(chunkSize, (int) streamBufferMaxSize / chunkSize,
+            xceiverClientManager.byteBufferToByteStringConversion());
   }
 
-  public BlockOutputStreamEntryPool() {
+  /**
+   * A constructor for testing purpose only.
+   *
+   * @see KeyOutputStream#KeyOutputStream()
+   */
+  @VisibleForTesting
+  BlockOutputStreamEntryPool() {
     streamEntries = new ArrayList<>();
     omClient = null;
     keyArgs = null;

hadoop-ozone/client/src/main/java/org/apache/hadoop/ozone/client/rpc/RpcClient.java

@@ -30,7 +30,6 @@ import org.apache.hadoop.hdds.conf.OzoneConfiguration;
 import org.apache.hadoop.hdds.protocol.StorageType;
 import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos
     .ChecksumType;
-import org.apache.hadoop.hdds.scm.ByteStringHelper;
 import org.apache.hadoop.hdds.scm.client.HddsClientUtils;
 import org.apache.hadoop.hdds.tracing.TracingUtil;
 import org.apache.hadoop.io.IOUtils;
@@ -219,10 +218,6 @@ public class RpcClient implements ClientProtocol {
         OzoneConfigKeys.OZONE_CLIENT_RETRY_INTERVAL,
         OzoneConfigKeys.OZONE_CLIENT_RETRY_INTERVAL_DEFAULT);
     dtService = getOMProxyProvider().getCurrentProxyDelegationToken();
-    boolean isUnsafeByteOperationsEnabled = conf.getBoolean(
-        OzoneConfigKeys.OZONE_UNSAFEBYTEOPERATIONS_ENABLED,
-        OzoneConfigKeys.OZONE_UNSAFEBYTEOPERATIONS_ENABLED_DEFAULT);
-    ByteStringHelper.init(isUnsafeByteOperationsEnabled);
     topologyAwareReadEnabled = conf.getBoolean(
         OzoneConfigKeys.OZONE_NETWORK_TOPOLOGY_AWARE_READ_KEY,
         OzoneConfigKeys.OZONE_NETWORK_TOPOLOGY_AWARE_READ_DEFAULT);

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/container/ContainerTestHelper.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.ozone.container;
 
 import java.io.IOException;
 import java.net.ServerSocket;
+import java.nio.ByteBuffer;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
@@ -193,10 +194,10 @@ public final class ContainerTestHelper {
    * @param len - Number of bytes.
    * @return byte array with valid data.
    */
-  public static byte[] getData(int len) {
+  public static ByteBuffer getData(int len) {
     byte[] data = new byte[len];
     r.nextBytes(data);
-    return data;
+    return ByteBuffer.wrap(data);
   }
 
   /**
@@ -206,7 +207,7 @@ public final class ContainerTestHelper {
    * @param data - data array
    * @throws NoSuchAlgorithmException
    */
-  public static void setDataChecksum(ChunkInfo info, byte[] data)
+  public static void setDataChecksum(ChunkInfo info, ByteBuffer data)
       throws OzoneChecksumException {
     Checksum checksum = new Checksum();
     info.setChecksumData(checksum.computeChecksum(data));
@@ -232,7 +233,7 @@ public final class ContainerTestHelper {
 
     writeRequest.setBlockID(blockID.getDatanodeBlockIDProtobuf());
 
-    byte[] data = getData(datalen);
+    ByteBuffer data = getData(datalen);
     ChunkInfo info = getChunk(blockID.getLocalID(), 0, 0, datalen);
     setDataChecksum(info, data);
 
@@ -262,7 +263,7 @@ public final class ContainerTestHelper {
       throws Exception {
     ContainerProtos.PutSmallFileRequestProto.Builder smallFileRequest =
         ContainerProtos.PutSmallFileRequestProto.newBuilder();
-    byte[] data = getData(dataLen);
+    ByteBuffer data = getData(dataLen);
     ChunkInfo info = getChunk(blockID.getLocalID(), 0, 0, dataLen);
     setDataChecksum(info, data);
 

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/container/common/impl/TestContainerPersistence.java

@@ -70,7 +70,6 @@ import java.nio.file.Paths;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
@@ -349,11 +348,11 @@ public class TestContainerPersistence {
     }
     ChunkInfo info = getChunk(
         blockID.getLocalID(), 0, 0, datalen);
-    byte[] data = getData(datalen);
+    ByteBuffer data = getData(datalen);
     setDataChecksum(info, data);
     commitBytesBefore = container.getContainerData()
         .getVolume().getCommittedBytes();
-    chunkManager.writeChunk(container, blockID, info, ByteBuffer.wrap(data),
+    chunkManager.writeChunk(container, blockID, info, data,
         getDispatcherContext());
     commitBytesAfter = container.getContainerData()
         .getVolume().getCommittedBytes();
@@ -397,9 +396,9 @@ public class TestContainerPersistence {
     Map<String, ChunkInfo> fileHashMap = new HashMap<>();
     for (int x = 0; x < chunkCount; x++) {
       ChunkInfo info = getChunk(blockID.getLocalID(), x, 0, datalen);
-      byte[] data = getData(datalen);
+      ByteBuffer data = getData(datalen);
       setDataChecksum(info, data);
-      chunkManager.writeChunk(container, blockID, info, ByteBuffer.wrap(data),
+      chunkManager.writeChunk(container, blockID, info, data,
           getDispatcherContext());
       String fileName = String.format("%s.data.%d", blockID.getLocalID(), x);
       fileHashMap.put(fileName, info);
@@ -431,7 +430,7 @@ public class TestContainerPersistence {
       for (int x = 0; x < chunkCount; x++) {
         String fileName = String.format("%s.data.%d", blockID.getLocalID(), x);
         ChunkInfo info = fileHashMap.get(fileName);
-        byte[] data = chunkManager
+        ByteBuffer data = chunkManager
             .readChunk(container, blockID, info, getDispatcherContext());
         ChecksumData checksumData = checksum.computeChecksum(data);
         Assert.assertEquals(info.getChecksumData(), checksumData);
@@ -456,21 +455,22 @@ public class TestContainerPersistence {
     BlockID blockID = ContainerTestHelper.getTestBlockID(testContainerID);
     ChunkInfo info = getChunk(
         blockID.getLocalID(), 0, 0, datalen);
-    byte[] data = getData(datalen);
+    ByteBuffer data = getData(datalen);
     setDataChecksum(info, data);
-    chunkManager.writeChunk(container, blockID, info, ByteBuffer.wrap(data),
+    chunkManager.writeChunk(container, blockID, info, data,
         getDispatcherContext());
 
-    byte[] readData = chunkManager
+    ByteBuffer readData = chunkManager
         .readChunk(container, blockID, info, getDispatcherContext());
-    assertTrue(Arrays.equals(data, readData));
+    assertTrue(data.rewind().equals(readData.rewind()));
 
     ChunkInfo info2 = getChunk(blockID.getLocalID(), 0, start, length);
-    byte[] readData2 = chunkManager
+    ByteBuffer readData2 = chunkManager
         .readChunk(container, blockID, info2, getDispatcherContext());
-    assertEquals(length, readData2.length);
+    assertEquals(length, info2.getLen());
-    assertTrue(Arrays.equals(
+    boolean equals =
-        Arrays.copyOfRange(data, start, start + length), readData2));
+        data.position(start).limit(start+length).equals(readData2.rewind());
+    assertTrue(equals);
   }
 
   /**
@@ -491,15 +491,17 @@ public class TestContainerPersistence {
     BlockID blockID = ContainerTestHelper.getTestBlockID(testContainerID);
     ChunkInfo info = getChunk(
         blockID.getLocalID(), 0, 0, datalen);
-    byte[] data = getData(datalen);
+    ByteBuffer data = getData(datalen);
     setDataChecksum(info, data);
-    chunkManager.writeChunk(container, blockID, info, ByteBuffer.wrap(data),
+    chunkManager.writeChunk(container, blockID, info, data,
         getDispatcherContext());
-    chunkManager.writeChunk(container, blockID, info, ByteBuffer.wrap(data),
+    data.rewind();
+    chunkManager.writeChunk(container, blockID, info, data,
         getDispatcherContext());
+    data.rewind();
     // With the overwrite flag it should work now.
     info.addMetadata(OzoneConsts.CHUNK_OVERWRITE, "true");
-    chunkManager.writeChunk(container, blockID, info, ByteBuffer.wrap(data),
+    chunkManager.writeChunk(container, blockID, info, data,
         getDispatcherContext());
     long bytesUsed = container.getContainerData().getBytesUsed();
     Assert.assertEquals(datalen, bytesUsed);
@@ -531,17 +533,18 @@ public class TestContainerPersistence {
       long offset = x * datalen;
       ChunkInfo info = getChunk(
           blockID.getLocalID(), 0, offset, datalen);
-      byte[] data = getData(datalen);
+      ByteBuffer data = getData(datalen);
       oldSha.update(data);
+      data.rewind();
       setDataChecksum(info, data);
-      chunkManager.writeChunk(container, blockID, info, ByteBuffer.wrap(data),
+      chunkManager.writeChunk(container, blockID, info, data,
           getDispatcherContext());
     }
 
     // Request to read the whole data in a single go.
     ChunkInfo largeChunk = getChunk(blockID.getLocalID(), 0, 0,
         datalen * chunkCount);
-    byte[] newdata =
+    ByteBuffer newdata =
         chunkManager.readChunk(container, blockID, largeChunk,
             getDispatcherContext());
     MessageDigest newSha = MessageDigest.getInstance(OzoneConsts.FILE_HASH);
@@ -566,9 +569,9 @@ public class TestContainerPersistence {
     BlockID blockID = ContainerTestHelper.getTestBlockID(testContainerID);
     ChunkInfo info = getChunk(
         blockID.getLocalID(), 0, 0, datalen);
-    byte[] data = getData(datalen);
+    ByteBuffer data = getData(datalen);
     setDataChecksum(info, data);
-    chunkManager.writeChunk(container, blockID, info, ByteBuffer.wrap(data),
+    chunkManager.writeChunk(container, blockID, info, data,
         getDispatcherContext());
     chunkManager.deleteChunk(container, blockID, info);
     exception.expect(StorageContainerException.class);
@@ -681,9 +684,9 @@ public class TestContainerPersistence {
     for (int x = 1; x < chunkCount; x++) {
       // with holes in the front (before x * datalen)
       info = getChunk(blockID.getLocalID(), x, x * datalen, datalen);
-      byte[] data = getData(datalen);
+      ByteBuffer data = getData(datalen);
       setDataChecksum(info, data);
-      chunkManager.writeChunk(container, blockID, info, ByteBuffer.wrap(data),
+      chunkManager.writeChunk(container, blockID, info, data,
           getDispatcherContext());
       totalSize += datalen;
       chunkList.add(info);