HDDS-10511. Support ByteBufferPositionedReadable in OzoneFSInputStream.

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/fs/ozone/TestOzoneFSInputStream.java

@@ -19,6 +19,7 @@
 package org.apache.hadoop.fs.ozone;
 
 import java.io.BufferedInputStream;
+import java.io.EOFException;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -58,6 +59,7 @@
 import static org.apache.hadoop.hdds.StringUtils.string2Bytes;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 /**
  * Test OzoneFSInputStream by reading through multiple interfaces.
@@ -162,6 +164,76 @@ public void testO3FSSingleByteRead() throws IOException {
     }
   }
 
+  @Test
+  public void testByteBufferPositionedRead() throws IOException {
+    try (FSDataInputStream inputStream = fs.open(filePath)) {
+      ByteBuffer buffer = ByteBuffer.allocate(20);
+      // Read positional from 50th index
+      int readBytes = inputStream.read(50, buffer);
+      byte[] value1 = new byte[readBytes];
+      System.arraycopy(buffer.array(), 0, value1, 0, readBytes);
+      byte[] value2 = new byte[readBytes];
+      System.arraycopy(data, 50, value2, 0, readBytes);
+      // Verify input and positional read data
+      assertArrayEquals(value1, value2, "value mismatch");
+
+      buffer.clear();
+      // Verify offset of file didn't change
+      // Read positional from 8th index again using same inputStream
+      readBytes = inputStream.read(8, buffer);
+      byte[] value3 = new byte[readBytes];
+      System.arraycopy(buffer.array(), 0, value3, 0, readBytes);
+      byte[] value4 = new byte[readBytes];
+      System.arraycopy(data, 8, value4, 0, readBytes);
+      // Verify input and positional read data
+      assertArrayEquals(value3, value4, "value mismatch");
+
+      // Buffer size more than actual data, still read should succeed
+      ByteBuffer buffer1 = ByteBuffer.allocate(30 * 1024 * 1024 * 2);
+      readBytes = inputStream.read(12, buffer1);
+      byte[] value5 = new byte[readBytes];
+      System.arraycopy(buffer1.array(), 0, value5, 0, readBytes);
+      byte[] value6 = new byte[readBytes];
+      System.arraycopy(data, 12, value6, 0, readBytes);
+      // Verify input and positional read data
+      assertArrayEquals(value5, value6, "value mismatch");
+    }
+  }
+
+
+  @Test
+  public void testByteBufferPositionedReadFully() throws IOException {
+    try (FSDataInputStream inputStream = fs.open(filePath)) {
+      int bufferCapacity = 20;
+      ByteBuffer buffer = ByteBuffer.allocate(bufferCapacity);
+      // Read positional from 50th index
+      inputStream.readFully(50, buffer);
+      byte[] value1 = new byte[bufferCapacity];
+      System.arraycopy(buffer.array(), 0, value1, 0, bufferCapacity);
+      byte[] value2 = new byte[bufferCapacity];
+      System.arraycopy(data, 50, value2, 0, bufferCapacity);
+      // Verify input and positional read data
+      assertArrayEquals(value1, value2, "value mismatch");
+
+      buffer.clear();
+      // Verify offset of file didn't change
+      // Read positional from 8th index again using same inputStream
+      inputStream.readFully(8, buffer);
+      byte[] value3 = new byte[bufferCapacity];
+      System.arraycopy(buffer.array(), 0, value3, 0, bufferCapacity);
+      byte[] value4 = new byte[bufferCapacity];
+      System.arraycopy(data, 8, value4, 0, bufferCapacity);
+      // Verify input and positional read data
+      assertArrayEquals(value3, value4, "value mismatch");
+
+      // Buffer size is more than actual data, readFully should fail in this case
+      ByteBuffer buffer1 = ByteBuffer.allocate(30 * 1024 * 1024 * 2);
+      assertThrows(EOFException.class, () -> inputStream.readFully(12, buffer1));
+    }
+  }
+
+
+
   @Test
   public void testO3FSMultiByteRead() throws IOException {
     try (FSDataInputStream inputStream = fs.open(filePath)) {

hadoop-ozone/ozonefs-common/src/main/java/org/apache/hadoop/fs/ByteBufferPositionedReadable.java

@@ -0,0 +1,92 @@
+/**
+ * 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.fs;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+
+/**
+ * FIXME: Hack: This is copied from Hadoop 3.3.6. Remove this interface once
+ * we drop Hadoop 3.1, 3.2 support.
+ * Implementers of this interface provide a positioned read API that writes to a
+ * {@link ByteBuffer} rather than a {@code byte[]}.
+ *
+ * @see PositionedReadable
+ * @see ByteBufferReadable
+ */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public interface ByteBufferPositionedReadable {
+  /**
+   * Reads up to {@code buf.remaining()} bytes into buf from a given position
+   * in the file and returns the number of bytes read. Callers should use
+   * {@code buf.limit(...)} to control the size of the desired read and
+   * {@code buf.position(...)} to control the offset into the buffer the data
+   * should be written to.
+   * <p>
+   * After a successful call, {@code buf.position()} will be advanced by the
+   * number of bytes read and {@code buf.limit()} will be unchanged.
+   * <p>
+   * In the case of an exception, the state of the buffer (the contents of the
+   * buffer, the {@code buf.position()}, the {@code buf.limit()}, etc.) is
+   * undefined, and callers should be prepared to recover from this
+   * eventuality.
+   * <p>
+   * Callers should use {@link StreamCapabilities#hasCapability(String)} with
+   * {@link StreamCapabilities#PREADBYTEBUFFER} to check if the underlying
+   * stream supports this interface, otherwise they might get a
+   * {@link UnsupportedOperationException}.
+   * <p>
+   * Implementations should treat 0-length requests as legitimate, and must not
+   * signal an error upon their receipt.
+   * <p>
+   * This does not change the current offset of a file, and is thread-safe.
+   *
+   * @param position position within file
+   * @param buf the ByteBuffer to receive the results of the read operation.
+   * @return the number of bytes read, possibly zero, or -1 if reached
+   *         end-of-stream
+   * @throws IOException if there is some error performing the read
+   */
+  int read(long position, ByteBuffer buf) throws IOException;
+
+  /**
+   * Reads {@code buf.remaining()} bytes into buf from a given position in
+   * the file or until the end of the data was reached before the read
+   * operation completed. Callers should use {@code buf.limit(...)} to
+   * control the size of the desired read and {@code buf.position(...)} to
+   * control the offset into the buffer the data should be written to.
+   * <p>
+   * This operation provides similar semantics to
+   * {@link #read(long, ByteBuffer)}, the difference is that this method is
+   * guaranteed to read data until the {@link ByteBuffer} is full, or until
+   * the end of the data stream is reached.
+   *
+   * @param position position within file
+   * @param buf the ByteBuffer to receive the results of the read operation.
+   * @throws IOException if there is some error performing the read
+   * @throws EOFException the end of the data was reached before
+   * the read operation completed
+   * @see #read(long, ByteBuffer)
+   */
+  void readFully(long position, ByteBuffer buf) throws IOException;
+}

hadoop-ozone/ozonefs-common/src/main/java/org/apache/hadoop/fs/ozone/CapableOzoneFSInputStream.java

@@ -35,6 +35,7 @@ public boolean hasCapability(String capability) {
     switch (StringUtils.toLowerCase(capability)) {
     case StreamCapabilities.READBYTEBUFFER:
     case StreamCapabilities.UNBUFFER:
+    case StreamCapabilities.PREADBYTEBUFFER:
       return true;
     default:
       return false;

hadoop-ozone/ozonefs-common/src/main/java/org/apache/hadoop/fs/ozone/OzoneFSInputStream.java

@@ -18,6 +18,7 @@
 
 package org.apache.hadoop.fs.ozone;
 
+import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.ByteBuffer;
@@ -27,6 +28,7 @@
 import org.apache.hadoop.hdds.annotation.InterfaceAudience;
 import org.apache.hadoop.hdds.annotation.InterfaceStability;
 import org.apache.hadoop.fs.ByteBufferReadable;
+import org.apache.hadoop.fs.ByteBufferPositionedReadable;
 import org.apache.hadoop.fs.FSInputStream;
 import org.apache.hadoop.fs.FileSystem.Statistics;
 import org.apache.hadoop.fs.Seekable;
@@ -40,7 +42,7 @@
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
 public class OzoneFSInputStream extends FSInputStream
-    implements ByteBufferReadable, CanUnbuffer {
+    implements ByteBufferReadable, CanUnbuffer, ByteBufferPositionedReadable {
 
   private final InputStream inputStream;
   private final Statistics statistics;
@@ -137,4 +139,49 @@ public void unbuffer() {
       ((CanUnbuffer) inputStream).unbuffer();
     }
   }
+
+  /**
+   * @param buf the ByteBuffer to receive the results of the read operation.
+   * @param position offset
+   * @return the number of bytes read, possibly zero, or -1 if
+   *         reach end-of-stream
+   * @throws IOException if there is some error performing the read
+   */
+  @Override
+  public int read(long position, ByteBuffer buf) throws IOException {
+    if (!buf.hasRemaining()) {
+      return 0;
+    }
+    long oldPos = this.getPos();
+    int bytesRead;
+    try {
+      ((Seekable) inputStream).seek(position);
+      bytesRead = ((ByteBufferReadable) inputStream).read(buf);
+    } catch (EOFException e) {
+      // Either position is negative or it has reached EOF
+      return -1;
+    } finally {
+      ((Seekable) inputStream).seek(oldPos);
+    }
+    return bytesRead;
+  }
+
+  /**
+   * @param buf the ByteBuffer to receive the results of the read operation.
+   * @param position offset
+   * @return void
+   * @throws IOException if there is some error performing the read
+   * @throws EOFException if end of file reched before reading fully
+   */
+  @Override
+  public void readFully(long position, ByteBuffer buf) throws IOException {
+    int bytesRead;
+    for (int readCount = 0; buf.hasRemaining(); readCount += bytesRead) {
+      bytesRead = this.read(position + (long)readCount, buf);
+      if (bytesRead < 0) {
+        // Still buffer had space to read but stream has already reached EOF
+        throw new EOFException("End of file reached before reading fully.");
+      }
+    }
+  }
 }