HDFS-14564: Add libhdfs APIs for readFully; add readFully to ByteBufferPositionedReadable

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/CryptoInputStream.java

@@ -330,8 +330,8 @@ public int read(long position, byte[] buffer, int offset, int length)
       throws IOException {
     checkStream();
     if (!(in instanceof PositionedReadable)) {
-      throw new UnsupportedOperationException("This stream does not support " +
-          "positioned read.");
+      throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+          + " does not support positioned read.");
     }
     final int n = ((PositionedReadable) in).read(position, buffer, offset,
         length);
@@ -351,8 +351,8 @@ public int read(long position, final ByteBuffer buf)
       throws IOException {
     checkStream();
     if (!(in instanceof ByteBufferPositionedReadable)) {
-      throw new UnsupportedOperationException("This stream does not support " +
-          "positioned reads with byte buffers.");
+      throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+          + " does not support positioned reads with byte buffers.");
     }
     int bufPos = buf.position();
     final int n = ((ByteBufferPositionedReadable) in).read(position, buf);
@@ -363,7 +363,27 @@ public int read(long position, final ByteBuffer buf)
 
     return n;
   }
-
+
+  /**
+   * Positioned readFully using {@link ByteBuffer}s. This method is thread-safe.
+   */
+  @Override
+  public void readFully(long position, final ByteBuffer buf)
+      throws IOException {
+    checkStream();
+    if (!(in instanceof ByteBufferPositionedReadable)) {
+      throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+          + " does not support positioned reads with byte buffers.");
+    }
+    int bufPos = buf.position();
+    ((ByteBufferPositionedReadable) in).readFully(position, buf);
+    final int n = buf.position() - bufPos;
+    if (n > 0) {
+      // This operation does not change the current offset of the file
+      decrypt(position, buf, n, bufPos);
+    }
+  }
+
   /**
    * Decrypt length bytes in buffer starting at offset. Output is also put 
    * into buffer starting at offset. It is thread-safe.
@@ -480,8 +500,8 @@ public void readFully(long position, byte[] buffer, int offset, int length)
       throws IOException {
     checkStream();
     if (!(in instanceof PositionedReadable)) {
-      throw new UnsupportedOperationException("This stream does not support " +
-          "positioned readFully.");
+      throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+          + " does not support positioned readFully.");
     }
     ((PositionedReadable) in).readFully(position, buffer, offset, length);
     if (length > 0) {
@@ -513,8 +533,8 @@ public void seek(long pos) throws IOException {
       }
     } else {
       if (!(in instanceof Seekable)) {
-        throw new UnsupportedOperationException("This stream does not " +
-                "support seek.");
+        throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+            + " does not support seek.");
       }
       ((Seekable) in).seek(pos);
       resetStreamOffset(pos);
@@ -672,8 +692,8 @@ public boolean seekToNewSource(long targetPos) throws IOException {
         "Cannot seek to negative offset.");
     checkStream();
     if (!(in instanceof Seekable)) {
-      throw new UnsupportedOperationException("This stream does not support " +
-          "seekToNewSource.");
+      throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+          + " does not support seekToNewSource.");
     }
     boolean result = ((Seekable) in).seekToNewSource(targetPos);
     resetStreamOffset(targetPos);
@@ -687,16 +707,16 @@ public ByteBuffer read(ByteBufferPool bufferPool, int maxLength,
     checkStream();
     if (outBuffer.remaining() > 0) {
       if (!(in instanceof Seekable)) {
-        throw new UnsupportedOperationException("This stream does not " +
-                "support seek.");
+        throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+            + " does not support seek.");
       }
       // Have some decrypted data unread, need to reset.
       ((Seekable) in).seek(getPos());
       resetStreamOffset(getPos());
     }
     if (!(in instanceof HasEnhancedByteBufferAccess)) {
-      throw new UnsupportedOperationException("This stream does not support " +
-          "enhanced byte buffer access.");
+      throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+          + " does not support enhanced byte buffer access.");
     }
     final ByteBuffer buffer = ((HasEnhancedByteBufferAccess) in).
         read(bufferPool, maxLength, opts);
@@ -714,8 +734,8 @@ public ByteBuffer read(ByteBufferPool bufferPool, int maxLength,
   @Override
   public void releaseBuffer(ByteBuffer buffer) {
     if (!(in instanceof HasEnhancedByteBufferAccess)) {
-      throw new UnsupportedOperationException("This stream does not support " + 
-          "release buffer.");
+      throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+          + " does not support release buffer.");
     }
     ((HasEnhancedByteBufferAccess) in).releaseBuffer(buffer);
   }
@@ -724,8 +744,8 @@ public void releaseBuffer(ByteBuffer buffer) {
   public void setReadahead(Long readahead) throws IOException,
       UnsupportedOperationException {
     if (!(in instanceof CanSetReadahead)) {
-      throw new UnsupportedOperationException("This stream does not support " +
-          "setting the readahead caching strategy.");
+      throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+          + " does not support setting the readahead caching strategy.");
     }
     ((CanSetReadahead) in).setReadahead(readahead);
   }
@@ -734,8 +754,9 @@ public void setReadahead(Long readahead) throws IOException,
   public void setDropBehind(Boolean dropCache) throws IOException,
       UnsupportedOperationException {
     if (!(in instanceof CanSetReadahead)) {
-      throw new UnsupportedOperationException("This stream does not " +
-          "support setting the drop-behind caching setting.");
+      throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+          + " stream does not support setting the drop-behind caching"
+          + " setting.");
     }
     ((CanSetDropBehind) in).setDropBehind(dropCache);
   }
@@ -842,8 +863,8 @@ public boolean hasCapability(String capability) {
     case StreamCapabilities.READBYTEBUFFER:
     case StreamCapabilities.PREADBYTEBUFFER:
       if (!(in instanceof StreamCapabilities)) {
-        throw new UnsupportedOperationException("This stream does not expose " +
-          "its stream capabilities.");
+        throw new UnsupportedOperationException(in.getClass().getCanonicalName()
+          + " does not expose its stream capabilities.");
       }
       return ((StreamCapabilities) in).hasCapability(capability);
     default:

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

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.fs;
 
+import java.io.EOFException;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 
@@ -55,6 +56,8 @@ public interface ByteBufferPositionedReadable {
    * <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.
@@ -63,4 +66,25 @@ public interface ByteBufferPositionedReadable {
    * @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-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FSDataInputStream.java

@@ -52,8 +52,8 @@ public class FSDataInputStream extends DataInputStream
   public FSDataInputStream(InputStream in) {
     super(in);
     if( !(in instanceof Seekable) || !(in instanceof PositionedReadable) ) {
-      throw new IllegalArgumentException(
-          "In is not an instance of Seekable or PositionedReadable");
+      throw new IllegalArgumentException(in.getClass().getCanonicalName() +
+          " is not an instance of Seekable or PositionedReadable");
     }
   }
 
@@ -150,7 +150,7 @@ public int read(ByteBuffer buf) throws IOException {
     }
 
     throw new UnsupportedOperationException("Byte-buffer read unsupported " +
-            "by input stream");
+            "by " + in.getClass().getCanonicalName());
   }
 
   @Override
@@ -170,9 +170,8 @@ public void setReadahead(Long readahead)
     try {
       ((CanSetReadahead)in).setReadahead(readahead);
     } catch (ClassCastException e) {
-      throw new UnsupportedOperationException(
-          "this stream does not support setting the readahead " +
-          "caching strategy.");
+      throw new UnsupportedOperationException(in.getClass().getCanonicalName() +
+          " does not support setting the readahead caching strategy.");
     }
   }
 
@@ -256,6 +255,16 @@ public int read(long position, ByteBuffer buf) throws IOException {
       return ((ByteBufferPositionedReadable) in).read(position, buf);
     }
     throw new UnsupportedOperationException("Byte-buffer pread unsupported " +
-        "by input stream");
+        "by " + in.getClass().getCanonicalName());
+  }
+
+  @Override
+  public void readFully(long position, ByteBuffer buf) throws IOException {
+    if (in instanceof ByteBufferPositionedReadable) {
+      ((ByteBufferPositionedReadable) in).readFully(position, buf);
+    } else {
+      throw new UnsupportedOperationException("Byte-buffer pread " +
+              "unsupported by " + in.getClass().getCanonicalName());
+    }
   }
 }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/CryptoStreamsTestBase.java

@@ -388,42 +388,41 @@ private void positionedReadCheckWithByteBuffer(InputStream in, int pos)
     Assert.assertArrayEquals(readData, expectedData);
   }
 
-  /** Test read fully */
+  /** Test read fully. */
   @Test(timeout=120000)
   public void testReadFully() throws Exception {
     OutputStream out = getOutputStream(defaultBufferSize);
     writeData(out);
 
-    InputStream in = getInputStream(defaultBufferSize);
-    final int len1 = dataLen / 4;
-    // Read len1 bytes
-    byte[] readData = new byte[len1];
-    readAll(in, readData, 0, len1);
-    byte[] expectedData = new byte[len1];
-    System.arraycopy(data, 0, expectedData, 0, len1);
-    Assert.assertArrayEquals(readData, expectedData);
-
-    // Pos: 1/3 dataLen
-    readFullyCheck(in, dataLen / 3);
-
-    // Read len1 bytes
-    readData = new byte[len1];
-    readAll(in, readData, 0, len1);
-    expectedData = new byte[len1];
-    System.arraycopy(data, len1, expectedData, 0, len1);
-    Assert.assertArrayEquals(readData, expectedData);
-
-    // Pos: 1/2 dataLen
-    readFullyCheck(in, dataLen / 2);
-
-    // Read len1 bytes
-    readData = new byte[len1];
-    readAll(in, readData, 0, len1);
-    expectedData = new byte[len1];
-    System.arraycopy(data, 2 * len1, expectedData, 0, len1);
-    Assert.assertArrayEquals(readData, expectedData);
-
-    in.close();
+    try (InputStream in = getInputStream(defaultBufferSize)) {
+      final int len1 = dataLen / 4;
+      // Read len1 bytes
+      byte[] readData = new byte[len1];
+      readAll(in, readData, 0, len1);
+      byte[] expectedData = new byte[len1];
+      System.arraycopy(data, 0, expectedData, 0, len1);
+      Assert.assertArrayEquals(readData, expectedData);
+
+      // Pos: 1/3 dataLen
+      readFullyCheck(in, dataLen / 3);
+
+      // Read len1 bytes
+      readData = new byte[len1];
+      readAll(in, readData, 0, len1);
+      expectedData = new byte[len1];
+      System.arraycopy(data, len1, expectedData, 0, len1);
+      Assert.assertArrayEquals(readData, expectedData);
+
+      // Pos: 1/2 dataLen
+      readFullyCheck(in, dataLen / 2);
+
+      // Read len1 bytes
+      readData = new byte[len1];
+      readAll(in, readData, 0, len1);
+      expectedData = new byte[len1];
+      System.arraycopy(data, 2 * len1, expectedData, 0, len1);
+      Assert.assertArrayEquals(readData, expectedData);
+    }
   }
 
   private void readFullyCheck(InputStream in, int pos) throws Exception {
@@ -441,6 +440,60 @@ private void readFullyCheck(InputStream in, int pos) throws Exception {
     } catch (EOFException e) {
     }
   }
+
+  /** Test byte byffer read fully. */
+  @Test(timeout=120000)
+  public void testByteBufferReadFully() throws Exception {
+    OutputStream out = getOutputStream(defaultBufferSize);
+    writeData(out);
+
+    try (InputStream in = getInputStream(defaultBufferSize)) {
+      final int len1 = dataLen / 4;
+      // Read len1 bytes
+      byte[] readData = new byte[len1];
+      readAll(in, readData, 0, len1);
+      byte[] expectedData = new byte[len1];
+      System.arraycopy(data, 0, expectedData, 0, len1);
+      Assert.assertArrayEquals(readData, expectedData);
+
+      // Pos: 1/3 dataLen
+      byteBufferReadFullyCheck(in, dataLen / 3);
+
+      // Read len1 bytes
+      readData = new byte[len1];
+      readAll(in, readData, 0, len1);
+      expectedData = new byte[len1];
+      System.arraycopy(data, len1, expectedData, 0, len1);
+      Assert.assertArrayEquals(readData, expectedData);
+
+      // Pos: 1/2 dataLen
+      byteBufferReadFullyCheck(in, dataLen / 2);
+
+      // Read len1 bytes
+      readData = new byte[len1];
+      readAll(in, readData, 0, len1);
+      expectedData = new byte[len1];
+      System.arraycopy(data, 2 * len1, expectedData, 0, len1);
+      Assert.assertArrayEquals(readData, expectedData);
+    }
+  }
+
+  private void byteBufferReadFullyCheck(InputStream in, int pos)
+          throws Exception {
+    ByteBuffer result = ByteBuffer.allocate(dataLen - pos);
+    ((ByteBufferPositionedReadable) in).readFully(pos, result);
+
+    byte[] expectedData = new byte[dataLen - pos];
+    System.arraycopy(data, pos, expectedData, 0, dataLen - pos);
+    Assert.assertArrayEquals(result.array(), expectedData);
+
+    result = ByteBuffer.allocate(dataLen); // Exceeds maximum length
+    try {
+      ((ByteBufferPositionedReadable) in).readFully(pos, result);
+      Assert.fail("Read fully exceeds maximum length should fail.");
+    } catch (EOFException e) {
+    }
+  }
 
   /** Test seek to different position. */
   @Test(timeout=120000)