Revert "HDFS-14564: Add libhdfs APIs for readFully; add readFully to ByteBufferPositionedReadable (apache#963) Contributed by Sahil Takiar."

This reverts commit 12d7d26.

Author: harshith-212

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

@@ -33,7 +33,6 @@
 import com.google.common.base.Preconditions;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
-import org.apache.hadoop.fs.ByteBufferPositionedReadable;
 import org.apache.hadoop.fs.ByteBufferReadable;
 import org.apache.hadoop.fs.CanSetDropBehind;
 import org.apache.hadoop.fs.CanSetReadahead;
@@ -329,40 +328,20 @@ public int read(long position, byte[] buffer, int offset, int length)
       throws IOException {
     checkStream();
     try {
-      final int n = ((PositionedReadable) in).read(position, buffer, offset,
+      final int n = ((PositionedReadable) in).read(position, buffer, offset, 
           length);
       if (n > 0) {
         // This operation does not change the current offset of the file
         decrypt(position, buffer, offset, n);
       }
-
+      
       return n;
     } catch (ClassCastException e) {
       throw new UnsupportedOperationException("This stream does not support " +
           "positioned read.");
     }
   }
-
-  /**
-   * 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.
@@ -396,7 +375,7 @@ private void decrypt(long position, byte[] buffer, int offset, int length)
       returnDecryptor(decryptor);
     }
   }
-
+  
   /** Positioned read fully. It is thread-safe */
   @Override
   public void readFully(long position, byte[] buffer, int offset, int length)
@@ -428,7 +407,7 @@ public void seek(long pos) throws IOException {
     checkStream();
     try {
       /*
-       * If data of target pos in the underlying stream has already been read
+       * If data of target pos in the underlying stream has already been read 
        * and decrypted in outBuffer, we just need to re-position outBuffer.
        */
       if (pos <= streamOffset && pos >= (streamOffset - outBuffer.remaining())) {
@@ -544,7 +523,7 @@ public int read(ByteBuffer buf) throws IOException {
    * Output is also buf and same start position.
    * buf.position() and buf.limit() should be unchanged after decryption.
    */
-  private void decrypt(ByteBuffer buf, int n, int start)
+  private void decrypt(ByteBuffer buf, int n, int start) 
       throws IOException {
     final int pos = buf.position();
     final int limit = buf.limit();
@@ -626,7 +605,7 @@ public ByteBuffer read(ByteBufferPool bufferPool, int maxLength,
       }
       return buffer;
     } catch (ClassCastException e) {
-      throw new UnsupportedOperationException("This stream does not support " +
+      throw new UnsupportedOperationException("This stream does not support " + 
           "enhanced byte buffer access.");
     }
   }

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

@@ -38,8 +38,7 @@
 public class FSDataInputStream extends DataInputStream
     implements Seekable, PositionedReadable, 
       ByteBufferReadable, HasFileDescriptor, CanSetDropBehind, CanSetReadahead,
-      HasEnhancedByteBufferAccess, CanUnbuffer, StreamCapabilities,
-      ByteBufferPositionedReadable {
+      HasEnhancedByteBufferAccess, CanUnbuffer, StreamCapabilities {
   /**
    * Map ByteBuffers that we have handed out to readers to ByteBufferPool 
    * objects
@@ -51,8 +50,8 @@ public class FSDataInputStream extends DataInputStream
   public FSDataInputStream(InputStream in) {
     super(in);
     if( !(in instanceof Seekable) || !(in instanceof PositionedReadable) ) {
-      throw new IllegalArgumentException(in.getClass().getCanonicalName() +
-          " is not an instance of Seekable or PositionedReadable");
+      throw new IllegalArgumentException(
+          "In is not an instance of Seekable or PositionedReadable");
     }
   }
 
@@ -148,8 +147,7 @@ public int read(ByteBuffer buf) throws IOException {
       return ((ByteBufferReadable)in).read(buf);
     }
 
-    throw new UnsupportedOperationException("Byte-buffer read unsupported " +
-            "by " + in.getClass().getCanonicalName());
+    throw new UnsupportedOperationException("Byte-buffer read unsupported by input stream");
   }
 
   @Override
@@ -169,8 +167,9 @@ public void setReadahead(Long readahead)
     try {
       ((CanSetReadahead)in).setReadahead(readahead);
     } catch (ClassCastException e) {
-      throw new UnsupportedOperationException(in.getClass().getCanonicalName() +
-          " does not support setting the readahead caching strategy.");
+      throw new UnsupportedOperationException(
+          "this stream does not support setting the readahead " +
+          "caching strategy.");
     }
   }
 
@@ -247,23 +246,4 @@ public boolean hasCapability(String capability) {
   public String toString() {
     return super.toString() + ": " + in;
   }
-
-  @Override
-  public int read(long position, ByteBuffer buf) throws IOException {
-    if (in instanceof ByteBufferPositionedReadable) {
-      return ((ByteBufferPositionedReadable) in).read(position, buf);
-    }
-    throw new UnsupportedOperationException("Byte-buffer pread unsupported " +
-        "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/main/java/org/apache/hadoop/fs/FSDataInputStream.java

@@ -316,41 +316,42 @@ private void positionedReadCheck(InputStream in, int pos) throws Exception {
     Assert.assertArrayEquals(readData, expectedData);
   }
 
-  /** Test read fully. */
+  /** Test read fully */
   @Test(timeout=120000)
   public void testReadFully() 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
-      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);
-    }
+    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();
   }
 
   private void readFullyCheck(InputStream in, int pos) throws Exception {
@@ -368,60 +369,6 @@ 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)