commit 595594756257beb8d4d3349f2117d677389f3c6f

Author: Arun C Murthy <acmurthy@apache.org>
Date:   Sun Jan 23 00:09:31 2011 -0800

    . Added Data(In,Out)putByteBuffer to work with ByteBuffer similar to Data(In,Out)putBuffer for byte[]. Contributed by Chris Douglas.
    
    +++ b/YAHOO-CHANGES.txt
    +    . Added Data(In,Out)putByteBuffer to work with ByteBuffer
    +    similar to Data(In,Out)putBuffer for byte[]. (cdouglas via acmurthy)
    +


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/yahoo-merge@1079163 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/hadoop/io/DataInputByteBuffer.java

@@ -0,0 +1,82 @@
+package org.apache.hadoop.io;
+
+import java.io.DataInputStream;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.util.LinkedList;
+import java.util.List;
+
+public class DataInputByteBuffer extends DataInputStream {
+
+  private static class Buffer extends InputStream {
+    private final byte[] scratch = new byte[1];
+    ByteBuffer[] buffers = new ByteBuffer[0];
+    int bidx, pos, length;
+    @Override
+    public int read() {
+      if (-1 == read(scratch, 0, 1)) {
+        return -1;
+      }
+      return scratch[0] & 0xFF;
+    }
+    @Override
+    public int read(byte[] b, int off, int len) {
+      if (bidx >= buffers.length) {
+        return -1;
+      }
+      int cur = 0;
+      do {
+        int rem = Math.min(len, buffers[bidx].remaining());
+        buffers[bidx].get(b, off, rem);
+        cur += rem;
+        off += rem;
+        len -= rem;
+      } while (len > 0 && ++bidx < buffers.length);
+      pos += cur;
+      return cur;
+    }
+    public void reset(ByteBuffer[] buffers) {
+      bidx = pos = length = 0;
+      this.buffers = buffers;
+      for (ByteBuffer b : buffers) {
+        length += b.remaining();
+      }
+    }
+    public int getPosition() {
+      return pos;
+    }
+    public int getLength() {
+      return length;
+    }
+    public ByteBuffer[] getData() {
+      return buffers;
+    }
+  }
+
+  private Buffer buffers;
+
+  public DataInputByteBuffer() {
+    this(new Buffer());
+  }
+
+  private DataInputByteBuffer(Buffer buffers) {
+    super(buffers);
+    this.buffers = buffers;
+  }
+
+  public void reset(ByteBuffer... input) {
+    buffers.reset(input);
+  }
+
+  public ByteBuffer[] getData() {
+    return buffers.getData();
+  }
+
+  public int getPosition() {
+    return buffers.getPosition();
+  }
+
+  public int getLength() {
+    return buffers.getLength();
+  }
+}

src/java/org/apache/hadoop/io/DataOutputByteBuffer.java

@@ -0,0 +1,119 @@
+package org.apache.hadoop.io;
+
+import java.io.DataOutputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.util.List;
+import java.util.ArrayList;
+import java.util.LinkedList;
+
+public class DataOutputByteBuffer extends DataOutputStream {
+
+   static class Buffer extends OutputStream {
+
+    final byte[] b = new byte[1];
+    final boolean direct;
+    final List<ByteBuffer> active = new ArrayList<ByteBuffer>();
+    final List<ByteBuffer> inactive = new LinkedList<ByteBuffer>();
+    int size;
+    int length;
+    ByteBuffer current;
+
+    Buffer(int size, boolean direct) {
+      this.direct = direct;
+      this.size = size;
+      current = direct
+          ? ByteBuffer.allocateDirect(size)
+          : ByteBuffer.allocate(size);
+    }
+    @Override
+    public void write(int b) {
+      this.b[0] = (byte)(b & 0xFF);
+      write(this.b);
+    }
+    @Override
+    public void write(byte[] b) {
+      write(b, 0, b.length);
+    }
+    @Override
+    public void write(byte[] b, int off, int len) {
+      int rem = current.remaining();
+      while (len > rem) {
+        current.put(b, off, rem);
+        length += rem;
+        current.flip();
+        active.add(current);
+        off += rem;
+        len -= rem;
+        rem = getBuffer(len);
+      }
+      current.put(b, off, len);
+      length += len;
+    }
+    int getBuffer(int newsize) {
+      if (inactive.isEmpty()) {
+        size = Math.max(size << 1, newsize);
+        current = direct
+            ? ByteBuffer.allocateDirect(size)
+            : ByteBuffer.allocate(size);
+      } else {
+        current = inactive.remove(0);
+      }
+      return current.remaining();
+    }
+    ByteBuffer[] getData() {
+      ByteBuffer[] ret = active.toArray(new ByteBuffer[active.size() + 1]);
+      ByteBuffer tmp = current.duplicate();
+      tmp.flip();
+      ret[ret.length - 1] = tmp.slice();
+      return ret;
+    }
+    int getLength() {
+      return length;
+    }
+    void reset() {
+      length = 0;
+      current.rewind();
+      inactive.add(0, current);
+      for (int i = active.size() - 1; i >= 0; --i) {
+        ByteBuffer b = active.remove(i);
+        b.rewind();
+        inactive.add(0, b);
+      }
+      current = inactive.remove(0);
+    }
+  }
+
+  private final Buffer buffers;
+
+  public DataOutputByteBuffer() {
+    this(32);
+  }
+
+  public DataOutputByteBuffer(int size) {
+    this(size, false);
+  }
+
+  public DataOutputByteBuffer(int size, boolean direct) {
+    this(new Buffer(size, direct));
+  }
+
+  private DataOutputByteBuffer(Buffer buffers) {
+    super(buffers);
+    this.buffers = buffers;
+  }
+
+  public ByteBuffer[] getData() {
+    return buffers.getData();
+  }
+
+  public int getLength() {
+    return buffers.getLength();
+  }
+
+  public void reset() {
+    this.written = 0;
+    buffers.reset();
+  }
+
+}

src/test/core/org/apache/hadoop/io/TestDataByteBuffers.java

@@ -0,0 +1,177 @@
+package org.apache.hadoop.io;
+
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Random;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class TestDataByteBuffers {
+
+  private static void readJunk(DataInput in, Random r, long seed, int iter) 
+      throws IOException {
+    r.setSeed(seed);
+    for (int i = 0; i < iter; ++i) {
+      switch (r.nextInt(7)) {
+        case 0:
+          assertEquals((byte)(r.nextInt() & 0xFF), in.readByte()); break;
+        case 1:
+          assertEquals((short)(r.nextInt() & 0xFFFF), in.readShort()); break;
+        case 2:
+          assertEquals(r.nextInt(), in.readInt()); break;
+        case 3:
+          assertEquals(r.nextLong(), in.readLong()); break;
+        case 4:
+          assertEquals(Double.doubleToLongBits(r.nextDouble()),
+                       Double.doubleToLongBits(in.readDouble())); break;
+        case 5:
+          assertEquals(Float.floatToIntBits(r.nextFloat()),
+                       Float.floatToIntBits(in.readFloat())); break;
+        case 6:
+          int len = r.nextInt(1024);
+          byte[] vb = new byte[len];
+          r.nextBytes(vb);
+          byte[] b = new byte[len];
+          in.readFully(b, 0, len);
+          assertArrayEquals(vb, b);
+          break;
+      }
+    }
+  }
+
+  private static void writeJunk(DataOutput out, Random r, long seed, int iter)
+      throws IOException  {
+    r.setSeed(seed);
+    for (int i = 0; i < iter; ++i) {
+      switch (r.nextInt(7)) {
+        case 0: out.writeByte(r.nextInt()); break;
+        case 1: out.writeShort((short)(r.nextInt() & 0xFFFF)); break;
+        case 2: out.writeInt(r.nextInt()); break;
+        case 3: out.writeLong(r.nextLong()); break;
+        case 4: out.writeDouble(r.nextDouble()); break;
+        case 5: out.writeFloat(r.nextFloat()); break;
+        case 6:
+          byte[] b = new byte[r.nextInt(1024)];
+          r.nextBytes(b);
+          out.write(b);
+          break;
+      }
+    }
+  }
+
+  @Test
+  public void testBaseBuffers() throws IOException {
+    DataOutputBuffer dob = new DataOutputBuffer();
+    Random r = new Random();
+    long seed = r.nextLong();
+    r.setSeed(seed);
+    System.out.println("SEED: " + seed);
+    writeJunk(dob, r, seed, 1000);
+    DataInputBuffer dib = new DataInputBuffer();
+    dib.reset(dob.getData(), 0, dob.getLength());
+    readJunk(dib, r, seed, 1000);
+
+    dob.reset();
+    writeJunk(dob, r, seed, 1000);
+    dib.reset(dob.getData(), 0, dob.getLength());
+    readJunk(dib, r, seed, 1000);
+  }
+
+  @Test
+  public void testByteBuffers() throws IOException {
+    DataOutputByteBuffer dob = new DataOutputByteBuffer();
+    Random r = new Random();
+    long seed = r.nextLong();
+    r.setSeed(seed);
+    System.out.println("SEED: " + seed);
+    writeJunk(dob, r, seed, 1000);
+    DataInputByteBuffer dib = new DataInputByteBuffer();
+    dib.reset(dob.getData());
+    readJunk(dib, r, seed, 1000);
+
+    dob.reset();
+    writeJunk(dob, r, seed, 1000);
+    dib.reset(dob.getData());
+    readJunk(dib, r, seed, 1000);
+  }
+
+  private static byte[] toBytes(ByteBuffer[] bufs, int len) {
+    byte[] ret = new byte[len];
+    int pos = 0;
+    for (int i = 0; i < bufs.length; ++i) {
+      int rem = bufs[i].remaining();
+      bufs[i].get(ret, pos, rem);
+      pos += rem;
+    }
+    return ret;
+  }
+
+  @Test
+  public void testDataOutputByteBufferCompatibility() throws IOException {
+    DataOutputBuffer dob = new DataOutputBuffer();
+    DataOutputByteBuffer dobb = new DataOutputByteBuffer();
+    Random r = new Random();
+    long seed = r.nextLong();
+    r.setSeed(seed);
+    System.out.println("SEED: " + seed);
+    writeJunk(dob, r, seed, 1000);
+    writeJunk(dobb, r, seed, 1000);
+    byte[] check = toBytes(dobb.getData(), dobb.getLength());
+    assertEquals(dob.getLength(), check.length);
+    assertArrayEquals(Arrays.copyOf(dob.getData(), dob.getLength()), check);
+
+    dob.reset();
+    dobb.reset();
+    writeJunk(dob, r, seed, 3000);
+    writeJunk(dobb, r, seed, 3000);
+    check = toBytes(dobb.getData(), dobb.getLength());
+    assertEquals(dob.getLength(), check.length);
+    assertArrayEquals(Arrays.copyOf(dob.getData(), dob.getLength()), check);
+
+    dob.reset();
+    dobb.reset();
+    writeJunk(dob, r, seed, 1000);
+    writeJunk(dobb, r, seed, 1000);
+    check = toBytes(dobb.getData(), dobb.getLength());
+    assertEquals(dob.getLength(), check.length);
+    assertArrayEquals(Arrays.copyOf(dob.getData(), dob.getLength()), check);
+  }
+
+  @Test
+  public void TestDataInputByteBufferCompatibility() throws IOException {
+    DataOutputBuffer dob = new DataOutputBuffer();
+    Random r = new Random();
+    long seed = r.nextLong();
+    r.setSeed(seed);
+    System.out.println("SEED: " + seed);
+    writeJunk(dob, r, seed, 1000);
+    ByteBuffer buf = ByteBuffer.wrap(dob.getData(), 0, dob.getLength());
+
+    DataInputByteBuffer dib = new DataInputByteBuffer();
+    dib.reset(buf);
+    readJunk(dib, r, seed, 1000);
+  }
+
+  @Test
+  public void TestDataOutputByteBufferCompatibility() throws IOException {
+    DataOutputByteBuffer dob = new DataOutputByteBuffer();
+    Random r = new Random();
+    long seed = r.nextLong();
+    r.setSeed(seed);
+    System.out.println("SEED: " + seed);
+    writeJunk(dob, r, seed, 1000);
+    ByteBuffer buf = ByteBuffer.allocate(dob.getLength());
+    for (ByteBuffer b : dob.getData()) {
+      buf.put(b);
+    }
+    buf.flip();
+    DataInputBuffer dib = new DataInputBuffer();
+    dib.reset(buf.array(), 0, buf.remaining());
+    readJunk(dib, r, seed, 1000);
+  }
+
+}