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diff --git a/java/core/src/main/java/com/google/protobuf/AllocatedBuffer.java b/java/core/src/main/java/com/google/protobuf/AllocatedBuffer.java
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+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static com.google.protobuf.Internal.checkNotNull;
+
+import java.nio.ByteBuffer;
+
+/**
+ * A buffer that was allocated by a {@link BufferAllocator}. For every buffer, it is guaranteed that
+ * at least one of {@link #hasArray()} or {@link #hasNioBuffer()} will be {@code true}.
+ */
+@ExperimentalApi
+public abstract class AllocatedBuffer {
+  /**
+   * Indicates whether this buffer contains a backing {@link ByteBuffer} (i.e. it is safe to call
+   * {@link #nioBuffer()}).
+   */
+  public abstract boolean hasNioBuffer();
+
+  /**
+   * Indicates whether this buffer contains a backing array (i.e. it is safe to call {@link
+   * #array()}).
+   */
+  public abstract boolean hasArray();
+
+  /**
+   * Returns the {@link ByteBuffer} that backs this buffer <i>(optional operation)</i>.
+   *
+   * <p>Call {@link #hasNioBuffer()} before invoking this method in order to ensure that this buffer
+   * has a backing {@link ByteBuffer}.
+   *
+   * @return The {@link ByteBuffer} that backs this buffer
+   * @throws UnsupportedOperationException If this buffer is not backed by a {@link ByteBuffer}.
+   */
+  public abstract ByteBuffer nioBuffer();
+
+  /**
+   * Returns the byte array that backs this buffer <i>(optional operation)</i>.
+   *
+   * <p>Call {@link #hasArray()} before invoking this method in order to ensure that this buffer has
+   * an accessible backing array.
+   *
+   * @return The array that backs this buffer
+   * @throws java.nio.ReadOnlyBufferException If this buffer is backed by an array but is read-only
+   * @throws UnsupportedOperationException If this buffer is not backed by an accessible array
+   */
+  public abstract byte[] array();
+
+  /**
+   * Returns the offset within this buffer's backing array of the first element of the buffer
+   * <i>(optional operation)</i>.
+   *
+   * <p>If this buffer is backed by an array then {@link #position()} corresponds to the array index
+   * {@link #position()} {@code +} {@link #arrayOffset()}.
+   *
+   * <p>Invoke the {@link #hasArray hasArray} method before invoking this method in order to ensure
+   * that this buffer has an accessible backing array.
+   *
+   * @return The offset within this buffer's array of the first element of the buffer
+   * @throws java.nio.ReadOnlyBufferException If this buffer is backed by an array but is read-only
+   * @throws UnsupportedOperationException If this buffer is not backed by an accessible array
+   */
+  public abstract int arrayOffset();
+
+  /**
+   * Returns this buffer's position.
+   *
+   * @return The position of this buffer
+   */
+  public abstract int position();
+
+  /**
+   * Sets this buffer's position.
+   *
+   * @param position The new position value; must be non-negative and no larger than the current
+   *     limit
+   * @return This buffer
+   * @throws IllegalArgumentException If the preconditions on {@code position} do not hold
+   */
+  public abstract AllocatedBuffer position(int position);
+
+  /**
+   * Returns this buffer's limit.
+   *
+   * @return The limit of this buffer
+   */
+  public abstract int limit();
+
+  /**
+   * Returns the number of elements between the current {@link #position()} and the {@link #limit()}
+   * .
+   *
+   * @return The number of elements remaining in this buffer
+   */
+  public abstract int remaining();
+
+  /**
+   * Creates a new {@link AllocatedBuffer} that is backed by the given array. The returned buffer
+   * will have {@link #hasArray} == {@code true}, {@link #arrayOffset()} == {@code 0}, {@link
+   * #position()} == {@code 0} and {@link #limit()} equal to the length of {@code bytes}.
+   */
+  public static AllocatedBuffer wrap(byte[] bytes) {
+    return wrapNoCheck(bytes, 0, bytes.length);
+  }
+
+  /**
+   * Creates a new {@link AllocatedBuffer} that is backed by the given array. The returned buffer
+   * will have {@link #hasArray} == {@code true}, {@link #arrayOffset()} == {@code offset}, {@link
+   * #position()} == {@code 0} and {@link #limit()} == {@code length}.
+   */
+  public static AllocatedBuffer wrap(final byte[] bytes, final int offset, final int length) {
+    if (offset < 0 || length < 0 || (offset + length) > bytes.length) {
+      throw new IndexOutOfBoundsException(
+          String.format("bytes.length=%d, offset=%d, lenght=%d", bytes.length, offset, length));
+    }
+
+    return wrapNoCheck(bytes, offset, length);
+  }
+
+  /**
+   * Creates a new {@link AllocatedBuffer} that is backed by the given {@link ByteBuffer}. The
+   * returned buffer will have {@link #hasNioBuffer} == {@code true}.
+   */
+  public static AllocatedBuffer wrap(final ByteBuffer buffer) {
+    checkNotNull(buffer, "buffer");
+
+    return new AllocatedBuffer() {
+
+      @Override
+      public boolean hasNioBuffer() {
+        return true;
+      }
+
+      @Override
+      public ByteBuffer nioBuffer() {
+        return buffer;
+      }
+
+      @Override
+      public boolean hasArray() {
+        return buffer.hasArray();
+      }
+
+      @Override
+      public byte[] array() {
+        return buffer.array();
+      }
+
+      @Override
+      public int arrayOffset() {
+        return buffer.arrayOffset();
+      }
+
+      @Override
+      public int position() {
+        return buffer.position();
+      }
+
+      @Override
+      public AllocatedBuffer position(int position) {
+        buffer.position(position);
+        return this;
+      }
+
+      @Override
+      public int limit() {
+        return buffer.limit();
+      }
+
+      @Override
+      public int remaining() {
+        return buffer.remaining();
+      }
+    };
+  }
+
+  private static AllocatedBuffer wrapNoCheck(
+      final byte[] bytes, final int offset, final int length) {
+    return new AllocatedBuffer() {
+      // Relative to offset.
+      private int position;
+
+      @Override
+      public boolean hasNioBuffer() {
+        return false;
+      }
+
+      @Override
+      public ByteBuffer nioBuffer() {
+        throw new UnsupportedOperationException();
+      }
+
+      @Override
+      public boolean hasArray() {
+        return true;
+      }
+
+      @Override
+      public byte[] array() {
+        return bytes;
+      }
+
+      @Override
+      public int arrayOffset() {
+        return offset;
+      }
+
+      @Override
+      public int position() {
+        return position;
+      }
+
+      @Override
+      public AllocatedBuffer position(int position) {
+        if (position < 0 || position > length) {
+          throw new IllegalArgumentException("Invalid position: " + position);
+        }
+        this.position = position;
+        return this;
+      }
+
+      @Override
+      public int limit() {
+        // Relative to offset.
+        return length;
+      }
+
+      @Override
+      public int remaining() {
+        return length - position;
+      }
+    };
+  }
+}