1 files changed, 23 insertions, 2 deletions
diff --git a/java/core/src/main/java/com/google/protobuf/UnsafeByteOperations.java b/java/core/src/main/java/com/google/protobuf/UnsafeByteOperations.java
index f443ee39..0fbf4d40 100644
--- a/java/core/src/main/java/com/google/protobuf/UnsafeByteOperations.java
+++ b/java/core/src/main/java/com/google/protobuf/UnsafeByteOperations.java
@@ -30,6 +30,7 @@
 
 package com.google.protobuf;
 
+import java.io.IOException;
 import java.nio.ByteBuffer;
 
 /**
@@ -49,8 +50,8 @@ public final class UnsafeByteOperations {
   /**
    * An unsafe operation that returns a {@link ByteString} that is backed by the provided buffer.
    *
-   * @param buffer the Java NIO buffer to be wrapped.
-   * @return a {@link ByteString} backed by the provided buffer.
+   * @param buffer the Java NIO buffer to be wrapped
+   * @return a {@link ByteString} backed by the provided buffer
    */
   public static ByteString unsafeWrap(ByteBuffer buffer) {
     if (buffer.hasArray()) {
@@ -60,4 +61,24 @@ public final class UnsafeByteOperations {
       return new NioByteString(buffer);
     }
   }
+
+  /**
+   * Writes the given {@link ByteString} to the provided {@link ByteOutput}. Calling this method may
+   * result in multiple operations on the target {@link ByteOutput}
+   * (i.e. for roped {@link ByteString}s).
+   *
+   * <p>This method exposes the internal backing buffer(s) of the {@link ByteString} to the {@link
+   * ByteOutput} in order to avoid additional copying overhead. It would be possible for a malicious
+   * {@link ByteOutput} to corrupt the {@link ByteString}. Use with caution!
+   *
+   * <p> NOTE: The {@link ByteOutput} <strong>MUST NOT</strong> modify the provided buffers. Doing
+   * so may result in corrupted data, which would be difficult to debug.
+   *
+   * @param bytes the {@link ByteString} to be written
+   * @param  output  the output to receive the bytes
+   * @throws IOException  if an I/O error occurs
+   */
+  public static void unsafeWriteTo(ByteString bytes, ByteOutput output) throws IOException {
+    bytes.writeTo(output);
+  }
 }