1 files changed, 21 insertions, 0 deletions
diff --git a/protobuf-lite/src/main/java/io/grpc/protobuf/lite/ProtoLiteUtils.java b/protobuf-lite/src/main/java/io/grpc/protobuf/lite/ProtoLiteUtils.java
index 2a88a3f89..fc578b2c2 100644
--- a/protobuf-lite/src/main/java/io/grpc/protobuf/lite/ProtoLiteUtils.java
+++ b/protobuf-lite/src/main/java/io/grpc/protobuf/lite/ProtoLiteUtils.java
@@ -32,6 +32,7 @@ import io.grpc.Status;
 import io.grpc.internal.GrpcUtil;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.lang.ref.Reference;
 import java.lang.ref.WeakReference;
 
@@ -44,6 +45,8 @@ public class ProtoLiteUtils {
   private static volatile ExtensionRegistryLite globalRegistry =
       ExtensionRegistryLite.getEmptyRegistry();
 
+  private static final int BUF_SIZE = 8192;
+
   /**
    * Sets the global registry for proto marshalling shared across all servers and clients.
    *
@@ -202,6 +205,24 @@ public class ProtoLiteUtils {
     };
   }
 
+  /** Copies the data from input stream to output stream. */
+  static long copy(InputStream from, OutputStream to) throws IOException {
+    // Copied from guava com.google.common.io.ByteStreams because its API is unstable (beta)
+    checkNotNull(from);
+    checkNotNull(to);
+    byte[] buf = new byte[BUF_SIZE];
+    long total = 0;
+    while (true) {
+      int r = from.read(buf);
+      if (r == -1) {
+        break;
+      }
+      to.write(buf, 0, r);
+      total += r;
+    }
+    return total;
+  }
+
   private ProtoLiteUtils() {
   }
 }