Make a list of ByteBuffers up-front instead of a running iterator.

protobuf-lite/src/main/java/io/grpc/protobuf/lite/ProtoLiteUtils.java

@@ -37,8 +37,8 @@
 import java.lang.ref.Reference;
 import java.lang.ref.WeakReference;
 import java.nio.ByteBuffer;
-import java.util.Iterator;
-import java.util.NoSuchElementException;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Utility methods for using protobuf with grpc.
@@ -180,7 +180,15 @@ public T parse(InputStream stream) {
           // TODO(chengyuanzhang): we may still want to go with the byte array approach for small
           //  messages.
           if (stream instanceof HasByteBuffer && stream.markSupported()) {
-            cis = CodedInputStream.newInstance(new KnownLengthByteBufferIterable(stream, size));
+            List<ByteBuffer> buffers = new ArrayList<>();
+            stream.mark(size);
+            while (stream.available() != 0) {
+              ByteBuffer buffer = ((HasByteBuffer) stream).getByteBuffer();
+              stream.skip(buffer.remaining());
+              buffers.add(buffer);
+            }
+            stream.reset();
+            cis = CodedInputStream.newInstance(buffers);
           } else if (size > 0 && size <= DEFAULT_MAX_MESSAGE_SIZE) {
             Reference<byte[]> ref;
             // buf should not be used after this method has returned.
@@ -263,57 +271,4 @@ public T parseBytes(byte[] serialized) {
       }
     }
   }
-
-  private static final class KnownLengthByteBufferIterable implements Iterable<ByteBuffer> {
-    private final InputStream stream;
-    private final int length;
-
-    private KnownLengthByteBufferIterable(InputStream stream, int length) {
-      this.stream = stream;
-      this.length = length;
-      stream.mark(length);
-    }
-
-    @Override
-    public Iterator<ByteBuffer> iterator() {
-      try {
-        stream.reset();
-        stream.mark(length);
-        return new Iterator<ByteBuffer>() {
-          private ByteBuffer buffer;
-
-          @Override
-          public boolean hasNext() {
-            if (buffer != null) {
-              return true;
-            }
-            buffer = ((HasByteBuffer) stream).getByteBuffer();
-            return buffer != null;
-          }
-
-          @Override
-          public ByteBuffer next() {
-            if (!hasNext()) {
-              throw new NoSuchElementException();
-            }
-            ByteBuffer res = buffer;
-            try {
-              stream.skip(buffer.remaining());
-            } catch (IOException e) {
-              throw new RuntimeException(e);
-            }
-            buffer = null;
-            return res;
-          }
-
-          @Override
-          public void remove() {
-            throw new UnsupportedOperationException();
-          }
-        };
-      } catch (IOException e) {
-        throw new RuntimeException(e);
-      }
-    }
-  }
 }