Retry support.

1 files changed, 24 insertions, 0 deletions

diff --git a/src/core/lib/transport/metadata_batch.cc b/src/core/lib/transport/metadata_batch.cc
index b23f516516..49740fcd1e 100644
--- a/src/core/lib/transport/metadata_batch.cc
+++ b/src/core/lib/transport/metadata_batch.cc
@@ -303,3 +303,27 @@ grpc_error* grpc_metadata_batch_filter(grpc_metadata_batch* batch,
   }
   return error;
 }
+
+void grpc_metadata_batch_copy(grpc_metadata_batch* src,
+                              grpc_metadata_batch* dst,
+                              grpc_linked_mdelem* storage) {
+  grpc_metadata_batch_init(dst);
+  dst->deadline = src->deadline;
+  size_t i = 0;
+  for (grpc_linked_mdelem* elem = src->list.head; elem != nullptr;
+       elem = elem->next) {
+    grpc_error* error = grpc_metadata_batch_add_tail(dst, &storage[i++],
+                                                     GRPC_MDELEM_REF(elem->md));
+    // The only way that grpc_metadata_batch_add_tail() can fail is if
+    // there's a duplicate entry for a callout.  However, that can't be
+    // the case here, because we would not have been allowed to create
+    // a source batch that had that kind of conflict.
+    GPR_ASSERT(error == GRPC_ERROR_NONE);
+  }
+}
+
+void grpc_metadata_batch_move(grpc_metadata_batch* src,
+                              grpc_metadata_batch* dst) {
+  *dst = *src;
+  grpc_metadata_batch_init(src);
+}