1 files changed, 30 insertions, 12 deletions

diff --git a/include/grpc/impl/codegen/grpc_types.h b/include/grpc/impl/codegen/grpc_types.h
index 8efd570bad..ee8101aab8 100644
--- a/include/grpc/impl/codegen/grpc_types.h
+++ b/include/grpc/impl/codegen/grpc_types.h
@@ -294,11 +294,9 @@ typedef enum grpc_call_error {
 
 /** A single metadata element */
 typedef struct grpc_metadata {
-  /* the key, value values are expected to line up with grpc_mdelem: if changing
-     them, update metadata.h at the same time. */
-  grpc_slice key;
-  grpc_slice value;
-
+  const char *key;
+  const char *value;
+  size_t value_length;
   uint32_t flags;
 
   /** The following fields are reserved for grpc internal use.
@@ -340,8 +338,10 @@ typedef struct {
 } grpc_metadata_array;
 
 typedef struct {
-  grpc_slice method;
-  grpc_slice host;
+  char *method;
+  size_t method_capacity;
+  char *host;
+  size_t host_capacity;
   gpr_timespec deadline;
   uint32_t flags;
   void *reserved;
@@ -423,10 +423,7 @@ typedef struct grpc_op {
       size_t trailing_metadata_count;
       grpc_metadata *trailing_metadata;
       grpc_status_code status;
-      /* optional: set to NULL if no details need sending, non-NULL if they do
-       * pointer will not be retained past the start_batch call
-       */
-      grpc_slice *status_details;
+      const char *status_details;
     } send_status_from_server;
     /** ownership of the array is with the caller, but ownership of the elements
         stays with the call object (ie key, value members are owned by the call
@@ -447,7 +444,28 @@ typedef struct grpc_op {
           value, or reuse it in a future op. */
       grpc_metadata_array *trailing_metadata;
       grpc_status_code *status;
-      grpc_slice *status_details;
+      /** status_details is a buffer owned by the application before the op
+          completes and after the op has completed. During the operation
+          status_details may be reallocated to a size larger than
+          *status_details_capacity, in which case *status_details_capacity will
+          be updated with the new array capacity.
+
+          Pre-allocating space:
+          size_t my_capacity = 8;
+          char *my_details = gpr_malloc(my_capacity);
+          x.status_details = &my_details;
+          x.status_details_capacity = &my_capacity;
+
+          Not pre-allocating space:
+          size_t my_capacity = 0;
+          char *my_details = NULL;
+          x.status_details = &my_details;
+          x.status_details_capacity = &my_capacity;
+
+          After the call:
+          gpr_free(my_details); */
+      char **status_details;
+      size_t *status_details_capacity;
     } recv_status_on_client;
     struct {
       /** out argument, set to 1 if the call failed in any way (seen as a