Initial interface rework to allow knowing whether to pull payload at registration, not at request time

include/grpc/grpc.h

@@ -289,6 +289,14 @@ GRPCAPI grpc_call_error grpc_server_request_call(
     grpc_completion_queue *cq_bound_to_call,
     grpc_completion_queue *cq_for_notification, void *tag_new);
 
+/** How to handle payloads for a registered method */
+typedef enum {
+  /** Don't try to read the payload */
+  GRPC_SRM_PAYLOAD_NONE,
+  /** Read the initial payload as a byte buffer */
+  GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER
+} grpc_server_register_method_payload_handling;
+
 /** Registers a method in the server.
     Methods to this (host, method) pair will not be reported by
     grpc_server_request_call, but instead be reported by
@@ -296,9 +304,10 @@ GRPCAPI grpc_call_error grpc_server_request_call(
     registered_method (as returned by this function).
     Must be called before grpc_server_start.
     Returns NULL on failure. */
-GRPCAPI void *grpc_server_register_method(grpc_server *server,
-                                          const char *method, const char *host,
-                                          uint32_t flags);
+GRPCAPI void *grpc_server_register_method(
+    grpc_server *server, const char *method, const char *host,
+    grpc_server_register_method_payload_handling payload_handling,
+    uint32_t flags);
 
 /** Request notification of a new pre-registered call. 'cq_for_notification'
     must have been registered to the server via

include/grpc/impl/codegen/grpc_types.h

@@ -185,7 +185,9 @@ typedef enum grpc_call_error {
       server */
   GRPC_CALL_ERROR_NOT_SERVER_COMPLETION_QUEUE,
   /** this batch of operations leads to more operations than allowed */
-  GRPC_CALL_ERROR_BATCH_TOO_BIG
+  GRPC_CALL_ERROR_BATCH_TOO_BIG,
+  /** payload type requested is not the type registered */
+  GRPC_CALL_ERROR_PAYLOAD_TYPE_MISMATCH
 } grpc_call_error;
 
 /* Write Flags: */

src/core/lib/surface/server.c

@@ -173,6 +173,7 @@ struct request_matcher {
 struct registered_method {
   char *method;
   char *host;
+  grpc_server_register_method_payload_handling payload_handling;
   uint32_t flags;
   request_matcher request_matcher;
   registered_method *next;
@@ -417,6 +418,69 @@ static void destroy_channel(grpc_exec_ctx *exec_ctx, channel_data *chand) {
                        &op);
 }
 
+static void publish_registered_or_batch(grpc_exec_ctx *exec_ctx,
+                                        void *user_data, bool success);
+
+static void cpstr(char **dest, size_t *capacity, grpc_mdstr *value) {
+  gpr_slice slice = value->slice;
+  size_t len = GPR_SLICE_LENGTH(slice);
+
+  if (len + 1 > *capacity) {
+    *capacity = GPR_MAX(len + 1, *capacity * 2);
+    *dest = gpr_realloc(*dest, *capacity);
+  }
+  memcpy(*dest, grpc_mdstr_as_c_string(value), len + 1);
+}
+
+static void begin_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
+                       call_data *calld, requested_call *rc) {
+  grpc_op ops[1];
+  grpc_op *op = ops;
+
+  memset(ops, 0, sizeof(ops));
+
+  /* called once initial metadata has been read by the call, but BEFORE
+     the ioreq to fetch it out of the call has been executed.
+     This means metadata related fields can be relied on in calld, but to
+     fill in the metadata array passed by the client, we need to perform
+     an ioreq op, that should complete immediately. */
+
+  grpc_call_set_completion_queue(exec_ctx, calld->call, rc->cq_bound_to_call);
+  grpc_closure_init(&rc->publish, publish_registered_or_batch, rc);
+  *rc->call = calld->call;
+  calld->cq_new = rc->cq_for_notification;
+  GPR_SWAP(grpc_metadata_array, *rc->initial_metadata, calld->initial_metadata);
+  switch (rc->type) {
+    case BATCH_CALL:
+      GPR_ASSERT(calld->host != NULL);
+      GPR_ASSERT(calld->path != NULL);
+      cpstr(&rc->data.batch.details->host,
+            &rc->data.batch.details->host_capacity, calld->host);
+      cpstr(&rc->data.batch.details->method,
+            &rc->data.batch.details->method_capacity, calld->path);
+      rc->data.batch.details->deadline = calld->deadline;
+      rc->data.batch.details->flags =
+          0 | (calld->recv_idempotent_request
+                   ? GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST
+                   : 0);
+      break;
+    case REGISTERED_CALL:
+      *rc->data.registered.deadline = calld->deadline;
+      if (rc->data.registered.optional_payload) {
+        op->op = GRPC_OP_RECV_MESSAGE;
+        op->data.recv_message = rc->data.registered.optional_payload;
+        op++;
+      }
+      break;
+    default:
+      GPR_UNREACHABLE_CODE(return );
+  }
+
+  GRPC_CALL_INTERNAL_REF(calld->call, "server");
+  grpc_call_start_batch_and_execute(exec_ctx, calld->call, ops,
+                                    (size_t)(op - ops), &rc->publish);
+}
+
 static void finish_start_new_rpc(grpc_exec_ctx *exec_ctx, grpc_server *server,
                                  grpc_call_element *elem, request_matcher *rm) {
   call_data *calld = elem->call_data;
@@ -840,8 +904,10 @@ static int streq(const char *a, const char *b) {
   return 0 == strcmp(a, b);
 }
 
-void *grpc_server_register_method(grpc_server *server, const char *method,
-                                  const char *host, uint32_t flags) {
+void *grpc_server_register_method(
+    grpc_server *server, const char *method, const char *host,
+    grpc_server_register_method_payload_handling payload_handling,
+    uint32_t flags) {
   registered_method *m;
   GRPC_API_TRACE(
       "grpc_server_register_method(server=%p, method=%s, host=%s, "
@@ -1209,6 +1275,12 @@ grpc_call_error grpc_server_request_registered_call(
     error = GRPC_CALL_ERROR_NOT_SERVER_COMPLETION_QUEUE;
     goto done;
   }
+  if ((optional_payload == NULL) !=
+      (rm->payload_handling == GRPC_SRM_PAYLOAD_NONE)) {
+    gpr_free(rc);
+    error = GRPC_CALL_ERROR_PAYLOAD_TYPE_MISMATCH;
+    goto done;
+  }
   grpc_cq_begin_op(cq_for_notification, tag);
   rc->type = REGISTERED_CALL;
   rc->server = server;
@@ -1226,69 +1298,6 @@ done:
   return error;
 }
 
-static void publish_registered_or_batch(grpc_exec_ctx *exec_ctx,
-                                        void *user_data, bool success);
-
-static void cpstr(char **dest, size_t *capacity, grpc_mdstr *value) {
-  gpr_slice slice = value->slice;
-  size_t len = GPR_SLICE_LENGTH(slice);
-
-  if (len + 1 > *capacity) {
-    *capacity = GPR_MAX(len + 1, *capacity * 2);
-    *dest = gpr_realloc(*dest, *capacity);
-  }
-  memcpy(*dest, grpc_mdstr_as_c_string(value), len + 1);
-}
-
-static void begin_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
-                       call_data *calld, requested_call *rc) {
-  grpc_op ops[1];
-  grpc_op *op = ops;
-
-  memset(ops, 0, sizeof(ops));
-
-  /* called once initial metadata has been read by the call, but BEFORE
-     the ioreq to fetch it out of the call has been executed.
-     This means metadata related fields can be relied on in calld, but to
-     fill in the metadata array passed by the client, we need to perform
-     an ioreq op, that should complete immediately. */
-
-  grpc_call_set_completion_queue(exec_ctx, calld->call, rc->cq_bound_to_call);
-  grpc_closure_init(&rc->publish, publish_registered_or_batch, rc);
-  *rc->call = calld->call;
-  calld->cq_new = rc->cq_for_notification;
-  GPR_SWAP(grpc_metadata_array, *rc->initial_metadata, calld->initial_metadata);
-  switch (rc->type) {
-    case BATCH_CALL:
-      GPR_ASSERT(calld->host != NULL);
-      GPR_ASSERT(calld->path != NULL);
-      cpstr(&rc->data.batch.details->host,
-            &rc->data.batch.details->host_capacity, calld->host);
-      cpstr(&rc->data.batch.details->method,
-            &rc->data.batch.details->method_capacity, calld->path);
-      rc->data.batch.details->deadline = calld->deadline;
-      rc->data.batch.details->flags =
-          0 | (calld->recv_idempotent_request
-                   ? GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST
-                   : 0);
-      break;
-    case REGISTERED_CALL:
-      *rc->data.registered.deadline = calld->deadline;
-      if (rc->data.registered.optional_payload) {
-        op->op = GRPC_OP_RECV_MESSAGE;
-        op->data.recv_message = rc->data.registered.optional_payload;
-        op++;
-      }
-      break;
-    default:
-      GPR_UNREACHABLE_CODE(return );
-  }
-
-  GRPC_CALL_INTERNAL_REF(calld->call, "server");
-  grpc_call_start_batch_and_execute(exec_ctx, calld->call, ops,
-                                    (size_t)(op - ops), &rc->publish);
-}
-
 static void done_request_event(grpc_exec_ctx *exec_ctx, void *req,
                                grpc_cq_completion *c) {
   requested_call *rc = req;

src/cpp/server/server.cc

@@ -321,6 +321,19 @@ void Server::SetGlobalCallbacks(GlobalCallbacks* callbacks) {
   g_callbacks.reset(callbacks);
 }
 
+static grpc_server_register_method_payload_handling PayloadHandlingForMethod(
+    RpcServiceMethod* method) {
+  switch (method->method_type()) {
+    case RpcMethod::NORMAL_RPC:
+    case RpcMethod::SERVER_STREAMING:
+      return GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER;
+    case RpcMethod::CLIENT_STREAMING:
+    case RpcMethod::BIDI_STREAMING:
+      return GRPC_SRM_PAYLOAD_NONE;
+  }
+  GPR_UNREACHABLE_CODE(return GRPC_SRM_PAYLOAD_NONE;);
+}
+
 bool Server::RegisterService(const grpc::string* host, Service* service) {
   bool has_async_methods = service->has_async_methods();
   if (has_async_methods) {
@@ -334,8 +347,9 @@ bool Server::RegisterService(const grpc::string* host, Service* service) {
       continue;
     }
     RpcServiceMethod* method = it->get();
-    void* tag = grpc_server_register_method(server_, method->name(),
-                                            host ? host->c_str() : nullptr, 0);
+    void* tag = grpc_server_register_method(
+        server_, method->name(), host ? host->c_str() : nullptr,
+        PayloadHandlingForMethod(method), 0);
     if (tag == nullptr) {
       gpr_log(GPR_DEBUG, "Attempt to register %s multiple times",
               method->name());

test/core/bad_client/bad_client.c

@@ -107,9 +107,9 @@ void grpc_run_bad_client_test(grpc_bad_client_server_side_validator validator,
   gpr_event_init(&a.done_write);
   a.validator = validator;
   grpc_server_register_completion_queue(a.server, a.cq, NULL);
-  a.registered_method =
-      grpc_server_register_method(a.server, GRPC_BAD_CLIENT_REGISTERED_METHOD,
-                                  GRPC_BAD_CLIENT_REGISTERED_HOST, 0);
+  a.registered_method = grpc_server_register_method(
+      a.server, GRPC_BAD_CLIENT_REGISTERED_METHOD,
+      GRPC_BAD_CLIENT_REGISTERED_HOST, GRPC_SRM_PAYLOAD_NONE, 0);
   grpc_server_start(a.server);
   transport = grpc_create_chttp2_transport(&exec_ctx, NULL, sfd.server, 0);
   server_setup_transport(&a, transport);

test/core/surface/server_test.c

@@ -42,19 +42,25 @@ void test_register_method_fail(void) {
   grpc_server *server = grpc_server_create(NULL, NULL);
   void *method;
   void *method_old;
-  method = grpc_server_register_method(server, NULL, NULL, 0);
+  method =
+      grpc_server_register_method(server, NULL, NULL, GRPC_SRM_PAYLOAD_NONE, 0);
   GPR_ASSERT(method == NULL);
-  method_old = grpc_server_register_method(server, "m", "h", 0);
+  method_old =
+      grpc_server_register_method(server, "m", "h", GRPC_SRM_PAYLOAD_NONE, 0);
   GPR_ASSERT(method_old != NULL);
-  method = grpc_server_register_method(server, "m", "h", 0);
+  method = grpc_server_register_method(
+      server, "m", "h", GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER, 0);
   GPR_ASSERT(method == NULL);
-  method_old = grpc_server_register_method(
-      server, "m2", "h2", GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST);
+  method_old =
+      grpc_server_register_method(server, "m2", "h2", GRPC_SRM_PAYLOAD_NONE,
+                                  GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST);
   GPR_ASSERT(method_old != NULL);
-  method = grpc_server_register_method(server, "m2", "h2", 0);
+  method =
+      grpc_server_register_method(server, "m2", "h2", GRPC_SRM_PAYLOAD_NONE, 0);
   GPR_ASSERT(method == NULL);
   method = grpc_server_register_method(
-      server, "m2", "h2", GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST);
+      server, "m2", "h2", GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER,
+      GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST);
   GPR_ASSERT(method == NULL);
   grpc_server_destroy(server);
 }