Add the ability to send metadata from the client

PiperOrigin-RevId: 687424273

Author: Jonathan Godbout

client.cc

@@ -63,6 +63,14 @@ void* new_tag(int num) {
   return new int(num);
 }
 
+grpc_metadata_array* create_new_grpc_metadata_array_with_data(grpc_metadata* metadata, size_t count) {
+  grpc_metadata_array* arr = new grpc_metadata_array();
+  grpc_metadata_array_init(arr);
+  arr->count = count;
+  if (count > 0) arr->metadata = metadata;
+  return arr;
+}
+
 grpc_metadata_array* create_new_grpc_metadata_array() {
   grpc_metadata_array* arr = new grpc_metadata_array();
   grpc_metadata_array_init(arr);
@@ -118,6 +126,19 @@ void grpc_ops_free(grpc_op* ops, int size) {
   free(ops);
 }
 
+grpc_metadata* lisp_make_grpc_metadata(const char* key,
+                                       const char* value) {
+  grpc_slice slice_key = grpc_slice_from_copied_string(key);
+  grpc_slice slice_value = grpc_slice_from_copied_string(value);
+
+  grpc_metadata* metadata = new grpc_metadata;
+  *metadata = grpc_metadata {
+    slice_key,
+    slice_value,
+  };
+  return metadata;
+}
+
 // Takes in a preallocated grpc_op array.
 // Stores the given metadata, flags, and count for the
 // GRPC_OP_SEND_INITIAL_METADATA operation.

client.lisp

@@ -155,7 +155,7 @@ RECEIVE_STATUS_ON_CLIENT op and RECEIVE-STATUS-ON-CLIENT-INDEX in the ops."
 
 (defconstant +num-ops-for-starting-call+ 3)
 
-(defun start-grpc-call (channel service-method-name)
+(defun start-grpc-call (channel service-method-name client-context)
   "Start a grpc call. Requires a pointer to a grpc CHANNEL object, and a SERVICE-METHOD-NAME
 string to direct the call to."
   (let* ((num-ops-for-sending-message +num-ops-for-starting-call+)
@@ -171,9 +171,10 @@ string to direct the call to."
     (make-call :c-call c-call
                :c-tag tag
                :c-ops ops
-               :ops-plist ops-plist)))
+               :ops-plist ops-plist
+               :context client-context)))
 
-(defun grpc-call (channel service-method-name bytes-to-send
+(defun grpc-call (channel service-method-name bytes-to-send client-context
                   server-stream client-stream)
   "Uses CHANNEL to call SERVICE-METHOD-NAME on the server with BYTES-TO-SEND
 as the arguement to the method and returns the response<list of byte arrays>
@@ -182,7 +183,7 @@ BYTES-TO-SEND should be a list of byte-vectors each containing a message to
 send in a single call to the server. In the case of a server or bidirectional
 call we return a list a list of byte vectors each being a response from the server,
 otherwise it's a single byte vector list containing a single response."
-  (let* ((call (start-grpc-call channel service-method-name)))
+  (let* ((call (start-grpc-call channel service-method-name client-context)))
     (unwind-protect
          (progn
            (if client-stream

shared.lisp

@@ -418,18 +418,39 @@ i of grpc_byte_buffer BUFFER."
 these operation guide the interaction between the client and server."
   (num-ops :int))
 
+(defun make-metadata (metadata)
+  "Sets OP[INDEX] to a Send Initial Metadata operation by adding metadata
+METADATA, the count of metadata COUNT, and the flag FLAG."
+  (let* ((arr-size (length metadata))
+         (metadata
+          (loop for (key value) in metadata
+                collect
+                (cffi:foreign-funcall "lisp_make_grpc_metadata"
+                                      :string key
+                                      :string value)))
+         (l-arr (make-array (list arr-size)
+                            :initial-contents metadata)))
+    (cffi:with-foreign-array (arr l-arr (list :array :int64 arr-size))
+      (cffi:foreign-funcall "create_new_grpc_metadata_array_with_data"
+                            :pointer arr
+                            :size arr-size))))
+
 (defun make-send-metadata-op (op metadata
                               &key count flag
-                                index)
+                              index)
   "Sets OP[INDEX] to a Send Initial Metadata operation by adding metadata
 METADATA, the count of metadata COUNT, and the flag FLAG."
-  (cffi:foreign-funcall "lisp_grpc_make_send_metadata_op"
-                        :pointer op
-                        :int index
-                        :pointer metadata
-                        :int count
-                        :int (convert-metadata-flag-to-integer flag)
-                        :void))
+  (let ((metadata-ptr (if metadata
+                          (make-metadata metadata)
+                          (cffi:null-pointer))))
+
+    (cffi:foreign-funcall "lisp_grpc_make_send_metadata_op"
+                          :pointer op
+                          :int index
+                          :pointer metadata-ptr
+                          :int count
+                          :int (convert-metadata-flag-to-integer flag)
+                          :void))
 
 (defun make-send-message-op (op message &key index)
   "Sets OP[INDEX] to a 'Send Message' operation that sends MESSAGE
@@ -509,7 +530,7 @@ want. Returns a plist containing keys being the op type and values being the ind
              (setf (getf ops-plist message-type) (incf cur-index))))
 
       (when send-metadata
-        (make-send-metadata-op ops (cffi:null-pointer)
+        (make-send-metadata-op ops send-metadata
                                :count 0 :flag 0 :index (next-marker :send-metadata)))
       (when send-message
         (make-send-message-op ops send-message :index (next-marker :send-message)))
@@ -585,9 +606,12 @@ macros and only call once."
   (method-name "" :type string)
   ;; This is a plist where the key is a keyword for a type of op
   ;; and the value is the index of that op in an op-array.
-  (ops-plist nil :type list))
+  (ops-plist nil :type list)
+  (context nil :type (or null client-context server-context)))
 
-;; Shared call functions
+(defstruct context
+  (deadline -1 :type integer)
+  (metadata nil :type list))
 
 (defun receive-message (call)
   "Receive a message from the client for a CALL."
@@ -628,7 +652,12 @@ macros and only call once."
          (ops (create-new-grpc-ops num-ops))
          (grpc-slice
           (convert-bytes-to-grpc-byte-buffer bytes-to-send))
-         (ops-plist (prepare-ops ops :send-message grpc-slice))
+         (context (call-context call))
+         (ops-plist (prepare-ops
+                     ops
+                     :send-message grpc-slice
+                     :send-metadata (and context
+                                         (context-metadata context))))
          (call-code (call-start-batch c-call ops num-ops tag)))
     (declare (ignore ops-plist))
     (unless (eql call-code :grpc-call-ok)

tests/integration-test.lisp

@@ -66,9 +66,13 @@ Parameters
          (grpc:with-insecure-channel
              (channel
               (concatenate 'string hostname ":" (write-to-string port-number)))
-           (let* ((message "Hello World")
+           (let* ((client-context
+                   (grpc::make-context :metadata '(("my" "name")
+                                                          ("is" "Lyra"))))
+                  (message "Hello World")
                   (response (grpc:grpc-call channel method-name
                                             (flexi-streams:string-to-octets message)
+                                            client-context
                                             nil nil))
                   (actual-client-response (flexi-streams:octets-to-string
                                            (car response))))