Simplify GATTS API

Remove offset and trans_id.
Stack is expected to deal with long reads/writes, app doesn't need to worry.

include/mgos_bt_gatts.h

@@ -49,19 +49,14 @@ struct mgos_bt_gatts_read_arg {
   struct mgos_bt_uuid char_uuid;
   struct mgos_bt_uuid desc_uuid;
   uint16_t handle;
-  uint32_t trans_id;
-  uint16_t offset;
 };
 
 struct mgos_bt_gatts_write_arg {
   struct mgos_bt_uuid svc_uuid;
   struct mgos_bt_uuid char_uuid;
   struct mgos_bt_uuid desc_uuid;
   uint16_t handle;
-  uint32_t trans_id;
-  uint16_t offset;
   struct mg_str data;
-  bool need_rsp;
 };
 
 struct mgos_bt_gatts_notify_mode_arg {

src/esp32/esp32_bt_gatts.c

@@ -344,9 +344,9 @@ static int esp32_bt_gatts_mtu_event(uint16_t conn_id,
                                     uint16_t mtu, void *arg) {
   struct esp32_bt_gatts_connection_entry *ce = arg;
   LOG(LL_DEBUG, ("MTU_FN %d st %d mtu %d", conn_id, err->status, mtu));
-  // Peer may not support MTU exchange procedure.
+  // Peer may not support MTU exchange procedure, proceed anyway.
   if (err->status == 0) {
-    // ce->gc.mtu = mtu;
+    ce->gc.mtu = mtu;
   }
   esp32_bt_gatts_create_sessions(ce);
   return 0;
@@ -374,8 +374,7 @@ int esp32_bt_gatts_event(const struct ble_gap_event *ev, void *arg) {
         break;
       }
       ce->gc.conn_id = conn_id;
-      // ce->gc.mtu = ble_att_mtu(conn_id);
-      ce->gc.mtu = 1024;  // mtu;
+      ce->gc.mtu = ble_att_mtu(conn_id);
       esp32_bt_addr_to_mgos(&cd.peer_ota_addr, &ce->gc.addr);
       SLIST_INIT(&ce->pending_nm);
       STAILQ_INIT(&ce->pending_inds);
@@ -608,8 +607,6 @@ static int esp32_gatts_attr_access_cb(uint16_t ch, uint16_t ah,
       struct mgos_bt_gatts_read_arg rarg = {
           .svc_uuid = sse->se->uuid,
           .handle = ah,
-          .trans_id = 0,
-          .offset = 0,
       };
       struct esp32_bt_service_attr_info *cai = arg;
       if (ctxt->op == BLE_GATT_ACCESS_OP_READ_CHR) {
@@ -648,9 +645,6 @@ static int esp32_gatts_attr_access_cb(uint16_t ch, uint16_t ah,
           .svc_uuid = sse->se->uuid,
           .handle = ah,
           .data = data,
-          .trans_id = 0,
-          .offset = 0,
-          .need_rsp = true,
       };
       struct esp32_bt_service_attr_info *cai = arg;
       if (ctxt->op == BLE_GATT_ACCESS_OP_WRITE_CHR) {
@@ -911,7 +905,6 @@ void mgos_bt_gatts_notify_uuid(struct mgos_bt_gatts_conn *gsc,
 }
 
 bool esp32_bt_gatts_start(void) {
-  LOG(LL_INFO, ("GATTS start, synced? %d", ble_hs_synced()));
   return esp32_bt_register_services();
 }
 

src/mgos_bt_gatts.c

@@ -24,7 +24,6 @@ static enum mgos_bt_gatt_status mgos_bt_gatts_read_n(
     return MGOS_BT_GATT_STATUS_REQUEST_NOT_SUPPORTED;
   }
   struct mgos_bt_gatts_read_arg *arg = ev_arg;
-  if (arg->offset != 0) return MGOS_BT_GATT_STATUS_INVALID_OFFSET;
   mgos_bt_gatts_send_resp_data(c, arg, mg_mk_str_n((void *) &handler_arg, n));
   (void) c;
   (void) ev_arg;

src/mgos_bt_js.c

@@ -196,10 +196,6 @@ static const struct mjs_c_struct_member gatts_read_arg_def[] = {
      MJS_STRUCT_FIELD_TYPE_CUSTOM, bt_uuid_to_str},
     {"handle", offsetof(struct mgos_bt_gatts_read_arg, handle),
      MJS_STRUCT_FIELD_TYPE_UINT16, NULL},
-    {"transId", offsetof(struct mgos_bt_gatts_read_arg, trans_id),
-     MJS_STRUCT_FIELD_TYPE_INT, NULL},
-    {"offset", offsetof(struct mgos_bt_gatts_read_arg, offset),
-     MJS_STRUCT_FIELD_TYPE_UINT16, NULL},
     {NULL},
 };
 
@@ -216,10 +212,6 @@ static const struct mjs_c_struct_member gatts_write_arg_def[] = {
      MJS_STRUCT_FIELD_TYPE_CUSTOM, bt_uuid_to_str},
     {"handle", offsetof(struct mgos_bt_gatts_write_arg, handle),
      MJS_STRUCT_FIELD_TYPE_UINT16, NULL},
-    {"transId", offsetof(struct mgos_bt_gatts_write_arg, trans_id),
-     MJS_STRUCT_FIELD_TYPE_INT, NULL},
-    {"offset", offsetof(struct mgos_bt_gatts_write_arg, offset),
-     MJS_STRUCT_FIELD_TYPE_UINT16, NULL},
     {"data", offsetof(struct mgos_bt_gatts_write_arg, data),
      MJS_STRUCT_FIELD_TYPE_MG_STR, NULL},
     {NULL},

tools/rpc.py

@@ -97,15 +97,19 @@ def call(self, method, params=None, resp=True):
         self._tx_ctl_char.write(struct.pack(">I", reqLen), withResponse=True)
         logging.debug(f"Sending request...")
         self._data_char.write(reqJSON.encode("ascii"), withResponse=True)
-        prev_frame_len = 0
         while True:
-            frame_len = struct.unpack(">I", self._rx_ctl_char.read())
+            frame_len = struct.unpack(">I", self._rx_ctl_char.read())[0]
             logging.debug(f"RX frame len: {frame_len}")
             if frame_len == 0:
                 time.sleep(0.1)
                 continue
-            frame = json.loads(self._data_char.read())
-            logging.debug(f"RX Frame data: {frame}")
+            frame_data, n_chunks = b"", 0
+            while len(frame_data) < frame_len:
+                chunk = self._data_char.read()
+                frame_data += chunk
+                n_chunks += 1
+            logging.debug(f"RX Frame data (rec'd in {n_chunks} chunks): {frame_data}")
+            frame = json.loads(frame_data)
             if frame.get("id", 0) != req["id"]:
                 continue
             if "result" in frame: