device_link_service: new function and docs updated

New function: device_link_service_get_process_message.
This function receives a DLMessageProcessMessage and extracts
the message (a PLIST_DICT). Fails if the received plist is not
a DLMessageProcessMessage.

1 files changed, 69 insertions, 2 deletions

diff --git a/src/device_link_service.c b/src/device_link_service.c
index 10e9e9c..4140911 100644
--- a/src/device_link_service.c
+++ b/src/device_link_service.c
@@ -253,9 +253,20 @@ device_link_service_error_t device_link_service_disconnect(device_link_service_c
         return err;
 }
 
+/**
+ * Sends a DLMessageProcessMessage plist.
+ *
+ * @param client The device link service client to use.
+ * @param message PLIST_DICT to send.
+ *
+ * @return DEVICE_LINK_SERVICE_E_SUCCESS on success,
+ *     DEVICE_LINK_SERVICE_E_INVALID_ARG if client or message is invalid or
+ *     message is not a PLIST_DICT, or DEVICE_LINK_SERVICE_E_MUX_ERROR if
+ *     the DLMessageProcessMessage plist could not be sent.
+ */
 device_link_service_error_t device_link_service_process_message(device_link_service_client_t client, plist_t message)
 {
-        if (!client || !message)
+        if (!client || !client->parent || !message)
                 return DEVICE_LINK_SERVICE_E_INVALID_ARG;
 
         if (plist_get_node_type(message) != PLIST_DICT)
@@ -263,7 +274,7 @@ device_link_service_error_t device_link_service_process_message(device_link_serv
 
         plist_t array = plist_new_array();
         plist_array_append_item(array, plist_new_string("DLMessageProcessMessage"));
-        plist_array_append_item(array, message);
+        plist_array_append_item(array, plist_copy(message));
 
         device_link_service_error_t err = DEVICE_LINK_SERVICE_E_SUCCESS;
         if (property_list_service_send_binary_plist(client->parent, array) != PROPERTY_LIST_SERVICE_E_SUCCESS) {
@@ -274,6 +285,62 @@ device_link_service_error_t device_link_service_process_message(device_link_serv
 }
 
 /**
+ * Receives a DLMessageProcessMessage plist.
+ *
+ * @param client The connected device link service client used for receiving.
+ * @param message Pointer to a plist that will be set to the contents of the
+ *    message contents upon successful return.
+ *
+ * @return DEVICE_LINK_SERVICE_E_SUCCESS when a DLMessageProcessMessage was
+ *    received, DEVICE_LINK_SERVICE_E_INVALID_ARG when client or message is
+ *    invalid, DEVICE_LINK_SERVICE_E_PLIST_ERROR if the received plist is
+ *    invalid or is not a DLMessageProcessMessage,
+ *    or DEVICE_LINK_SERVICE_E_MUX_ERROR if receiving from device fails.
+ */
+device_link_service_error_t device_link_service_get_process_message(device_link_service_client_t client, plist_t *message)
+{
+        if (!client || !client->parent || !message)
+                return DEVICE_LINK_SERVICE_E_INVALID_ARG;
+
+        plist_t pmsg = NULL;
+        if (property_list_service_receive_plist(client->parent, &pmsg) != PROPERTY_LIST_SERVICE_E_SUCCESS) {
+                return DEVICE_LINK_SERVICE_E_MUX_ERROR;
+        }
+
+        device_link_service_error_t err = DEVICE_LINK_SERVICE_E_UNKNOWN_ERROR;
+
+        char *msg = device_link_service_get_message(pmsg);
+        if (!msg || strcmp(msg, "DLMessageProcessMessage")) {
+                debug_info("Did not receive DLMessageProcessMessage as expected!");
+                err = DEVICE_LINK_SERVICE_E_PLIST_ERROR;
+                goto leave;
+        }
+
+        if (plist_array_get_size(pmsg) != 2) {
+                debug_info("Malformed plist received for DLMessageProcessMessage");
+                err = DEVICE_LINK_SERVICE_E_PLIST_ERROR;
+                goto leave;
+        }
+
+        plist_t msg_loc = plist_array_get_item(pmsg, 1);
+        if (msg_loc) {
+                *message = plist_copy(msg_loc);
+                err = DEVICE_LINK_SERVICE_E_SUCCESS;
+        } else {
+                *message = NULL;
+                err = DEVICE_LINK_SERVICE_E_PLIST_ERROR;
+        }
+
+leave:
+        if (msg)
+                free(msg);
+        if (pmsg)
+                plist_free(pmsg);
+
+        return err;
+}
+
+/**
  * Generic device link service send function.
  *
  * @param client The device link service client to use for sending