adds message module

diff --git a/inc/message.h b/inc/message.h
new file mode 100644 (file)
index 0000000..eb8ecc1
--- /dev/null
+++ b/inc/message.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2017 Samsung Electronics Co., Ltd.
+ *
+ * Licensed under the Flora License, Version 1.1 (the License);
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://floralicense.org/license/
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __CAR_APP_MESSAGE_H__
+#define __CAR_APP_MESSAGE_H__
+
+typedef enum __message_cmd_e {
+       MESSAGE_CMD_HELLO, /* to use keep alive, if needed */
+       MESSAGE_CMD_CALIBRATION,
+       MESSAGE_CMD_DRIVE,
+       MESSAGE_CMD_BYE, /* to notify explicitly closing connection */
+} message_cmd_e;
+
+typedef struct __message_type_s message_s;
+
+int message_new(message_cmd_e cmd, int servo, int speed, message_s *new_msg);
+void message_reset_seq_num(void);
+
+/* To encapsulate message struction,
+ * we need to discuss about it.
+ * which one is better, hiding its members or direct accessing its members?
+ */
+int message_get_seq_num(message_s *msg, unsigned long long int *seq_num);
+int message_get_cmd(message_s *msg, message_cmd_e *cmd);
+int message_get_servo_value(message_s *msg, int *speed);
+int message_get_servo_value(message_s *msg, int *servo);
+
+#endif /* __CAR_APP_MESSAGE_H__ */

diff --git a/src/message.c b/src/message.c
new file mode 100644 (file)
index 0000000..db44f37
--- /dev/null
+++ b/src/message.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2017 Samsung Electronics Co., Ltd.
+ *
+ * Licensed under the Flora License, Version 1.1 (the License);
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://floralicense.org/license/
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <time.h>
+#include <limits.h>
+#include "log.h"
+#include "message.h"
+
+struct __message_type_s {
+       unsigned long long int seq_num;
+       message_cmd_e cmd;
+       int servo;
+       int speed;
+       unsigned long long int time; /* to be used to order messages */
+};
+
+static unsigned long long int sequence_number = 0;
+
+static unsigned long long int __message_get_monotonic_time(void)
+{
+       unsigned long long int c_time = 0;
+       struct timespec ts;
+       int ret = 0;
+
+       ret = clock_gettime(CLOCK_MONOTONIC, &ts);
+       if (ret)
+               _E("failed to get monotonic time");
+       else
+               c_time = (((unsigned long long int)ts.tv_sec) * 1000000)
+                       + (ts.tv_nsec / 1000);
+
+       return c_time;
+}
+
+int message_new(message_cmd_e cmd, int servo, int speed, message_s *new_msg)
+{
+       retv_if(!new_msg, -1);
+
+       new_msg->seq_num = sequence_number++;
+       new_msg->cmd = cmd;
+       new_msg->servo = servo;
+       new_msg->speed = speed;
+       new_msg->time = __message_get_monotonic_time();
+
+       if (new_msg->seq_num >= ULLONG_MAX) {
+               /* maybe never reach here */
+               _W("seq number reachs max value, reset it to 0");
+               sequence_number = 0;
+       }
+
+       return 0;
+}
+
+void message_reset_seq_num(void)
+{
+       sequence_number = 0;
+
+       return;
+}
+
+int message_get_seq_num(message_s *msg, unsigned long long int *seq_num)
+{
+       retv_if(!msg, -1);
+
+       *seq_num = msg->seq_num;
+
+       return 0;
+}
+
+int message_get_cmd(message_s *msg, message_cmd_e *cmd)
+{
+       retv_if(!msg, -1);
+
+       *cmd = msg->cmd;
+
+       return 0;
+}
+
+int message_get_speed_value(message_s *msg, int *speed)
+{
+       retv_if(!msg, -1);
+
+       *speed = msg->speed;
+
+       return 0;
+}
+
+int message_get_servo_value(message_s *msg, int *servo)
+{
+       retv_if(!msg, -1);
+
+       *servo = msg->servo;
+
+       return 0;
+}