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add func

    1: #ifndef __AITMQTT_H
    2: #define __AITMQTT_H
    3: 
    4: 
    5: struct mqtthdr {
    6: 	unsigned char	mqtt_retain : 1, 
    7: 			mqtt_qos : 2,
    8: 			mqtt_dup : 1,
    9: 			mqtt_type : 4;
   10: 	unsigned char	mqtt_len;
   11: };
   12: 
   13: #define MQTT_TYPE_UNKNOWN	0	/* reserved */
   14: #define MQTT_TYPE_CONNECT	1	/* client request to connect to server */
   15: #define MQTT_TYPE_CONNACK	2	/* connect acknowledgment */
   16: #define MQTT_TYPE_PUBLISH	3	/* publish message */
   17: #define MQTT_TYPE_PUBACK	4	/* publish acknowledgment */
   18: #define MQTT_TYPE_PUBREC	5	/* publish received (assured delivery part 1) */
   19: #define MQTT_TYPE_PUBREL	6	/* publish release (assured delivery part 2) */
   20: #define MQTT_TYPE_PUBCOMP	7	/* publish complete (assured delivery part 3) */
   21: #define MQTT_TYPE_SUBSCRIBE	8	/* client subscribe request */
   22: #define MQTT_TYPE_SUBACK	9	/* subscribe acknowledgment */
   23: #define MQTT_TYPE_UNSUBSCRIBE	10	/* client unsubscribe request */
   24: #define MQTT_TYPE_UNSUBACK	11	/* unsubscribe acknowledgment */
   25: #define MQTT_TYPE_PINGREQ	12	/* PING request */
   26: #define MQTT_TYPE_PINGRESP	13	/* PING response */
   27: #define MQTT_TYPE_DISCONNECT	14	/* client is disconnecting */
   28: #define MQTT_TYPE_RESERVED	15	/* reserved */
   29: 
   30: #define MQTT_FLAG_DUP		1	/* This flag is set when the client or server attempts to re-deliver 
   31: 					   a PUBLISH, PUBREL, SUBSCRIBE or UNSUBSCRIBE message. 
   32: 					   This applies to messages where the value of QoS is greater than 
   33: 					   zero (0), and an acknowledgment is required. 
   34: 					   When the DUP bit is set, the variable header includes a Message ID.
   35: 
   36: 					   The recipient should treat this flag as a hint as to whether 
   37: 					   the message may have been previously received. 
   38: 					   It should not be relied on to detect duplicates. */
   39: 
   40: #define MQTT_QOS_ONCE		0	/* At most once, Fire and Forget, <=1 */
   41: #define MQTT_QOS_ACK		1	/* At least once, Acknowledged delivery, >=1 */
   42: #define MQTT_QOS_EXACTLY	2	/* Exactly once, Assured delivery, =1 */
   43: #define MQTT_QOS_RESERVED	3	/* reserved */
   44: 
   45: #define MQTT_FLAG_RETAIN	1	/* This flag is only used on PUBLISH messages.
   46: 
   47: 					   When a client sends a PUBLISH to a server, 
   48: 					   if the Retain flag is set (1), 
   49: 					   the server should hold on to the message after it has been 
   50: 					   delivered to the current subscribers.
   51: 					   When a new subscription is established on a topic, 
   52: 					   the last retained message on that topic should be sent to 
   53: 					   the subscriber with the Retain flag set.
   54: 					   If there is no retained message, nothing is sent
   55: 					   This is useful where publishers send messages on a 
   56: 					   "report by exception" basis, where it might be some time between messages. 
   57: 					   This allows new subscribers to instantly receive data with the retained, 
   58: 					   or Last Known Good, value.
   59: 
   60: 					   When a server sends a PUBLISH to a client as a result of 
   61: 					   a subscription that already existed when the original PUBLISH arrived, 
   62: 					   the Retain flag should not be set, regardless of the Retain flag 
   63: 					   of the original PUBLISH. This allows a client to distinguish messages 
   64: 					   that are being received because they were retained and those 
   65: 					   that are being received "live".
   66: 
   67: 					   Retained messages should be kept over restarts of the server.
   68: 					   A server may delete a retained message if it receives a message 
   69: 					   with a zero-length payload and the Retain flag set on the same topic. */
   70: 
   71: 
   72: // -------------------------------------------------------
   73: // mqtt_GetErrno() Get error code of last operation
   74: inline int mqtt_GetErrno();
   75: // mqtt_GetError() Get error text of last operation
   76: inline const char *mqtt_GetError();
   77: // -------------------------------------------------------
   78: 
   79: 
   80: /*
   81:  * mqtt_encodeLen() Encode number to MQTT length field
   82:  * @num = number for encode
   83:  * return: -1 error or >-1 length
   84:  */
   85: inline unsigned int mqtt_encodeLen(unsigned int num);
   86: /*
   87:  * mqtt_decodeLen() Decode length from MQTT packet
   88:  * @len = length
   89:  * @n = sizeof bytes, if !=NULL
   90:  * return: -1 error, >-1 length of message
   91:  */
   92: inline unsigned int mqtt_decodeLen(unsigned int len, char *n);
   93: /*
   94:  * mqtt_sizeLen Return sizeof len field
   95:  * @len = length
   96:  * return: -1 error, >-1 sizeof len in bytes
   97:  */
   98: inline char mqtt_sizeLen(unsigned int len);
   99: 
  100: 
  101: #endif