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Annotation of mqtt/inc/aitmqtt.h, revision 1.1.1.1.2.2

1.1       misho       1: #ifndef __AITMQTT_H
                      2: #define __AITMQTT_H
                      3: 
                      4: 
1.1.1.1.2.1  misho       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: 
1.1       misho      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: 
1.1.1.1.2.1  misho      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
1.1.1.1.2.2! misho      89:  * @n = sizeof bytes, if !=NULL
1.1.1.1.2.1  misho      90:  * return: -1 error, >-1 length of message
                     91:  */
1.1.1.1.2.2! misho      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);
1.1.1.1.2.1  misho      99: 
                    100: 
1.1       misho     101: #endif