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Add more callbacks to the API so we can subscribe after successful connection for example

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This commit is contained in:
Johannes Schriewer 2018-07-30 02:56:05 +02:00
parent 5a17278cc9
commit 1d134a23c9
2 changed files with 60 additions and 55 deletions
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70
src/mqtt.c
View file

@ -23,17 +23,6 @@ static inline void disconnect(MQTTHandle *handle) {
// FIXME: Do we have to do anything else?
}
static inline bool find_waiting(MQTTHandle *handle, MQTTPacket *packet) {
// TODO: Try to find a waiting task and call its callback
// TODO: Remove waiting task from queue
return false;
}
static inline void send_subscription(MQTTHandle *handle, PublishPayload *payload) {
// TODO: find subscriber and call the callback
}
static inline void parse_packet(MQTTHandle *handle, MQTTPacket *packet) {
switch (packet->packet_type) {
case PacketTypeConnAck:
@ -43,13 +32,20 @@ static inline void parse_packet(MQTTHandle *handle, MQTTPacket *packet) {
case PacketTypePubComp:
case PacketTypeSubAck:
case PacketTypeUnsubAck:
case PacketTypePingResp:
if (!find_waiting(handle, packet)) {
if (!dispatch_packet(handle, packet)) {
DEBUG_LOG("Unexpected packet!");
disconnect(handle);
}
break;
case PacketTypePublish:
send_subscription(handle, packet->payload);
dispatch_subscription(handle, packet->payload);
// TODO: Handle QoS
break;
// just for keepalive, do not handle
case PacketTypePingResp:
break;
// client -> server, will not be handled in client
case PacketTypeConnect:
@ -57,13 +53,14 @@ static inline void parse_packet(MQTTHandle *handle, MQTTPacket *packet) {
case PacketTypeUnsubscribe:
case PacketTypePingReq:
case PacketTypeDisconnect:
DEBUG_LOG("Server packet on client connection? What's up with the broker?");
disconnect(handle);
break;
}
}
static void _reader(MQTTHandle *handle) {
int num_bytes;
ssize_t num_bytes;
char *read_buffer = malloc(max_receive_buffer_size);
uint8_t offset = 0;
@ -78,13 +75,11 @@ static void _reader(MQTTHandle *handle) {
return;
} else if (num_bytes < 0) {
if ((errno == EINTR) || (errno == EAGAIN)) {
DEBUG_LOG("Interrupted");
continue;
}
/* Set reader task to dead */
handle->reader_alive = false;
DEBUG_LOG("Read error: %s", strerror(errno));
return;
}
@ -92,13 +87,11 @@ static void _reader(MQTTHandle *handle) {
Buffer *buffer = buffer_from_data_no_copy(read_buffer, num_bytes);
MQTTPacket *packet = mqtt_packet_decode(buffer);
if (packet == NULL) {
DEBUG_LOG("Invalid packet");
// invalid packet
if (num_bytes < max_receive_buffer_size) {
// maybe not long enough, try to fetch the rest
offset += num_bytes;
free(buffer);
DEBUG_LOG("Trying to read more...");
break;
} else {
// no space in buffer, bail and reconnect
@ -109,12 +102,12 @@ static void _reader(MQTTHandle *handle) {
return;
}
} else {
DEBUG_LOG("Packet parsed");
// hexdump(buffer->data, num_bytes, 2);
parse_packet(handle, packet);
free_MQTTPacket(packet);
if (!buffer_eof(buffer)) {
DEBUG_LOG("Residual buffer data");
// Not complete recv buffer was consumed, so we have more than one packet in there
size_t remaining = max_receive_buffer_size - buffer->position;
memmove(read_buffer, read_buffer + buffer->position, remaining);
@ -122,7 +115,6 @@ static void _reader(MQTTHandle *handle) {
num_bytes -= remaining;
free(buffer);
} else {
DEBUG_LOG("Buffer consumed");
// buffer consumed completely, read another chunk
offset = 0;
free(buffer);
@ -133,7 +125,7 @@ static void _reader(MQTTHandle *handle) {
}
}
static void _mqtt_connect(MQTTHandle *handle) {
static void _mqtt_connect(MQTTHandle *handle, MQTTEventHandler callback, void *context) {
int ret;
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof(servaddr));
@ -176,18 +168,20 @@ static void _mqtt_connect(MQTTHandle *handle) {
run_read_task(handle, _reader);
expect_packet(handle, PacketTypeConnAck, 0, callback, context);
bool result = send_connect_packet(handle);
if (result == false) {
DEBUG_LOG("Sending connect packet failed, running error handler");
bool free_handle = handle->error_handler(handle, MQTT_Error_Broker_Disconnected);
if (free_handle) {
mqtt_free(handle);
}
DEBUG_LOG("Sending connect packet failed...");
close(handle->sock);
}
}
MQTTHandle *mqtt_connect(MQTTConfig *config, MQTTErrorHandler callback) {
MQTTHandle *mqtt_connect(MQTTConfig *config, MQTTEventHandler callback, void *context, MQTTErrorHandler error_callback) {
MQTTHandle *handle = calloc(sizeof(struct _MQTTHandle), 1);
initialize_platform(handle);
@ -196,32 +190,37 @@ MQTTHandle *mqtt_connect(MQTTConfig *config, MQTTErrorHandler callback) {
}
handle->config = config;
handle->error_handler = callback;
handle->error_handler = error_callback;
_mqtt_connect(handle);
_mqtt_connect(handle, callback, context);
return handle;
}
MQTTStatus mqtt_reconnect(MQTTHandle *handle) {
MQTTStatus mqtt_reconnect(MQTTHandle *handle, MQTTEventHandler callback, void *context) {
if (handle->reader_alive) {
DEBUG_LOG("Closing old connection");
close(handle->sock);
join_read_task(handle);
}
_mqtt_connect(handle);
// TODO: re-submit unacknowledged packages with QoS > 0
// TODO: clear waiting packets
// TODO: re-subscribe all subscriptions
_mqtt_connect(handle, callback, context);
return MQTT_STATUS_OK;
}
MQTTStatus mqtt_subscribe(MQTTHandle *handle, char *topic, MQTTEventHandler callback) {
MQTTStatus mqtt_subscribe(MQTTHandle *handle, char *topic, MQTTPublishEventHandler callback) {
if (!handle->reader_alive) {
handle->error_handler(handle, MQTT_Error_Connection_Reset);
return MQTT_STATUS_ERROR;
}
add_subscription(handle, topic, callback);
return (send_subscribe_packet(handle, topic) ? MQTT_STATUS_OK : MQTT_STATUS_ERROR);
// TODO: add subscription to list
}
MQTTStatus mqtt_unsubscribe(MQTTHandle *handle, char *topic) {
@ -229,8 +228,8 @@ MQTTStatus mqtt_unsubscribe(MQTTHandle *handle, char *topic) {
handle->error_handler(handle, MQTT_Error_Connection_Reset);
return MQTT_STATUS_ERROR;
}
remove_subscription(handle, topic);
return (send_unsubscribe_packet(handle, topic) ? MQTT_STATUS_OK : MQTT_STATUS_ERROR);
// TODO: remove subscription from list
}
MQTTStatus mqtt_publish(MQTTHandle *handle, char *topic, char *payload, MQTTQosLevel qos_level) {
@ -241,13 +240,16 @@ MQTTStatus mqtt_publish(MQTTHandle *handle, char *topic, char *payload, MQTTQosL
return (send_publish_packet(handle, topic, payload, qos_level) ? MQTT_STATUS_OK : MQTT_STATUS_ERROR);
}
MQTTStatus mqtt_disconnect(MQTTHandle *handle) {
DEBUG_LOG("Disconnecting...")
MQTTStatus mqtt_disconnect(MQTTHandle *handle, MQTTEventHandler callback, void *callback_context) {
send_disconnect_packet(handle);
if (close(handle->sock)) {
return MQTT_STATUS_ERROR;
}
join_read_task(handle);
mqtt_free(handle);
if (callback) {
callback(NULL, callback_context);
}
return MQTT_STATUS_OK;
}

13
src/mqtt.h
View file

@ -43,7 +43,10 @@ typedef enum {
typedef bool (*MQTTErrorHandler)(MQTTHandle *handle, MQTTErrorCode code);
/** Event handler callback */
typedef void (*MQTTEventHandler)(MQTTHandle *handle, char *topic, char *payload);
typedef void (*MQTTEventHandler)(MQTTHandle *handle, void *context);
/** publish event callback */
typedef void (*MQTTPublishEventHandler)(MQTTHandle *handle, char *topic, char *payload);
/**
* Connect to MQTT broker
@ -56,7 +59,7 @@ typedef void (*MQTTEventHandler)(MQTTHandle *handle, char *topic, char *payload)
* the handler is in charge of freeing the handle by returning true
* or re-trying by changing settings and calling mqtt_reconnect() and returning false
*/
MQTTHandle *mqtt_connect(MQTTConfig *config, MQTTErrorHandler callback);
MQTTHandle *mqtt_connect(MQTTConfig *config, MQTTEventHandler callback, void *callback_context, MQTTErrorHandler error_callback);
/**
* Re-Connect to MQTT broker
@ -70,7 +73,7 @@ MQTTHandle *mqtt_connect(MQTTConfig *config, MQTTErrorHandler callback);
* @param handle: MQTT Handle from `mqtt_connect`
* @returns: Status code
*/
MQTTStatus mqtt_reconnect(MQTTHandle *handle);
MQTTStatus mqtt_reconnect(MQTTHandle *handle, MQTTEventHandler callback, void *callback_context);
/**
* Subscribe to a topic
@ -80,7 +83,7 @@ MQTTStatus mqtt_reconnect(MQTTHandle *handle);
* @param callback: Callback function to call when receiving something for that topic
* @returns: Status code
*/
MQTTStatus mqtt_subscribe(MQTTHandle *handle, char *topic, MQTTEventHandler callback);
MQTTStatus mqtt_subscribe(MQTTHandle *handle, char *topic, MQTTPublishEventHandler callback);
/**
* Un-Subscribe from a topic
@ -110,6 +113,6 @@ MQTTStatus mqtt_publish(MQTTHandle *handle, char *topic, char *payload, MQTTQosL
* @attention: do not use the handle after calling this function,
* all resources will be freed, this handle is now invalid!
*/
MQTTStatus mqtt_disconnect(MQTTHandle *handle);
MQTTStatus mqtt_disconnect(MQTTHandle *handle, MQTTEventHandler callback, void *callback_context);
#endif /* mqtt_h__included */