lwes_listener.h File Reference

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Detailed Description

Functions for listening to LWES events.

Go to the source code of this file.

Data Structures
struct	lwes_listener
	Listens for LWES events. More...
Functions
lwes_listener *	lwes_listener_create (LWES_SHORT_STRING address, LWES_SHORT_STRING iface, LWES_U_INT_32 port)
	Create a Listener.
int	lwes_listener_add_header_fields (struct lwes_listener *listener, LWES_BYTE_P bytes, size_t max, size_t *len)
	Copy some date from the UDP packet into the event.
int	lwes_listener_event_has_name (LWES_BYTE_P bytes, size_t len, LWES_CONST_SHORT_STRING name)
	Determine if a serialized event is of a given type.
int	lwes_listener_recv_process_event (struct lwes_listener *listener, struct lwes_event *event, int len)
	This adds headers and deserializes the event.
int	lwes_listener_recv (struct lwes_listener *listener, struct lwes_event *event)
	Receive an event from the listener in a blocking manner.
int	lwes_listener_recv_by (struct lwes_listener *listener, struct lwes_event *event, unsigned int timeout_ms)
	Receive an event from the listener with a timeout.
int	lwes_listener_recv_bytes (struct lwes_listener *listener, LWES_BYTE_P bytes, size_t max)
	Receive bytes from the listener in a blocking manner.
int	lwes_listener_recv_bytes_by (struct lwes_listener *listener, LWES_BYTE_P bytes, size_t max, unsigned int timeout_ms)
	Receive bytes from the listener with a timeout.
int	lwes_listener_destroy (struct lwes_listener *listener)
	Destroy a Listener.

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Function Documentation

struct lwes_listener* lwes_listener_create (  LWES_SHORT_STRING  address, LWES_SHORT_STRING  iface, LWES_U_INT_32  port )

Create a Listener. Parameters: [in]  address  The multicast ip address as a dotted quad string of the channel to listen on. [in]  iface  The dotted quad ip address of the interface to receive messages on, can be NULL to use default. [in]  port  The port of the channel to listen on. See also: lwes_listener_destroy Returns: A newly created listener, use lwes_listener_destroy to free

int lwes_listener_add_header_fields (  struct lwes_listener *  listener, LWES_BYTE_P  bytes, size_t  max, size_t *  len )

Copy some date from the UDP packet into the event. This will add the following fields to the event as additional attributes SenderIP - the ip address of the sender of the event SenderPort - the port of the sender of the event ReceiptTime - a timestamp of receipt time, as milliseconds since epoch This should be called immediately after one of lwes_listener_recv lwes_listener_recv_by lwes_listener_recv_bytes lwes_listener_recv_bytes_by in order for the sender ip and port to be accurate Parameters: [in]  listener  The listener which just received the event [in]  bytes  The serialized event to add the attributes to [in]  max  The maximum size of the serialzed event [in,out]  len  The current size of the serialized event See also: lwes_listener_recv lwes_listener_recv_by lwes_listener_recv_bytes lwes_listener_recv_bytes_by Returns: 0 upon success, a negative number upon failure

int lwes_listener_event_has_name (  LWES_BYTE_P  bytes, size_t  len, LWES_CONST_SHORT_STRING  name )

Determine if a serialized event is of a given type. This function will compare the name in a serialized event against a given name, if they match 0 is returned, if not a non-zero value is returned Parameters: [in]  bytes  The serialized event [in]  len  The current size of the serialized event [in]  name  The name to check Returns: 0 if the serialized event is of type name, non-zero if it is not.

int lwes_listener_recv_process_event (  struct lwes_listener *  listener, struct lwes_event *  event, int  len )

This adds headers and deserializes the event. This is actually a private function, which will be removed next major version bump of lwes. Parameters: [in]  listener  the listener which just received the event [out]  event  the event object to deserialize into [in]  len  the size of the serialized event waiting in the listener Returns: 0 on success, a negative number on failure

int lwes_listener_recv (  struct lwes_listener *  listener, struct lwes_event *  event )

Receive an event from the listener in a blocking manner. Parameters: [in]  listener  the listener to receive the event from [out]  event  the event to fill out Returns: 0 on success, a negative number on failure

int lwes_listener_recv_by (  struct lwes_listener *  listener, struct lwes_event *  event, unsigned int  timeout_ms )

Receive an event from the listener with a timeout. Parameters: [in]  listener  the listener to receive the event from [out]  event  the event to fill out [in]  timeout_ms  the maximum amount of time to wait for an event Returns: 0 on success, a negative number on failure

int lwes_listener_recv_bytes (  struct lwes_listener *  listener, LWES_BYTE_P  bytes, size_t  max )

Receive bytes from the listener in a blocking manner. This returns the raw bytes and returns them, it will not add header fields nor deserialize the event. This is useful if you want to journal without the cost of deserialization. Parameters: [in]  listener  the listener to receive the bytes from [out]  bytes  the byte array to write into [in]  max  the maximum number of bytes to write into the bytes array Returns: the number of bytes read on success, a negative number on failure

int lwes_listener_recv_bytes_by (  struct lwes_listener *  listener, LWES_BYTE_P  bytes, size_t  max, unsigned int  timeout_ms )

Receive bytes from the listener with a timeout. This returns the raw bytes and returns them, it will not add header fields nor deserialize the event. This is useful if you want to journal without the cost of deserialization. Parameters: [in]  listener  the listener to receive the bytes from [out]  bytes  the byte array to write into [in]  max  the maximum number of bytes to write into the bytes array [in]  timeout_ms  the maximum amount of time to wait for bytes Returns: the number of bytes read on success, a negative number on failure

int lwes_listener_destroy (  struct lwes_listener *  listener  )

Destroy a Listener. Parameters: [in]  listener  The listener to destroy by freeing all of it's used memory. Returns: 0 on success, negative number on failure

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