cwist_nats.c File Reference

cwist_nats.c interface. More...

#include <cwist/net/nats/cwist_nats.h>
#include <cwist/core/mem/alloc.h>
#include <nats.h>
#include <stdlib.h>
#include <string.h>

Include dependency graph for cwist_nats.c:

Go to the source code of this file.

Macros
#define	_GNU_SOURCE

Functions
cwist_error_t	cwist_nats_connect (cwist_nats_t **nats, const char *url)
	Connect to a NATS server and create a handle.
cwist_error_t	cwist_nats_subscribe (cwist_nats_t *nats, const char *subject, cwist_nats_msg_cb cb, void *ctx)
	Subscribe to a NATS subject and register a message callback.
cwist_error_t	cwist_nats_publish_string (cwist_nats_t *nats, const char *subject, const char *data)
	Publish a NUL-terminated string message to a subject.
void	cwist_nats_dispatch (cwist_nats_t *nats)
	Pump pending I/O on the connection.
void	cwist_nats_destroy (cwist_nats_t *nats)
	Destroy a handle and release its resources.
natsConnection *	cwist_nats_native (cwist_nats_t *nats)
	Access the underlying NATS connection.

Detailed Description

cwist_nats.c interface.

Definition in file cwist_nats.c.

Macro Definition Documentation

_GNU_SOURCE

#define _GNU_SOURCE

Definition at line 5 of file cwist_nats.c.

Function Documentation

cwist_nats_connect()

cwist_error_t cwist_nats_connect	(	cwist_nats_t **	nats,
		const char *	url
	)

Connect to a NATS server and create a handle.

Connect to a NATS server.

Allocates a cwist_nats_t and connects to the given URL, or to the NATS default URL when url is NULL.

Parameters

[out]	nats	Receives the new handle on success; must not be NULL.
	url	Server URL, or NULL for the default server.

Returns

cwist_error_t with err_i16 set to 0 on success, CWIST_ERROR_INVALID_PARAM if nats is NULL, CWIST_ERROR_NOMEM on allocation failure, or the natsStatus code on connection failure.

Definition at line 56 of file cwist_nats.c.

References cap, cwist_alloc(), CWIST_ERR_INT16, CWIST_ERROR_INVALID_PARAM, CWIST_ERROR_NOMEM, cwist_free(), and make_error().

cwist_nats_destroy()

void cwist_nats_destroy

(

cwist_nats_t *

nats

)

Destroy a handle and release its resources.

Disconnect and destroy the NATS handle.

Unsubscribes and disconnects if still active, then frees the handle. Safe to call with NULL; the handle must not be used afterwards.

Parameters

nats	Handle to destroy, or NULL.

Definition at line 161 of file cwist_nats.c.

References cap, and cwist_free().

cwist_nats_dispatch()

void cwist_nats_dispatch

(

cwist_nats_t *

nats

)

Pump pending I/O on the connection.

Dispatch incoming messages.

Flushes the connection, pushing buffered outgoing messages and processing incoming traffic so delivered callbacks can run. Safe to call with a NULL or disconnected handle; such calls are no-ops.

Parameters

nats	Handle to flush, or NULL.

Definition at line 148 of file cwist_nats.c.

References cap.

cwist_nats_native()

natsConnection * cwist_nats_native

(

cwist_nats_t *

nats

)

Access the underlying NATS connection.

Borrow the underlying cnats connection.

The returned pointer is owned by the handle and remains valid until cwist_nats_destroy is called.

Parameters

nats	Handle to query, or NULL.

Returns

The native natsConnection, or NULL if nats is NULL.

Definition at line 180 of file cwist_nats.c.

References cap.

cwist_nats_publish_string()

cwist_error_t cwist_nats_publish_string	(	cwist_nats_t *	nats,
		const char *	subject,
		const char *	data
	)

Publish a NUL-terminated string message to a subject.

Publish a string message.

A NULL data is published as an empty string. Flushes the connection after publishing so the message is written out before returning.

Parameters

nats	Handle with an active connection; must not be NULL.
subject	Subject to publish to; must not be NULL.
data	Payload string, or NULL to send an empty payload.

Returns

cwist_error_t with err_i16 set to 0 on success, CWIST_ERROR_INVALID_PARAM on NULL arguments, or the natsStatus code on publish/flush failure.

Definition at line 126 of file cwist_nats.c.

References cap, CWIST_ERR_INT16, CWIST_ERROR_INVALID_PARAM, and make_error().

cwist_nats_subscribe()

cwist_error_t cwist_nats_subscribe	(	cwist_nats_t *	nats,
		const char *	subject,
		cwist_nats_msg_cb	cb,
		void *	ctx
	)

Subscribe to a NATS subject and register a message callback.

Subscribe to a subject.

Replaces any existing subscription on the handle: the previous subscription is destroyed before the new one is created. The callback is invoked from the NATS delivery thread via cwist_nats_adapter.

Parameters

nats	Handle with an active connection; must not be NULL.
subject	Subject to subscribe to; must not be NULL.
cb	Callback invoked for each incoming message; may be NULL.
ctx	Opaque pointer passed back to cb.

Returns

cwist_error_t with err_i16 set to 0 on success, CWIST_ERROR_INVALID_PARAM on NULL arguments, or the natsStatus code on failure.

Definition at line 92 of file cwist_nats.c.

References cap, CWIST_ERR_INT16, CWIST_ERROR_INVALID_PARAM, and make_error().