A Redis client library that compiles on older and newer platforms alike, such as LynxOS 3.1.0 PowerPCs. It is quite full featured, supporting multiple Redis instances, pipelining, user-specified connect and disconnect hooks, multiple user-specified subscription listeners, and user-specified pipeline processors. More...

Functions
RESP *	redisxArrayRequest (Redis redis, char args[], int lengths[], int n, int *status)

int	redisxCheckDestroyRESP (RESP *resp, char expectedType, int expectedSize)

int	redisxCheckRESP (const RESP *resp, char expectedType, int expectedSize)

void	redisxDebugTraffic (boolean value)

void	redisxDestroyRESP (RESP *resp)

int	redisxError (const char *func, int errorCode)

const char *	redisxErrorDescription (int code)

int	redisxGetTime (Redis redis, struct timespec t)

boolean	redisxHasPipeline (Redis *redis)

boolean	redisxIsVerbose ()

int	redisxPing (Redis redis, const char message)

RESP *	redisxRequest (Redis redis, const char command, const char arg1, const char arg2, const char arg3, int status)

int	redisxSelectDB (Redis *redis, int idx)

int	redisxSetPassword (Redis redis, const char passwd)

int	redisxSetPipelineConsumer (Redis redis, void(f)(RESP *))

int	redisxSetTransmitErrorHandler (Redis *redis, RedisErrorHandler f)

int	redisxSetUser (Redis redis, const char username)

void	redisxSetVerbose (boolean value)

Detailed Description

A Redis client library that compiles on older and newer platforms alike, such as LynxOS 3.1.0 PowerPCs. It is quite full featured, supporting multiple Redis instances, pipelining, user-specified connect and disconnect hooks, multiple user-specified subscription listeners, and user-specified pipeline processors.

Date: May 4, 2018

Author: Attila Kovacs

Function Documentation

◆ redisxArrayRequest()

RESP * redisxArrayRequest	(	Redis *	redis,
		char *	args[],
		int	lengths[],
		int	n,
		int *	status
	)

Returns the result of the most generic type of Redis request with any number of arguments. This is not the highest throughput mode (that would be sending asynchronous pipeline request, and then asynchronously collecting the results such as with redisxSendArrayRequestAsync() / redisxReadReplyAsync(), because it requires separate network roundtrips for each and every request. But, it is simple and perfectly good method when one needs to retrieve only a few (<1000) variables per second...

Parameters

redis	Pointer to a Redis instance.
args	An array of strings to send to Redis, corresponding to a single query.
lengths	Array indicating the number of bytes to send from each string argument. Zero values can be used to determine the string length automatically using strlen(), and the length argument itself may be NULL to determine the lengths of all string arguments automatically.
n	Number of string arguments.
status	Pointer to the return error status, which is either X_SUCCESS on success. X_NO_INIT if the Redis client librarywas not initialized via initRedis. X_NULL if the argument is NULL or n<1. X_NO_SERVICE if not connected to Redis. X_FAILURE If there was a socket level error.

Returns: A freshly allocated RESP array containing the Redis response, or NULL if no valid response could be obtained.

See also: redisxRequest(); redisxSendArrayRequestAsync(); redisxReadReplyAsync()

References Redis::interactive, redisxLockConnected(), redisxReadReplyAsync(), redisxSendArrayRequestAsync(), redisxUnlockClient(), x_error(), X_NULL, X_SUCCESS, x_trace_null(), and xvprintf.

◆ redisxCheckDestroyRESP()

int redisxCheckDestroyRESP	(	RESP *	resp,
		char	expectedType,
		int	expectedSize
	)

Like redisxCheckRESP(), but it also destroys the RESP in case of an error.

Parameters

resp	Pointer to the RESP structure from Redis.
expectedType	The RESP type expected (e.g. RESP_ARRAY) or 0 if not checking type.
expectedSize	The expected size of the RESP (array or bytes) or <=0 to skip checking

Returns: The return value of redisxCheckRESP().

See also: redisxCheckRESP()

References redisxCheckRESP(), and redisxDestroyRESP().

◆ redisxCheckRESP()

int redisxCheckRESP	(	const RESP *	resp,
		char	expectedType,
		int	expectedSize
	)

Checks a Redis RESP for NULL values or unexpected values.

Parameters

resp	Pointer to the RESP structure from Redis.
expectedType	The RESP type expected (e.g. RESP_ARRAY) or 0 if not checking type.
expectedSize	The expected size of the RESP (array or bytes) or <=0 to skip checking

Returns: X_SUCCESS (0) if the RESP passes the tests, or X_NULL if the RESP is NULL (garbled response). REDIS_NULL if Redis returned (nil), REDIS_UNEXPECTED_TYPE if got a reply of a different type than expected REDIS_UNEXPECTED_ARRAY_SIZE if got a reply of different size than expected.

or the error returned in resp->n.

References RESP::n, REDIS_NULL, REDIS_UNEXPECTED_RESP, RESP_INT, RESP::type, RESP::value, x_error(), X_FAILURE, X_NULL, and X_SUCCESS.

◆ redisxDebugTraffic()

void redisxDebugTraffic ( boolean value )

Enable or disable verbose reporting of all Redis bound traffic. It may be useful when debugging programs that use the redisx interface. Verbose reporting is DISABLED by default.

Parameters

value TRUE to enable verbose reporting, or FALSE to disable.

See also: redisxSetVerbose()

References FALSE, and TRUE.

◆ redisxDestroyRESP()

void redisxDestroyRESP ( RESP * resp )

Frees up the resources used by a RESP structure that was dynamically allocated. The call will segfault if the same RESP is destroyed twice or if the argument is a static allocation.

Parameters

resp	Pointer to the RESP structure to be destroyed, which may be NULL (no action taken).

References RESP::n, redisxDestroyRESP(), RESP_ARRAY, RESP::type, and RESP::value.

◆ redisxError()

int redisxError	(	const char *	func,
		int	errorCode
	)

Prints a descriptive error message to stderr, and returns the error code.

Parameters

func	A string that describes the function or location where the error occurred.
errorCode	The error code that describes the failure.

Returns: the error code.

References MAX_DEBUG_ERROR_COUNT, REDIS_INCOMPLETE_TRANSFER, redisxErrorDescription(), and xDebug.

◆ redisxErrorDescription()

const char * redisxErrorDescription ( int code )

Returns a string description for one of the RM error codes.

Parameters

code	One of the error codes defined in 'rm.h' or in 'redisrm.h' (e.g. X_NO_PIPELINE)

Returns: A constant string with the error description.

References REDIS_ERROR, REDIS_INCOMPLETE_TRANSFER, REDIS_INVALID_CHANNEL, REDIS_NULL, REDIS_UNEXPECTED_ARRAY_SIZE, REDIS_UNEXPECTED_RESP, and xErrorDescription().

◆ redisxGetTime()

int redisxGetTime	(	Redis *	redis,
		struct timespec *	t
	)

Returns the current time on the Redis server instance.

Parameters

	redis	Pointer to a Redis instance.
[out]	t	Pointer to a timespec structure in which to return the server time.

Returns: X_SUCCESS (0) if successful, or X_NULL if either argument is NULL, or X_PARSE_ERROR if could not parse the response, or another error returned by redisxCheckRESP().

References redisxCheckDestroyRESP(), redisxCheckRESP(), redisxDestroyRESP(), redisxRequest(), RESP_ARRAY, RESP_BULK_STRING, RESP::value, x_error(), X_NULL, X_PARSE_ERROR, X_SUCCESS, and x_trace().

◆ redisxHasPipeline()

boolean redisxHasPipeline ( Redis * redis )

Checks if a Redis instance has the pipeline connection enabled.

Parameters

redis Pointer to a Redis instance.

Returns: TRUE (1) if the pipeline client is enabled on the Redis intance, or FALSE (0) otherwise.

References FALSE, and Redis::pipeline.

◆ redisxIsVerbose()

boolean redisxIsVerbose ( )

Checks id verbose reporting is enabled.

Returns: TRUE if verbose reporting is enabled, otherwise FALSE.

References xIsVerbose().

◆ redisxPing()

int redisxPing	(	Redis *	redis,
		const char *	message
	)

Pings the Redis server (see the Redis PING command), and checks the response.

Parameters

redis	Pointer to a Redis instance.
message	Optional message , or NULL for `PING` without an argument.

Returns: X_SUCCESS (0) if successful, or else an error code (<0) from redisx.h / xchange.h.

References REDIS_UNEXPECTED_RESP, redisxCheckRESP(), redisxDestroyRESP(), redisxRequest(), RESP_BULK_STRING, RESP_SIMPLE_STRING, RESP::value, x_error(), X_NULL, and X_SUCCESS.

◆ redisxRequest()

RESP * redisxRequest	(	Redis *	redis,
		const char *	command,
		const char *	arg1,
		const char *	arg2,
		const char *	arg3,
		int *	status
	)

Returns the result of a Redis command with up to 3 regularly terminated string arguments. This is not the highest throughput mode (that would be sending asynchronous pipeline request, and then asynchronously collecting the results such as with redisxSendRequestAsync() / redisxReadReplyAsync(), because it requires separate network roundtrips for each and every request. But, it is simple and perfectly good method when one needs to retrieve only a few (<1000) variables per second...

To make Redis calls with binary (non-string) data, you can use redisxArrayRequest() instead, where you can set the number of bytes for each argument explicitly.

Parameters

redis	Pointer to a Redis instance.
command	Redis command, e.g. "HGET"
arg1	First terminated string argument or NULL.
arg2	Second terminated string argument or NULL.
arg3	Third terminated string argument or NULL.
status	Pointer to the return error status, which is either X_SUCCESS on success or else the error code set by redisxArrayRequest().

Returns: A freshly allocated RESP array containing the Redis response, or NULL if no valid response could be obtained.

See also: redisxArrayRequest(); redisxSendRequestAsync(); redisxReadReplyAsync()

References redisxArrayRequest(), x_error(), X_NULL, and x_trace_null().

◆ redisxSelectDB()

int redisxSelectDB	(	Redis *	redis,
		int	idx
	)

Switches to another database index on the Redis server. Note that you cannot change the database on an active PUB/SUB channel, hence the call will return X_INCOMPLETE if attempted. You should instead switch DB when there are no active subscriptions.

Parameters

redis	Pointer to a Redis instance.
idx	zero-based database index

Returns: X_SUCCESS (0) if successful, or X_NULL if the redis argument is NULL, X_INCOMPLETE if there is an active subscription channel that cannot be switched or one of the channels could not confirm the switch, or else another error code (<0) from redisx.h / xchange.h.

See also: redisxSelectDB(); redisxLockConnected()

References REDIS_INVALID_CHANNEL, REDISX_CHANNELS, REDISX_PIPELINE_CHANNEL, REDISX_SUBSCRIPTION_CHANNEL, redisxAddConnectHook(), redisxGetClient(), redisxIsConnected(), redisxLockConnected(), redisxRemoveConnectHook(), redisxUnlockClient(), x_error(), X_INCOMPLETE, X_NULL, X_SUCCESS, and x_trace().

◆ redisxSetPassword()

int redisxSetPassword	(	Redis *	redis,
		const char *	passwd
	)

Sets the password to use for authenticating on the Redis server after connection. See the AUTH Redis command for more explanation. Naturally, you need to call this prior to connecting your Redis instance to have the desired effect.

Parameters

redis	Pointer to the Redis instance for which to set credentials
passwd	the password to use for authenticating on the server, or NULL to clear a previously configured password.

Returns: X_SUCCESS (0) if successful, X_NULL if the redis argument is NULL, or X_ALREADY_OPEN if called after Redis was already connected.

See also: redisxSetUser()

References redisxIsConnected(), X_ALREADY_OPEN, x_error(), X_NULL, X_SUCCESS, and xStringCopyOf().

◆ redisxSetPipelineConsumer()

int redisxSetPipelineConsumer	(	Redis *	redis,
		void()(RESP )	f
	)

Sets the function processing valid pipeline responses.

Parameters

redis	Pointer to a Redis instance.
f	T he function that processes a single argument of type RESP pointer.

Returns: X_SUCCESS (0) if successful, or X_NULL if the Redis instance is NULL.

References x_error(), X_NULL, and X_SUCCESS.

◆ redisxSetTransmitErrorHandler()

int redisxSetTransmitErrorHandler	(	Redis *	redis,
		RedisErrorHandler	f
	)

Sets the user-specific error handler to call if a socket level trasmit error occurs. It replaces any prior handlers set earlier.

Parameters

redis The Redis instance to configure.

f The error handler function, which is called with the pointer to the redis instance that had the errror, the redis channel index (e.g. REDIS_INTERACTIVE_CHANNEL) and the operation (e.g. 'send' or 'read') that failed. Note, that the call may be made with the affected Redis channel being in a locked state. As such the handler should not directly attempt to change the connection state of the Redis instance. Any calls that require exlusive access to the affected channel should instead be spawn off into a separate thread, which can obtain the necessary lock when it is released.

Returns: X_SUCCESS if the handler was successfully configured, or X_NULL if the Redis instance is NULL.

References x_error(), X_NULL, and X_SUCCESS.

◆ redisxSetUser()

int redisxSetUser	(	Redis *	redis,
		const char *	username
	)

Sets the user name to use for authenticating on the Redis server after connection. See the AUTH Redis command for more explanation. Naturally, you need to call this prior to connecting your Redis instance to have the desired effect.

Parameters

redis	Pointer to the Redis instance for which to set credentials
username	the password to use for authenticating on the server, or NULL to clear a previously configured password.

Returns: X_SUCCESS (0) if successful, X_NULL if the redis argument is NULL, or X_ALREADY_OPEN if called after Redis was already connected.

See also: redisxSetPassword()

References redisxIsConnected(), X_ALREADY_OPEN, x_error(), X_NULL, X_SUCCESS, and xStringCopyOf().

◆ redisxSetVerbose()

void redisxSetVerbose ( boolean value )

Enable or disable verbose reporting of all Redis operations (and possibly some details of them). Reporting is done on the standard output (stdout). It may be useful when debugging programs that use the redisx interface. Verbose reporting is DISABLED by default.

Parameters

value TRUE to enable verbose reporting, or FALSE to disable.

See also: redisxDebugTraffic()

References xSetVerbose().

Functions

Detailed Description

Function Documentation

◆ redisxArrayRequest()

◆ redisxCheckDestroyRESP()

◆ redisxCheckRESP()

◆ redisxDebugTraffic()

◆ redisxDestroyRESP()

◆ redisxError()

◆ redisxErrorDescription()

◆ redisxGetTime()

◆ redisxHasPipeline()

◆ redisxIsVerbose()

◆ redisxPing()

◆ redisxRequest()

◆ redisxSelectDB()

◆ redisxSetPassword()

◆ redisxSetPipelineConsumer()

◆ redisxSetTransmitErrorHandler()

◆ redisxSetUser()

◆ redisxSetVerbose()