Issues a command on the Redis server.

This function sends command to the Redis server and returns the response returned by Redis. pid must be the pid of a Redix connection. command must be a list of strings making up the Redis command and its arguments.

The return value is {:ok, response} if the request is successful and the response is not a Redis error. {:error, reason} is returned in case there’s an error in the request (such as losing the connection to Redis in between the request). If Redis returns an error (such as a type error), a Redix.Error exception is raised; the reason for this is that these errors are semantic errors that most of the times won’t go away by themselves over time and users of Redix should be notified of them as soon as possible. Connection errors, instead, are often temporary errors that will go away when the connection is back.

If the given command is an empty command ([]), an ArgumentError exception is raised.

Options

• :timeout - (integer or :infinity) request timeout (in milliseconds). Defaults to 5000. If the Redis server doesn’t reply within this timeout, {:error, %Redix.ConnectionError{reason: :timeout}} is returned.

Examples

iex> Redix.command(conn, ["SET", "mykey", "foo"])
{:ok, "OK"}
iex> Redix.command(conn, ["GET", "mykey"])
{:ok, "foo"}

iex> Redix.command(conn, ["INCR", "mykey"])
{:error, "ERR value is not an integer or out of range"}

If Redis goes down (before a reconnection happens):

iex> {:error, error} = Redix.command(conn, ["GET", "mykey"])
iex> error.reason
:closed

Issues a command on the Redis server, raising if there’s an error.

This function works exactly like command/3 but:

• if the command is successful, then the result is returned not wrapped in a {:ok, result} tuple.
• if there’s a Redis error, a Redix.Error error is raised (with the original message).
• if there’s a connection error, a Redix.ConnectionError error is raised.

This function accepts the same options as command/3.

Options

• :timeout - (integer or :infinity) request timeout (in milliseconds). Defaults to 5000. If the Redis server doesn’t reply within this timeout, {:error, %Redix.ConnectionError{reason: :timeout}} is returned.

Examples

iex> Redix.command!(conn, ["SET", "mykey", "foo"])
"OK"

iex> Redix.command!(conn, ["INCR", "mykey"])
** (Redix.Error) ERR value is not an integer or out of range

If Redis goes down (before a reconnection happens):

iex> Redix.command!(conn, ["GET", "mykey"])
** (Redix.ConnectionError) :closed

Issues a pipeline of commands on the Redis server.

commands must be a list of commands, where each command is a list of strings making up the command and its arguments. The commands will be sent as a single “block” to Redis, and a list of ordered responses (one for each command) will be returned.

The return value is {:ok, results} if the request is successful, {:error, reason} otherwise.

Note that {:ok, results} is returned even if results contains one or more Redis errors (Redix.Error structs). This is done to avoid having to walk the list of results (a O(n) operation) to look for errors, leaving the responsibility to the user. That said, errors other than Redis errors (like network errors) always cause the return value to be {:error, reason}.

If commands is an empty list ([]) or any of the commands in commands is an empty command ([]) then an ArgumentError exception is raised right away.

Options

• :timeout - (integer or :infinity) request timeout (in milliseconds). Defaults to 5000. If the Redis server doesn’t reply within this timeout, {:error, %Redix.ConnectionError{reason: :timeout}} is returned.

Examples

iex> Redix.pipeline(conn, [["INCR", "mykey"], ["INCR", "mykey"], ["DECR", "mykey"]])
{:ok, [1, 2, 1]}

iex> Redix.pipeline(conn, [["SET", "k", "foo"], ["INCR", "k"], ["GET", "k"]])
{:ok, ["OK", %Redix.Error{message: "ERR value is not an integer or out of range"}, "foo"]}

If Redis goes down (before a reconnection happens):

iex> {:error, error} = Redix.pipeline(conn, [["SET", "mykey", "foo"], ["GET", "mykey"]])
iex> error.reason
:closed

Issues a pipeline of commands to the Redis server, raising if there’s an error.

This function works similarly to pipeline/3, except:

• if there are no errors in issuing the commands (even if there are one or more Redis errors in the results), the results are returned directly (not wrapped in a {:ok, results} tuple).
• if there’s a connection error then a Redix.ConnectionError exception is raised.

For more information on why nothing is raised if there are one or more Redis errors (Redix.Error structs) in the list of results, look at the documentation for pipeline/3.

This function accepts the same options as pipeline/3.

Options

• :timeout - (integer or :infinity) request timeout (in milliseconds). Defaults to 5000. If the Redis server doesn’t reply within this timeout, {:error, %Redix.ConnectionError{reason: :timeout}} is returned.

Examples

iex> Redix.pipeline!(conn, [["INCR", "mykey"], ["INCR", "mykey"], ["DECR", "mykey"]])
[1, 2, 1]

iex> Redix.pipeline!(conn, [["SET", "k", "foo"], ["INCR", "k"], ["GET", "k"]])
["OK", %Redix.Error{message: "ERR value is not an integer or out of range"}, "foo"]

If Redis goes down (before a reconnection happens):

iex> Redix.pipeline!(conn, [["SET", "mykey", "foo"], ["GET", "mykey"]])
** (Redix.ConnectionError) :closed

Closes the connection to the Redis server.

This function is synchronous and blocks until the given Redix connection frees all its resources and disconnects from the Redis server. timeout can be passed to limit the amout of time allowed for the connection to exit; if it doesn’t exit in the given interval, this call exits.

Examples

iex> Redix.stop(conn)
:ok