redis-erl

Synopsis

minimalistic redis client for erlang

Overview

redis-erl is a redis client implementation that only uses redis's multi bulk command protocol.

Install

with epm

ensure you have the latest version of epm:

$ epm latest

install

$ epm install bmizerany/redis-erl

with rebar

$ rebar compile

Raw examples

0> redis:connect([]).  % connect to default redis port on localhost
1> redis:q([set, "foo", "bar"]).
{ok,<<"OK">>}
2> redis:q([get, "foo"]).
{ok,<<"bar">>}
3> redis:q([sadd, "bar", "a"]).
{ok,1}
4> redis:q([sadd, "bar", "b"]).
{ok,1}
5> redis:q([sadd, "bar", "c"]).
{ok,1}
6> redis:q([lrange, 0, -1]).
{error,<<"ERR wrong number of arguments for 'lrange' command">>}
7> redis:q([lrange, "bar", 0, -1]).
{error,<<"ERR Operation against a key holding the wrong kind of value">>}
8> redis:q([smembers, "bar"]).
[{ok,<<"c">>},{ok,<<"a">>},{ok,<<"b">>}]
9> redis:q([incr, "counter"]).
{ok,1}
10>

Breakdance/Breakdown

redis:connect(Options) -> ok | {error, Reason}

  Types:

    Options = [Opt]
    Opt = {atom(), Value}
    Value = term()

  Connects to redis server

  The available options are:

  {ip, Ip}

    If the host has several network interfaces, this option
    specifies which one to use.  Default is "127.0.0.1".

  {port, Port}

    Specify which local port number to use.  Default is 6379.

  {pass, Pass}

    Specify to password to auth with upon a successful connect.
    Default is <<>>.

  {db, DbIndex}

    Sepcify the db to use.  Default is 0.


redis:q(Parts) -> {ok, binary()} | {ok, int()} | {error, binary()}

  Types

    Parts = [Part]

      The sections, in order, of the command to be executed

    Part = atom() | binary() | list()

      A section of a redis command

      NOTE:  An atom() is converted to an uppercase list().

  Tell redis to execute a command.

redis:keys(Pat) -> [binary()]

  Types

    Pat = list()

      The pattern to search for keys on

  See: http://code.google.com/p/redis/wiki/KeysCommand

In motion

The amazing SORT command:

redis:q([sort, "foo", by, "bar:*"]).

is converted to:

["SORT", "foo", "BY", "bar:*"]

which is then compiled to

*4
$4
SORT
$3
foo
$2
BY
$5
bar:*

and sent over the wire to redis.

Sugar

Sugar functions enable you to avoid the slightly less attractive raw redis:q/1 command.

There is currently only one sugar command, redis:keys/1

1> redis:keys("f*").
[<<"foo">>, <<"funk">>]

On Sugar commands and future additions too

Sugar commands must return an easy to use term() that resembles the closest erlang-esq expression of it's redis form.

I'm currently on the fence about how these commands look, and what they return, but thanks to the multi-bulk-request protocol redis uses, it's simple to use redis:q/1 function for all commands.

How can you get your Sugar functions in? See the next section.

Contribute

I'm very open to patches! Help is greatly appreciated.

• Fork this repo
• Add an issue to this repos issues with a link to you commit/compare-view
• I'll get to it as soon as possible

LICENSE

Copyright (c) 2010 Blake Mizerany

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.