# redis-lua

**Repository Path**: jianCat/redis-lua

## Basic Information

- **Project Name**: redis-lua
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 1
- **Created**: 2020-04-30
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# redis-lua #

[![Build Status](https://travis-ci.org/nrk/redis-lua.png?branch=master)](https://travis-ci.org/nrk/redis-lua)

## About ##

redis-lua is a pure Lua client library for the Redis advanced key-value database.

## Main features ##

- Support for Redis >= 1.2
- Command pipelining
- Redis transactions (MULTI/EXEC) with CAS
- User-definable commands
- UNIX domain sockets (when available in LuaSocket)

## Compatibility ##

This library is tested and works with __Lua 5.1__, __Lua 5.2__ (using a compatible
version of LuaSocket) and __LuaJit 2.0__.

## Examples of usage ##

### Include redis-lua in your script ###

Just require the `redis` module assigning it to a variable:

``` lua
local redis = require 'redis'
```

### Connect to a redis-server instance and send a PING command ###

``` lua
local redis = require 'redis'
local client = redis.connect('127.0.0.1', 6379)
local response = client:ping()           -- true
```

It is also possible to connect to a local redis instance using __UNIX domain sockets__
if LuaSocket has been compiled with them enabled (unfortunately this is not the default):

``` lua
local redis = require 'redis'
local client = redis.connect('unix:///tmp/redis.sock')
```

### Set keys and get their values ###

``` lua
client:set('usr:nrk', 10)
client:set('usr:nobody', 5)
local value = client:get('usr:nrk')      -- 10
```

### Sort list values by using various parameters supported by the server ###

``` lua
for _,v in ipairs({ 10,3,2,6,1,4,23 }) do
    client:rpush('usr:nrk:ids',v)
end

local sorted = client:sort('usr:nrk:ids', {
     sort = 'asc', alpha = true, limit = { 1, 5 }
})      -- {1=10,2=2,3=23,4=3,5=4}
```

### Pipeline commands

``` lua
local replies = client:pipeline(function(p)
    p:incrby('counter', 10)
    p:incrby('counter', 30)
    p:get('counter')
end)
```

### Variadic commands

Some commands such as RPUSH, SADD, SINTER and others have been improved in Redis 2.4
to accept a list of values or keys depending on the nature of the command. Sometimes
it can be useful to pass these arguments as a list in a table, but since redis-lua does
not currently do anything to handle such a case you can use `unpack()` albeit with a
limitation on the maximum number of items which is defined in Lua by LUAI_MAXCSTACK
(the default on Lua 5.1 is set to `8000`, see `luaconf.h`):

```lua
local values = { 'value1', 'value2', 'value3' }
client:rpush('list', unpack(values))

-- the previous line has the same effect of the following one:
client:rpush('list', 'value1', 'value2', 'value3')
```

### Leverage Redis MULTI / EXEC transaction (Redis > 2.0)

``` lua
local replies = client:transaction(function(t)
    t:incrby('counter', 10)
    t:incrby('counter', 30)
    t:get('counter')
end)
```

### Leverage WATCH / MULTI / EXEC for check-and-set (CAS) operations (Redis > 2.2)

``` lua
local options = { watch = "key_to_watch", cas = true, retry = 2 }
local replies = client:transaction(options, function(t)
    local val = t:get("key_to_watch")
    t:multi()
    t:set("akey", val)
    t:set("anotherkey", val)
end)
```

### Add or replace Redis commands ###

You can define new Redis commands or redefine existing ones at module level (commands
will be available on all client instances) or client level (commands will be available
only on that client instance).

```lua
local redis = require 'redis'
redis.commands.set = redis.command('set')   -- module level

local client = redis.connect()
client.get = redis.command('get')           -- client level
```

## Dependencies ##

- [Lua 5.1 and 5.2](http://www.lua.org/) or [LuaJIT 2.0](http://luajit.org/)
- [LuaSocket 2.0](http://www.tecgraf.puc-rio.br/~diego/professional/luasocket/)
- [Telescope](http://telescope.luaforge.net/) (required to run the test suite)

## Links ##

### Project ###
- [Source code](http://github.com/nrk/redis-lua/)
- [Issue tracker](http://github.com/nrk/redis-lua/issues)

### Related ###
- [Redis](http://redis.io/)
- [Git](http://git-scm.com/)

## Authors ##

[Daniele Alessandri](mailto:suppakilla@gmail.com)

### Contributors ###

[Leo Ponomarev](http://github.com/slact/)

## License ##

The code for redis-lua is distributed under the terms of the MIT/X11 license (see LICENSE).