bomeara / rredis

R client for Redis

rredis: An R client for Redis

Example

> library(rredis)
> redisConnect()         
> redisSet('foo', runif(10))
> bar <- redisGet('foo') 
> bar
 [1] 0.93499818 0.47159536 0.30597259 0.58325228 0.41589498 0.63914212
 [7] 0.34658694 0.08633471 0.18111369 0.15763507

> redisMSet(list(x=pi,y='Cazart',z=runif(2)))
> redisMGet(list('z','y'))
$z
[1] 0.1155711 0.7166137

$y
[1] "Cazart"

> redisClose()

Use redisCmd to run any Redis command

Most Redis commands have corresponding convenience wrappers with online help in the R package. Use the generic redisCmd function to run any Redis command, even ones not specifically implemented by the package. For example:

> redisCmd("set","key1","foobar")
> redisCmd("set","key2","abcdef")
> redisCmd("bitop", "and", "dest", "key1", "key2")
  [1] "6"
> redisCmd("get", "dest")
  [1] "`bc`ab"

New in version 1.7.0

Better value exchange between R and Redis

We implemented a great suggestion by Simon Urbanek. Values obtained from Redis that are not serialized R objects are now decorated with an attribute named "redis string value." The package uses this to automatically maintain fidelity of the original Redis value through repeated download/upload cycles. Previous versions of the rredis package uploaded everything as serialized R values unless explictly told otherwise.

Consider the following interplay between the redis-cli client and R:

redis-cli set key "string value"

And now in R:

> library(rredis)
> redisConnect()
> redisGet("key")
[1] "string value"
attr(,"redis string value")     # <- note the new attribute
[1] TRUE

> redisSet("new key", redisGet("key"))

Recovering the "new key" value from the redis-cli client returns a string value now:

redis-cli get "new key"
"string value"

Before this change, users needed to be careful about converting strings to raw values in R. Now things work much more intuitively.

API change, and option to revert behavior

Set options('redis:num'=TRUE) to return Redis ":" messages as numeric values. This was the default behavior of the rredis package for all versions prior to 1.6.9. For versions of the R package later than that, redis ":" messages are returned as raw Redis string values to correspond to the data types stored in Redis. Set this option to revert to the old behavior.

Redis commands affected by this option importantly include the increment and decrement operations. This change is outlined in the following example:

> library(rredis)
> redisConnect()
> redisSet('x',charToRaw('1'))
[1] "OK"

> redisIncr('x')
[1] "2"
attr(,"redis string value")
[1] TRUE

> options('redis:num'=TRUE)
> redisIncr('x')
[1] 3

> options('redis:num'=c())
> redisIncr('x')
[1] "4"
attr(,"redis string value")
[1] TRUE

Performance

Consider using the redisSetPipeline function to enable pipelining, and also read help about options available to the redisConnect function. Also see the available options in the redisConnect function.

Status

[](https://codecov.io/github/bwlewis/rredis?branch=master) [](http://cran.rstudio.com/web/packages/rredis/index.html)