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Redis Scala client

Key features of the library

  • Native Scala types Set and List responses.
  • Transparent serialization
  • Connection pooling
  • Consistent Hashing on the client.
  • Support for Clustering of Redis nodes.

Information about redis

Redis is a key-value database. It is similar to memcached but the dataset is not volatile, and values can be strings, exactly like in memcached, but also lists and sets with atomic operations to push/pop elements.

http://redis.io

Key features of Redis

  • Fast in-memory store with asynchronous save to disk.
  • Key value get, set, delete, etc.
  • Atomic operations on sets and lists, union, intersection, trim, etc.

Requirements

Usage

Start your redis instance (usually redis-server will do it)

$ cd scala-redis
$ sbt
> update
> console

And you are ready to start issuing commands to the server(s)

Redis 2 implements a new protocol for binary safe commands and replies

Let us connect and get a key:

scala> import com.redis._
import com.redis._

scala> val r = new RedisClient("localhost", 6379)
r: com.redis.RedisClient = localhost:6379

scala> r.set("key", "some value")
res3: Boolean = true

scala> r.get("key")
res4: Option[String] = Some(some value)

Let us try out some List operations:

scala> r.lpush("list-1", "foo")
res0: Option[Int] = Some(1)

scala> r.rpush("list-1", "bar")
res1: Option[Int] = Some(2)

scala> r.llen("list-1")
res2: Option[Int] = Some(2)

Let us look at some serialization stuff:

scala> import serialization._
import serialization._

scala> import Parse.Implicits._
import Parse.Implicits._

scala> r.hmset("hash", Map("field1" -> "1", "field2" -> 2))
res0: Boolean = true

scala> r.hmget[String,String]("hash", "field1", "field2")
res1: Option[Map[String,String]] = Some(Map(field1 -> 1, field2 -> 2))

scala> r.hmget[String,Int]("hash", "field1", "field2")
res2: Option[Map[String,Int]] = Some(Map(field1 -> 1, field2 -> 2))

scala> val x = "debasish".getBytes("UTF-8")
x: Array[Byte] = Array(100, 101, 98, 97, 115, 105, 115, 104)

scala> r.set("key", x)
res3: Boolean = true

scala> import Parse.Implicits.parseByteArray
import Parse.Implicits.parseByteArray

scala> val s = r.get[Array[Byte]]("key")
s: Option[Array[Byte]] = Some([B@6e8d02)

scala> new String(s.get)
res4: java.lang.String = debasish

scala> r.get[Array[Byte]]("keey")
res5: Option[Array[Byte]] = None

License

This software is licensed under the Apache 2 license, quoted below.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.