Redis Client for Crystal

A Redis client for the Crystal programming language.

Features

Performance (> 680,000 commands per second using pipeline on a MacBook Air with a single client thread)
Pipelining
Transactions
LUA Scripting
All string commands
All hash commands
All list commands
All set commands
All hyperloglog commands
All commands for bit operations
All sorted set commands
Publish/subscribe

Installation

Add it to your shard.yml:

dependencies:
  redis:
    github: stefanwille/crystal-redis
    version: ~> 1.10.1

and then install the library into your project:

$ crystal deps

Installation on MacOS X

On MacOS X you may get this warning:

Package libssl was not found in the pkg-config search path.
Perhaps you should add the directory containing `libssl.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libssl' found
Package libcrypto was not found in the pkg-config search path.
Perhaps you should add the directory containing `libcrypto.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libcrypto' found

The problem is that Crystal can't find openssl, because it is not installed by default on MacOS X.

The fix:

Install openssl via Homebrew:

$ brew install openssl

Set the environment variable PKG_CONFIG_PATH:

$ export PKG_CONFIG_PATH=/usr/local/opt/openssl/lib/pkgconfig

Required Crystal Version

This library needs Crystal version >= 0.24.2

I haven't tested older Crystal versions.

Usage

Require the package:

  require "redis"

then

  redis = Redis.new

Then you can call Redis commands on the redis object:

  redis.set("foo", "bar")
  redis.get("foo")

Examples

To get started, see the examples:

There is a separate git repository crystal-redis-examples with examples.
start with this basic example
look at the other examples
the spec contains even more usage examples

Documentation

API documentation - start reading it at the class Redis.
Redis commands documentation - the original Redis documentation is necessary, as the API documentation above is just a quick reference
Redis documentation page - general information about Redis and its concepts

Performance

I have benchmarked Crystal-Redis against several other client libraries in various programming languages in this blog article.

Here are some results:

Crystal: With this library I get > 680,000 commands per second using pipeline on a MacBook Air with a single client thread.
C: The equivalent program written in C with Hiredis gets me 340,000 commands per second.
Ruby: Ruby 2.2.1 with the redis-rb and Hiredis driver handles 150,000 commands per second.

Read more results for Go, Java, Node.js.

Status

I have exercised every API method in the spec and built some example programs. There is no production use yet.

I took great care to make this library very usable with respect to API, reliability and documentation.

Development

This project requires a locally running redis server running on port 6379 and with a unix socket located at /tmp/redis.sock. Then you can the specs via

$ crystal spec

See more information.

Questions, Bugs & Support

If you have questions or need help, please open a ticket in the GitHub issue tracker. This way others can benefit from the discussion.

CrystalDoc.info

redis