crystal-redis

To add crystal-redis to your project, add the following dependency to your shard.yml file:

dependencies:
  redis:
    github: stefanwille/crystal-redis

Then, run the following command in your terminal to install the library:

$ shards install

To run the project's test suite (crystal spec), you must have a local Redis server running with a Unix socket enabled at /tmp/redis.sock.

In your redis.conf file, ensure the following line is uncommented:

nunixsocket /tmp/redis.sock

WARNING: Running the test suite will delete all data in database 0.

If you encounter linker errors like ld: library not found for -lssl or warnings that libssl and libcrypto are not found in the pkg-config search path, it is because OpenSSL is not installed by default on MacOS X.

To fix this:

1. Install OpenSSL using Homebrew.
2. Set the PKG_CONFIG_PATH environment variable to point to the OpenSSL installation.

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

To use the client, require the redis package and instantiate a new Redis object. You can then call standard Redis commands directly on the instance.

require "redis"

redis = Redis.new
redis.set("foo", "bar")
redis.get("foo") # => "bar"

For applications that share a Redis instance across multiple fibers (such as web frameworks like Kemal), use Redis::PooledClient. This class provides a built-in connection pool that automatically allocates and frees connections per command, making it safe to share across fibers.

redis = Redis::PooledClient.new

10.times do |i|
  spawn do
    redis.set("foo#{i}", "bar")
    redis.get("foo#{i}") # => "bar"
  end
end