Module: RedisSelector

Defined in:
lib/redis_selector.rb,
lib/redis_selector/version.rb

Constant Summary collapse

DEFAULT_REDIS = 
{
  'host' => 'localhost',
}.freeze
VERSION = 
"0.1.0"

Class Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Class Attribute Details

.config ⇒ Object

Returns the value of attribute config.



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# File 'lib/redis_selector.rb', line 11

def config
  @config
end

.mock_redises ⇒ Object

Returns the value of attribute mock_redises.



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# File 'lib/redis_selector.rb', line 10

def mock_redises
  @mock_redises
end

.mocking ⇒ Object

Returns the value of attribute mocking.



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# File 'lib/redis_selector.rb', line 9

def mocking
  @mocking
end

Class Method Details

.configure(config) ⇒ Object 



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# File 'lib/redis_selector.rb', line 26

def self.configure(config)
  self.config = config
end

.mock! ⇒ Object 



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# File 'lib/redis_selector.rb', line 15

def self.mock!
  require 'mock_redis'
  self.mocking = true
end

.unmock! ⇒ Object 



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# File 'lib/redis_selector.rb', line 20

def self.unmock!
  require 'redis'
  self.mocking = false
end

Instance Method Details

#with_redis(what) ⇒ Object

Rather than have one big global Redis, we let you get a Redis for a specific purpose. That way, if thing X’s data set gets too large, you can point Redis.for(X) at a different redis-server instance, thus allowing for sharding based on logical data grouping.

This doesn’t address the problem of data migration.



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# File 'lib/redis_selector.rb', line 37

def with_redis(what)
  redis_selector = Module.nesting[0]

  config = redis_selector.config || {}
  redis_info = (config[what] || config['default'] || DEFAULT_REDIS).
    inject({}) do |opts, (k, v)|
      opts.merge!(k.to_sym => v)
    end

  redis = if redis_selector.mocking
            # A MockRedis instance doesn't persist anywhere once we
            # drop a reference to it, while a real Redis
            # does. That's why we hold onto this mock like this;
            # otherwise, repeated calls to with_redis(:foo) each get
            # a completely empty mock.
            redis_selector.mock_redises[redis_info[:host]] ||= MockRedis.new(redis_info)
          else
            Redis.new(redis_info)
          end

  result = yield redis
  result
ensure
  redis.quit if redis
end