Class: Guillotine::RedisAdapter

Inherits:
Adapter
  • Object
show all
Defined in:
lib/guillotine/adapters/redis_adapter.rb

Instance Method Summary collapse

Methods inherited from Adapter

#parse_url, #shorten

Constructor Details

#initialize(redis) ⇒ RedisAdapter

Public: Initialise the adapter with a Redis instance.

redis - A Redis instance to persist urls and codes to.



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# File 'lib/guillotine/adapters/redis_adapter.rb', line 6

def initialize(redis)
  @redis = redis
end

Instance Method Details

#add(url, code = nil) ⇒ Object

Public: Stores the shortened version of a URL.

url - The String URL to shorten and store. code - Optional String code for the URL.

Returns the unique String code for the URL. If the URL is added multiple times, this should return the same code.



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# File 'lib/guillotine/adapters/redis_adapter.rb', line 17

def add(url, code = nil)
  if existing_code = @redis.get(url_key(url))
    existing_code
  else
    code ||= shorten(url)
    if existing_url = @redis.get(code_key(code))
      raise DuplicateCodeError.new(existing_url, url, code) if url != existing_url
    end
    @redis.set code_key(code), url
    @redis.set url_key(url), code
    code
  end
end

#clear(url) ⇒ Object

Public: Removes the assigned short code for a URL.

url - The String URL to remove.

Returns nothing.



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# File 'lib/guillotine/adapters/redis_adapter.rb', line 54

def clear(url)
  if code = @redis.get(url_key(url))
    @redis.del url_key(url)
    @redis.del code_key(code)
  end
end

#code_for(url) ⇒ Object

Public: Retrieves the code for a given URL.

url - The String URL to lookup.

Returns the String code, or nil if none is found.



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# File 'lib/guillotine/adapters/redis_adapter.rb', line 45

def code_for(url)
  @redis.get url_key(url)
end

#code_key(code) ⇒ Object 



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# File 'lib/guillotine/adapters/redis_adapter.rb', line 61

def code_key(code)
  "guillotine:hash:#{code}"
end

#find(code) ⇒ Object

Public: Retrieves a URL from the code.

code - The String code to lookup the URL.

Returns the String URL, or nil if none is found.



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# File 'lib/guillotine/adapters/redis_adapter.rb', line 36

def find(code)
  @redis.get code_key(code)
end

#url_key(url) ⇒ Object 



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# File 'lib/guillotine/adapters/redis_adapter.rb', line 65

def url_key(url)
  "guillotine:urls:#{url}"
end