Class: Routemaster::Cache

Inherits:
Object
  • Object
show all
Includes:
Wisper::Publisher
Defined in:
lib/routemaster/cache.rb

Overview

Caches GET requests.

Emits cache_bust, cache_hit, and cache_miss events.

The requests themselves are handled by APIClient. Note that Cache-Control headers are intentionally ignored, as it is assumed one will call #bust when the cache becomes stale.

This is for instance done automatically by Middleware::Cache upon receiving events from Routemaster.

Defined Under Namespace

Classes: FutureResponse, Pool

Instance Method Summary collapse

Constructor Details

#initialize(redis: nil, client: nil) ⇒ Cache

Returns a new instance of Cache.



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# File 'lib/routemaster/cache.rb', line 63

def initialize(redis:nil, client:nil)
  @redis   = redis || Config.cache_redis
  @client = client || APIClient.new(listener: self)
end

Instance Method Details

#_publish(event, url) ⇒ Object

This is because wisper makes broadcasting methods private



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# File 'lib/routemaster/cache.rb', line 75

def _publish(event, url)
  publish(event, url)
end

#bust(url) ⇒ Object

Bust the cache for a given URL



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# File 'lib/routemaster/cache.rb', line 69

def bust(url)
  @redis.del("cache:#{url}")
  _publish(:cache_bust, url)
end

#fget(url, version: nil, locale: nil) ⇒ FutureResponse

Like #get, but schedules any request in the background using a thread pool. Handy to issue lots of requests in parallel.

like [Response].

Returns:



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# File 'lib/routemaster/cache.rb', line 104

def fget(url, version: nil, locale: nil)
  FutureResponse.new { get(url, version: version, locale: locale) }
end

#get(url, version: nil, locale: nil) ⇒ Response

Get the response from a URL, from the cache if possible. Stores to the cache on misses.

Different versions and locales are stored separately in the cache.

header.

Parameters:

  • version (Integer) (defaults to: nil) —

    The version to pass in headers, as Accept: application/json;v=2

  • locale (String) (defaults to: nil) —

    The language to request in the Accept-Language

Returns:

  • (Response) —

    , which responds to status, headers, and body.



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# File 'lib/routemaster/cache.rb', line 89

def get(url, version: nil, locale: nil)
  headers = {
    'Accept' => version ?
      "application/json;v=#{version}" :
      "application/json"
  }
  headers['Accept-Language'] = locale if locale
  @client.get(url, headers: headers)
end