Class: LWS::Middleware::Caching
- Inherits:
-
Faraday::Middleware
- Object
- Faraday::Middleware
- LWS::Middleware::Caching
- Extended by:
- Forwardable
- Defined in:
- lib/lws/middleware/caching.rb
Overview
Public: Caches GET responses and pulls subsequent ones from the cache.
Constant Summary collapse
- CACHEABLE_STATUS_CODES =
Internal: List of status codes that can be cached:
-
200 - ‘OK’
-
203 - ‘Non-Authoritative Information’
-
300 - ‘Multiple Choices’
-
301 - ‘Moved Permanently’
-
302 - ‘Found’
-
404 - ‘Not Found’
-
410 - ‘Gone’
-
[200, 203, 300, 301, 302, 404, 410].freeze
Instance Attribute Summary collapse
-
#cache ⇒ Object
readonly
Returns the value of attribute cache.
Instance Method Summary collapse
- #cache_key(env) ⇒ Object
- #cache_on_complete(env) ⇒ Object
- #call(env) ⇒ Object
- #custom_status_codes ⇒ Object
- #finalize_response(response, env) ⇒ Object
- #full_key? ⇒ Boolean
-
#initialize(app, cache = nil, options = {}) ⇒ Caching
constructor
Public: initialize the middleware.
- #params_to_ignore ⇒ Object
- #store_response_in_cache(key, response) ⇒ Object
Constructor Details
#initialize(app, cache = nil, options = {}) ⇒ Caching
Public: initialize the middleware.
cache - An object that responds to read and write (default: nil). options - An options Hash (default: {}):
:ignore_params - String name or Array names of query
params that should be ignored when forming
the cache key (default: []).
:write_options - Hash of settings that should be passed as the
third options parameter to the cache's #write
method. If not specified, no options parameter
will be passed.
:full_key - Boolean - use full URL as cache key:
(url.host + url.request_uri)
:status_codes - Array of http status code to be cache
(default: CACHEABLE_STATUS_CODE)
Yields if no cache is given. The block should return a cache object.
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# File 'lib/lws/middleware/caching.rb', line 66 def initialize(app, cache = nil, = {}) super(app) if cache.is_a?(Hash) && block_given? = cache cache = nil end @cache = cache || yield @options = end |
Instance Attribute Details
#cache ⇒ Object (readonly)
Returns the value of attribute cache.
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# File 'lib/lws/middleware/caching.rb', line 34 def cache @cache end |
Instance Method Details
#cache_key(env) ⇒ Object
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# File 'lib/lws/middleware/caching.rb', line 95 def cache_key(env) url = env[:url].dup if url.query && params_to_ignore.any? params = parse_query url.query params.reject! { |k,| params_to_ignore.include? k } url.query = params.any? ? build_query(params) : nil end url.normalize! digest = full_key? ? url.host + url.request_uri : url.request_uri Digest::SHA1.hexdigest(digest) end |
#cache_on_complete(env) ⇒ Object
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# File 'lib/lws/middleware/caching.rb', line 122 def cache_on_complete(env) key = cache_key(env) if (cached_response = cache.read(key)) finalize_response(cached_response, env) else # response.status is nil at this point # any checks need to be done inside on_complete block @app.call(env).on_complete do |response_env| store_response_in_cache(key, response_env.response) response_env end end end |
#call(env) ⇒ Object
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# File 'lib/lws/middleware/caching.rb', line 76 def call(env) if env[:method] == :get if env[:parallel_manager] # callback mode cache_on_complete(env) else # synchronous mode key = cache_key(env) unless (response = cache.read(key)) && response response = @app.call(env) store_response_in_cache(key, response) end finalize_response(response, env) end else @app.call(env) end end |
#custom_status_codes ⇒ Object
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# File 'lib/lws/middleware/caching.rb', line 115 def custom_status_codes @custom_status_codes ||= begin codes = CACHEABLE_STATUS_CODES & Array(@options[:status_codes]).map(&:to_i) codes.any? ? codes : CACHEABLE_STATUS_CODES end end |
#finalize_response(response, env) ⇒ Object
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# File 'lib/lws/middleware/caching.rb', line 146 def finalize_response(response, env) response = response.dup if response.frozen? env[:response] = response unless env[:response_headers] env.update response.env # FIXME: omg hax response.instance_variable_set('@env', env) end response end |
#full_key? ⇒ Boolean
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# File 'lib/lws/middleware/caching.rb', line 111 def full_key? @full_key ||= @options[:full_key] end |
#params_to_ignore ⇒ Object
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# File 'lib/lws/middleware/caching.rb', line 107 def params_to_ignore @params_to_ignore ||= Array(@options[:ignore_params]).map(&:to_s) end |
#store_response_in_cache(key, response) ⇒ Object
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# File 'lib/lws/middleware/caching.rb', line 136 def store_response_in_cache(key, response) return unless custom_status_codes.include?(response.status) if @options[:write_options] cache.write(key, response, @options[:write_options]) else cache.write(key, response) end end |