class Ahora::Middleware::LastModifiedCaching
Attributes
cache[R]
Public Class Methods
new(app, cache = nil, options = {}) { || ... }
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Public: initialize the middleware.
cache - An object that responds to read, write and fetch (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: []). :cache_header - String name of response header that should be used to retrieve cache timestamp from. Defaults to 'last-modified' :expire_in - Integer time to live value in seconds for a key. Defaults to never expire.
Yields if no cache is given. The block should return a cache object.
Calls superclass method
# File lib/ahora/middleware/last_modified_caching.rb, line 25 def initialize(app, cache = nil, options = {}) super(app) options, cache = cache, nil if cache.is_a? Hash and block_given? @cache = cache || yield @options = options end
Public Instance Methods
cache_key(env)
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# File lib/ahora/middleware/last_modified_caching.rb, line 63 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 = build_query params end url.normalize! url.to_s end
call(env)
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# File lib/ahora/middleware/last_modified_caching.rb, line 32 def call(env) if env[:method] == :get timestamp_key = cache_key(env) + ':timestamp' data_key = cache_key(env) + ':response' if date = cache.read(timestamp_key) # WARN FakeWeb cannot test this env[:request_headers]['If-Modified-Since'] = Time.parse(date).httpdate end response = @app.call(env) if response.status == 304 response = cache.read data_key elsif date = response.headers[@options[:cache_header] || 'Last-Modified'] response.env[:response_headers]['X-Ahora-Cache-Key'] = fragment_cache_key(env, date) cache.write timestamp_key, date, :expire_in => @options[:expire_in] cache.write data_key, response, :expire_in => @options[:expire_in] end finalize_response(response, env) else @app.call(env) end end
finalize_response(response, env)
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# File lib/ahora/middleware/last_modified_caching.rb, line 78 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
fragment_cache_key(env, last_modified)
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# File lib/ahora/middleware/last_modified_caching.rb, line 59 def fragment_cache_key(env, last_modified) cache_key(env) + ":fragment_#{last_modified}" end
params_to_ignore()
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# File lib/ahora/middleware/last_modified_caching.rb, line 74 def params_to_ignore @params_to_ignore ||= Array(@options[:ignore_params]).map { |p| p.to_s } end