Module: Restfulie::Client::HTTP::ResponseCacheCheck

Included in:
Net::HTTPResponse
Defined in:
lib/restfulie/client/cache/http_ext.rb

Instance Method Summary collapse

Instance Method Details

#cache_max_age ⇒ Object 



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# File 'lib/restfulie/client/cache/http_ext.rb', line 45

def cache_max_age
  val = header_value_from('cache-control', /^\s*max-age=(\d+)/)
  if val
    val.to_i
  else
    0
  end
end

#has_expired_cache? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/restfulie/client/cache/http_ext.rb', line 60

def has_expired_cache?
  return true if headers['date'].nil?
  max_time = Time.rfc2822(headers['date'][0]) + cache_max_age.seconds
  Time.now > max_time
end

#header_value_from(header, expression) ⇒ Object 



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# File 'lib/restfulie/client/cache/http_ext.rb', line 54

def header_value_from(header, expression)
  h = value_for(headers[header], expression)
  return nil if h.nil?
  h.match(expression)[1]
end

#may_cache? ⇒ Boolean

checks if the header’s max-age is available and no no-store if available.

Returns:

  • (Boolean) 


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# File 'lib/restfulie/client/cache/http_ext.rb', line 67

def may_cache?
  may_cache_method? && may_cache_field?(headers['cache-control'])
end

#may_cache_field?(field) ⇒ Boolean

Returns whether this cache control field allows caching

may_cache_field([‘max-age=2000’, ‘no-store’]) == false may_cache_field(‘max-age=2000,no-store’) == false may_cache_field(‘max-age=2000’) == true

Returns:

  • (Boolean) 


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# File 'lib/restfulie/client/cache/http_ext.rb', line 76

def may_cache_field?(field)
  return false if field.nil?
  
  if field.kind_of? Array
    field.each do |f|
      return false if !may_cache_field?(f)
    end
    return true
  end

  max_age_header = value_for(field, /^max-age=(\d+)/)
  return false if max_age_header.nil?
  
  return !value_for(field, /^no-store/)
end

#value_for(value, expression) ⇒ Object

extracts the header value for an specific expression, which can be located at the start or in the middle of the expression



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# File 'lib/restfulie/client/cache/http_ext.rb', line 94

def value_for(value, expression)
  value = value[0] if value.kind_of? Array
  value.split(",").find { |obj| obj.strip =~ expression }
end

#vary_headers_for(request) ⇒ Object

extracts all header values related to the Vary header from this response, in order to implement Vary support from the HTTP Specification

example if the response Vary header is ‘Accept’,‘Accept-Language’, we have vary_headers_for(‘Date’ =>‘…’, ‘Accept-Language’=>‘de’) == [‘application/xml’, ‘de’] vary_headers_for(=> ‘…’, ‘Accept-Language’=>‘de’) == [nil, ‘de’]



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# File 'lib/restfulie/client/cache/http_ext.rb', line 106

def vary_headers_for(request)
  return nil if headers['vary'].nil?
  headers['vary'].split(',').map do |key|
    request[key.strip]
  end
end