Class: GenericCachedDownloader

Inherits:
Object
  • Object
show all
Defined in:
lib/cartocss_helper/util/generic_cached_downloader.rb

Instance Method Summary collapse

Constructor Details

#initialize(timeout: 20, error_message: nil, stop_on_timeout: true, wrapper: RestClientWrapper.new) ⇒ GenericCachedDownloader

Returns a new instance of GenericCachedDownloader.



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# File 'lib/cartocss_helper/util/generic_cached_downloader.rb', line 6

def initialize(timeout: 20, error_message: nil, stop_on_timeout: true, wrapper: RestClientWrapper.new)
  @request_timeout = timeout
  @error_message = error_message
  @stop_on_timeout = stop_on_timeout
  @wrapper = wrapper
end

Instance Method Details

#download(url, description) ⇒ Object 



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# File 'lib/cartocss_helper/util/generic_cached_downloader.rb', line 41

def download(url, description)
  downloader = GenericDownloader.new(timeout: @request_timeout, error_message: @error_message, stop_on_timeout: @stop_on_timeout, wrapper: @wrapper)
  return downloader.get_specified_resource(url, description: description)
end

#get_cache_timestamp(cache_filename) ⇒ Object 



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# File 'lib/cartocss_helper/util/generic_cached_downloader.rb', line 33

def get_cache_timestamp(cache_filename)
  return nil unless File.exist?(cache_filename)
  f = File.new(cache_filename)
  timestamp = f.mtime.to_i
  f.close
  return timestamp
end

#get_specified_resource(url, cache_filename, description: nil, invalidate_cache: false) ⇒ Object 



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# File 'lib/cartocss_helper/util/generic_cached_downloader.rb', line 13

def get_specified_resource(url, cache_filename, description: nil, invalidate_cache: false)
  cache = read_from_cache(cache_filename)
  cache = nil if invalidate_cache
  return cache if cache != nil
  response = download(url, description)
  write_cache(response, cache_filename)

  return response
end

#read_from_cache(cache_filename) ⇒ Object 



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# File 'lib/cartocss_helper/util/generic_cached_downloader.rb', line 23

def read_from_cache(cache_filename)
  if File.exist?(cache_filename)
    file = File.new(cache_filename)
    cached = file.read
    file.close
    return cached
  end
  return nil
end

#write_cache(response, cache_filename) ⇒ Object 



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# File 'lib/cartocss_helper/util/generic_cached_downloader.rb', line 46

def write_cache(response, cache_filename)
  file = File.new(cache_filename, 'w')
  file.write response
  file.close
end