class UrlReader::FileCache

# File lib/url_reader/file_cache.rb, line 2
def initialize(cache_dir_path)
  @cache_dir_path = cache_dir_path
  @cache = {}
end

# File lib/url_reader/file_cache.rb, line 7
def read_entry(key)
  unless @cache.has_key?(key)
    ekey = encoded_key(key)
    hash = hash(ekey)
    file_path = File.join(@cache_dir_path, hash)
    value = nil
    if File.exist?(file_path)
      value = (decoded_value(File.open(file_path).read.strip.split("\n")
                               .select { |x| x.start_with?("#{ekey}\t") }[0].split("\t", 2)[1]) rescue nil)
    end
    @cache[key] = value
  end
  @cache[key]
end

# File lib/url_reader/file_cache.rb, line 22
def write_entry(key, value)
  @cache[key] = value
  ekey = encoded_key(key)
  hash = hash(ekey)
  file_path = File.join(@cache_dir_path, hash)
  File.open(file_path, 'a') { |f| f.puts("#{ekey}\t#{encoded_value(value)}") }
  true
end

# File lib/url_reader/file_cache.rb, line 41
def decoded_value(value)
  CGI.unescape(value)
end

# File lib/url_reader/file_cache.rb, line 33
def encoded_key(key)
  URI.encode_www_form_component(key)
end

# File lib/url_reader/file_cache.rb, line 37
def encoded_value(value)
  CGI.escape(value)
end

# File lib/url_reader/file_cache.rb, line 45
def hash(key)
  Digest::SHA256.hexdigest(key)
end