Class: Cacho::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/cacho.rb

Constant Summary collapse

Error = 
Class.new(StandardError)
NotFound = 
Class.new(Error)

Instance Method Summary collapse

Constructor Details

#initialize(callbacks = {}) ⇒ Client

Returns a new instance of Client.



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# File 'lib/cacho.rb', line 37

def initialize(callbacks = {})
  @http = Net::HTTP::Persistent.new
  @callbacks = callbacks
  @callbacks[:configure_http].(@http) if @callbacks[:configure_http]
end

Instance Method Details

#protect(options = {}) ⇒ Object 



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# File 'lib/cacho.rb', line 148

def protect(options = {})
  throttle = options.fetch(:throttle, 1)
  maximum_retries = options.fetch(:retries, nil)
  retries = 0

  begin
    result = yield

    retries = 0

    return result
  rescue SocketError, \
         EOFError, \
         Errno::ECONNREFUSED, \
         Errno::ECONNRESET, \
         Errno::EHOSTUNREACH, \
         Errno::ENETUNREACH, \
         Net::HTTP::Persistent::Error, \
         Errno::ETIMEDOUT

    retries += 1

    $stderr.puts("-> #{$!.class}: #{$!.message}")

    sleep([retries ** 2 * throttle, 300].min)

    retry if maximum_retries.nil? || retries < maximum_retries
  end
end

#request(verb, url, options = {}) ⇒ Object 



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# File 'lib/cacho.rb', line 55

def request(verb, url, options = {})
  uri = self.uri(url, options)

  loop do
    request = Net::HTTP.const_get(verb.capitalize).new(uri.request_uri)

    @callbacks[:before_request].(request) if @callbacks[:before_request]

    request["User-Agent"] = "Mozilla/5.0 (X11; Linux i586; rv:31.0) Gecko/20100101 Firefox/31.0"

    if options.include?(:headers)
      options[:headers].each do |key, value|
        request[key] = value
      end
    end

    request["Accept-Encoding"] = "gzip"

    if verb == :post
      post_data = options.fetch(:data, {})

      case options[:content_type]
      when :json
        request["Content-Type"] = "application/json; charset=utf-8"
        request.body = post_data.to_json
      else
        request.body = URI.encode_www_form(post_data)
      end
    end

    if options[:content_encoding] == :deflate
      request["Content-Encoding"] = "deflate"

      request.body = Zlib::Deflate.deflate(request.body)
    end

    $stderr.puts("-> #{verb.upcase} #{uri}")

    if verb_idempotent?(verb)
      res = protect { @http.request(uri, request) }
    else
      res = @http.request(uri, request)
    end

    body = res.body

    if res["Content-Encoding"] == "gzip"
      body = Zlib::GzipReader.new(StringIO.new(body)).read
    end

    if res["Content-Type"]
      if charset = res["Content-Type"][/\bcharset=(.+)\b/, 1]
        body.force_encoding(charset)
        body.encode!(Encoding.default_external)
      end

      if res["Content-Type"].start_with?("application/json")
        parsed = JSON.parse(body)
      else
        parsed = body
      end
    end

    if @callbacks[:rate_limit_detector]
      if seconds = @callbacks[:rate_limit_detector].(res, body, parsed)
        $stderr.puts("Rate limited for #{seconds} seconds.")
        sleep(seconds)
        next
      end
    end

    case res.code
    when "200"
      return parsed
    when "303" , "302" , "301"
      if res["Location"].to_s.index(/^https?:\/\//)
        uri = URI(res["Location"])
      else
        uri = URI.join(uri, res["Location"])
      end
      $stderr.puts("Redirected to #{res["Location"]} (#{uri})")
    when "404"
      return nil
    else
      raise "Got #{res.code}: #{body.inspect}"
    end
  end
end

#uri(url, options = {}) ⇒ Object 



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# File 'lib/cacho.rb', line 43

def uri(url, options = {})
  query = options.fetch(:query, {}).dup

  @callbacks[:process_query].(query) if @callbacks[:process_query]

  uri = URI(url)

  uri.query = URI.encode_www_form(query) if query.size > 0

  uri
end

#verb_idempotent?(verb) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cacho.rb', line 144

def verb_idempotent?(verb)
  verb == :get || verb == :head || verb == :options
end