Class: EventMachine::HttpClient

Inherits:
Connection
  • Object
show all
Includes:
Deferrable, HttpEncoding
Defined in:
lib/em-http/client.rb

Constant Summary collapse

TRANSFER_ENCODING = 
"TRANSFER_ENCODING"
CONTENT_ENCODING = 
"CONTENT_ENCODING"
CONTENT_LENGTH = 
"CONTENT_LENGTH"
KEEP_ALIVE = 
"CONNECTION"
"SET_COOKIE"
LOCATION = 
"LOCATION"
HOST = 
"HOST"
CRLF = 
"\r\n"

Constants included from HttpEncoding

EventMachine::HttpEncoding::BASIC_AUTH_ENCODING, EventMachine::HttpEncoding::FIELD_ENCODING, EventMachine::HttpEncoding::HTTP_REQUEST_HEADER

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from HttpEncoding

#encode_basic_auth, #encode_cookie, #encode_field, #encode_headers, #encode_host, #encode_param, #encode_query, #encode_request, #escape, #munge_header_keys, #unescape

Instance Attribute Details

#errors ⇒ Object (readonly)

Returns the value of attribute errors.



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# File 'lib/em-http/client.rb', line 183

def errors
  @errors
end

#method ⇒ Object

Returns the value of attribute method.



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# File 'lib/em-http/client.rb', line 182

def method
  @method
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/em-http/client.rb', line 182

def options
  @options
end

#response ⇒ Object (readonly)

Returns the value of attribute response.



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# File 'lib/em-http/client.rb', line 183

def response
  @response
end

#response_header ⇒ Object (readonly)

Returns the value of attribute response_header.



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# File 'lib/em-http/client.rb', line 183

def response_header
  @response_header
end

#uri ⇒ Object

Returns the value of attribute uri.



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# File 'lib/em-http/client.rb', line 182

def uri
  @uri
end

Instance Method Details

#connection_completed ⇒ Object

start HTTP request once we establish connection to host



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# File 'lib/em-http/client.rb', line 200

def connection_completed
  ssl = @options[:tls] || @options[:ssl] || {}
  start_tls(ssl) if @uri.scheme == "https" or @uri.port == 443

  send_request_header
  send_request_body
end

#dispatch ⇒ Object

Response processing



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# File 'lib/em-http/client.rb', line 317

def dispatch
  while case @state
    when :response_header
      parse_response_header
    when :chunk_header
      parse_chunk_header
    when :chunk_body
      process_chunk_body
    when :chunk_footer
      process_chunk_footer
    when :response_footer
      process_response_footer
    when :body
      process_body
    when :finished, :invalid
      break
    else raise RuntimeError, "invalid state: #{@state}"
    end
  end
end

#normalize_body ⇒ Object 



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# File 'lib/em-http/client.rb', line 232

def normalize_body
  if @options[:body].is_a? Hash
    @options[:body].to_params
  else
    @options[:body]
  end
end

#on_body_data(data) ⇒ Object

Called when part of the body has been read



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# File 'lib/em-http/client.rb', line 284

def on_body_data(data)
  if @content_decoder
    begin
      @content_decoder << data
    rescue HttpDecoders::DecoderError
      on_error "Content-decoder error"
    end
  else
    on_decoded_body_data(data)
  end
end

#on_decoded_body_data(data) ⇒ Object 



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# File 'lib/em-http/client.rb', line 296

def on_decoded_body_data(data)
  if @stream
    @stream.call(data)
  else
    @response << data
  end
end

#on_error(msg, dns_error = false) ⇒ Object

request failed, invoke errback



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# File 'lib/em-http/client.rb', line 219

def on_error(msg, dns_error = false)
  @errors = msg
  
  # no connection signature on DNS failures
  # fail the connection directly
  dns_error == true ? fail(self) : unbind
end

#on_request_complete ⇒ Object

request is done, invoke the callback



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# File 'lib/em-http/client.rb', line 209

def on_request_complete
  begin
    @content_decoder.finalize! if @content_decoder
  rescue HttpDecoders::DecoderError
    on_error "Content-decoder error"
  end
  unbind
end

#parse_chunk_header ⇒ Object 



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# File 'lib/em-http/client.rb', line 408

def parse_chunk_header
  return false unless parse_header(@chunk_header)

  @bytes_remaining = @chunk_header.chunk_size
  @chunk_header = HttpChunkHeader.new

  @state = @bytes_remaining > 0 ? :chunk_body : :response_footer
  true
end

#parse_header(header) ⇒ Object 



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# File 'lib/em-http/client.rb', line 338

def parse_header(header)
  return false if @data.empty?

  begin
    @parser_nbytes = @parser.execute(header, @data.to_str, @parser_nbytes)
  rescue EventMachine::HttpClientParserError
    @state = :invalid
    on_error "invalid HTTP format, parsing fails"
  end

  return false unless @parser.finished?

  # Clear parsed data from the buffer
  @data.read(@parser_nbytes)
  @parser.reset
  @parser_nbytes = 0

  true
end

#parse_response_header ⇒ Object 



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# File 'lib/em-http/client.rb', line 358

def parse_response_header
  return false unless parse_header(@response_header)

  unless @response_header.http_status and @response_header.http_reason
    @state = :invalid
    on_error "no HTTP response"
    return false
  end

  # correct location header - some servers will incorrectly give a relative URI
  if @response_header.location
    begin
      location = URI.parse @response_header.location
      if location.relative?
        location = (@uri.merge location).to_s
        @response_header[LOCATION] = location
      end
    rescue
      on_error "Location header format error"
      return false
    end
  end

  # shortcircuit on HEAD requests 
  if @method == "HEAD"
    @state = :finished
    on_request_complete
  end

  if @response_header.chunked_encoding?
    @state = :chunk_header
  elsif @response_header.content_length
    @state = :body
    @bytes_remaining = @response_header.content_length 
  else
    @state = :body
    @bytes_remaining = nil
  end

  if decoder_class = HttpDecoders.decoder_for_encoding(response_header[CONTENT_ENCODING])
    begin
      @content_decoder = decoder_class.new do |s| on_decoded_body_data(s) end
    rescue HttpDecoders::DecoderError
      on_error "Content-decoder error"
    end
  end
  
  true
end

#post_init ⇒ Object 



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# File 'lib/em-http/client.rb', line 185

def post_init
  @parser = HttpClientParser.new
  @data = EventMachine::Buffer.new
  @response_header = HttpResponseHeader.new
  @chunk_header = HttpChunkHeader.new

  @state = :response_header
  @parser_nbytes = 0
  @response = ''
  @errors = ''
  @content_decoder = nil
  @stream = nil
end

#process_body ⇒ Object 



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# File 'lib/em-http/client.rb', line 464

def process_body
  if @bytes_remaining.nil?
    on_body_data @data.read
    return false
  end

  if @bytes_remaining.zero?
    @state = :finished
    on_request_complete
    return false
  end

  if @data.size < @bytes_remaining
    @bytes_remaining -= @data.size
    on_body_data @data.read
    return false
  end

  on_body_data @data.read(@bytes_remaining)
  @bytes_remaining = 0

  # If Keep-Alive is enabled, the server may be pushing more data to us
  # after the first request is complete. Hence, finish first request, and
  # reset state.
  if @response_header.keep_alive?
    @data.clear # hard reset, TODO: add support for keep-alive connections!
    @state = :finished
    on_request_complete

  else
    if @data.empty?
      @state = :finished
      on_request_complete
    else
      @state = :invalid
      on_error "garbage at end of body"
    end
  end

  false
end

#process_chunk_body ⇒ Object 



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# File 'lib/em-http/client.rb', line 418

def process_chunk_body
  if @data.size < @bytes_remaining
    @bytes_remaining -= @data.size
    on_body_data @data.read
    return false
  end

  on_body_data @data.read(@bytes_remaining)
  @bytes_remaining = 0

  @state = :chunk_footer
  true
end

#process_chunk_footer ⇒ Object 



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# File 'lib/em-http/client.rb', line 432

def process_chunk_footer
  return false if @data.size < 2

  if @data.read(2) == CRLF
    @state = :chunk_header
  else
    @state = :invalid
    on_error "non-CRLF chunk footer"
  end

  true
end

#process_response_footer ⇒ Object 



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# File 'lib/em-http/client.rb', line 445

def process_response_footer
  return false if @data.size < 2

  if @data.read(2) == CRLF
    if @data.empty?
      @state = :finished
      on_request_complete
    else
      @state = :invalid
      on_error "garbage at end of chunked response"
    end
  else
    @state = :invalid
    on_error "non-CRLF response footer"
  end

  false
end

#receive_data(data) ⇒ Object 



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# File 'lib/em-http/client.rb', line 278

def receive_data(data)
  @data << data
  dispatch
end

#send_request_body ⇒ Object 



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# File 'lib/em-http/client.rb', line 272

def send_request_body
  return unless @options[:body]
  body = normalize_body
  send_data body
end

#send_request_header ⇒ Object 



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# File 'lib/em-http/client.rb', line 240

def send_request_header
  query   = @options[:query]
  head    = @options[:head] ? munge_header_keys(@options[:head]) : {}
  body    = normalize_body

  # Set the Host header if it hasn't been specified already
  head['host'] ||= encode_host

  # Set the Content-Length if body is given
  head['content-length'] =  body.length if body

  # Set the User-Agent if it hasn't been specified
  head['user-agent'] ||= "EventMachine HttpClient"

  # Set the cookie header if provided
  if cookie = head.delete('cookie')
    head['cookie'] = encode_cookie(cookie)
  end

  # Set content-type header if missing and body is a Ruby hash
  if not head['content-type'] and options[:body].is_a? Hash
    head['content-type'] = "application/x-www-form-urlencoded"
  end

  # Build the request
  request_header = encode_request(@method, @uri.path, query)
  request_header << encode_headers(head)
  request_header << CRLF

  send_data request_header
end

#stream(&blk) ⇒ Object

assign a stream processing block



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# File 'lib/em-http/client.rb', line 228

def stream(&blk)
  @stream = blk
end

#unbind ⇒ Object 



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# File 'lib/em-http/client.rb', line 304

def unbind
  if @state == :finished || (@state == :body && @bytes_remaining.nil?)
    succeed(self) 
  else
    fail(self)
  end
  close_connection
end