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_cookies, #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 151

def errors
  @errors
end

#method ⇒ Object

Returns the value of attribute method.



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# File 'lib/em-http/client.rb', line 150

def method
  @method
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/em-http/client.rb', line 150

def options
  @options
end

#response ⇒ Object (readonly)

Returns the value of attribute response.



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# File 'lib/em-http/client.rb', line 151

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 151

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 150

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 169

def connection_completed
  send_request_header
  send_request_body
end

#dispatch ⇒ Object

Response processing



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# File 'lib/em-http/client.rb', line 245

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

#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 232

def on_body_data(data)
  @response << data
end

#on_error(msg) ⇒ Object

request failed, invoke errback



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# File 'lib/em-http/client.rb', line 190

def on_error(msg)
  @errors = msg
  unbind
end

#on_request_complete ⇒ Object

request is done, invoke the callback



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# File 'lib/em-http/client.rb', line 175

def on_request_complete

  if @response_header.compressed? and @inflate.include?(response_header[CONTENT_ENCODING])
    case response_header[CONTENT_ENCODING]
    when 'deflate' then 
      @response = Zlib::Inflate.inflate(@response)
    when 'gzip', 'compressed' then
      @response = Zlib::GzipReader.new(StringIO.new(@response)).read
    end
  end
      
  unbind
end

#parse_chunk_header ⇒ Object 



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# File 'lib/em-http/client.rb', line 305

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 266

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 286

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

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

  true
end

#post_init ⇒ Object 



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# File 'lib/em-http/client.rb', line 153

def post_init
  self.comm_inactivity_timeout = 5

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

  @state = :response_header
  @parser_nbytes = 0
  @inflate = []
  @response = ''
  @errors = ''
end

#process_body ⇒ Object 



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# File 'lib/em-http/client.rb', line 361

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 315

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 329

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 342

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 226

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

#send_request_body ⇒ Object 



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# File 'lib/em-http/client.rb', line 222

def send_request_body
  send_data @options[:body] if @options[:body]
end

#send_request_header ⇒ Object 



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# File 'lib/em-http/client.rb', line 195

def send_request_header
  query   = @options[:query]
  head    = @options[:head] ? munge_header_keys(@options[:head]) : {}
  body    = @options[: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 auto-inflate flags
  if head['accept-encoding']
    @inflate = head['accept-encoding'].split(',').map {|t| t.strip}
  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

#unbind ⇒ Object 



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# File 'lib/em-http/client.rb', line 236

def unbind
  (@state == :finished) ? succeed : fail
  close_connection
end