Class: EventMachine::Protocols::HttpClient

Inherits:
Connection
  • Object
show all
Includes:
Deferrable
Defined in:
lib/protocols/httpclient.rb

Constant Summary collapse

MaxPostContentLength = 
20 * 1024 * 1024

Instance Attribute Summary

Attributes inherited from Connection

#signature

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Deferrable

#callback, #cancel_timeout, #errback, #fail, future, #set_deferred_failure, #set_deferred_status, #set_deferred_success, #succeed, #timeout

Methods inherited from Connection

#associate_callback_target, #close_connection, #close_connection_after_writing, #comm_inactivity_timeout, #comm_inactivity_timeout=, #detach, #error?, #get_outbound_data_size, #get_peer_cert, #get_peername, #get_pid, #get_sockname, #get_status, #initialize, new, #reconnect, #send_data, #send_datagram, #send_file_data, #set_comm_inactivity_timeout, #ssl_handshake_completed, #start_tls, #stream_file_data

Constructor Details

This class inherits a constructor from EventMachine::Connection

Class Method Details

.request(args = {}) ⇒ Object

Arg list

:host => ‘ip/dns’, :port => fixnum, :verb => ‘GET’, :request => ‘path’, :basic_auth => => ”, :password => ”, :content => ‘content’, :contenttype => ‘text/plain’, :query_string => ”, :host_header => ”, :cookie => ”



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# File 'lib/protocols/httpclient.rb', line 74

def self.request( args = {} )
  args[:port] ||= 80
  EventMachine.connect( args[:host], args[:port], self ) {|c|
    # According to the docs, we will get here AFTER post_init is called.
    c.instance_eval {@args = args}
  }
end

Instance Method Details

#connection_completed ⇒ Object

We send the request when we get a connection. AND, we set an instance variable to indicate we passed through here. That allows #unbind to know whether there was a successful connection. NB: This naive technique won’t work when we have to support multiple requests on a single connection.



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# File 'lib/protocols/httpclient.rb', line 93

def connection_completed
  @connected = true
  send_request @args
end

#dispatch_response ⇒ Object 



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# File 'lib/protocols/httpclient.rb', line 246

def dispatch_response
  @read_state = :base
  set_deferred_status :succeeded, {
    :content => @content,
    :headers => @headers,
    :status => @status
  }
  # TODO, we close the connection for now, but this is wrong for persistent clients.
  close_connection
end

#post_init ⇒ Object 



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# File 'lib/protocols/httpclient.rb', line 82

def post_init
  @start_time = Time.now
  @data = ""
  @read_state = :base
end

#receive_data(data) ⇒ Object 



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# File 'lib/protocols/httpclient.rb', line 165

def receive_data data
  while data and data.length > 0
    case @read_state
    when :base
      # Perform any per-request initialization here and don't consume any data.
      @data = ""
      @headers = []
      @content_length = nil # not zero
      @content = ""
      @status = nil
      @read_state = :header
	@connection_close = nil
    when :header
      ary = data.split( /\r?\n/m, 2 )
      if ary.length == 2
        data = ary.last
        if ary.first == ""
     if (@content_length and @content_length > 0) || @connection_close
  @read_state = :content
     else
  dispatch_response
  @read_state = :base
     end
        else
          @headers << ary.first
          if @headers.length == 1
            parse_response_line
          elsif ary.first =~ /\Acontent-length:\s*/i
            # Only take the FIRST content-length header that appears,
            # which we can distinguish because @content_length is nil.
            # TODO, it's actually a fatal error if there is more than one
            # content-length header, because the caller is presumptively
            # a bad guy. (There is an exploit that depends on multiple
            # content-length headers.)
            @content_length ||= $'.to_i
          elsif ary.first =~ /\Aconnection:\s*close/i
            @connection_close = true
          end
        end
      else
        @data << data
        data = ""
      end
    when :content
      # If there was no content-length header, we have to wait until the connection
      # closes. Everything we get until that point is content.
      # TODO: Must impose a content-size limit, and also must implement chunking.
      # Also, must support either temporary files for large content, or calling
      # a content-consumer block supplied by the user.
      if @content_length
        bytes_needed = @content_length - @content.length
        @content += data[0, bytes_needed]
        data = data[bytes_needed..-1] || ""
        if @content_length == @content.length
          dispatch_response
          @read_state = :base
        end
      else
        @content << data
        data = ""
      end
    end
  end
end

#send_request(args) ⇒ Object 



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# File 'lib/protocols/httpclient.rb', line 98

def send_request args
  args[:verb] ||= args[:method] # Support :method as an alternative to :verb.
  args[:verb] ||= :get # IS THIS A GOOD IDEA, to default to GET if nothing was specified?

  verb = args[:verb].to_s.upcase
  unless ["GET", "POST", "PUT", "DELETE", "HEAD"].include?(verb)
    set_deferred_status :failed, {:status => 0} # TODO, not signalling the error type
    return # NOTE THE EARLY RETURN, we're not sending any data.
  end

  request = args[:request] || "/"
  unless request[0,1] == "/"
    request = "/" + request
  end

  qs = args[:query_string] || ""
  if qs.length > 0 and qs[0,1] != '?'
    qs = "?" + qs
  end

  version = args[:version] || "1.1"

  # Allow an override for the host header if it's not the connect-string.
  host = args[:host_header] || args[:host] || "_"
  # For now, ALWAYS tuck in the port string, although we may want to omit it if it's the default.
  port = args[:port]

  # POST items.
  postcontenttype = args[:contenttype] || "application/octet-stream"
  postcontent = args[:content] || ""
  raise "oversized content in HTTP POST" if postcontent.length > MaxPostContentLength

  # ESSENTIAL for the request's line-endings to be CRLF, not LF. Some servers misbehave otherwise.
  # TODO: We ASSUME the caller wants to send a 1.1 request. May not be a good assumption.
  req = [
    "#{verb} #{request}#{qs} HTTP/#{version}",
    "Host: #{host}:#{port}",
    "User-agent: Ruby EventMachine",
  ]

  if verb == "POST" || verb == "PUT"
    req << "Content-type: #{postcontenttype}"
    req << "Content-length: #{postcontent.length}"
  end

  # TODO, this cookie handler assumes it's getting a single, semicolon-delimited string.
  # Eventually we will want to deal intelligently with arrays and hashes.
  if args[:cookie]
    req << "Cookie: #{args[:cookie]}"
  end

  # Basic-auth stanza contributed by Matt Murphy.
  if args[:basic_auth]
    basic_auth_string = ["#{args[:basic_auth][:username]}:#{args[:basic_auth][:password]}"].pack('m').strip.gsub(/\n/,'')
    req << "Authorization: Basic #{basic_auth_string}"
  end 

  req << ""
  reqstring = req.map {|l| "#{l}\r\n"}.join
  send_data reqstring

  if verb == "POST" || verb == "PUT"
    send_data postcontent
  end
end

#unbind ⇒ Object 



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# File 'lib/protocols/httpclient.rb', line 257

def unbind
  if !@connected
    set_deferred_status :failed, {:status => 0} # YECCCCH. Find a better way to signal no-connect/network error.
  elsif (@read_state == :content and @content_length == nil)
    dispatch_response
  end
end