Class: HTTP::Request::Writer

Inherits:
Object
  • Object
show all
Defined in:
lib/http/request/writer.rb

Overview

Streams HTTP requests to a socket

Constant Summary collapse

CRLF =

CRLF is the universal HTTP delimiter

"\r\n"
ZERO =

Chunked data terminator

"0"
CHUNKED_END =

End of a chunked transfer

"#{ZERO}#{CRLF}#{CRLF}".freeze

Instance Method Summary collapse

Constructor Details

#initialize(socket, body, headers, headline) ⇒ HTTP::Request::Writer

Initialize a new request writer

Examples:

Writer.new(socket, body, headers, "GET / HTTP/1.1")


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# File 'lib/http/request/writer.rb', line 25

def initialize(socket, body, headers, headline)
  @body           = body
  @socket         = socket
  @headers        = headers
  @request_header = [headline]
end

Instance Method Details

#add_body_type_headers ⇒ void

This method returns an undefined value.

Adds content length or transfer encoding headers

Examples:

writer.add_body_type_headers


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# File 'lib/http/request/writer.rb', line 77

def add_body_type_headers
  return if @headers[Headers::CONTENT_LENGTH] || chunked? || (
    @body.source.nil? && %w[GET HEAD DELETE CONNECT].any? do |method|
      @request_header.fetch(0).start_with?("#{method} ")
    end
  )

  @request_header << "#{Headers::CONTENT_LENGTH}: #{@body.size}"
end

#add_headers ⇒ void

This method returns an undefined value.

Adds headers to the request header array

Examples:

writer.add_headers


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# File 'lib/http/request/writer.rb', line 39

def add_headers
  @headers.each do |field, value|
    @request_header << "#{field}: #{value}"
  end
end

#chunked? ⇒ Boolean

Returns true if using chunked transfer encoding

Examples:

writer.chunked?

Returns:

  • (Boolean) 


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# File 'lib/http/request/writer.rb', line 162

def chunked?
  @headers[Headers::TRANSFER_ENCODING].eql?(Headers::CHUNKED)
end

#connect_through_proxy ⇒ void

This method returns an undefined value.

Send headers needed to connect through proxy

Examples:

writer.connect_through_proxy


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# File 'lib/http/request/writer.rb', line 65

def connect_through_proxy
  add_headers
  write(join_headers)
end

#each_chunk {|data| ... } ⇒ void

This method returns an undefined value.

Yields chunks of request data for the socket

It’s important to send the request in a single write call when possible in order to play nicely with Nagle’s algorithm. Making two writes in a row triggers a pathological case where Nagle is expecting a third write that never happens.

Examples:

writer.each_chunk { |chunk| socket.write(chunk) }

Yields:

  • (data) 


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# File 'lib/http/request/writer.rb', line 126

def each_chunk
  data = join_headers

  @body.each do |chunk|
    data << encode_chunk(chunk)
    yield data
    data.clear
  end

  yield data unless data.empty?

  yield CHUNKED_END if chunked?
end

#encode_chunk(chunk) ⇒ String

Returns chunk encoded per Transfer-Encoding header

Examples:

writer.encode_chunk("hello")

Returns:

  • (String) 


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# File 'lib/http/request/writer.rb', line 147

def encode_chunk(chunk)
  if chunked?
    chunk.bytesize.to_s(16) << CRLF << chunk << CRLF
  else
    chunk
  end
end

#join_headers ⇒ String

Joins headers into an HTTP request header string

Examples:

writer.join_headers

Returns:

  • (String) 


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# File 'lib/http/request/writer.rb', line 94

def join_headers
  # join the headers array with crlfs, stick two on the end because
  # that ends the request header
  @request_header.join(CRLF) + (CRLF * 2)
end

#send_request ⇒ void

This method returns an undefined value.

Writes HTTP request data into the socket

Examples:

writer.send_request


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# File 'lib/http/request/writer.rb', line 107

def send_request
  each_chunk { |chunk| write chunk }
rescue Errno::EPIPE
  # server doesn't need any more data
  nil
end

#stream ⇒ void

This method returns an undefined value.

Stream the request to a socket

Examples:

writer.stream


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# File 'lib/http/request/writer.rb', line 52

def stream
  add_headers
  add_body_type_headers
  send_request
end