class HttpRecognizer

# File lib/httprecognizer.rb, line 30
def initialize webserver=nil
  @data = Deque.new
  @data_pos = 0
  @connection_header = C_empty
  @header_missing_pieces = @name = @uri = @unparsed_uri = @http_version = @request_method = @none_match = @done_parsing = @header_data = nil
  @keepalive = true
  @webserver = webserver
end

# File lib/httprecognizer.rb, line 39
def done_parsing?
  @done_parsing
end

# File lib/httprecognizer.rb, line 205
def http_version; @http_version; end

# File lib/httprecognizer.rb, line 206
def none_match; @none_match; end

# File lib/httprecognizer.rb, line 200
def push
  raise NotImplemented
end

# File lib/httprecognizer.rb, line 57
def receive_data data
  if @done_parsing
    @data.unshift data
    push
  else
    if @header_missing_pieces
      # Hopefully this doesn't happen often.
      d = @data.to_s << data
      @header_missing_pieces = false
    else
      d = data
    end
    unless @uri
      # It's amazing how, when writing the code, the brain can be in a zone
      # where line noise like this regexp makes perfect sense, and is clear
      # as day; one looks at it and it reads like a sentence.  Then, one
      # comes back to it later, and looks at it when the brain is in a
      # different zone, and 'lo!  It looks like line noise again.
      #
      # data =~ /^(\w+) +(?:\w+:\/\/([^\/]+))?([^ \?]+)\S* +HTTP\/(\d\.\d)/
      #
      # In case it looks like line noise to you, dear reader, too:
      #
      # 1) Match and save the first set of word characters.
      #
      #    Followed by one or more spaces.
      #
      #    Match but do not save the word characters followed by ://
      #
      #    2) Match and save one or more characters that are not a slash
      #
      #    And allow this whole thing to match 1 or 0 times.
      #
      # 3) Match and save one or more characters that are not a question
      #    mark or a space.
      #
      #    Match zero or more non-whitespace characters, followed by one
      #    or more spaces, followed by "HTTP/".
      #
      # 4) Match and save a digit dot digit.
      #
      # Thus, this pattern will match both the standard:
      #   GET /bar HTTP/1.1
      # style request, as well as the valid (for a proxy) but less common:
      #   GET http://foo/bar HTTP/1.0
      #
      # If the match fails, then this is a bad request, and an appropriate
      # response will be returned.
      #
      # http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec5.1.2
      #
      if d =~ /^(\w+) +(?:\w+:\/\/([^ \/]+))?(([^ \?\#]*)\S*) +HTTP\/(\d\.\d)/
        @request_method = $1
        @unparsed_uri = $3
        @uri = $4
        @http_version = $5
        if $2
          @name = $2.intern
          @uri = C_slash if @uri.empty?
          # Rewrite the request to get rid of the http://foo portion.
          
          d.sub!(/^\w+ +\w+:\/\/[^ \/]+([^ \?]*)/,"#{@request_method} #{@uri}")
        end
        @uri = @uri.tr('+', ' ').gsub(/((?:%[0-9a-fA-F]{2})+)/n) {[$1.delete(C_percent)].pack('H*')} if @uri.include?(C_percent)
      elsif d.include?(Crn)
        raise Http400Error
        return
      end
    end
    unless @name
      if d =~ /^Host:\s*([^\r\0:]+)\r?\n/m
        @name = $1.intern
      end
    end
    if d.include?(Crnrn)
      @name = ( @webserver.respond_to?(:default_name) && @webserver.respond_to?(:known_name?) ) ?
        ( @webserver.known_name?(@name) ? @name : @webserver.default_name ) :
        @name
      if d =~ /If-None-Match: *([^\r]+)/
        @none_match = $1
      end
      @header_data = d.scan(/Cookie:.*/).collect {|c| c =~ /: ([^\r]*)/; $1}
      @done_parsing = true

      # Keep-Alive works differently on HTTP 1.0 versus HTTP 1.1
      # HTTP 1.0 was not written to support Keep-Alive initially; it was
      # bolted on.  Thus, for an HTTP 1.0 client to indicate that it
      # wants to initiate a Keep-Alive session, it must send a header:
      #
      # Connection: Keep-Alive
      #
      # Then, when the server sends the response, it must likewise add:
      #
      # Connection: Keep-Alive
      #
      # to the response.
      #
      # For HTTP 1.1, Keep-Alive is assumed.  If a client does not want
      # Keep-Alive, then it must send the following header:
      #
      # Connection: close
      #
      # Likewise, if the server does not want to keep the connection
      # alive, it must send the same header:
      #
      # Connection: close
      #
      # to the client.
      
      if @name
        unless @webserver.respond_to?(:keepalive) && @webserver.keepalive(@name) == false
          if @http_version == C1_0
            if data =~ /Connection: Keep-Alive/i
              # Nonstandard HTTP 1.0 situation; apply keepalive header.
              @connection_header = CConnection_KeepAlive
            else
              # Standard HTTP 1.0 situation; connection will be closed.
              @keepalive = false
              @connection_header = CConnection_close
            end
          else # The connection is an HTTP 1.1 connection.
            if data =~ /Connection: [Cc]lose/
              # Nonstandard HTTP 1.1 situation; connection will be closed.
              @keepalive = false
            end
          end
        end
        
        @webserver.add_client(self,@data,data) if @webserver.respond_to?(:add_client)
      else
        raise Http404Error
      end           
    else
      @data.push data
      @header_missing_pieces = true
    end
  end
end

# File lib/httprecognizer.rb, line 204
def request_method; @request_method; end

# File lib/httprecognizer.rb, line 43
def reset_state
  @data.clear
  @data_pos = 0
  @connection_header = C_empty
  @header_missing_pieces = @name = @uri = @unparsed_uri = @http_version = @request_method = @none_match = @done_parsing = @header_data = nil
  @keepalive = true
end

# File lib/httprecognizer.rb, line 208
def setup_for_redeployment
  @data_pos = 0
end