Import HTTPD Eiffel

http_encoding_facilities.e

@@ -0,0 +1,57 @@
+note
+	description: "[
+		Provides features to encode and decode messages
+	]"
+	legal: "See notice at end of class."
+	status: "Community Preview 1.0"
+	date: "$Date: 2009-09-01 19:15:37 -0300 (mar 01 de sep de 2009) $"
+	revision: "$Revision: 80577 $"
+
+class
+	HTTP_ENCODING_FACILITIES
+
+create
+	make
+
+feature -- Initialization
+
+	make
+		do
+		end
+
+feature -- Conversion
+
+	encode_natural(a_i: NATURAL; a_is_fragmented: BOOLEAN): NATURAL
+			-- Leftshift of the natural (don't use numbers >= 2^31) and subsequent append of the flag bit.
+			-- Use decode_natural and decode_flag for decoding.
+		require
+			no_too_big: a_i < 2147483648
+		do
+			Result := (a_i |<< 1) + a_is_fragmented.to_integer.as_natural_32
+		end
+
+	change_flag(a_i: NATURAL; a_new_flag: BOOLEAN): NATURAL
+			-- Changes the flag to "new_flag" and doesn't change the encoded natural.
+		do
+			Result := (a_i & 0xFFFFFFFE) + a_new_flag.to_integer.as_natural_32
+		end
+
+	decode_natural_and_flag (a_i: NATURAL): TUPLE [NATURAL, BOOLEAN]
+			-- Convenience feature which combines both decodings (natural and flag)
+		do
+			Result := [decode_natural (a_i), decode_flag (a_i)]
+		end
+
+	decode_natural  (a_i: NATURAL): NATURAL
+			-- The natural that was encoded in {ENCODING_FACILITIES}.encode_natural.
+		do
+			Result := (a_i |>> 1)
+		end
+
+	decode_flag (a_i: NATURAL): BOOLEAN
+			--`Result': the flag that was encoded in encode_natural
+		do
+			Result := (a_i.bit_and (1) = 1)
+		end
+
+end