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| -rw-r--r-- | doc/info/mds.texinfo | 66 |
1 files changed, 61 insertions, 5 deletions
diff --git a/doc/info/mds.texinfo b/doc/info/mds.texinfo index bcf3073..1aaba91 100644 --- a/doc/info/mds.texinfo +++ b/doc/info/mds.texinfo @@ -336,11 +336,12 @@ time they were closed. @chapter Protocol @menu -* Environment Variables:: Identifying the active display server -* Signals:: Signalling individual servers -* Filesystem:: The display server's footprint on the filesystem -* Message Passing:: Sending messages between servers and clients -* Interception:: Implementing protocols and writing unanticipated clients +* Environment Variables:: Identifying the active display server. +* Signals:: Signalling individual servers. +* Filesystem:: The display server's footprint on the filesystem. +* Message Passing:: Sending messages between servers and clients. +* Interception:: Implementing protocols and writing unanticipated clients. +* Portability:: Restrictions for portability on protocols. @end menu @@ -805,6 +806,61 @@ Command: keyboard-enumeration\n +@node Portability +@section Portability + +For optimal portability, there are some restrictions +on protocols. + +@itemize @bullet{} +@item +Because C allows unsigned integers to be encoded as +either sign and magnitude, one's complement or two's +complement@footnote{GCC only allows two's complement}, +the minimum value of any signed value with a fixed +bit-size is the negative of its maximum value, that +is, the minimum value @code{int16_t} is to be assumed +to be @code{-INT16_MAX} (@math{-32767}) rather than +@code{INT16_MIN} (@math{-32768} with two's complement.) + +@item +Integer that are not especially encoded must not be +larger than 64-bits if they use fixed bit-size. If +for example @code{size_t} is 128-bits on your platform +but you are using a language that only have native +integer up to 64-bits you must use arbitrary size +integers or otherwise make sure that the value can +be properly stored and used. + +@item +Integer 64-bits that are not especially encoded +must not be unsigned if the bit-size is fixed. + +@item +Native endianness when a endianness is choosen. +Do not assume big endianness, but the same +endianness that appear on the same machine when +using C. + +@item +All strings musts be encoded in UTF-8 without +any NUL-character unless expressive permission +is given. NUL-character may be encoded either +using a zero byte or using Modified UTF-8, where +it is encoded using two bytes. Which is used is +selected in the protocol, however headers and +their values must not include NUL-characters. +No character may be encoded with more bytes than +necessary. + +@item +The new line-character is always LF (@code{'\n'}, +10, line feed) and never a combination of LF and +any other character, or multiple LF:s. +@end itemize + + + @node Utilities @chapter Utilities |