From 1c11e3c98d7d5d24305b9b7dea42075af62de0a0 Mon Sep 17 00:00:00 2001
From: Sven Gestegard Robertz <sven.robertz@cs.lth.se>
Date: Fri, 23 Jan 2015 10:56:20 +0100
Subject: [PATCH] more on type_defs
---
doc/tech_report.tex | 28 ++++++++++++++++++++--------
1 file changed, 20 insertions(+), 8 deletions(-)
diff --git a/doc/tech_report.tex b/doc/tech_report.tex
index 25aa758..244cdd1 100644
--- a/doc/tech_report.tex
+++ b/doc/tech_report.tex
@@ -330,11 +330,7 @@ i.e.,
<sample_data> <user_id: 40> <length: 14> <packed_sample_data>
\end{verbatim}
-\section{Technical details}
-
-TODO: better section title
-
-\subsection{Type and sample declarations}
+\section{Type and sample declarations}
LabComm has two constructs for declaring sample types, \emph{sample
declarations} and \emph{type declarations}. A sample declaration is used
@@ -386,7 +382,7 @@ come from two independent number series. To identify which
\verb+TYPE_DECL+ a particular \verb+SAMPLE_DECL+ corresponds to, the
\verb+TYPE_BINDING+ packet is used.
-\subsubsection{Example}
+\subsection{Example}
The labcomm declaration
\lstinputlisting[basicstyle=\footnotesize\ttfamily]{../examples/user_types/test.lc}
@@ -418,6 +414,22 @@ Note that the id 0x40 is used both for the \verb+TYPE_DECL+ of
\verb+TYPE_BINDING+ binds the sample id \verb+0x40+ to the type id
\verb+0x44+.
+\subsection{Run-time behaviour}
+
+When a sample type is registered on an encoder, a \verb+SAMPLE_DECL+
+(i.e., the flat signature) is always generated on that encoder channel.
+
+If the sample depends on user types (i.e., typedefs), \verb+TYPE_DECL+
+packets are encoded, recursively, for the dependent types and a
+corresponding \verb+TYPE_BINDING+ is encoded.
+
+If a \verb+TYPE_DECL+ is included via multiple sample types, or
+dependency paths, an encoder may choose to only encode it once, but is
+not required to do so. However, if multiple \verb+TYPE_DECL+ packets are
+sent for the same \verb+typedef+, the encoder must use the same
+\verb+type_id+.
+
+
\section{Ideas/Discussion}:
@@ -515,8 +527,8 @@ The built-in data types are encoded as follows:
<type_binding> |
<sample_data> )
<version> := <string>
-<sample_def> := <sample_id> <string> <type>
-<type_def> := <type_id> <string> <type>
+<sample_decl> := <sample_id> <string> <type>
+<type_decl> := <type_id> <string> <type>
<type_binding> := <sample_id> <type_id>
<user_id> := 0x40..0xffffffff
<sample_id> : <user_id>
--
GitLab