Add the "Cactus version" attribute to a datafile indicating that variables

with multiple timelevels should be read in following the new timelevel scheme.

Thanks to Ken Smith for pointing this out.
This closes PR Documentation/1107.


git-svn-id: http://svn.cactuscode.org/arrangements/CactusPUGHIO/IOFlexIO/trunk@259 ebee0441-1374-4afa-a3b5-247f3ba15b9a

2 files changed, 17 insertions, 6 deletions

diff --git a/doc/CreateIOFlexIOdatafile.c b/doc/CreateIOFlexIOdatafile.c
index cd14c9c..7ba5059 100644
--- a/doc/CreateIOFlexIOdatafile.c
+++ b/doc/CreateIOFlexIOdatafile.c
@@ -32,10 +32,13 @@
    we didn't include these here. */
 #define CCTK_GF                  2
 
+/* the Cactus version that this datafile is (upwards) compatible with
+   (versions below beta10 use a different timelevel scheme) */
+#define CACTUS_VERSION  "4.0.b10"
+
 /* a simple macro to do a FlexIO call with return code checking
    in case of an error it will issue an error message and exit */
-#define CHECK_ERROR(flexio_call)                                                \
-          do                                                                  \
+#define CHECK_ERROR(flexio_call)                                              \
           {                                                                   \
             int _error_code = flexio_call;                                    \
                                                                               \
@@ -47,7 +50,7 @@
                                 __LINE__, #flexio_call, _error_code);         \
               return (-1);                                                    \
             }                                                                 \
-          } while (0)
+          }
 
 
  /*@@
@@ -108,7 +111,7 @@ int main (void)
   /* as a Cactus grid variable                                              */
   /**************************************************************************/
 
-  /* the variable's name (as specified in the interface.ccl file) */
+  /* the variable's full name (as specified in the interface.ccl file) */
   varname = "grid::x";
   CHECK_ERROR (IOwriteAttribute (datafile, "name", CHAR,
                                  strlen (varname) + 1, varname));
@@ -132,7 +135,7 @@ int main (void)
   timelevel = 0;
   CHECK_ERROR (IOwriteAttribute (datafile, "timelevel", INT32, 1, &timelevel));
 
-  /* the dimensions of the variable (must correspond with the grid size
+  /* the dimensions of the variable (must correspond to the grid size
      in your parameter file) */
   CHECK_ERROR (IOwriteAttribute (datafile, "global_size", INT32, NDIM, dimsI));
 
@@ -157,6 +160,10 @@ int main (void)
   CHECK_ERROR (IOwriteAttribute (datafile, "GH$ioproc_every", INT32, 1,
                                  &ioproc_every));
 
+  /* the version of Cactus that this datafile is (upwards) compatible with */
+  CHECK_ERROR (IOwriteAttribute (datafile, "Cactus version", CHAR,
+               strlen (CACTUS_VERSION) + 1, CACTUS_VERSION));
+
 
   /* close the file and free allocated resources */
   CHECK_ERROR (IOclose (datafile));
diff --git a/doc/documentation.tex b/doc/documentation.tex
index 5c7f020..5c58725 100644
--- a/doc/documentation.tex
+++ b/doc/documentation.tex
@@ -238,12 +238,16 @@ template for building your own data converter program.\\
           \item Does the file contain chunked or unchunked data ?
           \item How many processors were used to produce the data ?
           \item How many I/O processors were used to write the data ?
+          \item What Cactus version is this datafile compatible with ?
         \end{itemize}
         Such information is attached as attributes to the very first dataset
         in the file. Since we assume unchunked data here
         the processor information isn't relevant -- unchunked data can
         be fed back into a Cactus simulation running on an arbitrary
-        number of processors.
+        number of processors.\\
+        The Cactus version ID must be present to indicate that grid variables
+        with multiple timelevels should be recovered following the new
+        timelevel scheme (as introduced in Cactus beta 10).
 \end{enumerate}
 
 The example C program goes through all of these steps and creates a datafile