add option "alias" to read datasets into different variables

Extents the file readers capabilities to not only take a cctk_iteration string
but also a string alias. A value of

IO::filereader_vars = "hydrobase::vel[0]{alias=admbase::shiftx}"

will read the datasets admbase::shiftx into the variable hydrobase::vel[0]. The
idea is to be able to read variables of evolution thorns into postprocessing
thorns.



git-svn-id: http://svn.cactuscode.org/arrangements/CactusBase/IOUtil/trunk@304 b32723a9-ab3a-4a60-88e2-2e5d99d7c17a

2 files changed, 61 insertions, 3 deletions

diff --git a/src/CheckpointRecovery.c b/src/CheckpointRecovery.c
index 328053e..cac3690 100644
--- a/src/CheckpointRecovery.c
+++ b/src/CheckpointRecovery.c
@@ -426,8 +426,12 @@ int IOUtil_RecoverVarsFromDatafiles (cGH *GH,
 
   if (CCTK_NumVars () > 0)
   {
+    void *calldata[2];
     myGH->do_inVars = calloc (CCTK_NumVars (), sizeof (CCTK_INT));
-    if (CCTK_TraverseString (in_vars, SetInputFlag, myGH->do_inVars,
+    myGH->alias = calloc (CCTK_NumVars (), sizeof (char *));
+    calldata[0] = myGH->do_inVars;
+    calldata[1] = myGH->alias;
+    if (CCTK_TraverseString (in_vars, SetInputFlag, calldata,
                              CCTK_GROUP_OR_VAR) < 0)
     {
       CCTK_WARN (myGH->stop_on_parse_errors ? 0 : 1,
@@ -437,6 +441,7 @@ int IOUtil_RecoverVarsFromDatafiles (cGH *GH,
   else
   {
     myGH->do_inVars = NULL;
+    myGH->alias = NULL;
   }
 
   num_recovered_vars = 0;
@@ -492,6 +497,18 @@ int IOUtil_RecoverVarsFromDatafiles (cGH *GH,
     myGH->do_inVars = NULL;
   }
 
+  if (myGH->alias)
+  {
+    const int numVars = CCTK_NumVars ();
+    for (int i = 0; i < numVars; i++)
+    {
+      if (myGH->alias[i])
+        free ((void*)myGH->alias[i]);
+    }
+    free (myGH->alias);
+    myGH->alias = NULL;
+  }
+
   return (num_recovered_vars);
 }
 
@@ -1085,17 +1102,22 @@ static char *DecodeString (const char *string)
 
 /* callback for CCTK_TraverseString() to set the input flag
    for the given variable */
-static void SetInputFlag (int vindex, const char *optstring, void *flags)
+static void SetInputFlag (int vindex, const char *optstring, void *calldata)
 {
   int table, iterator;
   char key[128];
   CCTK_INT type, nelems;
-  CCTK_INT *do_inVars = (CCTK_INT *) flags;
+  void **flags = (void**)calldata;
+  CCTK_INT *do_inVars = (CCTK_INT *) flags[0];
+  const char **alias = (const char **) flags[1];
 
 
   /* default -1 is to read the last iteration number from the file */
   do_inVars[vindex] = -1;
 
+  /* default is NULL to use CCTK_FullName() */
+  alias[vindex] = NULL;
+
   if (optstring)
   {
     table = Util_TableCreateFromString (optstring);
@@ -1124,6 +1146,36 @@ static void SetInputFlag (int vindex, const char *optstring, void *flags)
         Util_TableDeleteKey (table, "cctk_iteration");
       }
 
+      if (Util_TableQueryValueInfo (table, &type, &nelems, "alias") >0)
+      {
+        if (type == CCTK_VARIABLE_CHAR)
+        {
+          char *buf = malloc(nelems+1);
+          if (! (buf))
+          {
+            CCTK_VError (__LINE__, __FILE__,"IOUtil",
+                         "Could not allocate %d bytes", nelems+1);
+          }
+          int len = Util_TableGetString (table, nelems+1, buf, "alias");
+          if (len != nelems)
+          {
+            CCTK_VError (__LINE__, __FILE__,"IOUtil",
+                         "Unexpected length %d of 'alias' option value in '%s'. Expected length %d.",
+                         len, optstring, nelems);
+          }
+
+          alias[vindex] = buf;
+        }
+        else
+        {
+          CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
+                      "Invalid value for option 'alias' in option "
+                      "string '%s' (must be a string)", optstring);
+          CCTK_WARN (1, "Option will be ignored by file reader routines");
+        }
+        Util_TableDeleteKey (table, "alias");
+      }
+
       /* warn about other options */
       for (iterator = Util_TableItCreate (table);
            Util_TableItQueryIsNonNull (iterator) > 0 &&
diff --git a/src/ioGH.h b/src/ioGH.h
index 998e6bf..7b5b16f 100644
--- a/src/ioGH.h
+++ b/src/ioGH.h
@@ -16,6 +16,10 @@ extern "C"
 {
 #endif
 
+/* advertise that this is the new version of this API, which has 'alias'
+ * members in the grid extension */
+#define IOUTIL_IOGH_HAS_ALIAS 1
+
 
 /* IOUtil's GH extension structure */
 typedef struct
@@ -36,6 +40,8 @@ typedef struct
   CCTK_INT *do_inVars;   /* flags indicating to read in variable i with
                             iteration number do_inVars[i] (or -1 to read
                             the last iteration */
+  const char **alias;    /* name under which a variable appears in data files.
+                            If NULL, use CCTK_FullName() */
 } ioGH;