more progress towards lazy read of atts for vars

libhdf5/hdf5attr.c

@@ -43,6 +43,54 @@ getattlist(NC_GRP_INFO_T *grp, int varid, NC_VAR_INFO_T **varp)
    }
 }
 
+/**
+ * @internal Get the attribute list for either a varid or NC_GLOBAL
+ *
+ * @param grp Group
+ * @param varid Variable ID | NC_BLOGAL
+ * @param varp Pointer that gets pointer to NC_VAR_INFO_T
+ * instance. Ignored if NULL.
+ * @param attlist Pointer that gets pointer to attribute list.
+ *
+ * @return NC_NOERR No error.
+ * @author Dennis Heimbigner, Ed Hartnett
+ */
+static int
+getattlist2(NC_GRP_INFO_T *grp, int varid, NC_VAR_INFO_T **varp,
+            NCindex **attlist)
+{
+   NC_VAR_INFO_T* var;
+   int retval;
+
+   if (varid == NC_GLOBAL)
+   {
+      /* Do we need to read the atts? */
+      if (grp->atts_not_read)
+         if ((retval = nc4_read_grp_atts(grp)))
+            return retval;
+
+      if (varp)
+         *varp = NULL;
+      *attlist = grp->att;
+   }
+   else
+   {
+      if (!(var = (NC_VAR_INFO_T *)ncindexith(grp->vars, varid)))
+         return NC_ENOTVAR;
+      assert(var->hdr.id == varid);
+
+      /* Do we need to read the atts? */
+      if (var->atts_not_read)
+         if ((retval = nc4_read_var_atts(grp, var)))
+            return retval;
+
+      if (varp)
+         *varp = var;
+      *attlist = var->att;
+   }
+   return NC_NOERR;
+}
+
 /**
  * @internal I think all atts should be named the exact same thing, to
  * avoid confusion!
@@ -92,11 +140,13 @@ NC4_rename_att(int ncid, int varid, const char *name, const char *newname)
    if ((retval = nc4_check_name(newname, norm_newname)))
       return retval;
 
-   /* Is new name in use? */
-   list = getattlist(grp,varid,&var);
-   if(list == NULL)
-      return NC_ENOTVAR;
+   /* Get the list of attributes. */
+   /* if (!(list = getattlist(grp,varid,&var))) */
+   /*    return NC_ENOTVAR; */
+   if ((retval = getattlist2(grp, varid, &var, &list)))
+      return retval;
 
+   /* Is new name in use? */
    att = (NC_ATT_INFO_T*)ncindexlookup(list,norm_newname);
    if(att != NULL)
       return NC_ENAMEINUSE;
@@ -204,17 +254,15 @@ NC4_del_att(int ncid, int varid, const char *name)
          BAIL(retval);
    }
 
-   /* Do we need to read the atts? */
-   if (varid == NC_GLOBAL)
-      if (grp->atts_not_read)
-         if ((retval = nc4_read_grp_atts(grp)))
-            return retval;
+   /* Get either the global or a variable attribute list. */
+   /* if (!(attlist = getattlist(grp,varid,NULL))) */
+   /*    return NC_ENOTVAR; */
+   if ((retval = getattlist2(grp, varid, &var, &attlist)))
+      return retval;
+   /* if (!(attlist = getattlist(grp,varid,NULL))) */
+   /*    return NC_ENOTVAR; */
 
-   /* Get either the global or a variable attribute list. Also figure
-      out the HDF5 location it's attached to. */
-   attlist = getattlist(grp,varid,&var);
-   if(attlist == NULL)
-      return NC_ENOTVAR;
+   /* Determine the location id in the HDF5 file. */
    if (varid == NC_GLOBAL)
       locid = grp->hdf_grpid;
    else if (var->created)
@@ -303,9 +351,11 @@ NC4_put_att(int ncid, int varid, const char *name, nc_type file_type,
 
    /* Find att, if it exists. (Must check varid first or nc_test will
     * break.) */
-   attlist = getattlist(grp,varid,&var);
-   if(attlist == NULL)
-      return NC_ENOTVAR;
+   if ((ret = getattlist2(grp, varid, &var, &attlist)))
+      return ret;
+   /* attlist = getattlist(grp,varid,&var); */
+   /* if(attlist == NULL) */
+   /*    return NC_ENOTVAR; */
 
    /* The length needs to be positive (cast needed for braindead
       systems with signed size_t). */

libhdf5/hdf5file.c

@@ -1827,6 +1827,9 @@ nc4_read_var_atts(NC_GRP_INFO_T *grp, NC_VAR_INFO_T *var)
                     att_read_var_callbk, &att_info)) < 0)
       return NC_EATTMETA;
 
+   /* Remember that we have read the atts for this var. */
+   var->atts_not_read = 0;
+
    return NC_NOERR;
 }
 

libsrc4/nc4internal.c

@@ -480,6 +480,12 @@ nc4_find_grp_att(NC_GRP_INFO_T *grp, int varid, const char *name, int attnum,
    {
       var = (NC_VAR_INFO_T*)ncindexith(grp->vars,varid);
       if (!var) return NC_ENOTVAR;
+
+      /* Do we need to read the var attributes? */
+      if (var->atts_not_read)
+         if ((retval = nc4_read_var_atts(grp, var)))
+            return retval;
+
       attlist = var->att;
       assert(var->hdr.id == varid);
    }