+#ifdef ODF_READ_SUPPORT
+static const bool ODF_READING_SUPPORTED = true;
+#else
+static const bool ODF_READING_SUPPORTED = false;
+#endif
+
+#ifdef GNM_READ_SUPPORT
+static const bool GNM_READING_SUPPORTED = true;
+#else
+static const bool GNM_READING_SUPPORTED = false;
+#endif
+
+void
+spreadsheet_ref (struct spreadsheet *s)
+{
+ s->ref_cnt++;
+}
+
+void
+spreadsheet_unref (struct spreadsheet *s)
+{
+ switch (s->type)
+ {
+ case SPREADSHEET_ODS:
+ assert (ODF_READING_SUPPORTED);
+ ods_unref (s);
+ break;
+
+ case SPREADSHEET_GNUMERIC:
+ assert (GNM_READING_SUPPORTED);
+ gnumeric_unref (s);
+ break;
+ default:
+ NOT_REACHED ();
+ break;
+ }
+}
+
+
+struct casereader *
+spreadsheet_make_reader (struct spreadsheet *s,
+ const struct spreadsheet_read_options *opts)
+{
+ if (ODF_READING_SUPPORTED)
+ if ( s->type == SPREADSHEET_ODS)
+ return ods_make_reader (s, opts);
+
+ if (GNM_READING_SUPPORTED)
+ if ( s->type == SPREADSHEET_GNUMERIC)
+ return gnumeric_make_reader (s, opts);
+
+ return NULL;
+}
+
+const char *
+spreadsheet_get_sheet_name (struct spreadsheet *s, int n)