[fdo-commits] r675 - branches/fdordbms-postgis/Providers/GenericRdbms/Src/PostGIS/Driver

[svn_fdo at osgeo.org]

Author: mloskot
Date: 2007-01-22 21:06:35 -0500 (Mon, 22 Jan 2007)
New Revision: 675

Added:
   branches/fdordbms-postgis/Providers/GenericRdbms/Src/PostGIS/Driver/digits.h
Log:
Added digits.h file with some hacks for integral type limits.

Added: branches/fdordbms-postgis/Providers/GenericRdbms/Src/PostGIS/Driver/digits.h
===================================================================
--- branches/fdordbms-postgis/Providers/GenericRdbms/Src/PostGIS/Driver/digits.h	2007-01-23 02:05:07 UTC (rev 674)
+++ branches/fdordbms-postgis/Providers/GenericRdbms/Src/PostGIS/Driver/digits.h	2007-01-23 02:06:35 UTC (rev 675)
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2006 Refractions Research, Inc. 
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of version 2.1 of the GNU Lesser
+ * General Public License as published by the Free Software Foundation.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifndef POSTGIS_DIGITS_H
+#define POSTGIS_DIGITS_H
+
+#ifdef _WIN32
+#pragma once
+#endif // _WIN32
+
+#include <limits.h>
+
+/*
+ * Compile time estimation of (log(10) / log(2)) used as precision for
+ * calculation of number of digits in numeric type.
+ */
+#define LOG10PERLOG2    301L / 1000
+
+/*
+ * For the sake of safety, overestimation should not hurt us.
+ */
+#define OVERESTIMATOR   3
+
+/*
+ * A shortcut macros for calculating number of digits in integral type.
+ */
+#define NUMBER_OF_DIGITS10(x) \
+    (((CHAR_BIT * sizeof(x) - 1) * LOG10PERLOG2) + OVERESTIMATOR)
+
+#define NUMBER_OF_CHAR_DIGITS10 \
+    ((CHAR_BIT - (CHAR_MIN != 0 ? 1 : 0)) * LOG10PERLOG2) + OVERESTIMATOR)
+
+#define NUMBER_OF_UCHAR_DIGITS10 \
+    ((CHAR_BIT - 1) * LOG10PERLOG2) + OVERESTIMATOR)
+
+/*
+ * Constants of number of digits for float types
+ */
+#define NUMBER_OF_FLOAT_DIGITS      100
+#define NUMBER_OF_DOUBLE_DIGITS     100
+
+#endif /* POSTGIS_DIGITS_H */
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