the begginning

utils/funcexp/func_unhex.cpp

@@ -0,0 +1,103 @@
+/* Copyright (C) 2014 InfiniDB, Inc.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; version 2 of
+   the License.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA. */
+
+/****************************************************************************
+* $Id: func_unhex.cpp 3923 2013-06-19 21:43:06Z bwilkinson $
+*
+*
+****************************************************************************/
+
+#include <cstdlib>
+#include <string>
+#include <sstream>
+using namespace std;
+
+#include "functor_str.h"
+#include "funchelpers.h"
+#include "functioncolumn.h"
+#include "rowgroup.h"
+using namespace execplan;
+
+#include "dataconvert.h"
+
+namespace
+{
+	int64_t hex_to_int(char c)
+	{
+	  if (c <= '9' && c >= '0')
+	    return c-'0';
+	  c = toupper(c);
+	  if (c <= 'F' && c >= 'A')
+	    return c-'A'+10;
+	  return -1;
+	}
+}
+
+namespace funcexp
+{
+
+CalpontSystemCatalog::ColType Func_unhex::operationType( FunctionParm& fp, CalpontSystemCatalog::ColType& resultType )
+{
+	return resultType;
+}
+
+
+string Func_unhex::getStrVal(rowgroup::Row& row,
+							FunctionParm& parm,
+							bool& isNull,
+							CalpontSystemCatalog::ColType& op_ct)
+{
+	const string& from = parm[0]->data()->getStrVal(row, isNull);
+	char* to = new char[2 + from.length()/2];
+	if (!to)
+	{
+		isNull = true;
+		return "";
+	}
+	
+	uint64_t from_pos = 0, to_pos = 0;
+	int64_t hex_char = 0;
+	if (strlen(from.c_str()) % 2)
+	{
+		hex_char = hex_to_int(from[from_pos++]);
+		to[to_pos++] = hex_char;
+		if (hex_char == -1)
+			goto nullHandling;
+	}
+
+	for (; from_pos < strlen(from.c_str()); from_pos+=2)
+	{
+		hex_char = hex_to_int(from[from_pos]) << 4;
+		if (hex_char == -1)
+			goto nullHandling;
+		to[to_pos] = hex_char;
+		hex_char = hex_to_int(from[from_pos+1]);
+		if (hex_char == -1)
+			goto nullHandling;
+		to[to_pos++] |= hex_char;
+	}
+	to[to_pos] = 0;
+	return string(to);
+
+nullHandling:
+	isNull = true;
+	return "";
+}
+
+
+} // namespace funcexp
+// vim:ts=4 sw=4: