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dbcon/execplan/objectreader.h

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+/* 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: objectreader.h 9633 2013-06-19 13:36:01Z rdempsey $
+ *
+ *****************************************************************************/
+
+/** @file 
+ * class ObjectReader interface
+ */
+
+#ifndef EXECPLAN_OBJECTREADER_H
+#define EXECPLAN_OBJECTREADER_H
+
+#include <exception>
+#include <string>
+#include <stdint.h>
+
+namespace messageqcpp {
+class ByteStream;
+}
+
+namespace execplan {
+
+	class TreeNode;
+	class ParseTree;
+	class CalpontExecutionPlan;
+	
+/** @brief A class for creating execplan classes from ByteStreams.
+ *
+ * A class currently used for recreating execplan polymorphic classes
+ * and dynamic objects from ByteStreams.
+ */
+
+class ObjectReader {
+
+public:
+
+	class UnserializeException : public std::exception {
+	public:
+		UnserializeException(std::string) throw();
+		virtual ~UnserializeException() throw();
+		virtual const char* what() const throw();
+	private:
+		std::string fWhat;
+	};
+
+	/** @brief Enumerates classes supporting serialization
+	 *
+	 * This defines one constant for each class that supports
+	 * serialization.
+	 */
+	enum CLASSID {
+		ZERO,      // an appropriate initializer
+		NULL_CLASS,		// to denote that some member is NULL
+
+		/**** TreeNodes */
+		TREENODE,
+		TREENODEIMPL,
+		RETURNEDCOLUMN,
+		AGGREGATECOLUMN,
+		GROUPCONCATCOLUMN,
+		ARITHMETICCOLUMN,
+		CONSTANTCOLUMN,
+		FUNCTIONCOLUMN,
+		ROWCOLUMN,
+		WINDOWFUNCTIONCOLUMN,
+		PSEUDOCOLUMN,
+
+		SIMPLECOLUMN,
+		SIMPLECOLUMN_INT1,
+		SIMPLECOLUMN_INT2,
+		SIMPLECOLUMN_INT4,
+		SIMPLECOLUMN_INT8,
+		SIMPLECOLUMN_UINT1,
+		SIMPLECOLUMN_UINT2,
+		SIMPLECOLUMN_UINT4,
+		SIMPLECOLUMN_UINT8,
+		SIMPLECOLUMN_DECIMAL1,
+		SIMPLECOLUMN_DECIMAL2,
+		SIMPLECOLUMN_DECIMAL4,
+		SIMPLECOLUMN_DECIMAL8,
+
+		FILTER,
+		CONDITIONFILTER,
+		EXISTSFILTER,
+		SELECTFILTER,
+		SIMPLEFILTER,
+		SIMPLESCALARFILTER,
+
+		OPERATOR,
+		ARITHMETICOPERATOR,
+		PREDICATEOPERATOR,
+		LOGICOPERATOR,
+
+		/**** /TreeNodes */
+
+		PARSETREE,
+		CALPONTSELECTEXECUTIONPLAN,
+		CONSTANTFILTER,
+		OUTERJOINONFILTER,
+	};
+
+	typedef uint8_t id_t;    //expand as necessary
+
+	/** @brief Creates a new TreeNode object from the ByteStream
+	 *
+	 * @param b The ByteStream to create it from
+	 * @return A newly allocated TreeNode
+	 */
+	static TreeNode* createTreeNode(messageqcpp::ByteStream& b);
+
+	/** @brief Creates a new ParseTree from the ByteStream
+	 *
+	 * @param b The ByteStream to create it from
+	 * @return A newly allocated ParseTree
+	 */
+	static ParseTree* createParseTree(messageqcpp::ByteStream& b);
+
+	/** @brief Creates a new CalpontExecutionPlan from the ByteStream
+	 *
+	 * @param b The ByteStream to create it from
+	 * @return A newly allocated CalpontExecutionPlan
+	 */
+	static CalpontExecutionPlan* createExecutionPlan(messageqcpp::ByteStream& b);
+
+	/** @brief Serialize() for ParseTrees
+	 *
+	 * This function effectively serializes a ParseTree.
+	 * @param tree The ParseTree to write out
+	 * @param b The ByteStream to write tree to
+	 */
+	static void writeParseTree(const ParseTree* tree,
+				   messageqcpp::ByteStream& b);
+
+	/** @brief Verify the type of the next object in the ByteStream
+	 *
+	 * @param b The ByteStream to read from
+	 * @param type The type it should be
+	 * @throw UnserializeException if the type does not match; this is a fatal error.
+	 */
+	static void checkType(messageqcpp::ByteStream &b, const CLASSID type);
+};
+
+}
+#endif // EXECPLAN_OBJECTREADER_H
+