You've already forked mariadb-columnstore-engine
							
							
				mirror of
				https://github.com/mariadb-corporation/mariadb-columnstore-engine.git
				synced 2025-10-31 18:30:33 +03:00 
			
		
		
		
	
		
			
				
	
	
		
			307 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			307 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /* Copyright (C) 2014 InfiniDB, Inc.
 | |
|    Copyright (c) 2019 MariaDB Corporation
 | |
| 
 | |
|    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. */
 | |
| 
 | |
| /***********************************************************************
 | |
|  *   $Id$
 | |
|  *
 | |
|  *
 | |
|  ***********************************************************************/
 | |
| 
 | |
| /**
 | |
|  * MariaDB ColumnStore interface for writing a user defined function (UDF).
 | |
|  *
 | |
|  * The basic steps are:
 | |
|  *
 | |
|  * 1. add the UDF function interface in udfsdk.h
 | |
|  * 2. add the UDF function implementation in udfsdk.cpp
 | |
|  * 3. add the connector stub for this UDF function in udfsdk.cpp
 | |
|  * 4. build the dynamic library libudfsdk
 | |
|  * 5. put the library in /usr/local/mariadb/columnstore/lib of all modules
 | |
|  * 6. restart MariaDB ColumnStore
 | |
|  * 7. Register the new functions with the commands like:
 | |
|  *
 | |
|  *    CREATE FUNCTION mcs_add returns REAL soname 'libudfsdk.so';
 | |
|  *    CREATE FUNCTION mcs_isnull returns BOOL soname 'libudfsdk.so';
 | |
|  *
 | |
|  * The UDF functions run distributedly in the ColumnStore engine. The evaluation
 | |
|  * is row by row. Aggregate UDF is currently not supported. Two examples are
 | |
|  * given in this file to demonstrate the steps that it takes to create a UDF
 | |
|  * function. More examples can be found in utils/funcexp/func_*.cpp.
 | |
|  */
 | |
| 
 | |
| #include "funcexp.h"
 | |
| #include "functor.h"
 | |
| 
 | |
| #define EXPORT
 | |
| 
 | |
| namespace udfsdk
 | |
| {
 | |
| /**
 | |
|  * UDFSDK interface. Do not make modification here.
 | |
|  */
 | |
| class UDFSDK
 | |
| {
 | |
|  public:
 | |
|   EXPORT UDFSDK();
 | |
| 
 | |
|   EXPORT ~UDFSDK();
 | |
| 
 | |
|   EXPORT funcexp::FuncMap UDFMap() const;
 | |
| 
 | |
|  protected:
 | |
|  private:
 | |
|   // defaults okay
 | |
|   // UDFSDK(const UDFSDK& rhs);
 | |
|   // UDFSDK& operator=(const UDFSDK& rhs);
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Example: MCS_add (args1, args2)
 | |
|  *
 | |
|  * MCS_add takes two arguments of any data type. It returns a double result.
 | |
|  *
 | |
|  * The function interface is defined here. All UDF functions are derived from
 | |
|  * class funcexp::Func. A set of getXXXval interface APIs are declared in the
 | |
|  * parent class Func, which will be called by IDB function and expression (F&E)
 | |
|  * framwork when evaluating the function. Which API to be called depends on
 | |
|  * the context of the function in the SQL query, i.e., the result type that
 | |
|  * the function is expected to return.
 | |
|  *
 | |
|  * For example, given the following two queries, different APIs will be called
 | |
|  * to evaluate the function MCS_add.
 | |
|  *
 | |
|  * select MCS_add(int1, int2) from t1;
 | |
|  * getDoubleVal() is called, because the result type of MCS_add is DOUBLE(real).
 | |
|  *
 | |
|  * select substr(string1, int1, MCS_add(int1+int2));
 | |
|  * getIntVal() will be called, because MCS_add() is passed as the third argument
 | |
|  * to substr function, and an integer result is expected.
 | |
|  *
 | |
|  * If one API is not implemented but called for a function, MCS-5001 error will
 | |
|  * be returned.
 | |
|  */
 | |
| class MCS_add : public funcexp::Func
 | |
| {
 | |
|  public:
 | |
|   /*
 | |
|    * Constructor. Pass the function name to the base constructor.
 | |
|    */
 | |
|   MCS_add() : Func("mcs_add")
 | |
|   {
 | |
|   }
 | |
| 
 | |
|   /*
 | |
|    * Destructor. MCS_add does not need to do anything here to clean up.
 | |
|    */
 | |
|   ~MCS_add() override = default;
 | |
| 
 | |
|   /**
 | |
|    * Decide on the function's operation type
 | |
|    *
 | |
|    * Operation type decides which API needs to be called for each function
 | |
|    * parameter. Sometimes it is obvious. e.g. for function substr (c1, c2, c3),
 | |
|    * one knows that getStrVal(), getIntVal() and getIntVal() should be called for
 | |
|    * the three parameters in sequence. In that case, a dummy type can be returned
 | |
|    * because it won't be used in the function implementation. Sometimes the
 | |
|    * operation type is decided by the data type of the function parameters.
 | |
|    * e.g., isnull(c1) function, one should call the corresponding getXXXval()
 | |
|    * function that in compatible with the result type of c1.
 | |
|    *
 | |
|    * @parm fp vector of function parameters
 | |
|    *       Each element is a boost::shared_ptr of execplan::ParseTree. class
 | |
|    *       ParseTree is defined in ~/dbcon/execplan/parsetree.h
 | |
|    * @parm resultType result type of this function
 | |
|    *       Sometimes it may affect the operation type, but most of the time it
 | |
|    *       can be ignored. Struct ColType is defined in ~/dbcon/execplan/calpontsystemcatalog.h
 | |
|    * @return operation type for this function
 | |
|    *
 | |
|    * This function is called only one from the connector. Once it's determined, it
 | |
|    * will be passed to the getXXXval() APIs during function evaluation.
 | |
|    */
 | |
|   execplan::CalpontSystemCatalog::ColType operationType(
 | |
|       funcexp::FunctionParm& fp, execplan::CalpontSystemCatalog::ColType& resultType) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns an integer result of this function.
 | |
|    * All the getXXXvalue APIs take the same arguments. They will be called
 | |
|    * for every row in the result set when the function is being evaluated.
 | |
|    * So these functions needs to be efficient.
 | |
|    *
 | |
|    * @parm row reference of the current row
 | |
|    * @parm fp function parameters
 | |
|    * @parm isNull NULL indicator throughout this function evaluation.
 | |
|    *       the same reference is passed to all the function argument
 | |
|    *       evaluations. One always need to know if any argument is NULL
 | |
|    *       to decide the result of the function. It's explained in detail
 | |
|    *       in MCS_isnull() function example.
 | |
|    * @parm op_ct the operation type that is determined in operationType().
 | |
|    *
 | |
|    */
 | |
|   int64_t getIntVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                     execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a double result of this function.
 | |
|    */
 | |
| 
 | |
|   double getDoubleVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                       execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a long double result of this function.
 | |
|    */
 | |
| 
 | |
|   long double getLongDoubleVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                                execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
|   /**
 | |
|    * Returns a float result of this function.
 | |
|    */
 | |
|   float getFloatVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                     execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a string result of this function.
 | |
|    */
 | |
|   std::string getStrVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                         execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a bool result of this function.
 | |
|    */
 | |
|   bool getBoolVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                   execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a decimal result of this function.
 | |
|    *
 | |
|    * IDB_Decimal is defined in ~/execplan/treenode.h
 | |
|    */
 | |
|   execplan::IDB_Decimal getDecimalVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                                       execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns an integer representation of a date result of the function.
 | |
|    *
 | |
|    * Check the date/time functions in ~/utils/funcexp for implementation
 | |
|    * example of this API.
 | |
|    */
 | |
|   int32_t getDateIntVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                         execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns an integer representation of a datetime result of the function.
 | |
|    *
 | |
|    * Check the date/time functions in ~/utils/funcexp for implementation
 | |
|    * example of this API.
 | |
|    */
 | |
|   int64_t getDatetimeIntVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                             execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Example: MCS_isnull(arg1)
 | |
|  *
 | |
|  * The purpose of this example is to demostrate the NULL handling in the UDF interface
 | |
|  */
 | |
| class MCS_isnull : public funcexp::Func
 | |
| {
 | |
|  public:
 | |
|   /*
 | |
|    * Constructor. Pass the function name to the base constructor.
 | |
|    */
 | |
|   MCS_isnull() : Func("mcs_isnull")
 | |
|   {
 | |
|   }
 | |
| 
 | |
|   /*
 | |
|    * Destructor. MCS_add does not need to do anything here to clean up.
 | |
|    */
 | |
|   ~MCS_isnull() override = default;
 | |
| 
 | |
|   /**
 | |
|    * Decide on the function's operation type
 | |
|    */
 | |
|   execplan::CalpontSystemCatalog::ColType operationType(
 | |
|       funcexp::FunctionParm& fp, execplan::CalpontSystemCatalog::ColType& resultType) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns an integer result of this function.
 | |
|    */
 | |
|   int64_t getIntVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                     execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a double result of this function.
 | |
|    */
 | |
|   double getDoubleVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                       execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a double result of this function.
 | |
|    */
 | |
|   long double getLongDoubleVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                                execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a float result of this function.
 | |
|    */
 | |
|   float getFloatVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                     execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a string result of this function.
 | |
|    */
 | |
|   std::string getStrVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                         execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a bool result of this function.
 | |
|    */
 | |
|   bool getBoolVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                   execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns a decimal result of this function.
 | |
|    *
 | |
|    * IDB_Decimal is defined in ~/execplan/treenode.h
 | |
|    */
 | |
|   execplan::IDB_Decimal getDecimalVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                                       execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns an integer representation of a date result of the function.
 | |
|    *
 | |
|    * Check the date/time functions in ~/utils/funcexp for implementation
 | |
|    * example of this API.
 | |
|    */
 | |
|   int32_t getDateIntVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                         execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| 
 | |
|   /**
 | |
|    * Returns an integer representation of a datetime result of the function.
 | |
|    *
 | |
|    * Check the date/time functions in ~/utils/funcexp for implementation
 | |
|    * example of this API.
 | |
|    */
 | |
|   int64_t getDatetimeIntVal(rowgroup::Row& row, funcexp::FunctionParm& fp, bool& isNull,
 | |
|                             execplan::CalpontSystemCatalog::ColType& op_ct) override;
 | |
| };
 | |
| 
 | |
| }  // namespace udfsdk
 | |
| 
 | |
| #undef EXPORT |