text: /*-------------------------------------------------------------------------
   *
   * executor.h
   *	  support for the POSTGRES executor module
   *
   *
   * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
   * Portions Copyright (c) 1994, Regents of the University of California
   *
   * src/include/executor/executor.h
   *
   *-------------------------------------------------------------------------
   */
  #ifndef EXECUTOR_H
  #define EXECUTOR_H
  
  #include "executor/execdesc.h"
  #include "nodes/parsenodes.h"
  
  
  /*
   * The "eflags" argument to ExecutorStart and the various ExecInitNode
   * routines is a bitwise OR of the following flag bits, which tell the
   * called plan node what to expect.  Note that the flags will get modified
   * as they are passed down the plan tree, since an upper node may require
   * functionality in its subnode not demanded of the plan as a whole
   * (example: MergeJoin requires mark/restore capability in its inner input),
   * or an upper node may shield its input from some functionality requirement
   * (example: Materialize shields its input from needing to do backward scan).
   *
   * EXPLAIN_ONLY indicates that the plan tree is being initialized just so
   * EXPLAIN can print it out; it will not be run.  Hence, no side-effects
   * of startup should occur.  However, error checks (such as permission checks)
   * should be performed.
   *
   * REWIND indicates that the plan node should try to efficiently support
   * rescans without parameter changes.  (Nodes must support ExecReScan calls
   * in any case, but if this flag was not given, they are at liberty to do it
   * through complete recalculation.  Note that a parameter change forces a
   * full recalculation in any case.)
   *
   * BACKWARD indicates that the plan node must respect the es_direction flag.
   * When this is not passed, the plan node will only be run forwards.
   *
   * MARK indicates that the plan node must support Mark/Restore calls.
   * When this is not passed, no Mark/Restore will occur.
   *
   * SKIP_TRIGGERS tells ExecutorStart/ExecutorFinish to skip calling
   * AfterTriggerBeginQuery/AfterTriggerEndQuery.  This does not necessarily
   * mean that the plan can't queue any AFTER triggers; just that the caller
   * is responsible for there being a trigger context for them to be queued in.
   *
   * WITH/WITHOUT_OIDS tell the executor to emit tuples with or without space
   * for OIDs, respectively.  These are currently used only for CREATE TABLE AS.
   * If neither is set, the plan may or may not produce tuples including OIDs.
   */
  #define EXEC_FLAG_EXPLAIN_ONLY	0x0001	/* EXPLAIN, no ANALYZE */
  #define EXEC_FLAG_REWIND		0x0002	/* need efficient rescan */
  #define EXEC_FLAG_BACKWARD		0x0004	/* need backward scan */
  #define EXEC_FLAG_MARK			0x0008	/* need mark/restore */
  #define EXEC_FLAG_SKIP_TRIGGERS 0x0010	/* skip AfterTrigger calls */
  #define EXEC_FLAG_WITH_OIDS		0x0020	/* force OIDs in returned tuples */
  #define EXEC_FLAG_WITHOUT_OIDS	0x0040	/* force no OIDs in returned tuples */
  #define EXEC_FLAG_WITH_NO_DATA	0x0080	/* rel scannability doesn't matter */
  
  
  /*
   * ExecEvalExpr was formerly a function containing a switch statement;
   * now it's just a macro invoking the function pointed to by an ExprState
   * node.  Beware of double evaluation of the ExprState argument!
   */
  #define ExecEvalExpr(expr, econtext, isNull, isDone) \
  	((*(expr)->evalfunc) (expr, econtext, isNull, isDone))
  
  
  /* Hook for plugins to get control in ExecutorStart() */
  typedef void (*ExecutorStart_hook_type) (QueryDesc *queryDesc, int eflags);
  extern PGDLLIMPORT ExecutorStart_hook_type ExecutorStart_hook;
  
  /* Hook for plugins to get control in ExecutorRun() */
  typedef void (*ExecutorRun_hook_type) (QueryDesc *queryDesc,
  												   ScanDirection direction,
  												   uint64 count);
  extern PGDLLIMPORT ExecutorRun_hook_type ExecutorRun_hook;
  
  /* Hook for plugins to get control in ExecutorFinish() */
  typedef void (*ExecutorFinish_hook_type) (QueryDesc *queryDesc);
  extern PGDLLIMPORT ExecutorFinish_hook_type ExecutorFinish_hook;
  
  /* Hook for plugins to get control in ExecutorEnd() */
  typedef void (*ExecutorEnd_hook_type) (QueryDesc *queryDesc);
  extern PGDLLIMPORT ExecutorEnd_hook_type ExecutorEnd_hook;
  
  /* Hook for plugins to get control in ExecCheckRTPerms() */
  typedef bool (*ExecutorCheckPerms_hook_type) (List *, bool);
  extern PGDLLIMPORT ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook;
  
  
  /*
   * prototypes from functions in execAmi.c
   */
  struct Path;					/* avoid including relation.h here */
  
  extern void ExecReScan(PlanState *node);
  extern void ExecMarkPos(PlanState *node);
  extern void ExecRestrPos(PlanState *node);
  extern bool ExecSupportsMarkRestore(struct Path *pathnode);
  extern bool ExecSupportsBackwardScan(Plan *node);
  extern bool ExecMaterializesOutput(NodeTag plantype);
  
  /*
   * prototypes from functions in execCurrent.c
   */
  extern bool execCurrentOf(CurrentOfExpr *cexpr,
  			  ExprContext *econtext,
  			  Oid table_oid,
  			  ItemPointer current_tid);
  
  /*
   * prototypes from functions in execGrouping.c
   */
  extern bool execTuplesMatch(TupleTableSlot *slot1,
  				TupleTableSlot *slot2,
  				int numCols,
  				AttrNumber *matchColIdx,
  				FmgrInfo *eqfunctions,
  				MemoryContext evalContext);
  extern bool execTuplesUnequal(TupleTableSlot *slot1,
  				  TupleTableSlot *slot2,
  				  int numCols,
  				  AttrNumber *matchColIdx,
  				  FmgrInfo *eqfunctions,
  				  MemoryContext evalContext);
  extern FmgrInfo *execTuplesMatchPrepare(int numCols,
  					   Oid *eqOperators);
  extern void execTuplesHashPrepare(int numCols,
  					  Oid *eqOperators,
  					  FmgrInfo **eqFunctions,
  					  FmgrInfo **hashFunctions);
  extern TupleHashTable BuildTupleHashTable(int numCols, AttrNumber *keyColIdx,
  					FmgrInfo *eqfunctions,
  					FmgrInfo *hashfunctions,
  					long nbuckets, Size entrysize,
  					MemoryContext tablecxt,
  					MemoryContext tempcxt);
  extern TupleHashEntry LookupTupleHashEntry(TupleHashTable hashtable,
  					 TupleTableSlot *slot,
  					 bool *isnew);
  extern TupleHashEntry FindTupleHashEntry(TupleHashTable hashtable,
  				   TupleTableSlot *slot,
  				   FmgrInfo *eqfunctions,
  				   FmgrInfo *hashfunctions);
  
  /*
   * prototypes from functions in execJunk.c
   */
  extern JunkFilter *ExecInitJunkFilter(List *targetList, bool hasoid,
  				   TupleTableSlot *slot);
  extern JunkFilter *ExecInitJunkFilterConversion(List *targetList,
  							 TupleDesc cleanTupType,
  							 TupleTableSlot *slot);
  extern AttrNumber ExecFindJunkAttribute(JunkFilter *junkfilter,
  					  const char *attrName);
  extern AttrNumber ExecFindJunkAttributeInTlist(List *targetlist,
  							 const char *attrName);
  extern Datum ExecGetJunkAttribute(TupleTableSlot *slot, AttrNumber attno,
  					 bool *isNull);
  extern TupleTableSlot *ExecFilterJunk(JunkFilter *junkfilter,
  			   TupleTableSlot *slot);
  
  
  /*
   * prototypes from functions in execMain.c
   */
  extern void ExecutorStart(QueryDesc *queryDesc, int eflags);
  extern void standard_ExecutorStart(QueryDesc *queryDesc, int eflags);
  extern void ExecutorRun(QueryDesc *queryDesc,
  			ScanDirection direction, uint64 count);
  extern void standard_ExecutorRun(QueryDesc *queryDesc,
  					 ScanDirection direction, uint64 count);
  extern void ExecutorFinish(QueryDesc *queryDesc);
  extern void standard_ExecutorFinish(QueryDesc *queryDesc);
  extern void ExecutorEnd(QueryDesc *queryDesc);
  extern void standard_ExecutorEnd(QueryDesc *queryDesc);
  extern void ExecutorRewind(QueryDesc *queryDesc);
  extern bool ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation);
  extern void CheckValidResultRel(Relation resultRel, CmdType operation);
  extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
  				  Relation resultRelationDesc,
  				  Index resultRelationIndex,
  				  int instrument_options);
  extern ResultRelInfo *ExecGetTriggerResultRel(EState *estate, Oid relid);
  extern bool ExecContextForcesOids(PlanState *planstate, bool *hasoids);
  extern void ExecConstraints(ResultRelInfo *resultRelInfo,
  				TupleTableSlot *slot, EState *estate);
  extern void ExecWithCheckOptions(WCOKind kind, ResultRelInfo *resultRelInfo,
  					 TupleTableSlot *slot, EState *estate);
  extern LockTupleMode ExecUpdateLockMode(EState *estate, ResultRelInfo *relinfo);
  extern ExecRowMark *ExecFindRowMark(EState *estate, Index rti, bool missing_ok);
  extern ExecAuxRowMark *ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist);
  extern TupleTableSlot *EvalPlanQual(EState *estate, EPQState *epqstate,
  			 Relation relation, Index rti, int lockmode,
  			 ItemPointer tid, TransactionId priorXmax);
  extern HeapTuple EvalPlanQualFetch(EState *estate, Relation relation,
  				  int lockmode, LockWaitPolicy wait_policy, ItemPointer tid,
  				  TransactionId priorXmax);
  extern void EvalPlanQualInit(EPQState *epqstate, EState *estate,
  				 Plan *subplan, List *auxrowmarks, int epqParam);
  extern void EvalPlanQualSetPlan(EPQState *epqstate,
  					Plan *subplan, List *auxrowmarks);
  extern void EvalPlanQualSetTuple(EPQState *epqstate, Index rti,
  					 HeapTuple tuple);
  extern HeapTuple EvalPlanQualGetTuple(EPQState *epqstate, Index rti);
  
  #define EvalPlanQualSetSlot(epqstate, slot)  ((epqstate)->origslot = (slot))
  extern void EvalPlanQualFetchRowMarks(EPQState *epqstate);
  extern TupleTableSlot *EvalPlanQualNext(EPQState *epqstate);
  extern void EvalPlanQualBegin(EPQState *epqstate, EState *parentestate);
  extern void EvalPlanQualEnd(EPQState *epqstate);
  
  /*
   * prototypes from functions in execProcnode.c
   */
  extern PlanState *ExecInitNode(Plan *node, EState *estate, int eflags);
  extern TupleTableSlot *ExecProcNode(PlanState *node);
  extern Node *MultiExecProcNode(PlanState *node);
  extern void ExecEndNode(PlanState *node);
  extern bool ExecShutdownNode(PlanState *node);
  
  /*
   * prototypes from functions in execQual.c
   */
  extern Datum GetAttributeByNum(HeapTupleHeader tuple, AttrNumber attrno,
  				  bool *isNull);
  extern Datum GetAttributeByName(HeapTupleHeader tuple, const char *attname,
  				   bool *isNull);
  extern Tuplestorestate *ExecMakeTableFunctionResult(ExprState *funcexpr,
  							ExprContext *econtext,
  							MemoryContext argContext,
  							TupleDesc expectedDesc,
  							bool randomAccess);
  extern Datum ExecEvalExprSwitchContext(ExprState *expression, ExprContext *econtext,
  						  bool *isNull, ExprDoneCond *isDone);
  extern ExprState *ExecInitExpr(Expr *node, PlanState *parent);
  extern ExprState *ExecPrepareExpr(Expr *node, EState *estate);
  extern bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull);
  extern int	ExecTargetListLength(List *targetlist);
  extern int	ExecCleanTargetListLength(List *targetlist);
  extern TupleTableSlot *ExecProject(ProjectionInfo *projInfo,
  			ExprDoneCond *isDone);
  
  /*
   * prototypes from functions in execScan.c
   */
  typedef TupleTableSlot *(*ExecScanAccessMtd) (ScanState *node);
  typedef bool (*ExecScanRecheckMtd) (ScanState *node, TupleTableSlot *slot);
  
  extern TupleTableSlot *ExecScan(ScanState *node, ExecScanAccessMtd accessMtd,
  		 ExecScanRecheckMtd recheckMtd);
  extern void ExecAssignScanProjectionInfo(ScanState *node);
  extern void ExecAssignScanProjectionInfoWithVarno(ScanState *node, Index varno);
  extern void ExecScanReScan(ScanState *node);
  
  /*
   * prototypes from functions in execTuples.c
   */
  extern void ExecInitResultTupleSlot(EState *estate, PlanState *planstate);
  extern void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate);
  extern TupleTableSlot *ExecInitExtraTupleSlot(EState *estate);
  extern TupleTableSlot *ExecInitNullTupleSlot(EState *estate,
  					  TupleDesc tupType);
  extern TupleDesc ExecTypeFromTL(List *targetList, bool hasoid);
  extern TupleDesc ExecCleanTypeFromTL(List *targetList, bool hasoid);
  extern TupleDesc ExecTypeFromExprList(List *exprList);
  extern void ExecTypeSetColNames(TupleDesc typeInfo, List *namesList);
  extern void UpdateChangedParamSet(PlanState *node, Bitmapset *newchg);
  
  typedef struct TupOutputState
  {
  	TupleTableSlot *slot;
  	DestReceiver *dest;
  } TupOutputState;
  
  extern TupOutputState *begin_tup_output_tupdesc(DestReceiver *dest,
  						 TupleDesc tupdesc);
  extern void do_tup_output(TupOutputState *tstate, Datum *values, bool *isnull);
  extern void do_text_output_multiline(TupOutputState *tstate, char *text);
  extern void end_tup_output(TupOutputState *tstate);
  
  /*
   * Write a single line of text given as a C string.
   *
   * Should only be used with a single-TEXT-attribute tupdesc.
   */
  #define do_text_output_oneline(tstate, str_to_emit) \
  	do { \
  		Datum	values_[1]; \
  		bool	isnull_[1]; \
  		values_[0] = PointerGetDatum(cstring_to_text(str_to_emit)); \
  		isnull_[0] = false; \
  		do_tup_output(tstate, values_, isnull_); \
  		pfree(DatumGetPointer(values_[0])); \
  	} while (0)
  
  
  /*
   * prototypes from functions in execUtils.c
   */
  extern EState *CreateExecutorState(void);
  extern void FreeExecutorState(EState *estate);
  extern ExprContext *CreateExprContext(EState *estate);
  extern ExprContext *CreateStandaloneExprContext(void);
  extern void FreeExprContext(ExprContext *econtext, bool isCommit);
  extern void ReScanExprContext(ExprContext *econtext);
  
  #define ResetExprContext(econtext) \
  	MemoryContextReset((econtext)->ecxt_per_tuple_memory)
  
  extern ExprContext *MakePerTupleExprContext(EState *estate);
  
  /* Get an EState's per-output-tuple exprcontext, making it if first use */
  #define GetPerTupleExprContext(estate) \
  	((estate)->es_per_tuple_exprcontext ? \
  	 (estate)->es_per_tuple_exprcontext : \
  	 MakePerTupleExprContext(estate))
  
  #define GetPerTupleMemoryContext(estate) \
  	(GetPerTupleExprContext(estate)->ecxt_per_tuple_memory)
  
  /* Reset an EState's per-output-tuple exprcontext, if one's been created */
  #define ResetPerTupleExprContext(estate) \
  	do { \
  		if ((estate)->es_per_tuple_exprcontext) \
  			ResetExprContext((estate)->es_per_tuple_exprcontext); \
  	} while (0)
  
  extern void ExecAssignExprContext(EState *estate, PlanState *planstate);
  extern void ExecAssignResultType(PlanState *planstate, TupleDesc tupDesc);
  extern void ExecAssignResultTypeFromTL(PlanState *planstate);
  extern TupleDesc ExecGetResultType(PlanState *planstate);
  extern ProjectionInfo *ExecBuildProjectionInfo(List *targetList,
  						ExprContext *econtext,
  						TupleTableSlot *slot,
  						TupleDesc inputDesc);
  extern void ExecAssignProjectionInfo(PlanState *planstate,
  						 TupleDesc inputDesc);
  extern void ExecFreeExprContext(PlanState *planstate);
  extern void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc);
  extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);
  
  extern bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid);
  
  extern Relation ExecOpenScanRelation(EState *estate, Index scanrelid, int eflags);
  extern void ExecCloseScanRelation(Relation scanrel);
  
  extern void RegisterExprContextCallback(ExprContext *econtext,
  							ExprContextCallbackFunction function,
  							Datum arg);
  extern void UnregisterExprContextCallback(ExprContext *econtext,
  							  ExprContextCallbackFunction function,
  							  Datum arg);
  
  /*
   * prototypes from functions in execIndexing.c
   */
  extern void ExecOpenIndices(ResultRelInfo *resultRelInfo, bool speculative);
  extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
  extern List *ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
  					  EState *estate, bool noDupErr, bool *specConflict,
  					  List *arbiterIndexes);
  extern bool ExecCheckIndexConstraints(TupleTableSlot *slot, EState *estate,
  						  ItemPointer conflictTid, List *arbiterIndexes);
  extern void check_exclusion_constraint(Relation heap, Relation index,
  						   IndexInfo *indexInfo,
  						   ItemPointer tupleid,
  						   Datum *values, bool *isnull,
  						   EState *estate, bool newIndex);
  
  
  #endif   /* EXECUTOR_H  */
  