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/* ------------------------------------------------------------------------
*
* nodeCustom.c
* Routines to handle execution of custom scan node
*
* Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* ------------------------------------------------------------------------
*/
#include "postgres.h"
#include "executor/executor.h"
#include "executor/nodeCustom.h"
#include "nodes/execnodes.h"
#include "nodes/plannodes.h"
#include "parser/parsetree.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
#include "utils/rel.h"
CustomScanState *
ExecInitCustomScan(CustomScan *cscan, EState *estate, int eflags)
{
CustomScanState *css;
Relation scan_rel;
/* populate a CustomScanState according to the CustomScan */
css = (CustomScanState *) cscan->methods->CreateCustomScanState(cscan);
Assert(IsA(css, CustomScanState));
/* fill up fields of ScanState */
css->ss.ps.plan = &cscan->scan.plan;
css->ss.ps.state = estate;
/* create expression context for node */
ExecAssignExprContext(estate, &css->ss.ps);
/* initialize child expressions */
css->ss.ps.targetlist = (List *)
ExecInitExpr((Expr *) cscan->scan.plan.targetlist,
(PlanState *) css);
css->ss.ps.qual = (List *)
ExecInitExpr((Expr *) cscan->scan.plan.qual,
(PlanState *) css);
/* tuple table initialization */
ExecInitScanTupleSlot(estate, &css->ss);
ExecInitResultTupleSlot(estate, &css->ss.ps);
/* initialize scan relation */
scan_rel = ExecOpenScanRelation(estate, cscan->scan.scanrelid, eflags);
css->ss.ss_currentRelation = scan_rel;
css->ss.ss_currentScanDesc = NULL; /* set by provider */
ExecAssignScanType(&css->ss, RelationGetDescr(scan_rel));
css->ss.ps.ps_TupFromTlist = false;
/*
* Initialize result tuple type and projection info.
*/
ExecAssignResultTypeFromTL(&css->ss.ps);
ExecAssignScanProjectionInfo(&css->ss);
/*
* The callback of custom-scan provider applies the final initialization
* of the custom-scan-state node according to its logic.
*/
css->methods->BeginCustomScan(css, estate, eflags);
return css;
}
TupleTableSlot *
ExecCustomScan(CustomScanState *node)
{
Assert(node->methods->ExecCustomScan != NULL);
return node->methods->ExecCustomScan(node);
}
void
ExecEndCustomScan(CustomScanState *node)
{
Assert(node->methods->EndCustomScan != NULL);
node->methods->EndCustomScan(node);
/* Free the exprcontext */
ExecFreeExprContext(&node->ss.ps);
/* Clean out the tuple table */
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
if (node->ss.ss_ScanTupleSlot)
ExecClearTuple(node->ss.ss_ScanTupleSlot);
/* Close the heap relation */
ExecCloseScanRelation(node->ss.ss_currentRelation);
}
void
ExecReScanCustomScan(CustomScanState *node)
{
Assert(node->methods->ReScanCustomScan != NULL);
node->methods->ReScanCustomScan(node);
}
void
ExecCustomMarkPos(CustomScanState *node)
{
if (!node->methods->MarkPosCustomScan)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("custom-scan \"%s\" does not support MarkPos",
node->methods->CustomName)));
node->methods->MarkPosCustomScan(node);
}
void
ExecCustomRestrPos(CustomScanState *node)
{
if (!node->methods->RestrPosCustomScan)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("custom-scan \"%s\" does not support MarkPos",
node->methods->CustomName)));
node->methods->RestrPosCustomScan(node);
}
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