nodeForeignscan.c File Reference

#include "postgres.h"
#include "executor/executor.h"
#include "executor/nodeForeignscan.h"
#include "foreign/fdwapi.h"
#include "utils/memutils.h"
#include "utils/rel.h"

Include dependency graph for nodeForeignscan.c:

Go to the source code of this file.

Functions
static TupleTableSlot *	ForeignNext (ForeignScanState *node)
static bool	ForeignRecheck (ForeignScanState *node, TupleTableSlot *slot)
TupleTableSlot *	ExecForeignScan (ForeignScanState *node)
ForeignScanState *	ExecInitForeignScan (ForeignScan *node, EState *estate, int eflags)
void	ExecEndForeignScan (ForeignScanState *node)
void	ExecReScanForeignScan (ForeignScanState *node)
void	ExecForeignScanEstimate (ForeignScanState *node, ParallelContext *pcxt)
void	ExecForeignScanInitializeDSM (ForeignScanState *node, ParallelContext *pcxt)
void	ExecForeignScanInitializeWorker (ForeignScanState *node, shm_toc *toc)
void	ExecShutdownForeignScan (ForeignScanState *node)

Function Documentation

void ExecEndForeignScan

(

ForeignScanState *

node

)

Definition at line 240 of file nodeForeignscan.c.

References CMD_SELECT, FdwRoutine::EndDirectModify, FdwRoutine::EndForeignScan, ExecClearTuple(), ExecCloseScanRelation(), ExecEndNode(), ExecFreeExprContext(), ForeignScanState::fdwroutine, ForeignScan::operation, outerPlanState, PlanState::plan, ScanState::ps, PlanState::ps_ResultTupleSlot, ForeignScanState::ss, ScanState::ss_currentRelation, and ScanState::ss_ScanTupleSlot.

Referenced by ExecEndNode().

{
    ForeignScan *plan = (ForeignScan *) node->ss.ps.plan;

    /* Let the FDW shut down */
    if (plan->operation != CMD_SELECT)
        node->fdwroutine->EndDirectModify(node);
    else
        node->fdwroutine->EndForeignScan(node);

    /* Shut down any outer plan. */
    if (outerPlanState(node))
        ExecEndNode(outerPlanState(node));

    /* Free the exprcontext */
    ExecFreeExprContext(&node->ss.ps);

    /* clean out the tuple table */
    ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
    ExecClearTuple(node->ss.ss_ScanTupleSlot);

    /* close the relation. */
    if (node->ss.ss_currentRelation)
        ExecCloseScanRelation(node->ss.ss_currentRelation);
}

TupleTableSlot* ExecForeignScan

(

ForeignScanState *

node

)

Definition at line 117 of file nodeForeignscan.c.

References ExecScan(), ForeignNext(), and ForeignRecheck().

Referenced by ExecProcNode().

{
    return ExecScan((ScanState *) node,
                    (ExecScanAccessMtd) ForeignNext,
                    (ExecScanRecheckMtd) ForeignRecheck);
}

void ExecForeignScanEstimate	(	ForeignScanState *	node,
		ParallelContext *	pcxt
	)

Definition at line 297 of file nodeForeignscan.c.

References FdwRoutine::EstimateDSMForeignScan, ParallelContext::estimator, ForeignScanState::fdwroutine, ForeignScanState::pscan_len, shm_toc_estimate_chunk, and shm_toc_estimate_keys.

Referenced by ExecParallelEstimate().

{
    FdwRoutine *fdwroutine = node->fdwroutine;

    if (fdwroutine->EstimateDSMForeignScan)
    {
        node->pscan_len = fdwroutine->EstimateDSMForeignScan(node, pcxt);
        shm_toc_estimate_chunk(&pcxt->estimator, node->pscan_len);
        shm_toc_estimate_keys(&pcxt->estimator, 1);
    }
}

void ExecForeignScanInitializeDSM	(	ForeignScanState *	node,
		ParallelContext *	pcxt
	)

Definition at line 316 of file nodeForeignscan.c.

References ForeignScanState::fdwroutine, FdwRoutine::InitializeDSMForeignScan, PlanState::plan, Plan::plan_node_id, ScanState::ps, ForeignScanState::pscan_len, shm_toc_allocate(), shm_toc_insert(), ForeignScanState::ss, and ParallelContext::toc.

Referenced by ExecParallelInitializeDSM().

{
    FdwRoutine *fdwroutine = node->fdwroutine;

    if (fdwroutine->InitializeDSMForeignScan)
    {
        int         plan_node_id = node->ss.ps.plan->plan_node_id;
        void       *coordinate;

        coordinate = shm_toc_allocate(pcxt->toc, node->pscan_len);
        fdwroutine->InitializeDSMForeignScan(node, pcxt, coordinate);
        shm_toc_insert(pcxt->toc, plan_node_id, coordinate);
    }
}

void ExecForeignScanInitializeWorker	(	ForeignScanState *	node,
		shm_toc *	toc
	)

Definition at line 338 of file nodeForeignscan.c.

References ForeignScanState::fdwroutine, FdwRoutine::InitializeWorkerForeignScan, PlanState::plan, Plan::plan_node_id, ScanState::ps, shm_toc_lookup(), and ForeignScanState::ss.

Referenced by ExecParallelInitializeWorker().

{
    FdwRoutine *fdwroutine = node->fdwroutine;

    if (fdwroutine->InitializeWorkerForeignScan)
    {
        int         plan_node_id = node->ss.ps.plan->plan_node_id;
        void       *coordinate;

        coordinate = shm_toc_lookup(toc, plan_node_id, false);
        fdwroutine->InitializeWorkerForeignScan(node, toc, coordinate);
    }
}

ForeignScanState* ExecInitForeignScan	(	ForeignScan *	node,
		EState *	estate,
		int	eflags
	)

Definition at line 130 of file nodeForeignscan.c.

References Assert, FdwRoutine::BeginDirectModify, FdwRoutine::BeginForeignScan, CMD_SELECT, EXEC_FLAG_BACKWARD, EXEC_FLAG_MARK, ExecAssignExprContext(), ExecAssignResultTypeFromTL(), ExecAssignScanProjectionInfoWithVarno(), ExecAssignScanType(), ExecInitNode(), ExecInitQual(), ExecInitResultTupleSlot(), ExecInitScanTupleSlot(), ExecOpenScanRelation(), ExecTypeFromTL(), ForeignScan::fdw_recheck_quals, ForeignScanState::fdw_recheck_quals, ForeignScan::fdw_scan_tlist, ForeignScanState::fdw_state, ForeignScanState::fdwroutine, ForeignScan::fs_server, GetFdwRoutineByServerId(), GetFdwRoutineForRelation(), INDEX_VAR, makeNode, NIL, NULL, ForeignScan::operation, outerPlan, outerPlanState, Scan::plan, PlanState::plan, ScanState::ps, Plan::qual, PlanState::qual, RelationGetDescr, ForeignScan::scan, Scan::scanrelid, ForeignScanState::ss, ScanState::ss_currentRelation, and PlanState::state.

Referenced by ExecInitNode().

{
    ForeignScanState *scanstate;
    Relation    currentRelation = NULL;
    Index       scanrelid = node->scan.scanrelid;
    Index       tlistvarno;
    FdwRoutine *fdwroutine;

    /* check for unsupported flags */
    Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));

    /*
     * create state structure
     */
    scanstate = makeNode(ForeignScanState);
    scanstate->ss.ps.plan = (Plan *) node;
    scanstate->ss.ps.state = estate;

    /*
     * Miscellaneous initialization
     *
     * create expression context for node
     */
    ExecAssignExprContext(estate, &scanstate->ss.ps);

    /*
     * initialize child expressions
     */
    scanstate->ss.ps.qual =
        ExecInitQual(node->scan.plan.qual, (PlanState *) scanstate);
    scanstate->fdw_recheck_quals =
        ExecInitQual(node->fdw_recheck_quals, (PlanState *) scanstate);

    /*
     * tuple table initialization
     */
    ExecInitResultTupleSlot(estate, &scanstate->ss.ps);
    ExecInitScanTupleSlot(estate, &scanstate->ss);

    /*
     * open the base relation, if any, and acquire an appropriate lock on it;
     * also acquire function pointers from the FDW's handler
     */
    if (scanrelid > 0)
    {
        currentRelation = ExecOpenScanRelation(estate, scanrelid, eflags);
        scanstate->ss.ss_currentRelation = currentRelation;
        fdwroutine = GetFdwRoutineForRelation(currentRelation, true);
    }
    else
    {
        /* We can't use the relcache, so get fdwroutine the hard way */
        fdwroutine = GetFdwRoutineByServerId(node->fs_server);
    }

    /*
     * Determine the scan tuple type.  If the FDW provided a targetlist
     * describing the scan tuples, use that; else use base relation's rowtype.
     */
    if (node->fdw_scan_tlist != NIL || currentRelation == NULL)
    {
        TupleDesc   scan_tupdesc;

        scan_tupdesc = ExecTypeFromTL(node->fdw_scan_tlist, false);
        ExecAssignScanType(&scanstate->ss, scan_tupdesc);
        /* Node's targetlist will contain Vars with varno = INDEX_VAR */
        tlistvarno = INDEX_VAR;
    }
    else
    {
        ExecAssignScanType(&scanstate->ss, RelationGetDescr(currentRelation));
        /* Node's targetlist will contain Vars with varno = scanrelid */
        tlistvarno = scanrelid;
    }

    /*
     * Initialize result tuple type and projection info.
     */
    ExecAssignResultTypeFromTL(&scanstate->ss.ps);
    ExecAssignScanProjectionInfoWithVarno(&scanstate->ss, tlistvarno);

    /*
     * Initialize FDW-related state.
     */
    scanstate->fdwroutine = fdwroutine;
    scanstate->fdw_state = NULL;

    /* Initialize any outer plan. */
    if (outerPlan(node))
        outerPlanState(scanstate) =
            ExecInitNode(outerPlan(node), estate, eflags);

    /*
     * Tell the FDW to initialize the scan.
     */
    if (node->operation != CMD_SELECT)
        fdwroutine->BeginDirectModify(scanstate, eflags);
    else
        fdwroutine->BeginForeignScan(scanstate, eflags);

    return scanstate;
}

void ExecReScanForeignScan

(

ForeignScanState *

node

)

Definition at line 273 of file nodeForeignscan.c.

References PlanState::chgParam, ExecReScan(), ExecScanReScan(), ForeignScanState::fdwroutine, NULL, outerPlan, outerPlanState, FdwRoutine::ReScanForeignScan, and ForeignScanState::ss.

Referenced by ExecReScan().

{
    PlanState  *outerPlan = outerPlanState(node);

    node->fdwroutine->ReScanForeignScan(node);

    /*
     * If chgParam of subnode is not null then plan will be re-scanned by
     * first ExecProcNode.  outerPlan may also be NULL, in which case there is
     * nothing to rescan at all.
     */
    if (outerPlan != NULL && outerPlan->chgParam == NULL)
        ExecReScan(outerPlan);

    ExecScanReScan(&node->ss);
}

void ExecShutdownForeignScan

(

ForeignScanState *

node

)

Definition at line 360 of file nodeForeignscan.c.

References ForeignScanState::fdwroutine, and FdwRoutine::ShutdownForeignScan.

Referenced by ExecShutdownNode().

{
    FdwRoutine *fdwroutine = node->fdwroutine;

    if (fdwroutine->ShutdownForeignScan)
        fdwroutine->ShutdownForeignScan(node);
}

static TupleTableSlot * ForeignNext ( ForeignScanState *  node )

static

Definition at line 42 of file nodeForeignscan.c.

References CMD_SELECT, ExecMaterializeSlot(), ForeignScanState::fdwroutine, ForeignScan::fsSystemCol, FdwRoutine::IterateDirectModify, FdwRoutine::IterateForeignScan, MemoryContextSwitchTo(), ForeignScan::operation, PlanState::plan, ScanState::ps, PlanState::ps_ExprContext, RelationGetRelid, ForeignScanState::ss, ScanState::ss_currentRelation, HeapTupleData::t_tableOid, and TupIsNull.

Referenced by ExecForeignScan().

{
    TupleTableSlot *slot;
    ForeignScan *plan = (ForeignScan *) node->ss.ps.plan;
    ExprContext *econtext = node->ss.ps.ps_ExprContext;
    MemoryContext oldcontext;

    /* Call the Iterate function in short-lived context */
    oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
    if (plan->operation != CMD_SELECT)
        slot = node->fdwroutine->IterateDirectModify(node);
    else
        slot = node->fdwroutine->IterateForeignScan(node);
    MemoryContextSwitchTo(oldcontext);

    /*
     * If any system columns are requested, we have to force the tuple into
     * physical-tuple form to avoid "cannot extract system attribute from
     * virtual tuple" errors later.  We also insert a valid value for
     * tableoid, which is the only actually-useful system column.
     */
    if (plan->fsSystemCol && !TupIsNull(slot))
    {
        HeapTuple   tup = ExecMaterializeSlot(slot);

        tup->t_tableOid = RelationGetRelid(node->ss.ss_currentRelation);
    }

    return slot;
}

static bool ForeignRecheck ( ForeignScanState *  node, TupleTableSlot *  slot  )

static

Definition at line 77 of file nodeForeignscan.c.

References ExprContext::ecxt_scantuple, ExecQual(), ForeignScanState::fdw_recheck_quals, ForeignScanState::fdwroutine, ScanState::ps, PlanState::ps_ExprContext, FdwRoutine::RecheckForeignScan, ResetExprContext, and ForeignScanState::ss.

Referenced by ExecForeignScan().

{
    FdwRoutine *fdwroutine = node->fdwroutine;
    ExprContext *econtext;

    /*
     * extract necessary information from foreign scan node
     */
    econtext = node->ss.ps.ps_ExprContext;

    /* Does the tuple meet the remote qual condition? */
    econtext->ecxt_scantuple = slot;

    ResetExprContext(econtext);

    /*
     * If an outer join is pushed down, RecheckForeignScan may need to store a
     * different tuple in the slot, because a different set of columns may go
     * to NULL upon recheck.  Otherwise, it shouldn't need to change the slot
     * contents, just return true or false to indicate whether the quals still
     * pass.  For simple cases, setting fdw_recheck_quals may be easier than
     * providing this callback.
     */
    if (fdwroutine->RecheckForeignScan &&
        !fdwroutine->RecheckForeignScan(node, slot))
        return false;

    return ExecQual(node->fdw_recheck_quals, econtext);
}