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)
static TupleTableSlot *	ExecForeignScan (PlanState *pstate)
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	ExecForeignScanReInitializeDSM (ForeignScanState *node, ParallelContext *pcxt)
void	ExecForeignScanInitializeWorker (ForeignScanState *node, ParallelWorkerContext *pwcxt)
void	ExecShutdownForeignScan (ForeignScanState *node)
void	ExecAsyncForeignScanRequest (AsyncRequest *areq)
void	ExecAsyncForeignScanConfigureWait (AsyncRequest *areq)
void	ExecAsyncForeignScanNotify (AsyncRequest *areq)

Function Documentation

ExecAsyncForeignScanConfigureWait()

void ExecAsyncForeignScanConfigureWait

(

AsyncRequest *

areq

)

Definition at line 462 of file nodeForeignscan.c.

References Assert, ForeignScanState::fdwroutine, and AsyncRequest::requestee.

Referenced by ExecAsyncConfigureWait().

{
    ForeignScanState *node = (ForeignScanState *) areq->requestee;
    FdwRoutine *fdwroutine = node->fdwroutine;

    Assert(fdwroutine->ForeignAsyncConfigureWait != NULL);
    fdwroutine->ForeignAsyncConfigureWait(areq);
}

ExecAsyncForeignScanNotify()

void ExecAsyncForeignScanNotify

(

AsyncRequest *

areq

)

Definition at line 478 of file nodeForeignscan.c.

References Assert, ForeignScanState::fdwroutine, and AsyncRequest::requestee.

Referenced by ExecAsyncNotify().

{
    ForeignScanState *node = (ForeignScanState *) areq->requestee;
    FdwRoutine *fdwroutine = node->fdwroutine;

    Assert(fdwroutine->ForeignAsyncNotify != NULL);
    fdwroutine->ForeignAsyncNotify(areq);
}

ExecAsyncForeignScanRequest()

void ExecAsyncForeignScanRequest

(

AsyncRequest *

areq

)

Definition at line 446 of file nodeForeignscan.c.

References Assert, ForeignScanState::fdwroutine, and AsyncRequest::requestee.

Referenced by ExecAsyncRequest().

{
    ForeignScanState *node = (ForeignScanState *) areq->requestee;
    FdwRoutine *fdwroutine = node->fdwroutine;

    Assert(fdwroutine->ForeignAsyncRequest != NULL);
    fdwroutine->ForeignAsyncRequest(areq);
}

ExecEndForeignScan()

void ExecEndForeignScan

(

ForeignScanState *

node

)

Definition at line 288 of file nodeForeignscan.c.

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

Referenced by ExecEndNode().

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

    /* Let the FDW shut down */
    if (plan->operation != CMD_SELECT)
    {
        if (estate->es_epq_active == NULL)
            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 */
    if (node->ss.ps.ps_ResultTupleSlot)
        ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
    ExecClearTuple(node->ss.ss_ScanTupleSlot);
}

ExecForeignScan()

static TupleTableSlot* ExecForeignScan ( PlanState *  pstate )

static

Definition at line 121 of file nodeForeignscan.c.

References castNode, ExecScan(), ForeignNext(), ForeignRecheck(), and ForeignScanState::ss.

Referenced by ExecInitForeignScan().

{
    ForeignScanState *node = castNode(ForeignScanState, pstate);

    return ExecScan(&node->ss,
                    (ExecScanAccessMtd) ForeignNext,
                    (ExecScanRecheckMtd) ForeignRecheck);
}

ExecForeignScanEstimate()

void ExecForeignScanEstimate	(	ForeignScanState *	node,
		ParallelContext *	pcxt
	)

Definition at line 346 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);
    }
}

ExecForeignScanInitializeDSM()

void ExecForeignScanInitializeDSM	(	ForeignScanState *	node,
		ParallelContext *	pcxt
	)

Definition at line 365 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);
    }
}

ExecForeignScanInitializeWorker()

void ExecForeignScanInitializeWorker	(	ForeignScanState *	node,
		ParallelWorkerContext *	pwcxt
	)

Definition at line 408 of file nodeForeignscan.c.

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

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

ExecForeignScanReInitializeDSM()

void ExecForeignScanReInitializeDSM	(	ForeignScanState *	node,
		ParallelContext *	pcxt
	)

Definition at line 387 of file nodeForeignscan.c.

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

Referenced by ExecParallelReInitializeDSM().

{
    FdwRoutine *fdwroutine = node->fdwroutine;

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

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

ExecInitForeignScan()

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

Definition at line 136 of file nodeForeignscan.c.

References Assert, PlanState::async_capable, FdwRoutine::BeginDirectModify, FdwRoutine::BeginForeignScan, CMD_SELECT, CreateTupleDescCopy(), elog, ERROR, EState::es_epq_active, EState::es_result_relations, EXEC_FLAG_BACKWARD, EXEC_FLAG_MARK, ExecAssignExprContext(), ExecAssignScanProjectionInfoWithVarno(), ExecForeignScan(), ExecInitNode(), ExecInitQual(), ExecInitResultTypeTL(), ExecInitScanTupleSlot(), ExecOpenScanRelation(), PlanState::ExecProcNode, ExecTypeFromTL(), ForeignScan::fdw_recheck_quals, ForeignScan::fdw_scan_tlist, ForeignScan::fs_server, GetFdwRoutineByServerId(), GetFdwRoutineForRelation(), INDEX_VAR, makeNode, NIL, ForeignScan::operation, outerPlan, outerPlanState, Scan::plan, PlanState::plan, ScanState::ps, Plan::qual, PlanState::qual, RelationGetDescr, ForeignScan::resultRelation, ForeignScan::scan, PlanState::scanopsfixed, PlanState::scanopsset, Scan::scanrelid, ForeignScanState::ss, ScanState::ss_currentRelation, PlanState::state, and TTSOpsHeapTuple.

Referenced by ExecInitNode().

{
    ForeignScanState *scanstate;
    Relation    currentRelation = NULL;
    Index       scanrelid = node->scan.scanrelid;
    int         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;
    scanstate->ss.ps.ExecProcNode = ExecForeignScan;

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

    /*
     * open the scan relation, if any; 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);
        ExecInitScanTupleSlot(estate, &scanstate->ss, scan_tupdesc,
                              &TTSOpsHeapTuple);
        /* Node's targetlist will contain Vars with varno = INDEX_VAR */
        tlistvarno = INDEX_VAR;
    }
    else
    {
        TupleDesc   scan_tupdesc;

        /* don't trust FDWs to return tuples fulfilling NOT NULL constraints */
        scan_tupdesc = CreateTupleDescCopy(RelationGetDescr(currentRelation));
        ExecInitScanTupleSlot(estate, &scanstate->ss, scan_tupdesc,
                              &TTSOpsHeapTuple);
        /* Node's targetlist will contain Vars with varno = scanrelid */
        tlistvarno = scanrelid;
    }

    /* Don't know what an FDW might return */
    scanstate->ss.ps.scanopsfixed = false;
    scanstate->ss.ps.scanopsset = true;

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

    /*
     * 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);

    /*
     * Determine whether to scan the foreign relation asynchronously or not;
     * this has to be kept in sync with the code in ExecInitAppend().
     */
    scanstate->ss.ps.async_capable = (((Plan *) node)->async_capable &&
                                      estate->es_epq_active == NULL);

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

    /*
     * For the FDW's convenience, look up the modification target relation's
     * ResultRelInfo.  The ModifyTable node should have initialized it for us,
     * see ExecInitModifyTable.
     *
     * Don't try to look up the ResultRelInfo when EvalPlanQual is active,
     * though.  Direct modififications cannot be re-evaluated as part of
     * EvalPlanQual.  The lookup wouldn't work anyway because during
     * EvalPlanQual processing, EvalPlanQual only initializes the subtree
     * under the ModifyTable, and doesn't run ExecInitModifyTable.
     */
    if (node->resultRelation > 0 && estate->es_epq_active == NULL)
    {
        if (estate->es_result_relations == NULL ||
            estate->es_result_relations[node->resultRelation - 1] == NULL)
        {
            elog(ERROR, "result relation not initialized");
        }
        scanstate->resultRelInfo = estate->es_result_relations[node->resultRelation - 1];
    }

    /* 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)
    {
        /*
         * Direct modifications cannot be re-evaluated by EvalPlanQual, so
         * don't bother preparing the FDW.  There can be ForeignScan nodes in
         * the EvalPlanQual subtree, but ExecForeignScan should never be
         * called on them when EvalPlanQual is active.
         */
        if (estate->es_epq_active == NULL)
            fdwroutine->BeginDirectModify(scanstate, eflags);
    }
    else
        fdwroutine->BeginForeignScan(scanstate, eflags);

    return scanstate;
}

ExecReScanForeignScan()

void ExecReScanForeignScan

(

ForeignScanState *

node

)

Definition at line 322 of file nodeForeignscan.c.

References PlanState::chgParam, ExecReScan(), ExecScanReScan(), ForeignScanState::fdwroutine, 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);
}

ExecShutdownForeignScan()

void ExecShutdownForeignScan

(

ForeignScanState *

node

)

Definition at line 431 of file nodeForeignscan.c.

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

Referenced by ExecShutdownNode().

{
    FdwRoutine *fdwroutine = node->fdwroutine;

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

ForeignNext()

static TupleTableSlot * ForeignNext ( ForeignScanState *  node )

static

Definition at line 42 of file nodeForeignscan.c.

References CMD_SELECT, elog, ERROR, ForeignScanState::fdwroutine, ForeignScan::fsSystemCol, FdwRoutine::IterateDirectModify, FdwRoutine::IterateForeignScan, MemoryContextSwitchTo(), ForeignScan::operation, PlanState::plan, ScanState::ps, PlanState::ps_ExprContext, RelationGetRelid, ForeignScanState::ss, ScanState::ss_currentRelation, PlanState::state, TupleTableSlot::tts_tableOid, and TupIsNull.

Referenced by ExecForeignScan().

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

    /* Call the Iterate function in short-lived context */
    oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
    if (plan->operation != CMD_SELECT)
    {
        /*
         * direct modifications cannot be re-evaluated, so shouldn't get here
         * during EvalPlanQual processing
         */
        if (estate->es_epq_active != NULL)
            elog(ERROR, "cannot re-evaluate a Foreign Update or Delete during EvalPlanQual");

        slot = node->fdwroutine->IterateDirectModify(node);
    }
    else
        slot = node->fdwroutine->IterateForeignScan(node);
    MemoryContextSwitchTo(oldcontext);

    /*
     * Insert valid value into tableoid, the only actually-useful system
     * column.
     */
    if (plan->fsSystemCol && !TupIsNull(slot))
        slot->tts_tableOid = RelationGetRelid(node->ss.ss_currentRelation);

    return slot;
}

ForeignRecheck()

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

static

Definition at line 81 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);
}