diff options
Diffstat (limited to 'src/backend/executor/nodeCustom.c')
| -rw-r--r-- | src/backend/executor/nodeCustom.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/src/backend/executor/nodeCustom.c b/src/backend/executor/nodeCustom.c new file mode 100644 index 0000000..c82060e --- /dev/null +++ b/src/backend/executor/nodeCustom.c @@ -0,0 +1,228 @@ +/* ------------------------------------------------------------------------ + * + * nodeCustom.c + * Routines to handle execution of custom scan node + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * ------------------------------------------------------------------------ + */ +#include "postgres.h" + +#include "access/parallel.h" +#include "executor/executor.h" +#include "executor/nodeCustom.h" +#include "miscadmin.h" +#include "nodes/execnodes.h" +#include "nodes/extensible.h" +#include "nodes/plannodes.h" +#include "parser/parsetree.h" +#include "utils/hsearch.h" +#include "utils/memutils.h" +#include "utils/rel.h" + +static TupleTableSlot *ExecCustomScan(PlanState *pstate); + + +CustomScanState * +ExecInitCustomScan(CustomScan *cscan, EState *estate, int eflags) +{ + CustomScanState *css; + Relation scan_rel = NULL; + Index scanrelid = cscan->scan.scanrelid; + Index tlistvarno; + + /* + * Allocate the CustomScanState object. We let the custom scan provider + * do the palloc, in case it wants to make a larger object that embeds + * CustomScanState as the first field. It must set the node tag and the + * methods field correctly at this time. Other standard fields should be + * set to zero. + */ + css = castNode(CustomScanState, + cscan->methods->CreateCustomScanState(cscan)); + + /* ensure flags is filled correctly */ + css->flags = cscan->flags; + + /* fill up fields of ScanState */ + css->ss.ps.plan = &cscan->scan.plan; + css->ss.ps.state = estate; + css->ss.ps.ExecProcNode = ExecCustomScan; + + /* create expression context for node */ + ExecAssignExprContext(estate, &css->ss.ps); + + /* + * open the scan relation, if any + */ + if (scanrelid > 0) + { + scan_rel = ExecOpenScanRelation(estate, scanrelid, eflags); + css->ss.ss_currentRelation = scan_rel; + } + + /* + * Determine the scan tuple type. If the custom scan provider provided a + * targetlist describing the scan tuples, use that; else use base + * relation's rowtype. + */ + if (cscan->custom_scan_tlist != NIL || scan_rel == NULL) + { + TupleDesc scan_tupdesc; + + scan_tupdesc = ExecTypeFromTL(cscan->custom_scan_tlist); + ExecInitScanTupleSlot(estate, &css->ss, scan_tupdesc, &TTSOpsVirtual); + /* Node's targetlist will contain Vars with varno = INDEX_VAR */ + tlistvarno = INDEX_VAR; + } + else + { + ExecInitScanTupleSlot(estate, &css->ss, RelationGetDescr(scan_rel), + &TTSOpsVirtual); + /* Node's targetlist will contain Vars with varno = scanrelid */ + tlistvarno = scanrelid; + } + + /* + * Initialize result slot, type and projection. + */ + ExecInitResultTupleSlotTL(&css->ss.ps, &TTSOpsVirtual); + ExecAssignScanProjectionInfoWithVarno(&css->ss, tlistvarno); + + /* initialize child expressions */ + css->ss.ps.qual = + ExecInitQual(cscan->scan.plan.qual, (PlanState *) css); + + /* + * 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; +} + +static TupleTableSlot * +ExecCustomScan(PlanState *pstate) +{ + CustomScanState *node = castNode(CustomScanState, pstate); + + CHECK_FOR_INTERRUPTS(); + + 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); + ExecClearTuple(node->ss.ss_ScanTupleSlot); +} + +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); +} + +void +ExecCustomScanEstimate(CustomScanState *node, ParallelContext *pcxt) +{ + const CustomExecMethods *methods = node->methods; + + if (methods->EstimateDSMCustomScan) + { + node->pscan_len = methods->EstimateDSMCustomScan(node, pcxt); + shm_toc_estimate_chunk(&pcxt->estimator, node->pscan_len); + shm_toc_estimate_keys(&pcxt->estimator, 1); + } +} + +void +ExecCustomScanInitializeDSM(CustomScanState *node, ParallelContext *pcxt) +{ + const CustomExecMethods *methods = node->methods; + + if (methods->InitializeDSMCustomScan) + { + int plan_node_id = node->ss.ps.plan->plan_node_id; + void *coordinate; + + coordinate = shm_toc_allocate(pcxt->toc, node->pscan_len); + methods->InitializeDSMCustomScan(node, pcxt, coordinate); + shm_toc_insert(pcxt->toc, plan_node_id, coordinate); + } +} + +void +ExecCustomScanReInitializeDSM(CustomScanState *node, ParallelContext *pcxt) +{ + const CustomExecMethods *methods = node->methods; + + if (methods->ReInitializeDSMCustomScan) + { + int plan_node_id = node->ss.ps.plan->plan_node_id; + void *coordinate; + + coordinate = shm_toc_lookup(pcxt->toc, plan_node_id, false); + methods->ReInitializeDSMCustomScan(node, pcxt, coordinate); + } +} + +void +ExecCustomScanInitializeWorker(CustomScanState *node, + ParallelWorkerContext *pwcxt) +{ + const CustomExecMethods *methods = node->methods; + + if (methods->InitializeWorkerCustomScan) + { + int plan_node_id = node->ss.ps.plan->plan_node_id; + void *coordinate; + + coordinate = shm_toc_lookup(pwcxt->toc, plan_node_id, false); + methods->InitializeWorkerCustomScan(node, pwcxt->toc, coordinate); + } +} + +void +ExecShutdownCustomScan(CustomScanState *node) +{ + const CustomExecMethods *methods = node->methods; + + if (methods->ShutdownCustomScan) + methods->ShutdownCustomScan(node); +} |