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|
#include "nodes/execnodes.h"
Go to the source code of this file.
Functions | |
| MaterialState * | ExecInitMaterial (Material *node, EState *estate, int eflags) |
| TupleTableSlot * | ExecMaterial (MaterialState *node) |
| void | ExecEndMaterial (MaterialState *node) |
| void | ExecMaterialMarkPos (MaterialState *node) |
| void | ExecMaterialRestrPos (MaterialState *node) |
| void | ExecReScanMaterial (MaterialState *node) |
| void ExecEndMaterial | ( | MaterialState * | node | ) |
Definition at line 240 of file nodeMaterial.c.
References ExecClearTuple(), ExecEndNode(), NULL, outerPlanState, MaterialState::ss, ScanState::ss_ScanTupleSlot, tuplestore_end(), and MaterialState::tuplestorestate.
Referenced by ExecEndNode().
{
/*
* clean out the tuple table
*/
ExecClearTuple(node->ss.ss_ScanTupleSlot);
/*
* Release tuplestore resources
*/
if (node->tuplestorestate != NULL)
tuplestore_end(node->tuplestorestate);
node->tuplestorestate = NULL;
/*
* shut down the subplan
*/
ExecEndNode(outerPlanState(node));
}
| MaterialState* ExecInitMaterial | ( | Material * | node, | |
| EState * | estate, | |||
| int | eflags | |||
| ) |
Definition at line 163 of file nodeMaterial.c.
References MaterialState::eflags, MaterialState::eof_underlying, EXEC_FLAG_BACKWARD, EXEC_FLAG_REWIND, ExecAssignResultTypeFromTL(), ExecAssignScanTypeFromOuterPlan(), ExecInitNode(), ExecInitResultTupleSlot(), ExecInitScanTupleSlot(), makeNode, outerPlan, outerPlanState, PlanState::plan, ScanState::ps, PlanState::ps_ProjInfo, MaterialState::ss, PlanState::state, and MaterialState::tuplestorestate.
Referenced by ExecInitNode().
{
MaterialState *matstate;
Plan *outerPlan;
/*
* create state structure
*/
matstate = makeNode(MaterialState);
matstate->ss.ps.plan = (Plan *) node;
matstate->ss.ps.state = estate;
/*
* We must have a tuplestore buffering the subplan output to do backward
* scan or mark/restore. We also prefer to materialize the subplan output
* if we might be called on to rewind and replay it many times. However,
* if none of these cases apply, we can skip storing the data.
*/
matstate->eflags = (eflags & (EXEC_FLAG_REWIND |
EXEC_FLAG_BACKWARD |
EXEC_FLAG_MARK));
/*
* Tuplestore's interpretation of the flag bits is subtly different from
* the general executor meaning: it doesn't think BACKWARD necessarily
* means "backwards all the way to start". If told to support BACKWARD we
* must include REWIND in the tuplestore eflags, else tuplestore_trim
* might throw away too much.
*/
if (eflags & EXEC_FLAG_BACKWARD)
matstate->eflags |= EXEC_FLAG_REWIND;
matstate->eof_underlying = false;
matstate->tuplestorestate = NULL;
/*
* Miscellaneous initialization
*
* Materialization nodes don't need ExprContexts because they never call
* ExecQual or ExecProject.
*/
/*
* tuple table initialization
*
* material nodes only return tuples from their materialized relation.
*/
ExecInitResultTupleSlot(estate, &matstate->ss.ps);
ExecInitScanTupleSlot(estate, &matstate->ss);
/*
* initialize child nodes
*
* We shield the child node from the need to support REWIND, BACKWARD, or
* MARK/RESTORE.
*/
eflags &= ~(EXEC_FLAG_REWIND | EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK);
outerPlan = outerPlan(node);
outerPlanState(matstate) = ExecInitNode(outerPlan, estate, eflags);
/*
* initialize tuple type. no need to initialize projection info because
* this node doesn't do projections.
*/
ExecAssignResultTypeFromTL(&matstate->ss.ps);
ExecAssignScanTypeFromOuterPlan(&matstate->ss);
matstate->ss.ps.ps_ProjInfo = NULL;
return matstate;
}
| TupleTableSlot* ExecMaterial | ( | MaterialState * | node | ) |
Definition at line 39 of file nodeMaterial.c.
References Assert, MaterialState::eflags, MaterialState::eof_underlying, EState::es_direction, EXEC_FLAG_MARK, ExecClearTuple(), ExecProcNode(), NULL, outerPlanState, ScanState::ps, PlanState::ps_ResultTupleSlot, ScanDirectionIsForward, MaterialState::ss, PlanState::state, TupIsNull, tuplestore_advance(), tuplestore_alloc_read_pointer(), tuplestore_ateof(), tuplestore_begin_heap(), tuplestore_gettupleslot(), tuplestore_puttupleslot(), tuplestore_set_eflags(), MaterialState::tuplestorestate, and work_mem.
Referenced by ExecProcNode().
{
EState *estate;
ScanDirection dir;
bool forward;
Tuplestorestate *tuplestorestate;
bool eof_tuplestore;
TupleTableSlot *slot;
/*
* get state info from node
*/
estate = node->ss.ps.state;
dir = estate->es_direction;
forward = ScanDirectionIsForward(dir);
tuplestorestate = node->tuplestorestate;
/*
* If first time through, and we need a tuplestore, initialize it.
*/
if (tuplestorestate == NULL && node->eflags != 0)
{
tuplestorestate = tuplestore_begin_heap(true, false, work_mem);
tuplestore_set_eflags(tuplestorestate, node->eflags);
if (node->eflags & EXEC_FLAG_MARK)
{
/*
* Allocate a second read pointer to serve as the mark. We know it
* must have index 1, so needn't store that.
*/
int ptrno PG_USED_FOR_ASSERTS_ONLY;
ptrno = tuplestore_alloc_read_pointer(tuplestorestate,
node->eflags);
Assert(ptrno == 1);
}
node->tuplestorestate = tuplestorestate;
}
/*
* If we are not at the end of the tuplestore, or are going backwards, try
* to fetch a tuple from tuplestore.
*/
eof_tuplestore = (tuplestorestate == NULL) ||
tuplestore_ateof(tuplestorestate);
if (!forward && eof_tuplestore)
{
if (!node->eof_underlying)
{
/*
* When reversing direction at tuplestore EOF, the first
* gettupleslot call will fetch the last-added tuple; but we want
* to return the one before that, if possible. So do an extra
* fetch.
*/
if (!tuplestore_advance(tuplestorestate, forward))
return NULL; /* the tuplestore must be empty */
}
eof_tuplestore = false;
}
/*
* If we can fetch another tuple from the tuplestore, return it.
*/
slot = node->ss.ps.ps_ResultTupleSlot;
if (!eof_tuplestore)
{
if (tuplestore_gettupleslot(tuplestorestate, forward, false, slot))
return slot;
if (forward)
eof_tuplestore = true;
}
/*
* If necessary, try to fetch another row from the subplan.
*
* Note: the eof_underlying state variable exists to short-circuit further
* subplan calls. It's not optional, unfortunately, because some plan
* node types are not robust about being called again when they've already
* returned NULL.
*/
if (eof_tuplestore && !node->eof_underlying)
{
PlanState *outerNode;
TupleTableSlot *outerslot;
/*
* We can only get here with forward==true, so no need to worry about
* which direction the subplan will go.
*/
outerNode = outerPlanState(node);
outerslot = ExecProcNode(outerNode);
if (TupIsNull(outerslot))
{
node->eof_underlying = true;
return NULL;
}
/*
* Append a copy of the returned tuple to tuplestore. NOTE: because
* the tuplestore is certainly in EOF state, its read position will
* move forward over the added tuple. This is what we want.
*/
if (tuplestorestate)
tuplestore_puttupleslot(tuplestorestate, outerslot);
/*
* We can just return the subplan's returned tuple, without copying.
*/
return outerslot;
}
/*
* Nothing left ...
*/
return ExecClearTuple(slot);
}
| void ExecMaterialMarkPos | ( | MaterialState * | node | ) |
Definition at line 267 of file nodeMaterial.c.
References Assert, MaterialState::eflags, EXEC_FLAG_MARK, tuplestore_copy_read_pointer(), tuplestore_trim(), and MaterialState::tuplestorestate.
Referenced by ExecMarkPos().
{
Assert(node->eflags & EXEC_FLAG_MARK);
/*
* if we haven't materialized yet, just return.
*/
if (!node->tuplestorestate)
return;
/*
* copy the active read pointer to the mark.
*/
tuplestore_copy_read_pointer(node->tuplestorestate, 0, 1);
/*
* since we may have advanced the mark, try to truncate the tuplestore.
*/
tuplestore_trim(node->tuplestorestate);
}
| void ExecMaterialRestrPos | ( | MaterialState * | node | ) |
Definition at line 295 of file nodeMaterial.c.
References Assert, MaterialState::eflags, EXEC_FLAG_MARK, tuplestore_copy_read_pointer(), and MaterialState::tuplestorestate.
Referenced by ExecRestrPos().
{
Assert(node->eflags & EXEC_FLAG_MARK);
/*
* if we haven't materialized yet, just return.
*/
if (!node->tuplestorestate)
return;
/*
* copy the mark to the active read pointer.
*/
tuplestore_copy_read_pointer(node->tuplestorestate, 1, 0);
}
| void ExecReScanMaterial | ( | MaterialState * | node | ) |
Definition at line 318 of file nodeMaterial.c.
References PlanState::chgParam, MaterialState::eflags, MaterialState::eof_underlying, EXEC_FLAG_REWIND, ExecClearTuple(), ExecReScan(), PlanState::lefttree, NULL, ScanState::ps, PlanState::ps_ResultTupleSlot, MaterialState::ss, tuplestore_end(), tuplestore_rescan(), and MaterialState::tuplestorestate.
Referenced by ExecReScan().
{
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
if (node->eflags != 0)
{
/*
* If we haven't materialized yet, just return. If outerplan's
* chgParam is not NULL then it will be re-scanned by ExecProcNode,
* else no reason to re-scan it at all.
*/
if (!node->tuplestorestate)
return;
/*
* If subnode is to be rescanned then we forget previous stored
* results; we have to re-read the subplan and re-store. Also, if we
* told tuplestore it needn't support rescan, we lose and must
* re-read. (This last should not happen in common cases; else our
* caller lied by not passing EXEC_FLAG_REWIND to us.)
*
* Otherwise we can just rewind and rescan the stored output. The
* state of the subnode does not change.
*/
if (node->ss.ps.lefttree->chgParam != NULL ||
(node->eflags & EXEC_FLAG_REWIND) == 0)
{
tuplestore_end(node->tuplestorestate);
node->tuplestorestate = NULL;
if (node->ss.ps.lefttree->chgParam == NULL)
ExecReScan(node->ss.ps.lefttree);
node->eof_underlying = false;
}
else
tuplestore_rescan(node->tuplestorestate);
}
else
{
/* In this case we are just passing on the subquery's output */
/*
* if chgParam of subnode is not null then plan will be re-scanned by
* first ExecProcNode.
*/
if (node->ss.ps.lefttree->chgParam == NULL)
ExecReScan(node->ss.ps.lefttree);
node->eof_underlying = false;
}
}
1.7.1