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Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
411 lines
11 KiB
C
411 lines
11 KiB
C
/*-------------------------------------------------------------------------
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*
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* nodeNestloop.c
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* routines to support nest-loop joins
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*
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* Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/backend/executor/nodeNestloop.c
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*
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*-------------------------------------------------------------------------
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*/
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/*
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* INTERFACE ROUTINES
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* ExecNestLoop - process a nestloop join of two plans
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* ExecInitNestLoop - initialize the join
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* ExecEndNestLoop - shut down the join
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*/
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#include "postgres.h"
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#include "executor/execdebug.h"
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#include "executor/nodeNestloop.h"
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#include "utils/memutils.h"
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/* ----------------------------------------------------------------
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* ExecNestLoop(node)
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*
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* old comments
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* Returns the tuple joined from inner and outer tuples which
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* satisfies the qualification clause.
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*
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* It scans the inner relation to join with current outer tuple.
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*
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* If none is found, next tuple from the outer relation is retrieved
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* and the inner relation is scanned from the beginning again to join
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* with the outer tuple.
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*
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* NULL is returned if all the remaining outer tuples are tried and
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* all fail to join with the inner tuples.
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*
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* NULL is also returned if there is no tuple from inner relation.
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*
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* Conditions:
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* -- outerTuple contains current tuple from outer relation and
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* the right son(inner relation) maintains "cursor" at the tuple
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* returned previously.
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* This is achieved by maintaining a scan position on the outer
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* relation.
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*
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* Initial States:
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* -- the outer child and the inner child
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* are prepared to return the first tuple.
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* ----------------------------------------------------------------
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*/
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TupleTableSlot *
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ExecNestLoop(NestLoopState *node)
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{
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NestLoop *nl;
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PlanState *innerPlan;
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PlanState *outerPlan;
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TupleTableSlot *outerTupleSlot;
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TupleTableSlot *innerTupleSlot;
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ExprState *joinqual;
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ExprState *otherqual;
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ExprContext *econtext;
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ListCell *lc;
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/*
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* get information from the node
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*/
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ENL1_printf("getting info from node");
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nl = (NestLoop *) node->js.ps.plan;
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joinqual = node->js.joinqual;
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otherqual = node->js.ps.qual;
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outerPlan = outerPlanState(node);
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innerPlan = innerPlanState(node);
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econtext = node->js.ps.ps_ExprContext;
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/*
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* Reset per-tuple memory context to free any expression evaluation
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* storage allocated in the previous tuple cycle.
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*/
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ResetExprContext(econtext);
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/*
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* Ok, everything is setup for the join so now loop until we return a
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* qualifying join tuple.
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*/
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ENL1_printf("entering main loop");
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for (;;)
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{
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/*
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* If we don't have an outer tuple, get the next one and reset the
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* inner scan.
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*/
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if (node->nl_NeedNewOuter)
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{
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ENL1_printf("getting new outer tuple");
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outerTupleSlot = ExecProcNode(outerPlan);
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/*
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* if there are no more outer tuples, then the join is complete..
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*/
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if (TupIsNull(outerTupleSlot))
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{
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ENL1_printf("no outer tuple, ending join");
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return NULL;
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}
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ENL1_printf("saving new outer tuple information");
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econtext->ecxt_outertuple = outerTupleSlot;
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node->nl_NeedNewOuter = false;
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node->nl_MatchedOuter = false;
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/*
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* fetch the values of any outer Vars that must be passed to the
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* inner scan, and store them in the appropriate PARAM_EXEC slots.
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*/
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foreach(lc, nl->nestParams)
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{
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NestLoopParam *nlp = (NestLoopParam *) lfirst(lc);
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int paramno = nlp->paramno;
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ParamExecData *prm;
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prm = &(econtext->ecxt_param_exec_vals[paramno]);
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/* Param value should be an OUTER_VAR var */
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Assert(IsA(nlp->paramval, Var));
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Assert(nlp->paramval->varno == OUTER_VAR);
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Assert(nlp->paramval->varattno > 0);
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prm->value = slot_getattr(outerTupleSlot,
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nlp->paramval->varattno,
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&(prm->isnull));
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/* Flag parameter value as changed */
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innerPlan->chgParam = bms_add_member(innerPlan->chgParam,
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paramno);
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}
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/*
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* now rescan the inner plan
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*/
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ENL1_printf("rescanning inner plan");
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ExecReScan(innerPlan);
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}
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/*
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* we have an outerTuple, try to get the next inner tuple.
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*/
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ENL1_printf("getting new inner tuple");
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innerTupleSlot = ExecProcNode(innerPlan);
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econtext->ecxt_innertuple = innerTupleSlot;
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if (TupIsNull(innerTupleSlot))
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{
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ENL1_printf("no inner tuple, need new outer tuple");
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node->nl_NeedNewOuter = true;
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if (!node->nl_MatchedOuter &&
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(node->js.jointype == JOIN_LEFT ||
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node->js.jointype == JOIN_ANTI))
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{
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/*
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* We are doing an outer join and there were no join matches
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* for this outer tuple. Generate a fake join tuple with
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* nulls for the inner tuple, and return it if it passes the
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* non-join quals.
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*/
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econtext->ecxt_innertuple = node->nl_NullInnerTupleSlot;
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ENL1_printf("testing qualification for outer-join tuple");
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if (otherqual == NULL || ExecQual(otherqual, econtext))
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{
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/*
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* qualification was satisfied so we project and return
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* the slot containing the result tuple using
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* ExecProject().
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*/
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ENL1_printf("qualification succeeded, projecting tuple");
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return ExecProject(node->js.ps.ps_ProjInfo);
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}
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else
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InstrCountFiltered2(node, 1);
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}
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/*
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* Otherwise just return to top of loop for a new outer tuple.
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*/
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continue;
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}
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/*
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* at this point we have a new pair of inner and outer tuples so we
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* test the inner and outer tuples to see if they satisfy the node's
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* qualification.
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*
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* Only the joinquals determine MatchedOuter status, but all quals
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* must pass to actually return the tuple.
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*/
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ENL1_printf("testing qualification");
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if (ExecQual(joinqual, econtext))
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{
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node->nl_MatchedOuter = true;
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/* In an antijoin, we never return a matched tuple */
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if (node->js.jointype == JOIN_ANTI)
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{
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node->nl_NeedNewOuter = true;
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continue; /* return to top of loop */
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}
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/*
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* If we only need to join to the first matching inner tuple, then
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* consider returning this one, but after that continue with next
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* outer tuple.
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*/
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if (node->js.single_match)
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node->nl_NeedNewOuter = true;
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if (otherqual == NULL || ExecQual(otherqual, econtext))
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{
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/*
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* qualification was satisfied so we project and return the
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* slot containing the result tuple using ExecProject().
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*/
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ENL1_printf("qualification succeeded, projecting tuple");
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return ExecProject(node->js.ps.ps_ProjInfo);
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}
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else
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InstrCountFiltered2(node, 1);
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}
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else
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InstrCountFiltered1(node, 1);
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/*
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* Tuple fails qual, so free per-tuple memory and try again.
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*/
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ResetExprContext(econtext);
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ENL1_printf("qualification failed, looping");
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}
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}
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/* ----------------------------------------------------------------
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* ExecInitNestLoop
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* ----------------------------------------------------------------
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*/
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NestLoopState *
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ExecInitNestLoop(NestLoop *node, EState *estate, int eflags)
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{
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NestLoopState *nlstate;
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/* check for unsupported flags */
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Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
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NL1_printf("ExecInitNestLoop: %s\n",
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"initializing node");
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/*
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* create state structure
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*/
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nlstate = makeNode(NestLoopState);
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nlstate->js.ps.plan = (Plan *) node;
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nlstate->js.ps.state = estate;
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/*
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* Miscellaneous initialization
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*
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* create expression context for node
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*/
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ExecAssignExprContext(estate, &nlstate->js.ps);
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/*
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* initialize child expressions
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*/
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nlstate->js.ps.qual =
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ExecInitQual(node->join.plan.qual, (PlanState *) nlstate);
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nlstate->js.jointype = node->join.jointype;
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nlstate->js.joinqual =
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ExecInitQual(node->join.joinqual, (PlanState *) nlstate);
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/*
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* initialize child nodes
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*
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* If we have no parameters to pass into the inner rel from the outer,
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* tell the inner child that cheap rescans would be good. If we do have
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* such parameters, then there is no point in REWIND support at all in the
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* inner child, because it will always be rescanned with fresh parameter
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* values.
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*/
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outerPlanState(nlstate) = ExecInitNode(outerPlan(node), estate, eflags);
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if (node->nestParams == NIL)
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eflags |= EXEC_FLAG_REWIND;
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else
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eflags &= ~EXEC_FLAG_REWIND;
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innerPlanState(nlstate) = ExecInitNode(innerPlan(node), estate, eflags);
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/*
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* tuple table initialization
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*/
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ExecInitResultTupleSlot(estate, &nlstate->js.ps);
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/*
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* detect whether we need only consider the first matching inner tuple
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*/
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nlstate->js.single_match = (node->join.inner_unique ||
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node->join.jointype == JOIN_SEMI);
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/* set up null tuples for outer joins, if needed */
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switch (node->join.jointype)
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{
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case JOIN_INNER:
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case JOIN_SEMI:
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break;
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case JOIN_LEFT:
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case JOIN_ANTI:
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nlstate->nl_NullInnerTupleSlot =
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ExecInitNullTupleSlot(estate,
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ExecGetResultType(innerPlanState(nlstate)));
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break;
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default:
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elog(ERROR, "unrecognized join type: %d",
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(int) node->join.jointype);
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}
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/*
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* initialize tuple type and projection info
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*/
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ExecAssignResultTypeFromTL(&nlstate->js.ps);
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ExecAssignProjectionInfo(&nlstate->js.ps, NULL);
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/*
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* finally, wipe the current outer tuple clean.
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*/
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nlstate->nl_NeedNewOuter = true;
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nlstate->nl_MatchedOuter = false;
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NL1_printf("ExecInitNestLoop: %s\n",
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"node initialized");
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return nlstate;
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}
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/* ----------------------------------------------------------------
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* ExecEndNestLoop
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*
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* closes down scans and frees allocated storage
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* ----------------------------------------------------------------
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*/
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void
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ExecEndNestLoop(NestLoopState *node)
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{
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NL1_printf("ExecEndNestLoop: %s\n",
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"ending node processing");
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/*
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* Free the exprcontext
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*/
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ExecFreeExprContext(&node->js.ps);
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/*
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* clean out the tuple table
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*/
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ExecClearTuple(node->js.ps.ps_ResultTupleSlot);
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/*
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* close down subplans
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*/
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ExecEndNode(outerPlanState(node));
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ExecEndNode(innerPlanState(node));
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NL1_printf("ExecEndNestLoop: %s\n",
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"node processing ended");
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}
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/* ----------------------------------------------------------------
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* ExecReScanNestLoop
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* ----------------------------------------------------------------
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*/
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void
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ExecReScanNestLoop(NestLoopState *node)
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{
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PlanState *outerPlan = outerPlanState(node);
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/*
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* If outerPlan->chgParam is not null then plan will be automatically
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* re-scanned by first ExecProcNode.
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*/
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if (outerPlan->chgParam == NULL)
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ExecReScan(outerPlan);
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/*
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* innerPlan is re-scanned for each new outer tuple and MUST NOT be
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* re-scanned from here or you'll get troubles from inner index scans when
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* outer Vars are used as run-time keys...
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*/
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node->nl_NeedNewOuter = true;
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node->nl_MatchedOuter = false;
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}
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