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to the existing X-direction tests. An rtree class now includes 4 actual 2-D tests, 4 1-D X-direction tests, and 4 1-D Y-direction tests. This involved adding four new Y-direction test operators for each of box and polygon; I followed the PostGIS project's lead as to the names of these operators. NON BACKWARDS COMPATIBLE CHANGE: the poly_overleft (&<) and poly_overright (&>) operators now have semantics comparable to box_overleft and box_overright. This is necessary to make r-tree indexes work correctly on polygons. Also, I changed circle_left and circle_right to agree with box_left and box_right --- formerly they allowed the boundaries to touch. This isn't actually essential given the lack of any r-tree opclass for circles, but it seems best to sync all the definitions while we are at it.
80 lines
2.4 KiB
C
80 lines
2.4 KiB
C
/*-------------------------------------------------------------------------
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*
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* rtstrat.c
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* strategy map data for rtrees.
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*
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* Portions Copyright (c) 1996-2005, 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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* $PostgreSQL: pgsql/src/backend/access/rtree/rtstrat.c,v 1.27 2005/06/24 20:53:30 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/rtree.h"
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/*
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* Here's something peculiar to rtrees that doesn't apply to most other
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* indexing structures: When we're searching a tree for a given value, we
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* can't do the same sorts of comparisons on internal node entries as we
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* do at leaves. The reason is that if we're looking for (say) all boxes
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* that are the same as (0,0,10,10), then we need to find all leaf pages
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* that overlap that region. So internally we search for overlap, and at
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* the leaf we search for equality.
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*
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* This array maps leaf search operators to the internal search operators.
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*/
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static const StrategyNumber RTOperMap[RTNStrategies] = {
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RTOverRightStrategyNumber, /* left */
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RTRightStrategyNumber, /* overleft */
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RTOverlapStrategyNumber, /* overlap */
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RTLeftStrategyNumber, /* overright */
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RTOverLeftStrategyNumber, /* right */
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RTContainsStrategyNumber, /* same */
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RTContainsStrategyNumber, /* contains */
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RTOverlapStrategyNumber, /* contained-by */
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RTAboveStrategyNumber, /* overbelow */
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RTOverAboveStrategyNumber, /* below */
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RTOverBelowStrategyNumber, /* above */
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RTBelowStrategyNumber /* overabove */
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};
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/*
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* We may need to negate the result of the selected operator. (This could
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* be avoided by expanding the set of operators required for an opclass.)
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*/
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static const bool RTNegateMap[RTNStrategies] = {
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true, /* left */
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true, /* overleft */
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false, /* overlap */
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true, /* overright */
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true, /* right */
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false, /* same */
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false, /* contains */
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false, /* contained-by */
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true, /* overbelow */
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true, /* below */
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true, /* above */
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true /* overabove */
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};
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StrategyNumber
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RTMapToInternalOperator(StrategyNumber strat)
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{
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Assert(strat > 0 && strat <= RTNStrategies);
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return RTOperMap[strat - 1];
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}
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bool
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RTMapToInternalNegate(StrategyNumber strat)
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{
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Assert(strat > 0 && strat <= RTNStrategies);
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return RTNegateMap[strat - 1];
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}
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