-
Notifications
You must be signed in to change notification settings - Fork 2.3k
/
StandardConfiguration.java
88 lines (79 loc) · 2.91 KB
/
StandardConfiguration.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
/*
* Copyright (c) 2002-2018 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.gis.spatial.index.curves;
import org.neo4j.gis.spatial.index.Envelope;
public class StandardConfiguration implements SpaceFillingCurveConfiguration
{
public static final int DEFAULT_EXTRA_LEVELS = 1;
/**
* After estimating the search ratio, we know the level at which tiles have approximately the same size as
* our search area. This number dictates the amount of levels we go deeper than that, to trim down the amount
* of false positives.
*/
protected int extraLevels;
public StandardConfiguration()
{
this( DEFAULT_EXTRA_LEVELS );
}
public StandardConfiguration( int extraLevels )
{
this.extraLevels = extraLevels;
}
/**
* This simply stops at the maxDepth calculated in the maxDepth() function, or
* if the overlap is over 99%.
* <p>
* {@inheritDoc}
*/
@Override
public boolean stopAtThisDepth( double overlap, int depth, int maxDepth )
{
return overlap >= 0.99 || depth >= maxDepth;
}
/**
* If the search area is exactly one of the finest grained tiles (tile at maxLevel), then
* we want the search to traverse to maxLevel, however, for each area that is 4x larger, we would
* traverse one level shallower. This is achieved by a log (base 4 for 2D, base 8 for 3D) of the ratio of areas.
* <p>
* {@inheritDoc}
*/
@Override
public int maxDepth( Envelope referenceEnvelope, Envelope range, int nbrDim, int maxLevel )
{
Envelope paddedEnvelope = referenceEnvelope.withSideRatioNotTooSmall();
double searchRatio = range.getArea() / paddedEnvelope.getArea();
if ( Double.isInfinite( searchRatio ) )
{
return maxLevel;
}
return Math.min( maxLevel, (int) (Math.log( searchRatio ) / Math.log( Math.pow( 2, nbrDim ) )) + extraLevels );
}
@Override
public String toString()
{
return getClass().getSimpleName() + "(" + extraLevels + ")";
}
@Override
public int initialRangesListCapacity()
{
// Probably big enough to for the majority of index queries.
return 1000;
}
}