NumberRangePrefixTree (Lucene 7.2.0 API)

java.lang.Object
- org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree
- - org.apache.lucene.spatial.prefix.tree.NumberRangePrefixTree

Direct Known Subclasses:

DateRangePrefixTree
```
public abstract class NumberRangePrefixTree
extends SpatialPrefixTree
```
A SpatialPrefixTree for single-dimensional numbers and number ranges of fixed precision values (not floating point). Despite its name, the indexed values (and queries) need not actually be ranges, they can be unit instance/values.
Why might you use this instead of Lucene's built-in integer/long support? Here are some reasons with features based on code in this class, or are possible based on this class but require a subclass to fully realize it.
- Index ranges, not just unit instances. This is especially useful when the requirement calls for a multi-valued range.
- Instead of a fixed "precisionStep", this prefixTree can have a customizable number of child values for any prefix (up to 32768). This allows exact alignment of the prefix-tree with typical/expected values, which results in better performance. For example in a Date implementation, every month can get its own dedicated prefix, every day, etc., even though months vary in duration.
- Arbitrary precision, like BigDecimal.
- Standard Lucene integer/long indexing always indexes the full precision of those data types but this one is customizable.
Unlike "normal" spatial components in this module, this special-purpose one only works with Shapes created by the methods on this class, not from any SpatialContext.
See Also:

NumberRangePrefixTreeStrategy, LUCENE-5648

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`protected class`	`NumberRangePrefixTree.NRCell` Most of the PrefixTree implementation is in this one class, which is both the Cell, the CellIterator, and the Shape to reduce object allocation.
`static interface`	`NumberRangePrefixTree.NRShape` Base interface for `Shape`s this prefix tree supports.
`class`	`NumberRangePrefixTree.SpanUnitsNRShape` A range Shape; based on a pair of `NumberRangePrefixTree.UnitNRShape`.
`static interface`	`NumberRangePrefixTree.UnitNRShape` A unit value Shape implemented as a stack of numbers, one for each level in the prefix tree.

Field Summary

Fields
Modifier and Type Field and Description

protected int[] levelByTermLen

protected int[] maxSubCellsByLevel

protected int maxTermLen

protected int[] termLenByLevel
- Fields inherited from class org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree
  ctx, maxLevels

Fields
Modifier and Type	Field and Description
`protected int[]`	`levelByTermLen`
`protected int[]`	`maxSubCellsByLevel`
`protected int`	`maxTermLen`
`protected int[]`	`termLenByLevel`

Constructor Summary

Constructors
Modifier Constructor and Description

protected NumberRangePrefixTree(int[] maxSubCellsByLevel)

Constructors
Modifier	Constructor and Description
`protected`	`NumberRangePrefixTree(int[] maxSubCellsByLevel)`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`protected static int`	`comparePrefix(NumberRangePrefixTree.UnitNRShape a, NumberRangePrefixTree.UnitNRShape b)` Compares a to b, returning less than 0, 0, or greater than 0, if a is less than, equal to, or greater than b, respectively, up to their common prefix (i.e.
`double`	`getDistanceForLevel(int level)` Given a cell having the specified level, returns the distance from opposite corners.
`int`	`getLevelForDistance(double dist)` Returns the level of the largest grid in which its longest side is less than or equal to the provided distance (in degrees).
`int`	`getNumSubCells(NumberRangePrefixTree.UnitNRShape lv)` Returns the number of sub-cells beneath the given UnitNRShape.
`Cell`	`getWorldCell()` Returns the level 0 cell which encompasses all spatial data.
`protected NumberRangePrefixTree.NRCell[]`	`newCellStack(int levels)`
`NumberRangePrefixTree.NRShape`	`parseShape(String str)` Detects a range pattern and parses it, otherwise it's parsed as one shape via `parseUnitShape(String)`.
`protected abstract NumberRangePrefixTree.UnitNRShape`	`parseUnitShape(String str)` Parse a String to a UnitNRShape.
`Cell`	`readCell(BytesRef term, Cell scratch)` This creates a new Cell (or re-using `scratch` if provided), initialized to the state as read by the bytes.
`abstract Object`	`toObject(NumberRangePrefixTree.UnitNRShape shape)` Converts a UnitNRShape shape to the corresponding type supported by this class, such as a Calendar/BigDecimal.
`NumberRangePrefixTree.NRShape`	`toRangeShape(NumberRangePrefixTree.UnitNRShape startUnit, NumberRangePrefixTree.UnitNRShape endUnit)` Returns a shape that represents the continuous range between `start` and `end`.
`protected NumberRangePrefixTree.UnitNRShape`	`toShape(int[] valStack, int len)`
`String`	`toString()`
`protected abstract String`	`toString(NumberRangePrefixTree.UnitNRShape lv)` A string representation of the UnitNRShape that is parse-able by `parseUnitShape(String)`.
`protected static String`	`toStringUnitRaw(NumberRangePrefixTree.UnitNRShape lv)`
`abstract NumberRangePrefixTree.UnitNRShape`	`toUnitShape(Object value)` Converts the value to a unit shape.

Methods inherited from class org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree
getMaxLevels, getSpatialContext, getTreeCellIterator

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - maxSubCellsByLevel
```
protected final int[] maxSubCellsByLevel
```
  - termLenByLevel
```
protected final int[] termLenByLevel
```
  - levelByTermLen
```
protected final int[] levelByTermLen
```
  - maxTermLen
```
protected final int maxTermLen
```
- Constructor Detail
  - NumberRangePrefixTree
```
protected NumberRangePrefixTree(int[] maxSubCellsByLevel)
```
- Method Detail
  - toUnitShape
```
public abstract NumberRangePrefixTree.UnitNRShape toUnitShape(Object value)
```
    Converts the value to a unit shape. Doesn't parse strings; see parseShape(String) for that. This is the reverse of toObject(org.apache.lucene.spatial.prefix.tree.NumberRangePrefixTree.UnitNRShape).
  - toRangeShape
```
public NumberRangePrefixTree.NRShape toRangeShape(NumberRangePrefixTree.UnitNRShape startUnit,
                                                  NumberRangePrefixTree.UnitNRShape endUnit)
```
    Returns a shape that represents the continuous range between start and end. It will be normalized, and so sometimes a NumberRangePrefixTree.UnitNRShape will be returned, other times a NumberRangePrefixTree.SpanUnitsNRShape will be.
    
    Throws:
    
    IllegalArgumentException - if the arguments are in the wrong order, or if either contains the other (yet they aren't equal).
  - toObject
```
public abstract Object toObject(NumberRangePrefixTree.UnitNRShape shape)
```
    Converts a UnitNRShape shape to the corresponding type supported by this class, such as a Calendar/BigDecimal. This is the reverse of toUnitShape(Object).
  - toString
```
protected abstract String toString(NumberRangePrefixTree.UnitNRShape lv)
```
    A string representation of the UnitNRShape that is parse-able by parseUnitShape(String).
  - toStringUnitRaw
```
protected static String toStringUnitRaw(NumberRangePrefixTree.UnitNRShape lv)
```
  - parseShape
```
public NumberRangePrefixTree.NRShape parseShape(String str)
                                         throws ParseException
```
    Detects a range pattern and parses it, otherwise it's parsed as one shape via parseUnitShape(String). The range pattern looks like this BNF:
```
   '[' + parseShapeLV + ' TO ' + parseShapeLV + ']'
 
```
    It's the same thing as the toString() of the range shape, notwithstanding range optimization.
    Parameters:
    
    str - not null or empty
    
    Returns:
    
    not null
    
    Throws:
    
    ParseException - If there is a problem
  - parseUnitShape
```
protected abstract NumberRangePrefixTree.UnitNRShape parseUnitShape(String str)
                                                             throws ParseException
```
    Parse a String to a UnitNRShape. "*" should be the full-range (level 0 shape).
    
    Throws:
    
    ParseException
  - comparePrefix
```
protected static int comparePrefix(NumberRangePrefixTree.UnitNRShape a,
                                   NumberRangePrefixTree.UnitNRShape b)
```
    Compares a to b, returning less than 0, 0, or greater than 0, if a is less than, equal to, or greater than b, respectively, up to their common prefix (i.e. only min(a.levels,b.levels) are compared).
    
    NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class SpatialPrefixTree
  - getLevelForDistance
```
public int getLevelForDistance(double dist)
```
    Description copied from class: SpatialPrefixTree
    
    Returns the level of the largest grid in which its longest side is less than or equal to the provided distance (in degrees). Consequently dist acts as an error epsilon declaring the amount of detail needed in the grid, such that you can get a grid with just the right amount of precision.
    
    Specified by:
    
    getLevelForDistance in class SpatialPrefixTree
    
    Parameters:
    
    dist - >= 0
    
    Returns:
    
    level [1 to maxLevels]
  - getDistanceForLevel
```
public double getDistanceForLevel(int level)
```
    Description copied from class: SpatialPrefixTree
    
    Given a cell having the specified level, returns the distance from opposite corners. Since this might vary depending on where the cell is, this method may over-estimate.
    
    Specified by:
    
    getDistanceForLevel in class SpatialPrefixTree
    
    Parameters:
    
    level - [1 to maxLevels]
    
    Returns:
    
    > 0
  - toShape
```
protected NumberRangePrefixTree.UnitNRShape toShape(int[] valStack,
                                                    int len)
```
  - getWorldCell
```
public Cell getWorldCell()
```
    Description copied from class: SpatialPrefixTree
    
    Returns the level 0 cell which encompasses all spatial data. Equivalent to SpatialPrefixTree.readCell(BytesRef,Cell) with no bytes.
    
    Specified by:
    
    getWorldCell in class SpatialPrefixTree
  - newCellStack
```
protected NumberRangePrefixTree.NRCell[] newCellStack(int levels)
```
  - readCell
```
public Cell readCell(BytesRef term,
                     Cell scratch)
```
    Description copied from class: SpatialPrefixTree
    
    This creates a new Cell (or re-using scratch if provided), initialized to the state as read by the bytes. Warning: An implementation may refer to the same byte array (no copy). If Cell.setLeaf() is subsequently called, it would then modify these bytes.
    
    Specified by:
    
    readCell in class SpatialPrefixTree
  - getNumSubCells
```
public int getNumSubCells(NumberRangePrefixTree.UnitNRShape lv)
```
    Returns the number of sub-cells beneath the given UnitNRShape.

Class NumberRangePrefixTree

Nested Class Summary

Field Summary

Fields inherited from class org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree

Constructor Summary

Method Summary

Methods inherited from class org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree

Methods inherited from class java.lang.Object

Field Detail

maxSubCellsByLevel

termLenByLevel

levelByTermLen

maxTermLen

Constructor Detail

NumberRangePrefixTree

Method Detail

toUnitShape

toRangeShape

toObject

toString

toStringUnitRaw

parseShape

parseUnitShape

comparePrefix

toString

getLevelForDistance

getDistanceForLevel

toShape

getWorldCell

newCellStack

readCell

getNumSubCells