com.carrotsearch.hppc

Class BoundedProportionalArraySizingStrategy

java.lang.Object

com.carrotsearch.hppc.BoundedProportionalArraySizingStrategy

All Implemented Interfaces:

ArraySizingStrategy

public final class BoundedProportionalArraySizingStrategy
extends java.lang.Object
implements ArraySizingStrategy

Array resizing proportional to the current buffer size, optionally kept within the given minimum and maximum growth limits. Java's ArrayList uses:

 minGrow = 1
 maxGrow = Integer.MAX_VALUE (unbounded)
 growRatio = 1.5f
 

Field Summary

Fields

Modifier and Type	Field and Description
static float	DEFAULT_GROW_RATIO Default resize is by half the current buffer's size.
static int	DEFAULT_MAX_GROW_COUNT Maximum grow count (unbounded).
static int	DEFAULT_MIN_GROW_COUNT Minimum grow count.
float	growRatio The current buffer length is multiplied by this ratio to get the first estimate for the new size.
static int	MAX_ARRAY_SIZE Used by ArrayList internally to account for reference sizes.
int	maxGrowCount Maximum number of elements to grow, if capacity exceeded.
int	minGrowCount Minimum number of elements to grow, if capacity exceeded.

Constructor Summary

Constructors

Constructor and Description
BoundedProportionalArraySizingStrategy() Create the default sizing strategy.
BoundedProportionalArraySizingStrategy(int minGrow, int maxGrow, float ratio) Create the sizing strategy with custom policies.

Method Summary

Methods

Modifier and Type	Method and Description
int	grow(int currentBufferLength, int elementsCount, int expectedAdditions) Grow according to growRatio, minGrowCount and maxGrowCount.
int	round(int capacity) No specific requirements in case of this strategy - the argument is returned.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAX_ARRAY_SIZE

public static final int MAX_ARRAY_SIZE

Used by ArrayList internally to account for reference sizes.

See Also:

Constant Field Values

DEFAULT_MIN_GROW_COUNT

public static final int DEFAULT_MIN_GROW_COUNT

Minimum grow count.

See Also:

Constant Field Values

DEFAULT_MAX_GROW_COUNT

public static final int DEFAULT_MAX_GROW_COUNT

Maximum grow count (unbounded).

See Also:

Constant Field Values

DEFAULT_GROW_RATIO

public static final float DEFAULT_GROW_RATIO

Default resize is by half the current buffer's size.

See Also:

Constant Field Values

minGrowCount

public final int minGrowCount

Minimum number of elements to grow, if capacity exceeded.

maxGrowCount

public final int maxGrowCount

Maximum number of elements to grow, if capacity exceeded.

growRatio

public final float growRatio

The current buffer length is multiplied by this ratio to get the first estimate for the new size. To double the size of the current buffer, for example, set to 2.

Constructor Detail

BoundedProportionalArraySizingStrategy

public BoundedProportionalArraySizingStrategy()

Create the default sizing strategy.

BoundedProportionalArraySizingStrategy

public BoundedProportionalArraySizingStrategy(int minGrow,
                                      int maxGrow,
                                      float ratio)

Create the sizing strategy with custom policies.

Method Detail

grow

public int grow(int currentBufferLength,
       int elementsCount,
       int expectedAdditions)

Grow according to growRatio, minGrowCount and maxGrowCount.

Specified by:

grow in interface ArraySizingStrategy

Parameters:

currentBufferLength - Current size of the array (buffer). This number should comply with the strategy's policies (it is a result of initial rounding or further growths). It can also be zero, indicating the growth from an empty buffer.

elementsCount - Number of elements stored in the buffer.

expectedAdditions - Expected number of additions (resize hint).

Returns:

Must return a new size at least as big as to hold elementsCount + expectedAdditions.

round

public int round(int capacity)

No specific requirements in case of this strategy - the argument is returned.

Specified by:

round in interface ArraySizingStrategy