Module com.carrotsearch.hppc

Package com.carrotsearch.hppc

Class BoundedProportionalArraySizingStrategy

java.lang.Object

com.carrotsearch.hppc.BoundedProportionalArraySizingStrategy

All Implemented Interfaces:

Accountable, ArraySizingStrategy

public final class BoundedProportionalArraySizingStrategy
extends 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	Description
static final float	DEFAULT_GROW_RATIO	Default resize is by half the current buffer's size.
static final BoundedProportionalArraySizingStrategy	DEFAULT_INSTANCE	Instance of BoundedProportionalArraySizingStrategy with default values.
static final int	DEFAULT_MAX_GROW_COUNT	Maximum grow count (unbounded).
static final int	DEFAULT_MIN_GROW_COUNT	Minimum grow count.
final float	growRatio	The current buffer length is multiplied by this ratio to get the first estimate for the new size.
static final int	MAX_ARRAY_LENGTH	Maximum allocable array length (approximately the largest positive integer decreased by the array's object header).
final int	maxGrowCount	Maximum number of elements to grow, if limit exceeded.
final int	minGrowCount	Minimum number of elements to grow, if limit exceeded.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
int	grow(int currentBufferLength, int elementsCount, int expectedAdditions)	Grow according to growRatio, minGrowCount and maxGrowCount.
long	ramBytesAllocated()	Allocated memory estimation
long	ramBytesUsed()	Bytes that is actually been used

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_INSTANCE

public static final BoundedProportionalArraySizingStrategy DEFAULT_INSTANCE

Instance of BoundedProportionalArraySizingStrategy with default values.

MAX_ARRAY_LENGTH

public static final int MAX_ARRAY_LENGTH

Maximum allocable array length (approximately the largest positive integer decreased by the array's object header).

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 limit exceeded.

maxGrowCount

public final int maxGrowCount

Maximum number of elements to grow, if limit 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 Details

BoundedProportionalArraySizingStrategy

public BoundedProportionalArraySizingStrategy()

Create the default sizing strategy.

BoundedProportionalArraySizingStrategy

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

Create the sizing strategy with custom policies.

Parameters:

minGrow - Minimum number of elements to grow by when expanding.

maxGrow - Maximum number of elements to grow by when expanding.

ratio - The ratio of expansion compared to the previous buffer size.

Method Details

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 - The current length of the buffer.

elementsCount - The number of elements stored in the buffer.

expectedAdditions - The number of expected additions to the buffer.

Returns:

New buffer size.

ramBytesAllocated

public long ramBytesAllocated()

Description copied from interface: Accountable

Allocated memory estimation

Specified by:

ramBytesAllocated in interface Accountable

Returns:

Ram allocated in bytes

ramBytesUsed

public long ramBytesUsed()

Description copied from interface: Accountable

Bytes that is actually been used

Specified by:

ramBytesUsed in interface Accountable

Returns:

Ram used in bytes