net.openhft.chronicle.core.pool

Class ParsingCache<E>

java.lang.Object

net.openhft.chronicle.core.pool.ParsingCache<E>

Type Parameters:

E - The type of object the cache stores. Typically, these are objects created from strings.

public class ParsingCache<E>
extends Object

A cache for parsed values that is optimized for fast lookup. This class is used to cache objects that are constructed from strings, often as a result of parsing. The cache has a fixed capacity and uses a hash function for fast indexing.

Use case is when there is a need to repeatedly parse the same strings into objects, such as BigDecimal in the example test case, and would like to reuse the parsed object rather than creating a new one each time.

Example usage:

 
 ParsingCache<BigDecimal> cache = new ParsingCache<>(128, BigDecimal::new);
 BigDecimal value = cache.intern("123.456");
 
 

Field Summary

Fields

Modifier and Type	Field and Description
protected net.openhft.chronicle.core.pool.ParsingCache.ParsedData<E>[]	interner
protected int	mask
protected int	shift
protected boolean	toggle

Constructor Summary

Constructors

Constructor and Description
ParsingCache(int capacity, Function<String,E> eFunction) Constructs a new ParsingCache with the specified capacity.

Method Summary

Modifier and Type	Method and Description
E	intern(@Nullable CharSequence cs) Retrieves the object associated with the given CharSequence from the cache.
protected boolean	toggle()
int	valueCount() Returns the number of values currently in the cache.

Methods inherited from class java.lang.Object

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

Field Detail

interner

protected final net.openhft.chronicle.core.pool.ParsingCache.ParsedData<E>[] interner

mask

protected final int mask

shift

protected final int shift

toggle

protected boolean toggle

Constructor Detail

ParsingCache

public ParsingCache(int capacity,
                    Function<String,E> eFunction)

Constructs a new ParsingCache with the specified capacity.

Parameters:

capacity - The capacity of the cache.

eFunction - A function that creates new instances of type E from a string.

Method Detail

intern

@Nullable
public E intern(@Nullable
                          @Nullable CharSequence cs)

Retrieves the object associated with the given CharSequence from the cache. If the object does not exist in the cache, it is created using the function provided in the constructor, stored in the cache, and then returned.

Parameters:

cs - The CharSequence to be parsed.

Returns:

The object of type E corresponding to the provided CharSequence.

toggle

protected boolean toggle()

valueCount

public int valueCount()

Returns the number of values currently in the cache.

Returns:

The number of values in the cache.