Package it.unimi.dsi.sux4j.mph

Class TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T>

java.lang.Object

it.unimi.dsi.sux4j.mph.TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T>

Enclosing class:

TwoStepsLcpMonotoneMinimalPerfectHashFunction<T>

public static class TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T>
extends Object

A builder class for TwoStepsLcpMonotoneMinimalPerfectHashFunction.

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	built	Whether build() has already been called.
protected Iterable<? extends T>	keys
protected long	numKeys
protected int	signatureWidth
protected File	tempDir
protected TransformationStrategy<? super T>	transform

Constructor Summary

Constructors

Constructor	Description
Builder()

Method Summary

Modifier and Type	Method	Description
TwoStepsLcpMonotoneMinimalPerfectHashFunction<T>	build()	Builds a two-steps LCP monotone minimal perfect hash function.
TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T>	keys(Iterable<? extends T> keys)	Specifies the keys to hash.
TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T>	numKeys(long numKeys)	Specifies the number of keys.
TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T>	signed(int signatureWidth)	Specifies that the resulting LcpMonotoneMinimalPerfectHashFunction should be signed using a given number of bits per key.
TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T>	tempDir(File tempDir)	Specifies a temporary directory for the BucketedHashStore.
TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T>	transform(TransformationStrategy<? super T> transform)	Specifies the transformation strategy for the keys to hash.

Methods inherited from class java.lang.Object

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

Field Details

keys

protected Iterable<? extends T> keys

transform

protected TransformationStrategy<? super T> transform

numKeys

protected long numKeys

signatureWidth

protected int signatureWidth

tempDir

protected File tempDir

built

protected boolean built

Whether build() has already been called.

Constructor Details

Builder

public Builder()

Method Details

keys

public TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T> keys(Iterable<? extends T> keys)

Specifies the keys to hash.

Parameters:

keys - the keys to hash.

Returns:

this builder.

numKeys

public TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T> numKeys(long numKeys)

Specifies the number of keys.

The argument must be equal to the number of keys returned by an iterator generated by the set of keys. Without this information, a first scan of the key set will be necessary to compute its cardinality, unless the set of keys implements Size64 or Collection.

Parameters:

numKeys - the keys to hash.

Returns:

this builder.

transform

public TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T> transform(TransformationStrategy<? super T> transform)

Specifies the transformation strategy for the keys to hash.

Parameters:

transform - a transformation strategy for the keys to hash.

Returns:

this builder.

signed

public TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T> signed(int signatureWidth)

Specifies that the resulting LcpMonotoneMinimalPerfectHashFunction should be signed using a given number of bits per key.

Parameters:

signatureWidth - a signature width, or 0 for no signature.

Returns:

this builder.

tempDir

public TwoStepsLcpMonotoneMinimalPerfectHashFunction.Builder<T> tempDir(File tempDir)

Specifies a temporary directory for the BucketedHashStore.

Parameters:

tempDir - a temporary directory for the BucketedHashStore. files, or null for the standard temporary directory.

Returns:

this builder.

build

public TwoStepsLcpMonotoneMinimalPerfectHashFunction<T> build()
                                                       throws IOException

Builds a two-steps LCP monotone minimal perfect hash function.

Returns:

a TwoStepsLcpMonotoneMinimalPerfectHashFunction instance with the specified parameters.

Throws:

IllegalStateException - if called more than once.

IOException