Package it.unimi.dsi.big.util

Class LongBigListSignedStringMap

java.lang.Object

it.unimi.dsi.fastutil.objects.AbstractObject2LongFunction<CharSequence>

it.unimi.dsi.big.util.LongBigListSignedStringMap

All Implemented Interfaces:

StringMap<CharSequence>, Function<CharSequence,Long>, Object2LongFunction<CharSequence>, Size64, Serializable, Function<CharSequence,Long>, ToLongFunction<CharSequence>

@Deprecated
public class LongBigListSignedStringMap
extends AbstractObject2LongFunction<CharSequence>
implements StringMap<CharSequence>, Serializable

Deprecated.

There are much better and faster hash functions.

A string map based on a function signed using a big list of longs.

The purpose of this map is identical to that of a ShiftAddXorSignedStringMap, but Shift-Add-Xor signatures are 64-bit and stored in a LongBigList. This approach makes it possible to store the signatures in a file and read them by memory mapping using a LongMappedBigList. If the map has a very large number of keys but the access pattern is strongly skewed towards a relatively small number of entries, using memory mapping might be advantageous.

The intended usage pattern is as follows:

• first, you generate a file of signatures (note that for this phase it might be necessary to keep the signatures in main memory; see sign(Iterator, String) for some elaboration);
• then, when you want to use the signed map you map the file using LongMappedBigList.map(java.nio.channels.FileChannel) and create on the fly a signed map.

To simplify the process, there is a constructor that will do the mapping for you.

Since:

2.0.13

Author:

Sebastiano Vigna

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected final Object2LongFunction<? extends CharSequence>	function	Deprecated. The underlying map.
protected final LongBigList	signatures	Deprecated. Signatures.

Fields inherited from class it.unimi.dsi.fastutil.objects.AbstractObject2LongFunction

defRetValue

Constructor Summary

Constructors

Constructor	Description
LongBigListSignedStringMap(Object2LongFunction<? extends CharSequence> function, LongBigList signatures)	Deprecated. Creates a signed string map using a given hash map and a big list of 64-bit signatures.
LongBigListSignedStringMap(Object2LongFunction<? extends CharSequence> function, String signatures)	Deprecated. Creates a signed string map using a given hash map and a big list of 64-bit signatures.

Method Summary

Modifier and Type	Method	Description
boolean	containsKey(Object o)	Deprecated.
Long	get(Object o)	Deprecated.
long	getLong(Object o)	Deprecated.
ObjectBigList<CharSequence>	list()	Deprecated. Returns a list view of the domain of this string map (optional operation).
static void	main(String[] arg)	Deprecated.
static long[][]	sign(Iterator<? extends CharSequence> iterator, Object2LongFunction<? extends CharSequence> function)	Deprecated. Generates a 64-bit signatures big array using a given function and string sequence.
static long[][]	sign(Iterator<? extends CharSequence> iterator, Object2LongFunction<? extends CharSequence> function, ProgressLogger pl)	Deprecated. Generates a 64-bit signatures big array using a given function and string sequence.
static void	sign(Iterator<? extends CharSequence> iterator, DataOutput signatures, ProgressLogger pl)	Deprecated. Generates an on-disk list 64-bit signatures big array using a given string sequence.
static void	sign(Iterator<? extends CharSequence> iterator, String signatureFile)	Deprecated. Generates an on-disk list 64-bit signatures big array using a given string sequence.
static void	sign(Iterator<? extends CharSequence> iterator, String signatureFile, ProgressLogger pl)	Deprecated. Generates an on-disk list 64-bit signatures big array using a given string sequence.
int	size()	Deprecated.
long	size64()	Deprecated. Returns the intended number of keys in this function, or -1 if no such number exists.

Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractObject2LongFunction

defaultReturnValue, defaultReturnValue

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unimi.dsi.fastutil.Function

apply, clear

Methods inherited from interface java.util.function.Function

compose

Methods inherited from interface it.unimi.dsi.fastutil.objects.Object2LongFunction

andThen, andThenByte, andThenChar, andThenDouble, andThenFloat, andThenInt, andThenLong, andThenObject, andThenReference, andThenShort, applyAsLong, composeByte, composeChar, composeDouble, composeFloat, composeInt, composeLong, composeObject, composeReference, composeShort, defaultReturnValue, defaultReturnValue, getOrDefault, getOrDefault, put, put, remove, removeLong

Field Details

function

protected final Object2LongFunction<? extends CharSequence> function

Deprecated.

The underlying map.

signatures

protected final LongBigList signatures

Deprecated.

Signatures.

Constructor Details

LongBigListSignedStringMap

public LongBigListSignedStringMap(Object2LongFunction<? extends CharSequence> function,
 LongBigList signatures)

Deprecated.

Creates a signed string map using a given hash map and a big list of 64-bit signatures.

Parameters:

function - a minimal perfect hash for the strings enumerated by iterator; it must support size(). and have default return value -1.

signatures - a big list of 64-bit signatures generated by sign(Iterator, Object2LongFunction, ProgressLogger).

LongBigListSignedStringMap

public LongBigListSignedStringMap(Object2LongFunction<? extends CharSequence> function,
 String signatures)
                           throws FileNotFoundException,
IOException

Deprecated.

Creates a signed string map using a given hash map and a big list of 64-bit signatures.

Parameters:

function - a minimal perfect hash for the strings enumerated by iterator; it must support size(). and have default return value -1.

signatures - a file containing a list of 64-bit signatures generated by sign(Iterator, Object2LongFunction, ProgressLogger) and stored in DataOutput format.

Throws:

FileNotFoundException

IOException

Method Details

sign

public static long[][] sign(Iterator<? extends CharSequence> iterator,
 Object2LongFunction<? extends CharSequence> function)

Deprecated.

Generates a 64-bit signatures big array using a given function and string sequence.

The resulting big array can be saved using BinIO.storeLongs(long[][], CharSequence) or similar BinIO methods.

Parameters:

iterator - an iterator over a list of strings.

function - the function to be signed.

Returns:

a big array of 64-bit signatures.

sign

public static long[][] sign(Iterator<? extends CharSequence> iterator,
 Object2LongFunction<? extends CharSequence> function,
 ProgressLogger pl)

Deprecated.

Generates a 64-bit signatures big array using a given function and string sequence.

The resulting big array can be saved using BinIO.storeLongs(long[][], CharSequence) or similar BinIO methods.

Parameters:

iterator - an iterator over a list of strings.

function - the function to be signed.

pl - a progress logger, or null.

Returns:

a big array of 64-bit signatures.

sign

public static void sign(Iterator<? extends CharSequence> iterator,
 String signatureFile)
                 throws IOException

Deprecated.

Generates an on-disk list 64-bit signatures big array using a given string sequence.

This methods generates on-disk signatures in the same order of the strings returned by the provided iterator. Thus, the signature file can be only used with a function that maps each string returned by the iterator in its ordinal position. This happens, for instance, if you have a sorted set of string and you use a monotone minimal perfect hash function.

Parameters:

iterator - an iterator over a list of strings.

signatureFile - the file name of the resulting signature file.

Throws:

IOException

sign

public static void sign(Iterator<? extends CharSequence> iterator,
 String signatureFile,
 ProgressLogger pl)
                 throws IOException

Deprecated.

Generates an on-disk list 64-bit signatures big array using a given string sequence.

Parameters:

iterator - an iterator over a list of strings.

signatureFile - the file name of the resulting signature file.

pl - a progress logger, or null.

Throws:

IOException

See Also:

• sign(Iterator, DataOutput, ProgressLogger)

sign

public static void sign(Iterator<? extends CharSequence> iterator,
 DataOutput signatures,
 ProgressLogger pl)
                 throws IOException

Deprecated.

Generates an on-disk list 64-bit signatures big array using a given string sequence.

This methods generates on-disk signatures in the same order of the strings returned by the provided iterator. Thus, the generated signatures can be only used with a function that maps each string returned by the iterator in its ordinal position. This happens, for instance, if you have a sorted set of string and you use a monotone minimal perfect hash function.

Parameters:

iterator - an iterator over a list of strings.

signatures - a DataOutput where the signatures will be written.

pl - a progress logger, or null.

Throws:

IOException

getLong

public long getLong(Object o)

Deprecated.

Specified by:

getLong in interface Object2LongFunction<CharSequence>

get

public Long get(Object o)

Deprecated.

Specified by:

get in interface Function<CharSequence,Long>

Specified by:

get in interface Object2LongFunction<CharSequence>

containsKey

public boolean containsKey(Object o)

Deprecated.

Specified by:

containsKey in interface Function<CharSequence,Long>

size

@Deprecated
public int size()

Deprecated.

Description copied from interface: StringMap

Specified by:

size in interface Function<CharSequence,Long>

Specified by:

size in interface Size64

Specified by:

size in interface StringMap<CharSequence>

size64

public long size64()

Deprecated.

Description copied from interface: StringMap

Returns the intended number of keys in this function, or -1 if no such number exists.

Most function implementations will have some knowledge of the intended number of keys in their domain. In some cases, however, this might not be possible. This default implementation, in particular, returns -1.

Specified by:

size64 in interface Size64

Specified by:

size64 in interface StringMap<CharSequence>

Returns:

the intended number of keys in this function, or -1 if that number is not available.

list

public ObjectBigList<CharSequence> list()

Deprecated.

Description copied from interface: StringMap

Returns a list view of the domain of this string map (optional operation).

Note that the list view acts as an inverse of the mapping implemented by this map.

Specified by:

list in interface StringMap<CharSequence>

Returns:

a list view of the domain of this string map, or null if this map does not support this operation.

main

public static void main(String[] arg)
                 throws NoSuchMethodException,
IOException,
JSAPException,
ClassNotFoundException

Deprecated.

Throws:

NoSuchMethodException

IOException

JSAPException

ClassNotFoundException