Package org.neo4j.gds.core.utils.paged

Class HugeLongArray

java.lang.Object

org.neo4j.gds.core.utils.paged.HugeArray<long[],java.lang.Long,HugeLongArray>

org.neo4j.gds.core.utils.paged.HugeLongArray

All Implemented Interfaces:

HugeCursorSupport<long[]>

public abstract class HugeLongArray
extends HugeArray<long[],java.lang.Long,HugeLongArray>

A long-indexable version of a primitive long array (long[]) that can contain more than 2 bn. elements.

It is implemented by paging of smaller long-arrays (long[][]) to support approx. 32k bn. elements. If the provided size is small enough, an optimized view of a single long[] might be used.

• The array is of a fixed size and cannot grow or shrink dynamically.
• The array is not optimized for sparseness and has a large memory overhead if the values written to it are very sparse (see HugeSparseLongArray for a different implementation that can profit from sparse data).
• The array does not support default values and returns the same default for unset values that a regular long[] does (0).

Basic Usage

 
 AllocationTracker allocationTracker = ...;
 long arraySize = 42L;
 HugeLongArray array = HugeLongArray.newArray(arraySize, allocationTracker);
 array.set(13L, 37L);
 long value = array.get(13L);
 // value = 37L
 
 

Constructor Summary

Constructors

Constructor	Description
HugeLongArray()

Method Summary

Modifier and Type	Method	Description
abstract void	addTo(long index, long value)	Adds (+) the existing value and the provided value at the given index and stored the result into the given index.
abstract long	and(long index, long value)	Computes the bit-wise AND (&) of the existing value and the provided value at the given index.
LongNodeProperties	asNodeProperties()
abstract long	binarySearch(long searchValue)	Find the index where (values[idx] <= searchValue) && (values[idx + 1] > searchValue).
HugeLongArray	copyOf(long newLength, AllocationTracker allocationTracker)	Creates a copy of the given array.
abstract void	copyTo(HugeLongArray dest, long length)	Copies the content of this array into the target array.
abstract void	fill(long value)	Assigns the specified long value to each element.
abstract long	get(long index)
static long	memoryEstimation(long size)
static HugeLongArray	newArray(long size, AllocationTracker allocationTracker)	Creates a new array of the given size, tracking the memory requirements into the given AllocationTracker.
abstract HugeCursor<long[]>	newCursor()	Returns a new HugeCursor for this array.
static HugeLongArray	of(long... values)
static HugeLongArray	of(long[][] array, long size)
abstract void	or(long index, long value)	Computes the bit-wise OR (|) of the existing value and the provided value at the given index.
abstract int	pages()
abstract long	release()	Destroys the data, allowing the underlying storage arrays to be collected as garbage.
abstract void	set(long index, long value)	Sets the long value at the given index to the given value.
abstract void	setAll(java.util.function.LongUnaryOperator gen)	Set all elements using the provided generator function to compute each element.
abstract long	size()	Returns the length of this array.
abstract long	sizeOf()
long[]	toArray()

Methods inherited from class org.neo4j.gds.core.utils.paged.HugeArray

copyFromArrayIntoSlice, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.neo4j.gds.core.utils.paged.HugeCursorSupport

initCursor, initCursor

Constructor Detail

HugeLongArray

public HugeLongArray()

Method Detail

get

public abstract long get(long index)

Returns:

the long value at the given index

Throws:

java.lang.ArrayIndexOutOfBoundsException - if the index is not within size()

set

public abstract void set(long index,
                         long value)

Sets the long value at the given index to the given value.

Throws:

java.lang.ArrayIndexOutOfBoundsException - if the index is not within size()

or

public abstract void or(long index,
                        long value)

Computes the bit-wise OR (|) of the existing value and the provided value at the given index. If there was no previous value, the final result is set to the provided value (x | 0 == x).

Throws:

java.lang.ArrayIndexOutOfBoundsException - if the index is not within size()

and

public abstract long and(long index,
                         long value)

Computes the bit-wise AND (&) of the existing value and the provided value at the given index. If there was no previous value, the final result is set to the 0 (x & 0 == 0).

Returns:

the now current value after the operation

Throws:

java.lang.ArrayIndexOutOfBoundsException - if the index is not within size()

addTo

public abstract void addTo(long index,
                           long value)

Adds (+) the existing value and the provided value at the given index and stored the result into the given index. If there was no previous value, the final result is set to the provided value (x + 0 == x).

Throws:

java.lang.ArrayIndexOutOfBoundsException - if the index is not within size()

setAll

public abstract void setAll(java.util.function.LongUnaryOperator gen)

Set all elements using the provided generator function to compute each element.

The behavior is identical to Arrays.setAll(long[], java.util.function.IntToLongFunction).

fill

public abstract void fill(long value)

Assigns the specified long value to each element.

The behavior is identical to Arrays.fill(long[], long).

size

public abstract long size()

Returns the length of this array.

If the size is greater than zero, the highest supported index is size() - 1

The behavior is identical to calling array.length on primitive arrays.

Specified by:

size in interface HugeCursorSupport<long[]>

Specified by:

size in class HugeArray<long[],java.lang.Long,HugeLongArray>

sizeOf

public abstract long sizeOf()

Specified by:

sizeOf in class HugeArray<long[],java.lang.Long,HugeLongArray>

Returns:

the amount of memory used by the instance of this array, in bytes. This should be the same as returned from HugeArray.release() without actually releasing the array.

binarySearch

public abstract long binarySearch(long searchValue)

Find the index where (values[idx] <= searchValue) && (values[idx + 1] > searchValue). The result differs from that of Arrays.binarySearch(long[], long) in that this method returns a positive index even if the array does not directly contain the searched value. It returns -1 iff the value is smaller than the smallest one in the array.

release

public abstract long release()

Destroys the data, allowing the underlying storage arrays to be collected as garbage. The array is unusable after calling this method and will throw NullPointerExceptions on virtually every method invocation.

Note that the data might not immediately collectible if there are still cursors alive that reference this array. You have to HugeCursor.close() every cursor instance as well.

The amount is not removed from the AllocationTracker that had been provided in the constructor.

Specified by:

release in class HugeArray<long[],java.lang.Long,HugeLongArray>

Returns:

the amount of memory freed, in bytes.

newCursor

public abstract HugeCursor<long[]> newCursor()

Returns a new HugeCursor for this array. The cursor is not positioned and in an invalid state. To position the cursor you must call HugeCursorSupport.initCursor(HugeCursor) or HugeCursorSupport.initCursor(HugeCursor, long, long). Then the cursor needs to be put in a valid state by calling HugeCursor.next(). Obtaining a HugeCursor for an empty array (where HugeCursorSupport.size() returns 0) is undefined and might result in a NullPointerException or another RuntimeException.

copyTo

public abstract void copyTo(HugeLongArray dest,
                            long length)

Copies the content of this array into the target array.

The behavior is identical to System.arraycopy(Object, int, Object, int, int).

Specified by:

copyTo in class HugeArray<long[],java.lang.Long,HugeLongArray>

copyOf

public final HugeLongArray copyOf(long newLength,
                                  AllocationTracker allocationTracker)

Creates a copy of the given array. The behavior is identical to Arrays.copyOf(int[], int).

Specified by:

copyOf in class HugeArray<long[],java.lang.Long,HugeLongArray>

pages

public abstract int pages()

toArray

public long[] toArray()

Specified by:

toArray in class HugeArray<long[],java.lang.Long,HugeLongArray>

Returns:

the contents of this array as a flat java primitive array. The returned array might be shared and changes would then be reflected and visible in this array.

asNodeProperties

public LongNodeProperties asNodeProperties()

Specified by:

asNodeProperties in class HugeArray<long[],java.lang.Long,HugeLongArray>

newArray

public static HugeLongArray newArray(long size,
                                     AllocationTracker allocationTracker)

Creates a new array of the given size, tracking the memory requirements into the given AllocationTracker. The tracker is no longer referenced, as the arrays do not dynamically change their size.

memoryEstimation

public static long memoryEstimation(long size)

of

public static HugeLongArray of(long... values)

of

public static HugeLongArray of(long[][] array,
                               long size)