Class HugeDoubleArray
- java.lang.Object
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- org.neo4j.gds.core.utils.paged.HugeArray<double[],java.lang.Double,HugeDoubleArray>
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- org.neo4j.gds.core.utils.paged.HugeDoubleArray
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- All Implemented Interfaces:
HugeCursorSupport<double[]>
public abstract class HugeDoubleArray extends HugeArray<double[],java.lang.Double,HugeDoubleArray>
A long-indexable version of a primitive double array (double[]
) that can contain more than 2 bn. elements.It is implemented by paging of smaller double-arrays (
double[][]
) to support approx. 32k bn. elements. If the provided size is small enough, an optimized view of a singledouble[]
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.
- The array does not support default values and returns the same default for unset values that a regular
double[]
does (0
).
Basic Usage
AllocationTracker tracker = ...; long arraySize = 42L; HugeDoubleArray array = HugeDoubleArray.newArray(arraySize, tracker); array.set(13L, 37D); double value = array.get(13L); // value = 37D
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Constructor Summary
Constructors Constructor Description HugeDoubleArray()
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Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description abstract void
addTo(long index, double value)
Adds (+
) the existing value and the provided value at the given index and stored the result into the given index.DoubleNodeProperties
asNodeProperties()
HugeDoubleArray
copyOf(long newLength, AllocationTracker tracker)
Creates a copy of the given array.abstract void
copyTo(HugeDoubleArray dest, long length)
Copies the content of this array into the target array.abstract void
fill(double value)
Assigns the specified double value to each element.abstract double
get(long index)
static long
memoryEstimation(long size)
static HugeDoubleArray
newArray(long size, AllocationTracker tracker)
Creates a new array of the given size, tracking the memory requirements into the givenAllocationTracker
.abstract HugeCursor<double[]>
newCursor()
Returns a newHugeCursor
for this array.static HugeDoubleArray
of(double... values)
abstract long
release()
Destroys the data, allowing the underlying storage arrays to be collected as garbage.abstract void
set(long index, double value)
Sets the double value at the given index to the given value.abstract void
setAll(java.util.function.LongToDoubleFunction 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()
abstract java.util.stream.DoubleStream
stream()
double[]
toArray()
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Methods inherited from class org.neo4j.gds.core.utils.paged.HugeArray
copyFromArrayIntoSlice, toString
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.neo4j.gds.core.utils.paged.HugeCursorSupport
initCursor, initCursor
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Method Detail
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get
public abstract double get(long index)
- Returns:
- the double value at the given index
- Throws:
java.lang.ArrayIndexOutOfBoundsException
- if the index is not withinsize()
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set
public abstract void set(long index, double value)
Sets the double value at the given index to the given value.- Throws:
java.lang.ArrayIndexOutOfBoundsException
- if the index is not withinsize()
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addTo
public abstract void addTo(long index, double 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 withinsize()
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setAll
public abstract void setAll(java.util.function.LongToDoubleFunction gen)
Set all elements using the provided generator function to compute each element.The behavior is identical to
Arrays.setAll(double[], java.util.function.IntToDoubleFunction)
.
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fill
public abstract void fill(double value)
Assigns the specified double value to each element.The behavior is identical to
Arrays.fill(double[], double)
.
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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 interfaceHugeCursorSupport<double[]>
- Specified by:
size
in classHugeArray<double[],java.lang.Double,HugeDoubleArray>
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sizeOf
public abstract long sizeOf()
- Specified by:
sizeOf
in classHugeArray<double[],java.lang.Double,HugeDoubleArray>
- 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.
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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 throwNullPointerException
s 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 classHugeArray<double[],java.lang.Double,HugeDoubleArray>
- Returns:
- the amount of memory freed, in bytes.
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newCursor
public abstract HugeCursor<double[]> newCursor()
Returns a newHugeCursor
for this array. The cursor is not positioned and in an invalid state. To position the cursor you must callHugeCursorSupport.initCursor(HugeCursor)
orHugeCursorSupport.initCursor(HugeCursor, long, long)
. Then the cursor needs to be put in a valid state by callingHugeCursor.next()
. Obtaining aHugeCursor
for an empty array (whereHugeCursorSupport.size()
returns0
) is undefined and might result in aNullPointerException
or anotherRuntimeException
.
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stream
public abstract java.util.stream.DoubleStream stream()
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copyTo
public abstract void copyTo(HugeDoubleArray 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 classHugeArray<double[],java.lang.Double,HugeDoubleArray>
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copyOf
public final HugeDoubleArray copyOf(long newLength, AllocationTracker tracker)
Creates a copy of the given array. The behavior is identical toArrays.copyOf(int[], int)
.- Specified by:
copyOf
in classHugeArray<double[],java.lang.Double,HugeDoubleArray>
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toArray
public double[] toArray()
- Specified by:
toArray
in classHugeArray<double[],java.lang.Double,HugeDoubleArray>
- 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.
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asNodeProperties
public DoubleNodeProperties asNodeProperties()
- Specified by:
asNodeProperties
in classHugeArray<double[],java.lang.Double,HugeDoubleArray>
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newArray
public static HugeDoubleArray newArray(long size, AllocationTracker tracker)
Creates a new array of the given size, tracking the memory requirements into the givenAllocationTracker
. The tracker is no longer referenced, as the arrays do not dynamically change their size.
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memoryEstimation
public static long memoryEstimation(long size)
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of
public static HugeDoubleArray of(double... values)
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