public class DistinctNumberList extends AbstractLongList
This class can, for example, be useful when making large lists of numbers persistent. Also useful when very large lists would otherwise consume too much main memory.
You can add, get and set elements quite similar to java.util.ArrayList.
Applicability: Applicable if data is highly skewed and legal values are known in advance. Robust in the presence of "outliers".
Performance: Operations get(), size() and clear() are O(1), i.e. run in constant time. Operations like add() and set() are O(log(distinctValues.length)).
Upon instantiation a contract is signed that defines the distinct values allowed to be hold in this list. It is not legal to store elements other than specified by the contract. Any attempt to violate the contract will throw an IllegalArgumentException.
Although access methods are only defined on long values you can also store all other primitive data types: boolean, byte, short, int, long, float, double and char. You can do this by explicitly representing them as long values. Use casts for discrete data types. Use the methods of java.lang.Float and java.lang.Double for floating point data types: Recall that with those methods you can convert any floating point value to a long value and back without losing any precision:
Example usage:
DistinctNumberList list = ... instantiation goes here
double d1 = 1.234;
list.add(Double.doubleToLongBits(d1));
double d2 = Double.longBitsToDouble(list.get(0));
if (d1!=d2) System.out.println("This is impossible!");
DistinctNumberList list2 = ... instantiation goes here
float f1 = 1.234f;
list2.add((long) Float.floatToIntBits(f1));
float f2 = Float.intBitsToFloat((int)list2.get(0));
if (f1!=f2) System.out.println("This is impossible!");
LongArrayList,
MinMaxNumberList,
Float,
Double,
Serialized Form| Modifier and Type | Field and Description |
|---|---|
protected long[] |
distinctValues |
protected MinMaxNumberList |
elements |
sizeserialVersionUID| Constructor and Description |
|---|
DistinctNumberList(long[] distinctValues,
int initialCapacity)
Constructs an empty list with the specified initial capacity and the specified distinct values allowed to be hold in this list.
|
| Modifier and Type | Method and Description |
|---|---|
void |
add(long element)
Appends the specified element to the end of this list.
|
protected int |
codeOf(long element)
Returns the code that shall be stored for the given element.
|
void |
ensureCapacity(int minCapacity)
Ensures that the receiver can hold at least the specified number of elements without needing to allocate new internal memory.
|
long |
getQuick(int index)
Returns the element at the specified position in the receiver; WARNING: Does not check preconditions.
|
void |
removeFromTo(int from,
int to)
Removes from the receiver all elements whose index is between
from, inclusive and to, inclusive. |
void |
setQuick(int index,
long element)
Replaces the element at the specified position in the receiver with the specified element; WARNING: Does not check preconditions.
|
protected void |
setSizeRaw(int newSize)
Sets the size of the receiver without modifying it otherwise.
|
protected void |
setUp(long[] distinctValues,
int initialCapacity)
Sets the receiver to an empty list with the specified initial capacity and the specified distinct values allowed to be hold in this list.
|
void |
trimToSize()
Trims the capacity of the receiver to be the receiver's current
size.
|
addAllOfFromTo, beforeInsert, beforeInsertAllOfFromTo, beforeInsertDummies, binarySearch, binarySearchFromTo, clone, contains, delete, elements, elements, equals, fillFromToWith, forEach, get, indexOf, indexOfFromTo, lastIndexOf, lastIndexOfFromTo, mergeSortFromTo, mergeSortFromTo, partFromTo, quickSortFromTo, quickSortFromTo, removeAll, replaceFromToWithFrom, replaceFromToWithFromTo, replaceFromWith, retainAll, reverse, set, shuffleFromTo, size, times, toList, toStringaddAllOf, beforeInsertAllOf, checkRange, checkRangeFromTo, clear, mergeSort, quickSort, remove, setSize, shuffle, sort, sortFromToisEmptyprotected long[] distinctValues
protected MinMaxNumberList elements
public DistinctNumberList(long[] distinctValues,
int initialCapacity)
distinctValues - an array sorted ascending containing the distinct values allowed to be hold in this list.initialCapacity - the number of elements the receiver can hold without auto-expanding itself by allocating new internal memory.public void add(long element)
add in class AbstractLongListelement - element to be appended to this list.protected int codeOf(long element)
public void ensureCapacity(int minCapacity)
ensureCapacity in class AbstractLongListminCapacity - the desired minimum capacity.public long getQuick(int index)
getQuick in class AbstractLongListindex - index of element to return.public void removeFromTo(int from,
int to)
from, inclusive and to, inclusive. Shifts any succeeding
elements to the left (reduces their index).
This call shortens the list by (to - from + 1) elements.removeFromTo in class AbstractLongListfrom - index of first element to be removed.to - index of last element to be removed.IndexOutOfBoundsException - index is out of range (size()>0 && (from<0 || from>to || to>=size())).public void setQuick(int index,
long element)
setQuick in class AbstractLongListindex - index of element to replace.element - element to be stored at the specified position.protected void setSizeRaw(int newSize)
setSizeRaw in class AbstractLongListprotected void setUp(long[] distinctValues,
int initialCapacity)
distinctValues - an array sorted ascending containing the distinct values allowed to be hold in this list.initialCapacity - the number of elements the receiver can hold without auto-expanding itself by allocating new internal memory.public void trimToSize()
trimToSize in class AbstractListCopyright © 2006–2019 SYSTAP, LLC DBA Blazegraph. All rights reserved.