org.apache.cassandra.utils.btree

Class BTree

java.lang.Object

org.apache.cassandra.utils.btree.BTree

public class BTree
extends java.lang.Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BTree.Builder<V>
static class	BTree.Dir

Constructor Summary

Constructors

Constructor and Description
BTree()

Method Summary

Modifier and Type	Method and Description
static <C,K extends C,V extends C> java.lang.Object[]	build(java.util.Collection<K> source, UpdateFunction<K,V> updateF)
static <C,K extends C,V extends C> java.lang.Object[]	build(java.lang.Iterable<K> source, int size, UpdateFunction<K,V> updateF) Creates a BTree containing all of the objects in the provided collection
static <C,K extends C,V extends C> java.lang.Object[]	build(java.lang.Iterable<K> source, UpdateFunction<K,V> updateF)
static <V> BTree.Builder<V>	builder(java.util.Comparator<? super V> comparator)
static <V> BTree.Builder<V>	builder(java.util.Comparator<? super V> comparator, int initialCapacity)
static <V> V	ceil(java.lang.Object[] btree, java.util.Comparator<? super V> comparator, V find)
static <V> int	ceilIndex(java.lang.Object[] btree, java.util.Comparator<? super V> comparator, V find)
static int	depth(java.lang.Object[] tree)
static java.lang.Object[]	empty()
static boolean	equals(java.lang.Object[] a, java.lang.Object[] b)
static <V> V	find(java.lang.Object[] node, java.util.Comparator<? super V> comparator, V find)
static <V> V	findByIndex(java.lang.Object[] tree, int index)
static <V> int	findIndex(java.lang.Object[] node, java.util.Comparator<? super V> comparator, V find) Honours result semantics of Arrays.binarySearch(long[], long), as though it were performed on the tree flattened into an array
static <V> V	floor(java.lang.Object[] btree, java.util.Comparator<? super V> comparator, V find)
static <V> int	floorIndex(java.lang.Object[] btree, java.util.Comparator<? super V> comparator, V find)
static int	hashCode(java.lang.Object[] btree)
static <V> V	higher(java.lang.Object[] btree, java.util.Comparator<? super V> comparator, V find)
static <V> int	higherIndex(java.lang.Object[] btree, java.util.Comparator<? super V> comparator, V find)
static boolean	isEmpty(java.lang.Object[] tree)
static boolean	isWellFormed(java.lang.Object[] btree, java.util.Comparator<? extends java.lang.Object> cmp)
static <V> java.lang.Iterable<V>	iterable(java.lang.Object[] btree)
static <V> java.lang.Iterable<V>	iterable(java.lang.Object[] btree, BTree.Dir dir)
static <V> java.lang.Iterable<V>	iterable(java.lang.Object[] btree, int lb, int ub, BTree.Dir dir)
static <V> java.util.Iterator<V>	iterator(java.lang.Object[] btree)
static <V> java.util.Iterator<V>	iterator(java.lang.Object[] btree, BTree.Dir dir)
static <V> java.util.Iterator<V>	iterator(java.lang.Object[] btree, int lb, int ub, BTree.Dir dir)
static <V> V	lower(java.lang.Object[] btree, java.util.Comparator<? super V> comparator, V find)
static <V> int	lowerIndex(java.lang.Object[] btree, java.util.Comparator<? super V> comparator, V find)
static <K> java.lang.Object[]	merge(java.lang.Object[] tree1, java.lang.Object[] tree2, java.util.Comparator<? super K> comparator, UpdateFunction<K,K> updateF)
static <V> void	replaceInSitu(java.lang.Object[] node, java.util.Comparator<? super V> comparator, V find, V replace) Modifies the provided btree directly.
static java.lang.Object[]	singleton(java.lang.Object value)
static int	size(java.lang.Object[] tree)
static long	sizeOfStructureOnHeap(java.lang.Object[] tree)
static <K,V> BTreeSearchIterator<K,V>	slice(java.lang.Object[] btree, java.util.Comparator<? super K> comparator, BTree.Dir dir) Returns an Iterator over the entire tree
static <K,V extends K> BTreeSearchIterator<K,V>	slice(java.lang.Object[] btree, java.util.Comparator<? super K> comparator, K start, boolean startInclusive, K end, boolean endInclusive, BTree.Dir dir)
static <K,V extends K> BTreeSearchIterator<K,V>	slice(java.lang.Object[] btree, java.util.Comparator<? super K> comparator, K start, K end, BTree.Dir dir)
static int	toArray(java.lang.Object[] tree, int treeStart, int treeEnd, java.lang.Object[] target, int targetOffset)
static int	toArray(java.lang.Object[] tree, java.lang.Object[] target, int targetOffset) Fill the target array with the contents of the provided subtree, in ascending order, starting at targetOffset
static <V> java.lang.Object[]	transformAndFilter(java.lang.Object[] btree, com.google.common.base.Function<? super V,? extends V> function) Takes a btree and transforms it using the provided function, filtering out any null results.
static int	treeIndexOfBranchKey(java.lang.Object[] root, int keyIndex)
static int	treeIndexOffsetOfChild(java.lang.Object[] root, int childIndex)
static int	treeIndexOfKey(java.lang.Object[] root, int keyIndex) tree index => index of key wrt all items in the tree laid out serially This version of the method permits requesting out-of-bounds indexes, -1 and size
static int	treeIndexOfLeafKey(int keyIndex)
static <C,K extends C,V extends C> java.lang.Object[]	update(java.lang.Object[] btree, java.util.Comparator<C> comparator, java.util.Collection<K> updateWith, UpdateFunction<K,V> updateF)
static <C,K extends C,V extends C> java.lang.Object[]	update(java.lang.Object[] btree, java.util.Comparator<C> comparator, java.lang.Iterable<K> updateWith, int updateWithLength, UpdateFunction<K,V> updateF) Returns a new BTree with the provided collection inserting/replacing as necessary any equal items

Methods inherited from class java.lang.Object

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

Constructor Detail

BTree

public BTree()

Method Detail

empty

public static java.lang.Object[] empty()

singleton

public static java.lang.Object[] singleton(java.lang.Object value)

build

public static <C,K extends C,V extends C> java.lang.Object[] build(java.util.Collection<K> source,
                                                                   UpdateFunction<K,V> updateF)

build

public static <C,K extends C,V extends C> java.lang.Object[] build(java.lang.Iterable<K> source,
                                                                   UpdateFunction<K,V> updateF)

build

public static <C,K extends C,V extends C> java.lang.Object[] build(java.lang.Iterable<K> source,
                                                                   int size,
                                                                   UpdateFunction<K,V> updateF)

Creates a BTree containing all of the objects in the provided collection

Parameters:

source - the items to build the tree with. MUST BE IN STRICTLY ASCENDING ORDER.

size - the size of the source iterable

Returns:

a btree representing the contents of the provided iterable

update

public static <C,K extends C,V extends C> java.lang.Object[] update(java.lang.Object[] btree,
                                                                    java.util.Comparator<C> comparator,
                                                                    java.util.Collection<K> updateWith,
                                                                    UpdateFunction<K,V> updateF)

update

public static <C,K extends C,V extends C> java.lang.Object[] update(java.lang.Object[] btree,
                                                                    java.util.Comparator<C> comparator,
                                                                    java.lang.Iterable<K> updateWith,
                                                                    int updateWithLength,
                                                                    UpdateFunction<K,V> updateF)

Returns a new BTree with the provided collection inserting/replacing as necessary any equal items

Type Parameters:

V -

Parameters:

btree - the tree to update

comparator - the comparator that defines the ordering over the items in the tree

updateWith - the items to either insert / update. MUST BE IN STRICTLY ASCENDING ORDER.

updateWithLength - then number of elements in updateWith

updateF - the update function to apply to any pairs we are swapping, and maybe abort early

Returns:

merge

public static <K> java.lang.Object[] merge(java.lang.Object[] tree1,
                                           java.lang.Object[] tree2,
                                           java.util.Comparator<? super K> comparator,
                                           UpdateFunction<K,K> updateF)

iterator

public static <V> java.util.Iterator<V> iterator(java.lang.Object[] btree)

iterator

public static <V> java.util.Iterator<V> iterator(java.lang.Object[] btree,
                                                 BTree.Dir dir)

iterator

public static <V> java.util.Iterator<V> iterator(java.lang.Object[] btree,
                                                 int lb,
                                                 int ub,
                                                 BTree.Dir dir)

iterable

public static <V> java.lang.Iterable<V> iterable(java.lang.Object[] btree)

iterable

public static <V> java.lang.Iterable<V> iterable(java.lang.Object[] btree,
                                                 BTree.Dir dir)

iterable

public static <V> java.lang.Iterable<V> iterable(java.lang.Object[] btree,
                                                 int lb,
                                                 int ub,
                                                 BTree.Dir dir)

slice

public static <K,V> BTreeSearchIterator<K,V> slice(java.lang.Object[] btree,
                                                   java.util.Comparator<? super K> comparator,
                                                   BTree.Dir dir)

Returns an Iterator over the entire tree

Type Parameters:

V -

Parameters:

btree - the tree to iterate over

dir - direction of iteration

Returns:

slice

public static <K,V extends K> BTreeSearchIterator<K,V> slice(java.lang.Object[] btree,
                                                             java.util.Comparator<? super K> comparator,
                                                             K start,
                                                             K end,
                                                             BTree.Dir dir)

Parameters:

btree - the tree to iterate over

comparator - the comparator that defines the ordering over the items in the tree

start - the beginning of the range to return, inclusive (in ascending order)

end - the end of the range to return, exclusive (in ascending order)

dir - if false, the iterator will start at the last item and move backwards

Returns:

an Iterator over the defined sub-range of the tree

slice

public static <K,V extends K> BTreeSearchIterator<K,V> slice(java.lang.Object[] btree,
                                                             java.util.Comparator<? super K> comparator,
                                                             K start,
                                                             boolean startInclusive,
                                                             K end,
                                                             boolean endInclusive,
                                                             BTree.Dir dir)

Parameters:

btree - the tree to iterate over

comparator - the comparator that defines the ordering over the items in the tree

start - low bound of the range

startInclusive - inclusivity of lower bound

end - high bound of the range

endInclusive - inclusivity of higher bound

dir - direction of iteration

Returns:

an Iterator over the defined sub-range of the tree

find

public static <V> V find(java.lang.Object[] node,
                         java.util.Comparator<? super V> comparator,
                         V find)

Returns:

the item in the tree that sorts as equal to the search argument, or null if no such item

replaceInSitu

public static <V> void replaceInSitu(java.lang.Object[] node,
                                     java.util.Comparator<? super V> comparator,
                                     V find,
                                     V replace)

Modifies the provided btree directly. THIS SHOULD NOT BE USED WITHOUT EXTREME CARE as BTrees are meant to be immutable. Finds and replaces the provided item in the tree. Both should sort as equal to each other (although this is not enforced)

findIndex

public static <V> int findIndex(java.lang.Object[] node,
                                java.util.Comparator<? super V> comparator,
                                V find)

Honours result semantics of Arrays.binarySearch(long[], long), as though it were performed on the tree flattened into an array

Returns:

index of item in tree, or (-(insertion point) - 1) if not present

findByIndex

public static <V> V findByIndex(java.lang.Object[] tree,
                                int index)

Returns:

the value at the index'th position in the tree, in tree order

lowerIndex

public static <V> int lowerIndex(java.lang.Object[] btree,
                                 java.util.Comparator<? super V> comparator,
                                 V find)

lower

public static <V> V lower(java.lang.Object[] btree,
                          java.util.Comparator<? super V> comparator,
                          V find)

floorIndex

public static <V> int floorIndex(java.lang.Object[] btree,
                                 java.util.Comparator<? super V> comparator,
                                 V find)

floor

public static <V> V floor(java.lang.Object[] btree,
                          java.util.Comparator<? super V> comparator,
                          V find)

higherIndex

public static <V> int higherIndex(java.lang.Object[] btree,
                                  java.util.Comparator<? super V> comparator,
                                  V find)

higher

public static <V> V higher(java.lang.Object[] btree,
                           java.util.Comparator<? super V> comparator,
                           V find)

ceilIndex

public static <V> int ceilIndex(java.lang.Object[] btree,
                                java.util.Comparator<? super V> comparator,
                                V find)

ceil

public static <V> V ceil(java.lang.Object[] btree,
                         java.util.Comparator<? super V> comparator,
                         V find)

size

public static int size(java.lang.Object[] tree)

sizeOfStructureOnHeap

public static long sizeOfStructureOnHeap(java.lang.Object[] tree)

isEmpty

public static boolean isEmpty(java.lang.Object[] tree)

depth

public static int depth(java.lang.Object[] tree)

toArray

public static int toArray(java.lang.Object[] tree,
                          java.lang.Object[] target,
                          int targetOffset)

Fill the target array with the contents of the provided subtree, in ascending order, starting at targetOffset

Parameters:

tree - source

target - array

targetOffset - offset in target array

Returns:

number of items copied (size of tree)

toArray

public static int toArray(java.lang.Object[] tree,
                          int treeStart,
                          int treeEnd,
                          java.lang.Object[] target,
                          int targetOffset)

transformAndFilter

public static <V> java.lang.Object[] transformAndFilter(java.lang.Object[] btree,
                                                        com.google.common.base.Function<? super V,? extends V> function)

Takes a btree and transforms it using the provided function, filtering out any null results. The result of any transformation must sort identically wrt the other results as their originals

equals

public static boolean equals(java.lang.Object[] a,
                             java.lang.Object[] b)

hashCode

public static int hashCode(java.lang.Object[] btree)

treeIndexOfKey

public static int treeIndexOfKey(java.lang.Object[] root,
                                 int keyIndex)

tree index => index of key wrt all items in the tree laid out serially This version of the method permits requesting out-of-bounds indexes, -1 and size

Parameters:

root - to calculate tree index within

keyIndex - root-local index of key to calculate tree-index

Returns:

the number of items preceding the key in the whole tree of root

treeIndexOfLeafKey

public static int treeIndexOfLeafKey(int keyIndex)

Parameters:

keyIndex - node-local index of the key to calculate index of

Returns:

keyIndex; this method is here only for symmetry and clarity

treeIndexOfBranchKey

public static int treeIndexOfBranchKey(java.lang.Object[] root,
                                       int keyIndex)

Parameters:

root - to calculate tree-index within

keyIndex - root-local index of key to calculate tree-index of

Returns:

the number of items preceding the key in the whole tree of root

treeIndexOffsetOfChild

public static int treeIndexOffsetOfChild(java.lang.Object[] root,
                                         int childIndex)

Parameters:

root - to calculate tree-index within

childIndex - root-local index of *child* to calculate tree-index of

Returns:

the number of items preceding the child in the whole tree of root

builder

public static <V> BTree.Builder<V> builder(java.util.Comparator<? super V> comparator)

builder

public static <V> BTree.Builder<V> builder(java.util.Comparator<? super V> comparator,
                                           int initialCapacity)

isWellFormed

public static boolean isWellFormed(java.lang.Object[] btree,
                                   java.util.Comparator<? extends java.lang.Object> cmp)