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

    All Methods Static Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `static <V> void` | `apply(java.lang.Object[] btree, java.util.function.Consumer<V> function, boolean reversed)` Simple method to walk the btree forwards or reversed and apply a function to each element Public method
    `static <V> void` | `apply(java.lang.Object[] btree, java.util.function.Consumer<V> function, com.google.common.base.Predicate<V> stopCondition, boolean reversed)` Simple method to walk the btree forwards or reversed and apply a function till a stop condition is reached Public method
    `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 <V> void` | `replaceInSitu(java.lang.Object[] tree, int index, 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[] tree,
                                               int index,
                                               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 item provided by index in the tree.

    - #### 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)

    - #### apply

          public static <V> void apply(java.lang.Object[] btree,
                                       java.util.function.Consumer<V> function,
                                       boolean reversed)

      Simple method to walk the btree forwards or reversed and apply a function to each element Public method

    - #### apply

          public static <V> void apply(java.lang.Object[] btree,
                                       java.util.function.Consumer<V> function,
                                       com.google.common.base.Predicate<V> stopCondition,
                                       boolean reversed)

      Simple method to walk the btree forwards or reversed and apply a function till a stop condition is reached Public method

Copyright © 2018 The Apache Software Foundation