gods: github.com/emirpasic/gods/trees/btree Index | Files

package btree

import "github.com/emirpasic/gods/trees/btree"

Package btree implements a B tree.

According to Knuth's definition, a B-tree of order m is a tree which satisfies the following properties: - Every node has at most m children. - Every non-leaf node (except root) has at least ⌈m/2⌉ children. - The root has at least two children if it is not a leaf node. - A non-leaf node with k children contains k−1 keys. - All leaves appear in the same level

Structure is not thread safe.

References: https://en.wikipedia.org/wiki/B-tree

Index

Package Files

btree.go iterator.go serialization.go

type Entry Uses

type Entry struct {
    Key   interface{}
    Value interface{}
}

Entry represents the key-value pair contained within nodes

func (*Entry) String Uses

func (entry *Entry) String() string

type Iterator Uses

type Iterator struct {
    // contains filtered or unexported fields
}

Iterator holding the iterator's state

func (*Iterator) Begin Uses

func (iterator *Iterator) Begin()

Begin resets the iterator to its initial state (one-before-first) Call Next() to fetch the first element if any.

func (*Iterator) End Uses

func (iterator *Iterator) End()

End moves the iterator past the last element (one-past-the-end). Call Prev() to fetch the last element if any.

func (*Iterator) First Uses

func (iterator *Iterator) First() bool

First moves the iterator to the first element and returns true if there was a first element in the container. If First() returns true, then first element's key and value can be retrieved by Key() and Value(). Modifies the state of the iterator

func (*Iterator) Key Uses

func (iterator *Iterator) Key() interface{}

Key returns the current element's key. Does not modify the state of the iterator.

func (*Iterator) Last Uses

func (iterator *Iterator) Last() bool

Last moves the iterator to the last element and returns true if there was a last element in the container. If Last() returns true, then last element's key and value can be retrieved by Key() and Value(). Modifies the state of the iterator.

func (*Iterator) Next Uses

func (iterator *Iterator) Next() bool

Next moves the iterator to the next element and returns true if there was a next element in the container. If Next() returns true, then next element's key and value can be retrieved by Key() and Value(). If Next() was called for the first time, then it will point the iterator to the first element if it exists. Modifies the state of the iterator.

func (*Iterator) Prev Uses

func (iterator *Iterator) Prev() bool

Prev moves the iterator to the previous element and returns true if there was a previous element in the container. If Prev() returns true, then previous element's key and value can be retrieved by Key() and Value(). Modifies the state of the iterator.

func (*Iterator) Value Uses

func (iterator *Iterator) Value() interface{}

Value returns the current element's value. Does not modify the state of the iterator.

type Node Uses

type Node struct {
    Parent   *Node
    Entries  []*Entry // Contained keys in node
    Children []*Node  // Children nodes
}

Node is a single element within the tree

type Tree Uses

type Tree struct {
    Root       *Node            // Root node
    Comparator utils.Comparator // Key comparator
    // contains filtered or unexported fields
}

Tree holds elements of the B-tree

func NewWith Uses

func NewWith(order int, comparator utils.Comparator) *Tree

NewWith instantiates a B-tree with the order (maximum number of children) and a custom key comparator.

func NewWithIntComparator Uses

func NewWithIntComparator(order int) *Tree

NewWithIntComparator instantiates a B-tree with the order (maximum number of children) and the IntComparator, i.e. keys are of type int.

func NewWithStringComparator Uses

func NewWithStringComparator(order int) *Tree

NewWithStringComparator instantiates a B-tree with the order (maximum number of children) and the StringComparator, i.e. keys are of type string.

func (*Tree) Clear Uses

func (tree *Tree) Clear()

Clear removes all nodes from the tree.

func (*Tree) Empty Uses

func (tree *Tree) Empty() bool

Empty returns true if tree does not contain any nodes

func (*Tree) FromJSON Uses

func (tree *Tree) FromJSON(data []byte) error

FromJSON populates the tree from the input JSON representation.

func (*Tree) Get Uses

func (tree *Tree) Get(key interface{}) (value interface{}, found bool)

Get searches the node in the tree by key and returns its value or nil if key is not found in tree. Second return parameter is true if key was found, otherwise false. Key should adhere to the comparator's type assertion, otherwise method panics.

func (*Tree) Height Uses

func (tree *Tree) Height() int

Height returns the height of the tree.

func (*Tree) Iterator Uses

func (tree *Tree) Iterator() Iterator

Iterator returns a stateful iterator whose elements are key/value pairs.

func (*Tree) Keys Uses

func (tree *Tree) Keys() []interface{}

Keys returns all keys in-order

func (*Tree) Left Uses

func (tree *Tree) Left() *Node

Left returns the left-most (min) node or nil if tree is empty.

func (*Tree) LeftKey Uses

func (tree *Tree) LeftKey() interface{}

LeftKey returns the left-most (min) key or nil if tree is empty.

func (*Tree) LeftValue Uses

func (tree *Tree) LeftValue() interface{}

LeftValue returns the left-most value or nil if tree is empty.

func (*Tree) Put Uses

func (tree *Tree) Put(key interface{}, value interface{})

Put inserts key-value pair node into the tree. If key already exists, then its value is updated with the new value. Key should adhere to the comparator's type assertion, otherwise method panics.

func (*Tree) Remove Uses

func (tree *Tree) Remove(key interface{})

Remove remove the node from the tree by key. Key should adhere to the comparator's type assertion, otherwise method panics.

func (*Tree) Right Uses

func (tree *Tree) Right() *Node

Right returns the right-most (max) node or nil if tree is empty.

func (*Tree) RightKey Uses

func (tree *Tree) RightKey() interface{}

RightKey returns the right-most (max) key or nil if tree is empty.

func (*Tree) RightValue Uses

func (tree *Tree) RightValue() interface{}

RightValue returns the right-most value or nil if tree is empty.

func (*Tree) Size Uses

func (tree *Tree) Size() int

Size returns number of nodes in the tree.

func (*Tree) String Uses

func (tree *Tree) String() string

String returns a string representation of container (for debugging purposes)

func (*Tree) ToJSON Uses

func (tree *Tree) ToJSON() ([]byte, error)

ToJSON outputs the JSON representation of the tree.

func (*Tree) Values Uses

func (tree *Tree) Values() []interface{}

Values returns all values in-order based on the key.

Package btree imports 7 packages (graph) and is imported by 5 packages. Updated 2018-10-22. Refresh now. Tools for package owners.