Documentation ¶
Overview ¶
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 ¶
- type Entry
- type Iterator
- func (iterator *Iterator[K, V]) Begin()
- func (iterator *Iterator[K, V]) End()
- func (iterator *Iterator[K, V]) First() bool
- func (iterator *Iterator[K, V]) Key() K
- func (iterator *Iterator[K, V]) Last() bool
- func (iterator *Iterator[K, V]) Next() bool
- func (iterator *Iterator[K, V]) NextTo(f func(key K, value V) bool) bool
- func (iterator *Iterator[K, V]) Node() *Node[K, V]
- func (iterator *Iterator[K, V]) Prev() bool
- func (iterator *Iterator[K, V]) PrevTo(f func(key K, value V) bool) bool
- func (iterator *Iterator[K, V]) Value() V
- type Node
- type Tree
- func (tree *Tree[K, V]) Clear()
- func (tree *Tree[K, V]) Empty() bool
- func (tree *Tree[K, V]) FromJSON(data []byte) error
- func (tree *Tree[K, V]) Get(key K) (value V, found bool)
- func (tree *Tree[K, V]) GetNode(key K) *Node[K, V]
- func (tree *Tree[K, V]) Height() int
- func (tree *Tree[K, V]) Iterator() *Iterator[K, V]
- func (tree *Tree[K, V]) Keys() []K
- func (tree *Tree[K, V]) Left() *Node[K, V]
- func (tree *Tree[K, V]) LeftKey() interface{}
- func (tree *Tree[K, V]) LeftValue() interface{}
- func (tree *Tree[K, V]) MarshalJSON() ([]byte, error)
- func (tree *Tree[K, V]) Put(key K, value V)
- func (tree *Tree[K, V]) Remove(key K)
- func (tree *Tree[K, V]) Right() *Node[K, V]
- func (tree *Tree[K, V]) RightKey() interface{}
- func (tree *Tree[K, V]) RightValue() interface{}
- func (tree *Tree[K, V]) Size() int
- func (tree *Tree[K, V]) String() string
- func (tree *Tree[K, V]) ToJSON() ([]byte, error)
- func (tree *Tree[K, V]) UnmarshalJSON(bytes []byte) error
- func (tree *Tree[K, V]) Values() []V
Constants ¶
This section is empty.
Variables ¶
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Functions ¶
This section is empty.
Types ¶
type Entry ¶
type Entry[K comparable, V any] struct { Key K Value V }
Entry represents the key-value pair contained within nodes
type Iterator ¶
type Iterator[K comparable, V any] struct { // contains filtered or unexported fields }
Iterator holding the iterator's state
func (*Iterator[K, V]) Begin ¶
func (iterator *Iterator[K, V]) Begin()
Begin resets the iterator to its initial state (one-before-first) Call Next() to fetch the first element if any.
func (*Iterator[K, V]) End ¶
func (iterator *Iterator[K, V]) End()
End moves the iterator past the last element (one-past-the-end). Call Prev() to fetch the last element if any.
func (*Iterator[K, V]) First ¶
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[K, V]) Key ¶
func (iterator *Iterator[K, V]) Key() K
Key returns the current element's key. Does not modify the state of the iterator.
func (*Iterator[K, V]) Last ¶
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[K, V]) Next ¶
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[K, V]) NextTo ¶
NextTo moves the iterator to the next element from current position that satisfies the condition given by the passed function, and returns true if there was a next element in the container. If NextTo() returns true, then next element's key and value can be retrieved by Key() and Value(). Modifies the state of the iterator.
func (*Iterator[K, V]) Node ¶
Node returns the current element's node. Does not modify the state of the iterator.
func (*Iterator[K, V]) Prev ¶
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[K, V]) PrevTo ¶
PrevTo moves the iterator to the previous element from current position that satisfies the condition given by the passed function, and returns true if there was a next element in the container. If PrevTo() returns true, then next element's key and value can be retrieved by Key() and Value(). Modifies the state of the iterator.
type Node ¶
type Node[K comparable, V any] struct { Parent *Node[K, V] Entries []*Entry[K, V] // Contained keys in node Children []*Node[K, V] // Children nodes }
Node is a single element within the tree
type Tree ¶
type Tree[K comparable, V any] struct { Root *Node[K, V] // Root node Comparator utils.Comparator[K] // Key comparator // contains filtered or unexported fields }
Tree holds elements of the B-tree
func New ¶
New instantiates a B-tree with the order (maximum number of children) and the built-in comparator for K
func NewWith ¶
func NewWith[K comparable, V any](order int, comparator utils.Comparator[K]) *Tree[K, V]
NewWith instantiates a B-tree with the order (maximum number of children) and a custom key comparator.
func (*Tree[K, V]) Get ¶
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[K, V]) GetNode ¶
GetNode searches the node in the tree by key and returns its node or nil if key is not found in tree. Key should adhere to the comparator's type assertion, otherwise method panics.
func (*Tree[K, V]) Iterator ¶
Iterator returns a stateful iterator whose elements are key/value pairs.
func (*Tree[K, V]) LeftKey ¶
func (tree *Tree[K, V]) LeftKey() interface{}
LeftKey returns the left-most (min) key or nil if tree is empty.
func (*Tree[K, V]) LeftValue ¶
func (tree *Tree[K, V]) LeftValue() interface{}
LeftValue returns the left-most value or nil if tree is empty.
func (*Tree[K, V]) MarshalJSON ¶
MarshalJSON @implements json.Marshaler
func (*Tree[K, V]) Put ¶
func (tree *Tree[K, V]) Put(key K, value V)
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[K, V]) Remove ¶
func (tree *Tree[K, V]) Remove(key K)
Remove remove the node from the tree by key. Key should adhere to the comparator's type assertion, otherwise method panics.
func (*Tree[K, V]) RightKey ¶
func (tree *Tree[K, V]) RightKey() interface{}
RightKey returns the right-most (max) key or nil if tree is empty.
func (*Tree[K, V]) RightValue ¶
func (tree *Tree[K, V]) RightValue() interface{}
RightValue returns the right-most value or nil if tree is empty.
func (*Tree[K, V]) String ¶
String returns a string representation of container (for debugging purposes)
func (*Tree[K, V]) UnmarshalJSON ¶
UnmarshalJSON @implements json.Unmarshaler