www.github.com/plar/go-adaptive-radix-tree.git

An Adaptive Radix Tree Implementation in Go

v1.x.x is a deprecated version. All development will be done in v2.

This library provides a Go implementation of the Adaptive Radix Tree (ART).

Features:

• Lookup performance surpasses highly tuned alternatives
• Support for highly efficient insertions and deletions
• Space efficient
• Performance is comparable to hash tables
• Maintains the data in sorted order, which enables additional operations like range scan and prefix lookup

  Keys are sorted lexicographically based on their byte values.

• O(k) search/insert/delete operations, where k is the length of the key
• Minimum / Maximum value lookups
• Ordered iteration
• Prefix-based iteration
• Support for keys with null bytes, any byte array could be a key

Usage

package main

import (
	"fmt"
	art "github.com/plar/go-adaptive-radix-tree"
)

func main() {
	// Initialize a new Adaptive Radix Tree
	tree := art.New()

	// Insert key-value pairs into the tree
	tree.Insert(art.Key("apple"), "A sweet red fruit")
	tree.Insert(art.Key("banana"), "A long yellow fruit")
	tree.Insert(art.Key("cherry"), "A small red fruit")
	tree.Insert(art.Key("date"), "A sweet brown fruit")

	// Search for a value by key
	if value, found := tree.Search(art.Key("banana")); found {
		fmt.Println("Found:", value)
	} else {
		fmt.Println("Key not found")
	}

	// Iterate over the tree in ascending order
	fmt.Println("\nAscending order iteration:")
	tree.ForEach(func(node art.Node) bool {
		fmt.Printf("Key: %s, Value: %s\n", node.Key(), node.Value())
		return true
	})

	// Iterate over the tree in descending order using reverse traversal
	fmt.Println("\nDescending order iteration:")
	tree.ForEach(func(node art.Node) bool {
		fmt.Printf("Key: %s, Value: %s\n", node.Key(), node.Value())
		return true
	})

	// Iterate over keys with a specific prefix
	fmt.Println("\nIteration with prefix 'c':")
	tree.ForEachPrefix(art.Key("c"), func(node art.Node) bool {
		fmt.Printf("Key: %s, Value: %s\n", node.Key(), node.Value())
		return true
	})
}

// Expected Output:
// Found: A long yellow fruit
//
// Ascending order iteration:
// Key: apple, Value: A sweet red fruit
// Key: banana, Value: A long yellow fruit
// Key: cherry, Value: A small red fruit
// Key: date, Value: A sweet brown fruit
//
// Descending order iteration:
// Key: date, Value: A sweet brown fruit
// Key: cherry, Value: A small red fruit
// Key: banana, Value: A long yellow fruit
// Key: apple, Value: A sweet red fruit
//
// Iteration with prefix 'c':
// Key: cherry, Value: A small red fruit

Documentation

Check out the documentation on godoc.org

Performance

plar/go-adaptive-radix-tree outperforms kellydunn/go-art by avoiding memory allocations during search operations. It also provides prefix based iteration over the tree.

Benchmarks were performed on datasets extracted from different projects:

• The "Words" dataset contains a list of 235,886 english words. [2]
• The "UUIDs" dataset contains 100,000 uuids. [2]
• The "HSK Words" dataset contains 4,995 words. [4]

go-adaptive-radix-tree	#	Average time	Bytes per operation	Allocs per operation
Tree Insert Words	9	117,888,698 ns/op	37,942,744 B/op	1,214,541 allocs/op
Tree Search Words	26	44,555,608 ns/op	0 B/op	0 allocs/op
Tree Insert UUIDs	18	59,360,135 ns/op	18,375,723 B/op	485,057 allocs/op
Tree Search UUIDs	54	21,265,931 ns/op	0 B/op	0 allocs/op
go-art
Tree Insert Words	5	272,047,975 ns/op	81,628,987 B/op	2,547,316 allocs/op
Tree Search Words	10	129,011,177 ns/op	13,272,278 B/op	1,659,033 allocs/op
Tree Insert UUIDs	10	140,309,246 ns/op	33,678,160 B/op	874,561 allocs/op
Tree Search UUIDs	20	82,120,943 ns/op	3,883,131 B/op	485,391 allocs/op

To see more benchmarks just run

$ ./make qa/benchmarks

References

[1] The Adaptive Radix Tree: ARTful Indexing for Main-Memory Databases (Specification)

[2] C99 implementation of the Adaptive Radix Tree

[3] Another Adaptive Radix Tree implementation in Go

[4] HSK Words. HSK(Hanyu Shuiping Kaoshi) - Standardized test of Standard Mandarin Chinese proficiency.