RankTree

RankTree is an in-memory data structure, written in Go. used as a ranking database. It is similar to Redis Sorted Sets, but based on Complete Binary Tree.

Features

• In-memory database
• High Performance
• Redis-like Commands

Restrictions: the value of score must be non-negative integers.

Installation

Install:

go get -u github.com/ng1091/ranktree

Import:

import "github.com/ng1091/ranktree"

Usage

// create
tree, err := New(0, 10000)
if err != nil {
    log.Fatal(err)
}

// add
tree.Add("Alice", 123)
tree.Add("Bob", 1234)
tree.Add("Charles", 12)

// get rank
n := tree.RevRank("Bob")
fmt.Printf("Bob is No.%d\n", n + 1)

// get range
result := tree.RevRange(0, -1)
for i, name := range result {
    fmt.Printf("No.%d: %s\n", i + 1, name)
}

Output:

 Output:
 Bob is No.1

 No.1: Bob
 No.2: Alice
 No.3: Charles

Documents

Commands

    New(low int, high int) (*RankTree, error)
    Add(member string, score int) bool
    Card() int
    Count(min, max int) int
    IncrementBy(member string, score int) int
    PopMax() (rank *RankWithScore)
    PopMaxN(n int) (ranks []RankWithScore)
    PopMin() (rank *RankWithScore)
    PopMinN(n int) (ranks []RankWithScore)
    Range(start, end int) []string
    RangeByScore(min, max int) (ranks []RankWithScore)
    RangeWithScore(start, end int) []RankWithScore
    Rank(member string) int
    Remove(members ...string) (sum int)
    RevRange(start, end int) []string
    RevRangeByScore(min, max int) (ranks []RankWithScore)
    RevRangeWithScore(start, end int) []RankWithScore
    RevRank(member string) int
    Score(member string) int
    UpdateScore(member string, score int, insert bool) bool

Please check GoDoc - ranktree for more details.