graphdb.go

package graphdb

import (
        "fmt"
        "sync"
)

type Nodes map[string]*Node

type Node struct {
        Id       string
        Value    interface{}
        Children Nodes
}

type Database struct {
        nodes Nodes
        mux   sync.Mutex
}

func NewDatabase() *Database {
        return &Database{
                nodes: Nodes{},
                mux:   sync.Mutex{},
        }
}

func (d *Database) CreateNode(id string) (*Node, error) {
        d.mux.Lock()
        defer d.mux.Unlock()

        if _, exists := d.nodes[id]; exists {
                return nil, fmt.Errorf("Node already exists for id: %s", id)
        }
        n := &Node{Id: id, Children: Nodes{}}
        d.nodes[id] = n

        return n, nil
}

func (n *Node) AddChild(node *Node) error {
        if _, exists := n.Children[node.Id]; exists {
                return fmt.Errorf("Child already exists: %s", node.Id)
        }
        n.Children[node.Id] = node
        return nil
}

func (n *Node) HasChildren() bool {
        return len(n.Children) > 0
}

func (n *Node) Traverse() <-chan *Node {
        c := make(chan *Node)
        go func() {
                for _, r := range n.Children {
                        c <- r
                }
                close(c)
        }()
        return c
}