server/id.go

package main

import (
	"crypto/md5"
	"fmt"
	"io"
	"time"
)

// This thing contains a channel that when initialized (see NewIdGenerator)
// will return a bunch of (as best as I can tell) unique md5 hashes.
//
// we use this for naming players, games, etc.
//
// It will consume a single goroutine
type IdGenerator struct {
	id chan int64
}

func NewIdGenerator() *IdGenerator {
	g := IdGenerator{}
	g.id = make(chan int64)
	go func() {
		var i int64
		for i = 0; ; i++ {
			g.id <- i
		}
	}()
	return &g
}

func (id *IdGenerator) Hash() string {
	h := md5.New()
	ns := time.Now().UnixNano() + <-id.id
	io.WriteString(h, fmt.Sprintf("%d", ns))
	return fmt.Sprintf("%x", h.Sum(nil))[:8]
}