server/id.go

44 lines
1002 B
Go

package server
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 {
return &IdGenerator{
id: make(chan int64),
}
}
// Run is called (typically in a gorotine) to allow for queries to be made
// against IdGenerator.id throgh the Hash method.
func (idg *IdGenerator) Run() {
var i int64
for i = 0; ; i++ {
idg.id <- i
}
}
// Hash is the method used by a properly instantiated IdGenerator that gives
// fairly unique strings. They are currently truncated md5 hashes of the time
// plus a unique counter
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]
}