From 5e215b925788d9fe2be06b0259d0f654cf04071b Mon Sep 17 00:00:00 2001
From: Paul Mach <paul@strava.com>
Date: Sun, 25 Aug 2013 22:41:58 -0700
Subject: [PATCH] Remove depenance on external libs for unique id

---
 client/client.go  |  2 +-
 client/id.go      | 34 +++++++++++++---------------------
 client/id_test.go | 18 ++++++++++++++++++
 3 files changed, 32 insertions(+), 22 deletions(-)
 create mode 100644 client/id_test.go

diff --git a/client/client.go b/client/client.go
index b0265c6..1fcb142 100644
--- a/client/client.go
+++ b/client/client.go
@@ -20,7 +20,7 @@ var (
 )
 
 func init() {
-    IdGen = NewObjectId()
+	IdGen = NewAutoIncId()
 }
 
 // Status handler
diff --git a/client/id.go b/client/id.go
index 1b86751..1afbaf0 100644
--- a/client/id.go
+++ b/client/id.go
@@ -1,37 +1,29 @@
 package client
 
 import (
-    "strconv"
-    "labix.org/v2/mgo/bson"
-    "github.com/mikespook/golib/autoinc"
+	"strconv"
+	"sync/atomic"
+	"time"
 )
 
 type IdGenerator interface {
-    Id() string
-}
-
-// ObjectId
-type objectId struct {
-    bson.ObjectId
-}
-
-func (id *objectId) Id() string {
-    return id.Hex()
-}
-
-func NewObjectId() IdGenerator {
-    return &objectId{bson.NewObjectId()}
+	Id() string
 }
 
 // AutoIncId
 type autoincId struct {
-    *autoinc.AutoInc
+	value int64
 }
 
-func (id *autoincId) Id() string {
-    return strconv.Itoa(id.AutoInc.Id())
+func (ai *autoincId) Id() string {
+	next := atomic.AddInt64(&ai.value, 1)
+	return strconv.FormatInt(next, 10)
 }
 
 func NewAutoIncId() IdGenerator {
-    return &autoincId{autoinc.New(1, 1)}
+	// we'll consider the nano fraction of a second at startup unique
+	// and count up from there.
+	return &autoincId{
+		value: int64(time.Now().Nanosecond()) << 32,
+	}
 }
diff --git a/client/id_test.go b/client/id_test.go
new file mode 100644
index 0000000..399d217
--- /dev/null
+++ b/client/id_test.go
@@ -0,0 +1,18 @@
+package client
+
+import (
+	"testing"
+)
+
+func TestAutoInc(t *testing.T) {
+	ai := NewAutoIncId()
+
+	previous := ai.Id()
+	for i := 0; i < 10; i++ {
+		id := ai.Id()
+		if id == previous {
+			t.Errorf("Id not unique, previous and current %s", id)
+		}
+		previous = id
+	}
+}