Add support for setting variant bits other than RFC4122.

generator.go

@@ -107,7 +107,7 @@ func (g *generator) NewV1() UUID {
  copy(u[10:], hardwareAddr)
 
  u.SetVersion(V1)
- u.SetVariant()
+ u.SetVariant(VariantRFC4122)
 
  return u
 }
@@ -133,7 +133,7 @@ func (g *generator) NewV2(domain byte) UUID {
  copy(u[10:], hardwareAddr)
 
  u.SetVersion(V2)
- u.SetVariant()
+ u.SetVariant(VariantRFC4122)
 
  return u
 }
@@ -142,7 +142,7 @@ func (g *generator) NewV2(domain byte) UUID {
 func (g *generator) NewV3(ns UUID, name string) UUID {
  u := newFromHash(md5.New(), ns, name)
  u.SetVersion(V3)
- u.SetVariant()
+ u.SetVariant(VariantRFC4122)
 
  return u
 }
@@ -152,7 +152,7 @@ func (g *generator) NewV4() UUID {
  u := UUID{}
  g.safeRandom(u[:])
  u.SetVersion(V4)
- u.SetVariant()
+ u.SetVariant(VariantRFC4122)
 
  return u
 }
@@ -161,7 +161,7 @@ func (g *generator) NewV4() UUID {
 func (g *generator) NewV5(ns UUID, name string) UUID {
  u := newFromHash(sha1.New(), ns, name)
  u.SetVersion(V5)
- u.SetVariant()
+ u.SetVariant(VariantRFC4122)
 
  return u
 }

uuid.go

@@ -92,14 +92,17 @@ func (u UUID) Version() byte {
 // Variant returns UUID layout variant.
 func (u UUID) Variant() byte {
  switch {
- case (u[8] & 0x80) == 0x00:
+ case (u[8] >> 7) == 0x00:
  return VariantNCS
- case (u[8]&0xc0)|0x80 == 0x80:
+ case (u[8] >> 6) == 0x02:
  return VariantRFC4122
- case (u[8]&0xe0)|0xc0 == 0xc0:
+ case (u[8] >> 5) == 0x06:
  return VariantMicrosoft
+ case (u[8] >> 5) == 0x07:
+ fallthrough
+ default:
+ return VariantFuture
  }
- return VariantFuture
 }
 
 // Bytes returns bytes slice representation of UUID.
@@ -130,9 +133,20 @@ func (u *UUID) SetVersion(v byte) {
  u[6] = (u[6] & 0x0f) | (v << 4)
 }
 
-// SetVariant sets variant bits as described in RFC 4122.
-func (u *UUID) SetVariant() {
- u[8] = (u[8] & 0xbf) | 0x80
+// SetVariant sets variant bits.
+func (u *UUID) SetVariant(v byte) {
+ switch v {
+ case VariantNCS:
+ u[8] = (u[8]&(0xff>>1) | (0x00 << 7))
+ case VariantRFC4122:
+ u[8] = (u[8]&(0xff>>2) | (0x02 << 6))
+ case VariantMicrosoft:
+ u[8] = (u[8]&(0xff>>3) | (0x06 << 5))
+ case VariantFuture:
+ fallthrough
+ default:
+ u[8] = (u[8]&(0xff>>3) | (0x07 << 5))
+ }
 }
 
 // Must is a helper that wraps a call to a function returning (UUID, error)

uuid_test.go

@@ -79,6 +79,12 @@ func (s *testSuite) TestVariant(c *C) {
 
 func (s *testSuite) TestSetVariant(c *C) {
  u := UUID{}
- u.SetVariant()
+ u.SetVariant(VariantNCS)
+ c.Assert(u.Variant(), Equals, VariantNCS)
+ u.SetVariant(VariantRFC4122)
  c.Assert(u.Variant(), Equals, VariantRFC4122)
+ u.SetVariant(VariantMicrosoft)
+ c.Assert(u.Variant(), Equals, VariantMicrosoft)
+ u.SetVariant(VariantFuture)
+ c.Assert(u.Variant(), Equals, VariantFuture)
 }