1 files changed, 22 insertions, 8 deletions
diff --git a/uuid_source.go b/uuid_source.go
index 211b052..83a569c 100644
--- a/uuid_source.go
+++ b/uuid_source.go
@@ -5,10 +5,18 @@ import (
 	"crypto/rand"
 )
 
+// A UuidSource holds a random number generator and generates UUIDs using it as its source.
+//
+// It is useful when a process need its own random number generator, 
+// e.g. when running some processes concurrently.
 type UuidSource struct {
 	rander io.Reader
 }
 
+// Creates a new UuidSource which holds its own random number generator.
+//
+// Calling NewSource with nil sets the random number generator to a default
+// generator.
 func NewSource(r io.Reader) UuidSource {
 	var uuidSource UuidSource
 	uuidSource.SetRand(r)
@@ -16,6 +24,12 @@ func NewSource(r io.Reader) UuidSource {
 
 }
 
+// SetRand sets the random number generator of the UuidSource to r, which implements io.Reader.
+// If r.Read returns an error when the package requests random data then
+// a panic will be issued.
+//
+// Calling SetRand with nil sets the random number generator to a default
+// generator.
 func (uuidSource *UuidSource) SetRand(r io.Reader) {
 	if r == nil {
 		uuidSource.rander = rand.Reader
@@ -24,17 +38,17 @@ func (uuidSource *UuidSource) SetRand(r io.Reader) {
 	uuidSource.rander = r
 }
 
+// NewRandom returns a Random (Version 4) UUID based on the random number generator in the UuidSource.
+//
+// See more detailed explanation here: https://godoc.org/github.com/google/uuid#NewRandom
 func (uuidSource UuidSource) NewRandom() (UUID, error) {
-	var uuid UUID
-	_, err := io.ReadFull(uuidSource.rander, uuid[:])
-	if err != nil {
-		return Nil, err
-	}
-	uuid[6] = (uuid[6] & 0x0f) | 0x40 // Version 4
-	uuid[8] = (uuid[8] & 0x3f) | 0x80 // Variant is 10
-	return uuid, nil
+	return newRandom(uuidSource.rander)
 }
 
+// New creates a new random UUID  based on the random number generator in the UuidSource or panics.  New is equivalent to
+// the expression
+//
+//    uuid.Must(uuid.NewRandom())
 func (uuidSource UuidSource) New() UUID {
 	return Must(uuidSource.NewRandom())
 }