[VOL-4291] OfAgent changes for gRPC migration

Change-Id: I8da1db6df49d478ef24ec8f9bd719e9692f48a7f
diff --git a/vendor/github.com/google/uuid/version4.go b/vendor/github.com/google/uuid/version4.go
index 84af91c..7697802 100644
--- a/vendor/github.com/google/uuid/version4.go
+++ b/vendor/github.com/google/uuid/version4.go
@@ -14,11 +14,21 @@
 	return Must(NewRandom())
 }
 
+// NewString creates a new random UUID and returns it as a string or panics.
+// NewString is equivalent to the expression
+//
+//    uuid.New().String()
+func NewString() string {
+	return Must(NewRandom()).String()
+}
+
 // NewRandom returns a Random (Version 4) UUID.
 //
 // The strength of the UUIDs is based on the strength of the crypto/rand
 // package.
 //
+// Uses the randomness pool if it was enabled with EnableRandPool.
+//
 // A note about uniqueness derived from the UUID Wikipedia entry:
 //
 //  Randomly generated UUIDs have 122 random bits.  One's annual risk of being
@@ -27,8 +37,16 @@
 //  equivalent to the odds of creating a few tens of trillions of UUIDs in a
 //  year and having one duplicate.
 func NewRandom() (UUID, error) {
+	if !poolEnabled {
+		return NewRandomFromReader(rander)
+	}
+	return newRandomFromPool()
+}
+
+// NewRandomFromReader returns a UUID based on bytes read from a given io.Reader.
+func NewRandomFromReader(r io.Reader) (UUID, error) {
 	var uuid UUID
-	_, err := io.ReadFull(rander, uuid[:])
+	_, err := io.ReadFull(r, uuid[:])
 	if err != nil {
 		return Nil, err
 	}
@@ -36,3 +54,23 @@
 	uuid[8] = (uuid[8] & 0x3f) | 0x80 // Variant is 10
 	return uuid, nil
 }
+
+func newRandomFromPool() (UUID, error) {
+	var uuid UUID
+	poolMu.Lock()
+	if poolPos == randPoolSize {
+		_, err := io.ReadFull(rander, pool[:])
+		if err != nil {
+			poolMu.Unlock()
+			return Nil, err
+		}
+		poolPos = 0
+	}
+	copy(uuid[:], pool[poolPos:(poolPos+16)])
+	poolPos += 16
+	poolMu.Unlock()
+
+	uuid[6] = (uuid[6] & 0x0f) | 0x40 // Version 4
+	uuid[8] = (uuid[8] & 0x3f) | 0x80 // Variant is 10
+	return uuid, nil
+}