diff options
Diffstat (limited to 'vendor/github.com/google/uuid/version4.go')
| -rw-r--r-- | vendor/github.com/google/uuid/version4.go | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/vendor/github.com/google/uuid/version4.go b/vendor/github.com/google/uuid/version4.go index 86160fbd..7697802e 100644 --- a/vendor/github.com/google/uuid/version4.go +++ b/vendor/github.com/google/uuid/version4.go @@ -27,6 +27,8 @@ func NewString() string { // 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 @@ -35,7 +37,10 @@ func NewString() string { // equivalent to the odds of creating a few tens of trillions of UUIDs in a // year and having one duplicate. func NewRandom() (UUID, error) { - return NewRandomFromReader(rander) + if !poolEnabled { + return NewRandomFromReader(rander) + } + return newRandomFromPool() } // NewRandomFromReader returns a UUID based on bytes read from a given io.Reader. @@ -49,3 +54,23 @@ func NewRandomFromReader(r io.Reader) (UUID, error) { 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 +} |