From 1a57267a17c2fc17fb6e104846fabc3e363c326c Mon Sep 17 00:00:00 2001
From: Emile <git@emile.space>
Date: Fri, 16 Aug 2024 19:50:26 +0200
Subject: initial commit

---
 vendor/github.com/google/uuid/version7.go | 104 ++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 vendor/github.com/google/uuid/version7.go

(limited to 'vendor/github.com/google/uuid/version7.go')

diff --git a/vendor/github.com/google/uuid/version7.go b/vendor/github.com/google/uuid/version7.go
new file mode 100644
index 0000000..3167b64
--- /dev/null
+++ b/vendor/github.com/google/uuid/version7.go
@@ -0,0 +1,104 @@
+// Copyright 2023 Google Inc.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package uuid
+
+import (
+	"io"
+)
+
+// UUID version 7 features a time-ordered value field derived from the widely
+// implemented and well known Unix Epoch timestamp source,
+// the number of milliseconds seconds since midnight 1 Jan 1970 UTC, leap seconds excluded.
+// As well as improved entropy characteristics over versions 1 or 6.
+//
+// see https://datatracker.ietf.org/doc/html/draft-peabody-dispatch-new-uuid-format-03#name-uuid-version-7
+//
+// Implementations SHOULD utilize UUID version 7 over UUID version 1 and 6 if possible.
+//
+// NewV7 returns a Version 7 UUID based on the current time(Unix Epoch).
+// Uses the randomness pool if it was enabled with EnableRandPool.
+// On error, NewV7 returns Nil and an error
+func NewV7() (UUID, error) {
+	uuid, err := NewRandom()
+	if err != nil {
+		return uuid, err
+	}
+	makeV7(uuid[:])
+	return uuid, nil
+}
+
+// NewV7FromReader returns a Version 7 UUID based on the current time(Unix Epoch).
+// it use NewRandomFromReader fill random bits.
+// On error, NewV7FromReader returns Nil and an error.
+func NewV7FromReader(r io.Reader) (UUID, error) {
+	uuid, err := NewRandomFromReader(r)
+	if err != nil {
+		return uuid, err
+	}
+
+	makeV7(uuid[:])
+	return uuid, nil
+}
+
+// makeV7 fill 48 bits time (uuid[0] - uuid[5]), set version b0111 (uuid[6])
+// uuid[8] already has the right version number (Variant is 10)
+// see function NewV7 and NewV7FromReader
+func makeV7(uuid []byte) {
+	/*
+		 0                   1                   2                   3
+		 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+		|                           unix_ts_ms                          |
+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+		|          unix_ts_ms           |  ver  |  rand_a (12 bit seq)  |
+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+		|var|                        rand_b                             |
+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+		|                            rand_b                             |
+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	*/
+	_ = uuid[15] // bounds check
+
+	t, s := getV7Time()
+
+	uuid[0] = byte(t >> 40)
+	uuid[1] = byte(t >> 32)
+	uuid[2] = byte(t >> 24)
+	uuid[3] = byte(t >> 16)
+	uuid[4] = byte(t >> 8)
+	uuid[5] = byte(t)
+
+	uuid[6] = 0x70 | (0x0F & byte(s>>8))
+	uuid[7] = byte(s)
+}
+
+// lastV7time is the last time we returned stored as:
+//
+//	52 bits of time in milliseconds since epoch
+//	12 bits of (fractional nanoseconds) >> 8
+var lastV7time int64
+
+const nanoPerMilli = 1000000
+
+// getV7Time returns the time in milliseconds and nanoseconds / 256.
+// The returned (milli << 12 + seq) is guarenteed to be greater than
+// (milli << 12 + seq) returned by any previous call to getV7Time.
+func getV7Time() (milli, seq int64) {
+	timeMu.Lock()
+	defer timeMu.Unlock()
+
+	nano := timeNow().UnixNano()
+	milli = nano / nanoPerMilli
+	// Sequence number is between 0 and 3906 (nanoPerMilli>>8)
+	seq = (nano - milli*nanoPerMilli) >> 8
+	now := milli<<12 + seq
+	if now <= lastV7time {
+		now = lastV7time + 1
+		milli = now >> 12
+		seq = now & 0xfff
+	}
+	lastV7time = now
+	return milli, seq
+}
-- 
cgit 1.4.1