From 72f3828ccae9413c3d93c93c77cc47177c40dbd0 Mon Sep 17 00:00:00 2001
From: oittaa <8972248+oittaa@users.noreply.github.com>
Date: Sun, 28 Nov 2021 20:27:23 +0100
Subject: [PATCH] UUIDv7 (#23)

---
 README.md          | 10 ++++++++--
 src/UUID.php       | 32 ++++++++++++++++++++++++++++++++
 tests/UuidTest.php | 30 ++++++++++++++++++++++++++++--
 3 files changed, 68 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index a8704cf..8abc8a5 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@
 
 # uuid-php
 
-A small PHP class for generating [RFC 4122](http://tools.ietf.org/html/rfc4122) version 3, 4, 5, and 6 ([draft](https://datatracker.ietf.org/doc/html/draft-peabody-dispatch-new-uuid-format-02)) universally unique identifiers (UUID).
+A small PHP class for generating [RFC 4122](http://tools.ietf.org/html/rfc4122) version 3, 4, and 5 universally unique identifiers (UUID). Additionally supports [draft](https://datatracker.ietf.org/doc/html/draft-peabody-dispatch-new-uuid-format-02) versions 6 and 7.
 
 If all you want is a unique ID, you should call `uuid4()`.
 
@@ -25,7 +25,7 @@ echo uuid4();
 
 ## Installation
 
-If you need comparison tools or sortable identifiers like in version 6, you might find this small and fast package useful. It doesn't require any other dependencies.
+If you need comparison tools or sortable identifiers like in versions 6 and 7, you might find this small and fast package useful. It doesn't require any other dependencies.
 
 ```bash
 composer require oittaa/uuid
@@ -58,6 +58,12 @@ echo $uuid6_first . "\n"; // e.g. 1ebacf4f-a4a8-68ee-b4ec-618c14d005d5
 $uuid6_second = UUID::uuid6();
 var_dump($uuid6_first < $uuid6_second); // bool(true)
 
+// Generate a version 7 (lexicographically sortable) UUID
+$uuid7_first = UUID::uuid7();
+echo $uuid7_first . "\n"; // e.g. 061a3d43-61d0-7cf4-bfce-753dadab55e1
+$uuid7_second = UUID::uuid7();
+var_dump($uuid7_first < $uuid7_second); // bool(true)
+
 // Test if a given string is a valid UUID
 $isvalid = UUID::isValid('11a38b9a-b3da-360f-9353-a5a725514269');
 var_dump($isvalid); // bool(true)
diff --git a/src/UUID.php b/src/UUID.php
index 36e2ece..ebd5016 100644
--- a/src/UUID.php
+++ b/src/UUID.php
@@ -176,6 +176,30 @@ public static function uuid6()
         return self::uuidFromHash($hash, 6);
     }
 
+    /**
+     * Generate a version 7 UUID. A v7 UUID is lexicographically sortable and is
+     * designed to encode a Unix timestamp with arbitrary sub-second precision.
+     *
+     * @return string The string standard representation of the UUID
+     */
+    public static function uuid7()
+    {
+        $time = microtime(false);
+        $unixts = substr($time, 11);
+        $subsec = substr($time, 2, 7);
+        $unixts = str_pad(dechex(intval($unixts, 10)), 9, '0', \STR_PAD_LEFT);
+        $subsec = str_pad(dechex(intval($subsec, 10)), 6, '0', \STR_PAD_LEFT);
+        $time = sprintf(
+            '%09s%03s7%03s',
+            $unixts,
+            substr($subsec, 0, 3),
+            substr($subsec, -3)
+        );
+        $bytes = random_bytes(8);
+        $hash = $time . bin2hex($bytes);
+        return self::uuidFromHash($hash, 7);
+    }
+
     /**
      * Check if a string is a valid UUID.
      *
@@ -276,4 +300,12 @@ public static function v6()
     {
         return self::uuid6();
     }
+    /**
+     * @see UUID::uuid7() Alias
+     * @return string
+     */
+    public static function v7()
+    {
+        return self::uuid7();
+    }
 }
diff --git a/tests/UuidTest.php b/tests/UuidTest.php
index 3048969..dd90071 100644
--- a/tests/UuidTest.php
+++ b/tests/UuidTest.php
@@ -23,7 +23,7 @@ public function testCanGenerateValidVersion3()
     public function testCanGenerateValidVersion4()
     {
         $uuid1 = UUID::uuid4();
-        for ($x = 0; $x < 10; $x++) {
+        for ($x = 0; $x < 1000; $x++) {
             $this->assertMatchesRegularExpression(
                 '/^[0-9a-f]{8}\-[0-9a-f]{4}\-4[0-9a-f]{3}\-[89ab][0-9a-f]{3}\-[0-9a-f]{12}$/',
                 $uuid1
@@ -48,7 +48,7 @@ public function testCanGenerateValidVersion5()
     public function testCanGenerateValidVersion6()
     {
         $uuid1 = UUID::uuid6();
-        for ($x = 0; $x < 10; $x++) {
+        for ($x = 0; $x < 1000; $x++) {
             $this->assertMatchesRegularExpression(
                 '/^[0-9a-f]{8}\-[0-9a-f]{4}\-6[0-9a-f]{3}\-[89ab][0-9a-f]{3}\-[0-9a-f]{12}$/',
                 $uuid1
@@ -67,6 +67,28 @@ public function testCanGenerateValidVersion6()
         }
     }
 
+    public function testCanGenerateValidVersion7()
+    {
+        $uuid1 = UUID::uuid7();
+        for ($x = 0; $x < 1000; $x++) {
+            $this->assertMatchesRegularExpression(
+                '/^[0-9a-f]{8}\-[0-9a-f]{4}\-7[0-9a-f]{3}\-[89ab][0-9a-f]{3}\-[0-9a-f]{12}$/',
+                $uuid1
+            );
+            usleep(1);
+            $uuid2 = UUID::uuid7();
+            $this->assertGreaterThan(
+                $uuid1,
+                $uuid2
+            );
+            $this->assertLessThan(
+                0,
+                UUID::cmp($uuid1, $uuid2)
+            );
+            $uuid1 = $uuid2;
+        }
+    }
+
     public function testCannotBeCreatedFromInvalidNamespace()
     {
         $this->expectException(\InvalidArgumentException::class);
@@ -155,5 +177,9 @@ public function testCanUseAliases()
             6,
             UUID::getVersion(UUID::v6())
         );
+        $this->assertSame(
+            7,
+            UUID::getVersion(UUID::v7())
+        );
     }
 }