Simplify Uuidv7 implementation

hfhbd · Aug 17, 2024 · 50c573a · 50c573a
1 parent f20d298
commit 50c573a
Show file tree

Hide file tree

Showing 4 changed files with 29 additions and 32 deletions.
diff --git a/detekt-baseline.xml b/detekt-baseline.xml
@@ -61,14 +61,19 @@
     <ID>MagicNumber:Uuid.kt$60</ID>
     <ID>MagicNumber:Uuid.kt$61</ID>
     <ID>MagicNumber:Uuid.kt$7</ID>
-    <ID>MagicNumber:Uuidv7.kt$0x0fffL</ID>
-    <ID>MagicNumber:Uuidv7.kt$0xffff0000L</ID>
+    <ID>MagicNumber:Uuidv7.kt$0x3F</ID>
+    <ID>MagicNumber:Uuidv7.kt$0x70</ID>
+    <ID>MagicNumber:Uuidv7.kt$0x80</ID>
+    <ID>MagicNumber:Uuidv7.kt$0xFF</ID>
     <ID>MagicNumber:Uuidv7.kt$16</ID>
-    <ID>MagicNumber:Uuidv7.kt$28672</ID>
+    <ID>MagicNumber:Uuidv7.kt$24</ID>
+    <ID>MagicNumber:Uuidv7.kt$3</ID>
     <ID>MagicNumber:Uuidv7.kt$32</ID>
-    <ID>MagicNumber:Uuidv7.kt$4095</ID>
-    <ID>MagicNumber:Uuidv7.kt$48</ID>
-    <ID>MagicNumber:Uuidv7.kt$62</ID>
+    <ID>MagicNumber:Uuidv7.kt$4</ID>
+    <ID>MagicNumber:Uuidv7.kt$40</ID>
+    <ID>MagicNumber:Uuidv7.kt$5</ID>
+    <ID>MagicNumber:Uuidv7.kt$6</ID>
+    <ID>MagicNumber:Uuidv7.kt$8</ID>
     <ID>TooManyFunctions:SHA1.kt$SHA1</ID>
   </CurrentIssues>
 </SmellBaseline>
diff --git a/kotlinx-uuid-core/src/commonMain/kotlin/app/softwork/uuid/Uuidv7.kt b/kotlinx-uuid-core/src/commonMain/kotlin/app/softwork/uuid/Uuidv7.kt
@@ -15,25 +15,19 @@ public fun Uuidv7(timeStamp: Long, random: Random): Uuid {
     require(timeStamp <= UNIX_48_TIMESTAMP) {
         "timeStamp $timeStamp must be <= 48 bits, was $timeStamp."
     }
-    val (
-        helperTimeStampAndVersionRaw,
-        helperClockSequenceVariantAndNodeRaw
-    ) = random.nextUuid().toLongs { mostSignificantBits, leastSignificantBits ->
-        mostSignificantBits to leastSignificantBits
-    }
-    val leftTimeStamp = timeStamp shl 16
-    // set version to 0b0111
-    val leftTimeStampAndVersion = leftTimeStamp or 28672
-    val randA = helperTimeStampAndVersionRaw.let { timeStampAndVersionRaw ->
-        (timeStampAndVersionRaw ushr 32) or
-            (timeStampAndVersionRaw and 0xffff0000L shl 16) or
-            (timeStampAndVersionRaw and 0x0fffL shl 48)
-    } and 4095
-    val timeStampAndVersionRaw = leftTimeStampAndVersion or randA
-    // set variant to 0b10
-    val clockSequenceVariantAndNodeRaw = (2L shl 62) or (helperClockSequenceVariantAndNodeRaw ushr 2)
+    val value = random.nextBytes(Uuid.SIZE_BYTES)
+
+    value[0] = ((timeStamp shr 40) and 0xFF).toByte()
+    value[1] = ((timeStamp shr 32) and 0xFF).toByte()
+    value[2] = ((timeStamp shr 24) and 0xFF).toByte()
+    value[3] = ((timeStamp shr 16) and 0xFF).toByte()
+    value[4] = ((timeStamp shr 8) and 0xFF).toByte()
+    value[5] = (timeStamp and 0xFF).toByte()
+
+    value[6] = (value[6].toInt() and 0x0F or 0x70).toByte()
+    value[8] = (value[8].toInt() and 0x3F or 0x80).toByte()
 
-    return Uuid.fromLongs(timeStampAndVersionRaw, clockSequenceVariantAndNodeRaw)
+    return Uuid.fromByteArray(value)
 }
 
 /**

diff --git a/kotlinx-uuid-core/src/commonTest/kotlin/app/softwork/uuid/Uuidv7Test.kt b/kotlinx-uuid-core/src/commonTest/kotlin/app/softwork/uuid/Uuidv7Test.kt
@@ -6,13 +6,11 @@ import kotlin.test.*
 class Uuidv7Test {
     @Test
     fun test() {
-        val one = Uuidv7(0x17F22E279B0, random = Random(4242))
-        val two = Uuidv7(1645557742000, random = Random(4242))
-        assertEquals(one, two)
+        val uuid = Uuidv7(1645557742000, random = Random(4242))
 
-        assertEquals(1645557742000, one.unixTimeStamp)
-        assertEquals(1645557742000, two.unixTimeStamp)
-        assertEquals("017f22e2-79b0-7b35-ab5c-c2334bd875e2", one.toString())
-        assertEquals(7, one.versionNumber)
+        assertEquals(1645557742000, uuid.unixTimeStamp)
+        assertEquals("017f22e2-79b0-7a1e-ad73-08cd2f61d78a", uuid.toString())
+        assertEquals(7, uuid.versionNumber)
+        assertEquals(5, uuid.variant)
     }
 }
diff --git a/kotlinx-uuid-datetime/src/commonTest/kotlin/app/softwork/uuid/datetime/InstantTest.kt b/kotlinx-uuid-datetime/src/commonTest/kotlin/app/softwork/uuid/datetime/InstantTest.kt
@@ -13,7 +13,7 @@ class InstantTest {
         val timestamp = Instant.parse("2020-02-20T10:21:42Z")
         val uuid = Uuidv7(timeStamp = timestamp, random = Random(4242))
         assertEquals(timestamp, uuid.instant)
-        assertEquals("0170621e-0ef0-7b35-ab5c-c2334bd875e2", uuid.toString())
+        assertEquals("0170621e-0ef0-7a1e-ad73-08cd2f61d78a", uuid.toString())
         assertEquals(7, uuid.versionNumber)
     }
 }