Add name based UUIDv5 implementation (#197)

Add name based UUIDv5 implementation

modules/core/.js/src/main/scala/io/chrisdavenport/fuuid/PlatformSpecificMethods.scala

@@ -0,0 +1,8 @@
+package io.chrisdavenport.fuuid
+
+import cats.ApplicativeError
+
+object PlatformSpecificMethods {
+ def nameBased[F[_]]: (FUUID, String, ApplicativeError[F, Throwable]) => F[FUUID] = (_, _, AE) =>
+ AE.raiseError(new NotImplementedError("Name based UUIDs are not supported for Scala.js"))
+}

modules/core/.jvm/src/main/scala/io/chrisdavenport/fuuid/PlatformSpecificMethods.scala

@@ -0,0 +1,50 @@
+package io.chrisdavenport.fuuid
+
+import cats._
+import cats.implicits._
+import java.util.UUID
+import java.security.MessageDigest
+
+object PlatformSpecificMethods {
+ def nameBased[F[_]]: (FUUID, String, ApplicativeError[F, Throwable]) => F[FUUID] = (namespace, name, AE) =>
+ Either
+ .catchNonFatal(
+ MessageDigest
+ .getInstance("SHA-1")
+ .digest(
+ uuidBytes(namespace) ++
+ name.getBytes("UTF-8")
+ )
+ )
+ .map { bs =>
+ val cs = bs.take(16) // Truncate 160 bits (20 bytes) SHA-1 to fit into our 128 bits of space
+ cs(6) = (cs(6) & 0x0f).asInstanceOf[Byte] /* clear version */
+ cs(6) = (cs(6) | 0x50).asInstanceOf[Byte] /* set to version 5, SHA1 UUID */
+ cs(8) = (cs(8) & 0x3f).asInstanceOf[Byte] /* clear variant */
+ cs(8) = (cs(8) | 0x80).asInstanceOf[Byte] /* set to IETF variant */
+ cs
+ }
+ .flatMap(
+ bs =>
+ Either.catchNonFatal {
+ val bb = java.nio.ByteBuffer.allocate(java.lang.Long.BYTES)
+ bb.put(bs, 0, 8)
+ bb.flip
+ val most = bb.getLong
+ bb.flip
+ bb.put(bs, 8, 8)
+ bb.flip
+ val least = bb.getLong
+ FUUID.fromUUID(new UUID(most, least))
+ }
+ )
+ .liftTo[F](AE)
+
+ private def uuidBytes(fuuid: FUUID): Array[Byte] = {
+ val bb = java.nio.ByteBuffer.allocate(2 * java.lang.Long.BYTES)
+ val uuid = FUUID.Unsafe.toUUID(fuuid)
+ bb.putLong(uuid.getMostSignificantBits)
+ bb.putLong(uuid.getLeastSignificantBits)
+ bb.array
+ }
+}

modules/core/.jvm/src/test/scala/io/chrisdavenport/fuuid/FUUIDJvmSpec.scala

@@ -0,0 +1,29 @@
+package io.chrisdavenport.fuuid
+
+import cats.effect.IO
+import org.specs2._
+
+class FUUIDJvmSpec extends mutable.Specification with ScalaCheck {
+
+ "FUUID.nameBased" should {
+ "produce a valid UUID" in {
+ (for {
+ namespace <- FUUID.randomFUUID[IO]
+ namebased <- FUUID.nameBased[IO](namespace, "What up yo!")
+ parsed <- FUUID.fromStringF[IO](namebased.toString)
+ } yield parsed)
+ .attempt
+ .unsafeRunSync
+ .isRight must_=== true
+ }
+
+ "conform to an example" in {
+ val namespace = FUUID.fromStringF[IO]("dc79a6bc-de3c-5bc7-a877-712bea708d8f").unsafeRunSync()
+ val name = "What up yo!"
+
+ val expected = FUUID.fromStringF[IO]("1cce4593-d217-5b33-be0d-2e81462e79d3").unsafeRunSync()
+
+ FUUID.nameBased[IO](namespace, name).unsafeRunSync must_=== expected
+ }
+ }
+}

modules/core/src/main/scala/io/chrisdavenport/fuuid/FUUID.scala

@@ -74,6 +74,13 @@ object FUUID {
  }
  }
 
+ /**
+ * Creates a new name-based UUIDv5.
+ * NOTE: Not implemented for Scala.js!
+ **/ 
+ def nameBased[F[_]](namespace: FUUID, name: String)(implicit AE: ApplicativeError[F, Throwable]): F[FUUID] =
+ PlatformSpecificMethods.nameBased[F](namespace, name, AE)
+
  /**
  * A Home For functions we don't trust
  * Hopefully making it very clear that this code needs

modules/core/src/test/scala/io/chrisdavenport/fuuid/FUUIDSpec.scala

@@ -4,7 +4,7 @@ import java.util.UUID
 import cats.effect.IO
 import org.specs2._
 
-object FUUIDSpec extends mutable.Specification with ScalaCheck {
+class FUUIDSpec extends mutable.Specification with ScalaCheck {
 
  "FUUID.fromString" should {
  "Fail when parsing an invalid string" in {