init commit

vendor/github.com/twinj/uuid/version.go

@@ -0,0 +1,71 @@
+package uuid
+
+// Version represents the type of UUID.
+type Version int
+
+// The following are the supported Versions.
+const (
+	VersionUnknown Version = iota // Unknown
+	VersionOne                    // Time based
+	VersionTwo                    // DCE security via POSIX UIDs
+	VersionThree                  // Namespace hash uses MD5
+	VersionFour                   // Crypto random
+	VersionFive                   // Namespace hash uses SHA-1
+)
+
+// The following are the supported Variants.
+const (
+	VariantNCS       uint8 = 0x00
+	VariantRFC4122   uint8 = 0x80 // or and A0 if masked with 1F
+	VariantMicrosoft uint8 = 0xC0
+	VariantFuture    uint8 = 0xE0
+)
+
+const (
+	// 3f used by RFC4122 although 1f works for all
+	variantSet = 0x3f
+
+	// rather than using 0xc0 we use 0xe0 to retrieve the variant
+	// The result is the same for all other variants
+	// 0x80 and 0xa0 are used to identify RFC4122 compliance
+	variantGet = 0xe0
+)
+
+// String returns English description of version.
+func (o Version) String() string {
+	switch o {
+	case VersionOne:
+		return "Version 1: Based on a 60 Bit Timestamp."
+	case VersionTwo:
+		return "Version 2: Based on DCE security domain and 60 bit timestamp."
+	case VersionThree:
+		return "Version 3: Namespace UUID and unique names hashed by MD5."
+	case VersionFour:
+		return "Version 4: Crypto-random generated."
+	case VersionFive:
+		return "Version 5: Namespace UUID and unique names hashed by SHA-1."
+	default:
+		return "Unknown: Not supported"
+	}
+}
+
+func resolveVersion(version uint8) Version {
+	switch Version(version) {
+	case VersionOne, VersionTwo, VersionThree, VersionFour, VersionFive:
+		return Version(version)
+	default:
+		return VersionUnknown
+	}
+}
+
+func variant(variant uint8) uint8 {
+	switch variant & variantGet {
+	case VariantRFC4122, 0xA0:
+		return VariantRFC4122
+	case VariantMicrosoft:
+		return VariantMicrosoft
+	case VariantFuture:
+		return VariantFuture
+	}
+	return VariantNCS
+}