// Copyright (C) 2013-2018 by Maxim Bublis <b@codemonkey.ru> // // Permission is hereby granted, free of charge, to any person obtaining // a copy of this software and associated documentation files (the // "Software"), to deal in the Software without restriction, including // without limitation the rights to use, copy, modify, merge, publish, // distribute, sublicense, and/or sell copies of the Software, and to // permit persons to whom the Software is furnished to do so, subject to // the following conditions: // // The above copyright notice and this permission notice shall be // included in all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. // Package uuid provides implementation of Universally Unique Identifier (UUID). // Supported versions are 1, 3, 4 and 5 (as specified in RFC 4122) and // version 2 (as specified in DCE 1.1). package uuid import ( "bytes" "encoding/hex" ) // Size of a UUID in bytes. const Size = 16 // UUID representation compliant with specification // described in RFC 4122. type UUID [Size]byte // UUID versions const ( _ byte = iota V1 V2 V3 V4 V5 ) // UUID layout variants. const ( VariantNCS byte = iota VariantRFC4122 VariantMicrosoft VariantFuture ) // UUID DCE domains. const ( DomainPerson = iota DomainGroup DomainOrg ) // String parse helpers. var ( urnPrefix = []byte("urn:uuid:") byteGroups = []int{8, 4, 4, 4, 12} ) // Nil is special form of UUID that is specified to have all // 128 bits set to zero. var Nil = UUID{} // Predefined namespace UUIDs. var ( NamespaceDNS = Must(FromString("6ba7b810-9dad-11d1-80b4-00c04fd430c8")) NamespaceURL = Must(FromString("6ba7b811-9dad-11d1-80b4-00c04fd430c8")) NamespaceOID = Must(FromString("6ba7b812-9dad-11d1-80b4-00c04fd430c8")) NamespaceX500 = Must(FromString("6ba7b814-9dad-11d1-80b4-00c04fd430c8")) ) // Equal returns true if u1 and u2 equals, otherwise returns false. func Equal(u1 UUID, u2 UUID) bool { return bytes.Equal(u1[:], u2[:]) } // Version returns algorithm version used to generate UUID. func (u UUID) Version() byte { return u[6] >> 4 } // Variant returns UUID layout variant. func (u UUID) Variant() byte { switch { case (u[8] >> 7) == 0x00: return VariantNCS case (u[8] >> 6) == 0x02: return VariantRFC4122 case (u[8] >> 5) == 0x06: return VariantMicrosoft case (u[8] >> 5) == 0x07: fallthrough default: return VariantFuture } } // Bytes returns bytes slice representation of UUID. func (u UUID) Bytes() []byte { return u[:] } // Returns canonical string representation of UUID: // xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. func (u UUID) String() string { buf := make([]byte, 36) hex.Encode(buf[0:8], u[0:4]) buf[8] = '-' hex.Encode(buf[9:13], u[4:6]) buf[13] = '-' hex.Encode(buf[14:18], u[6:8]) buf[18] = '-' hex.Encode(buf[19:23], u[8:10]) buf[23] = '-' hex.Encode(buf[24:], u[10:]) return string(buf) } // SetVersion sets version bits. func (u *UUID) SetVersion(v byte) { u[6] = (u[6] & 0x0f) | (v << 4) } // SetVariant sets variant bits. func (u *UUID) SetVariant(v byte) { switch v { case VariantNCS: u[8] = (u[8]&(0xff>>1) | (0x00 << 7)) case VariantRFC4122: u[8] = (u[8]&(0xff>>2) | (0x02 << 6)) case VariantMicrosoft: u[8] = (u[8]&(0xff>>3) | (0x06 << 5)) case VariantFuture: fallthrough default: u[8] = (u[8]&(0xff>>3) | (0x07 << 5)) } } // Must is a helper that wraps a call to a function returning (UUID, error) // and panics if the error is non-nil. It is intended for use in variable // initializations such as // var packageUUID = uuid.Must(uuid.FromString("123e4567-e89b-12d3-a456-426655440000")); func Must(u UUID, err error) UUID { if err != nil { panic(err) } return u }