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Diffstat (limited to 'vendor/github.com/xtgo/uuid/uuid.go')
| -rw-r--r-- | vendor/github.com/xtgo/uuid/uuid.go | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/vendor/github.com/xtgo/uuid/uuid.go b/vendor/github.com/xtgo/uuid/uuid.go new file mode 100644 index 000000000..a0fd7a5a5 --- /dev/null +++ b/vendor/github.com/xtgo/uuid/uuid.go @@ -0,0 +1,204 @@ +// Copyright (c) 2012 The gocql Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package uuid can be used to generate and parse universally unique +// identifiers, a standardized format in the form of a 128 bit number. +// +// http://tools.ietf.org/html/rfc4122 +package uuid + +import ( + "crypto/rand" + "encoding/hex" + "errors" + "io" + "net" + "strconv" + "time" +) + +type UUID [16]byte + +var hardwareAddr []byte + +const ( + VariantNCSCompat = 0 + VariantIETF = 2 + VariantMicrosoft = 6 + VariantFuture = 7 +) + +func init() { + if interfaces, err := net.Interfaces(); err == nil { + for _, i := range interfaces { + if i.Flags&net.FlagLoopback == 0 && len(i.HardwareAddr) > 0 { + hardwareAddr = i.HardwareAddr + break + } + } + } + if hardwareAddr == nil { + // If we failed to obtain the MAC address of the current computer, + // we will use a randomly generated 6 byte sequence instead and set + // the multicast bit as recommended in RFC 4122. + hardwareAddr = make([]byte, 6) + _, err := io.ReadFull(rand.Reader, hardwareAddr) + if err != nil { + panic(err) + } + hardwareAddr[0] = hardwareAddr[0] | 0x01 + } +} + +// Parse parses a 32 digit hexadecimal number (that might contain hyphens) +// representing an UUID. +func Parse(input string) (UUID, error) { + var u UUID + j := 0 + for i := 0; i < len(input); i++ { + b := input[i] + switch { + default: + fallthrough + case j == 32: + goto err + case b == '-': + continue + case '0' <= b && b <= '9': + b -= '0' + case 'a' <= b && b <= 'f': + b -= 'a' - 10 + case 'A' <= b && b <= 'F': + b -= 'A' - 10 + } + u[j/2] |= b << byte(^j&1<<2) + j++ + } + if j == 32 { + return u, nil + } +err: + return UUID{}, errors.New("invalid UUID " + strconv.Quote(input)) +} + +// FromBytes converts a raw byte slice to an UUID. It will panic if the slice +// isn't exactly 16 bytes long. +func FromBytes(input []byte) UUID { + var u UUID + if len(input) != 16 { + panic("UUIDs must be exactly 16 bytes long") + } + copy(u[:], input) + return u +} + +// NewRandom generates a totally random UUID (version 4) as described in +// RFC 4122. +func NewRandom() UUID { + var u UUID + io.ReadFull(rand.Reader, u[:]) + u[6] &= 0x0F // clear version + u[6] |= 0x40 // set version to 4 (random uuid) + u[8] &= 0x3F // clear variant + u[8] |= 0x80 // set to IETF variant + return u +} + +var timeBase = time.Date(1582, time.October, 15, 0, 0, 0, 0, time.UTC).Unix() + +// NewTime generates a new time based UUID (version 1) as described in RFC +// 4122. This UUID contains the MAC address of the node that generated the +// UUID, a timestamp and a sequence number. +func NewTime() UUID { + var u UUID + + now := time.Now().In(time.UTC) + t := uint64(now.Unix()-timeBase)*10000000 + uint64(now.Nanosecond()/100) + u[0], u[1], u[2], u[3] = byte(t>>24), byte(t>>16), byte(t>>8), byte(t) + u[4], u[5] = byte(t>>40), byte(t>>32) + u[6], u[7] = byte(t>>56)&0x0F, byte(t>>48) + + var clockSeq [2]byte + io.ReadFull(rand.Reader, clockSeq[:]) + u[8] = clockSeq[1] + u[9] = clockSeq[0] + + copy(u[10:], hardwareAddr) + + u[6] |= 0x10 // set version to 1 (time based uuid) + u[8] &= 0x3F // clear variant + u[8] |= 0x80 // set to IETF variant + + return u +} + +// String returns the UUID in it's canonical form, a 32 digit hexadecimal +// number in the form of xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. +func (u UUID) String() string { + buf := [36]byte{8: '-', 13: '-', 18: '-', 23: '-'} + hex.Encode(buf[0:], u[0:4]) + hex.Encode(buf[9:], u[4:6]) + hex.Encode(buf[14:], u[6:8]) + hex.Encode(buf[19:], u[8:10]) + hex.Encode(buf[24:], u[10:]) + return string(buf[:]) +} + +// Bytes returns the raw byte slice for this UUID. A UUID is always 128 bits +// (16 bytes) long. +func (u UUID) Bytes() []byte { + return u[:] +} + +// Variant returns the variant of this UUID. This package will only generate +// UUIDs in the IETF variant. +func (u UUID) Variant() int { + x := u[8] + switch byte(0) { + case x & 0x80: + return VariantNCSCompat + case x & 0x40: + return VariantIETF + case x & 0x20: + return VariantMicrosoft + } + return VariantFuture +} + +// Version extracts the version of this UUID variant. The RFC 4122 describes +// five kinds of UUIDs. +func (u UUID) Version() int { + return int(u[6] & 0xF0 >> 4) +} + +// Node extracts the MAC address of the node who generated this UUID. It will +// return nil if the UUID is not a time based UUID (version 1). +func (u UUID) Node() []byte { + if u.Version() != 1 { + return nil + } + return u[10:] +} + +// Timestamp extracts the timestamp information from a time based UUID +// (version 1). +func (u UUID) Timestamp() uint64 { + if u.Version() != 1 { + return 0 + } + return uint64(u[0])<<24 + uint64(u[1])<<16 + uint64(u[2])<<8 + + uint64(u[3]) + uint64(u[4])<<40 + uint64(u[5])<<32 + + uint64(u[7])<<48 + uint64(u[6]&0x0F)<<56 +} + +// Time is like Timestamp, except that it returns a time.Time. +func (u UUID) Time() time.Time { + t := u.Timestamp() + if t == 0 { + return time.Time{} + } + sec := t / 10000000 + nsec := t - sec + return time.Unix(int64(sec)+timeBase, int64(nsec)) +} |