go-ethereum/vendor/github.com/pborman/uuid/time.go
Péter Szilágyi 289b30715d Godeps, vendor: convert dependency management to trash (#3198)
This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.

You can update dependencies via trash --update.

All dependencies have been updated to their latest version.

Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.

The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.

golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.
2016-10-28 19:05:01 +02:00

133 lines
3.7 KiB
Go

// Copyright 2014 Google Inc. 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
import (
"encoding/binary"
"sync"
"time"
)
// A Time represents a time as the number of 100's of nanoseconds since 15 Oct
// 1582.
type Time int64
const (
lillian = 2299160 // Julian day of 15 Oct 1582
unix = 2440587 // Julian day of 1 Jan 1970
epoch = unix - lillian // Days between epochs
g1582 = epoch * 86400 // seconds between epochs
g1582ns100 = g1582 * 10000000 // 100s of a nanoseconds between epochs
)
var (
timeMu sync.Mutex
lasttime uint64 // last time we returned
clock_seq uint16 // clock sequence for this run
timeNow = time.Now // for testing
)
// UnixTime converts t the number of seconds and nanoseconds using the Unix
// epoch of 1 Jan 1970.
func (t Time) UnixTime() (sec, nsec int64) {
sec = int64(t - g1582ns100)
nsec = (sec % 10000000) * 100
sec /= 10000000
return sec, nsec
}
// GetTime returns the current Time (100s of nanoseconds since 15 Oct 1582) and
// clock sequence as well as adjusting the clock sequence as needed. An error
// is returned if the current time cannot be determined.
func GetTime() (Time, uint16, error) {
defer timeMu.Unlock()
timeMu.Lock()
return getTime()
}
func getTime() (Time, uint16, error) {
t := timeNow()
// If we don't have a clock sequence already, set one.
if clock_seq == 0 {
setClockSequence(-1)
}
now := uint64(t.UnixNano()/100) + g1582ns100
// If time has gone backwards with this clock sequence then we
// increment the clock sequence
if now <= lasttime {
clock_seq = ((clock_seq + 1) & 0x3fff) | 0x8000
}
lasttime = now
return Time(now), clock_seq, nil
}
// ClockSequence returns the current clock sequence, generating one if not
// already set. The clock sequence is only used for Version 1 UUIDs.
//
// The uuid package does not use global static storage for the clock sequence or
// the last time a UUID was generated. Unless SetClockSequence a new random
// clock sequence is generated the first time a clock sequence is requested by
// ClockSequence, GetTime, or NewUUID. (section 4.2.1.1) sequence is generated
// for
func ClockSequence() int {
defer timeMu.Unlock()
timeMu.Lock()
return clockSequence()
}
func clockSequence() int {
if clock_seq == 0 {
setClockSequence(-1)
}
return int(clock_seq & 0x3fff)
}
// SetClockSeq sets the clock sequence to the lower 14 bits of seq. Setting to
// -1 causes a new sequence to be generated.
func SetClockSequence(seq int) {
defer timeMu.Unlock()
timeMu.Lock()
setClockSequence(seq)
}
func setClockSequence(seq int) {
if seq == -1 {
var b [2]byte
randomBits(b[:]) // clock sequence
seq = int(b[0])<<8 | int(b[1])
}
old_seq := clock_seq
clock_seq = uint16(seq&0x3fff) | 0x8000 // Set our variant
if old_seq != clock_seq {
lasttime = 0
}
}
// Time returns the time in 100s of nanoseconds since 15 Oct 1582 encoded in
// uuid. It returns false if uuid is not valid. The time is only well defined
// for version 1 and 2 UUIDs.
func (uuid UUID) Time() (Time, bool) {
if len(uuid) != 16 {
return 0, false
}
time := int64(binary.BigEndian.Uint32(uuid[0:4]))
time |= int64(binary.BigEndian.Uint16(uuid[4:6])) << 32
time |= int64(binary.BigEndian.Uint16(uuid[6:8])&0xfff) << 48
return Time(time), true
}
// ClockSequence returns the clock sequence encoded in uuid. It returns false
// if uuid is not valid. The clock sequence is only well defined for version 1
// and 2 UUIDs.
func (uuid UUID) ClockSequence() (int, bool) {
if len(uuid) != 16 {
return 0, false
}
return int(binary.BigEndian.Uint16(uuid[8:10])) & 0x3fff, true
}