go package学习——time

package time提供测量和显示时间的能力。

Index

• Constants
• func After(d Duration) <-chan Time
• func Sleep(d Duration)
• func Tick(d Duration) <-chan Time
• type Duration
  • func ParseDuration(s string) (Duration, error)
  • func Since(t Time) Duration
  • func (d Duration) Hours() float64
  • func (d Duration) Minutes() float64
  • func (d Duration) Nanoseconds() int64
  • func (d Duration) Seconds() float64
  • func (d Duration) String() string
• type Location
  • func FixedZone(name string, offset int) *Location
  • func LoadLocation(name string) (*Location, error)
  • func (l *Location) String() string
• type Month
  • func (m Month) String() string
• type ParseError
  • func (e *ParseError) Error() string
• type Ticker
  • func NewTicker(d Duration) *Ticker
  • func (t *Ticker) Stop()
• type Time
  • func Date(year int, month Month, day, hour, min, sec, nsec int, loc *Location) Time
  • func Now() Time
  • func Parse(layout, value string) (Time, error)
  • func ParseInLocation(layout, value string, loc *Location) (Time, error)
  • func Unix(sec int64, nsec int64) Time
  • func (t Time) Add(d Duration) Time
  • func (t Time) AddDate(years int, months int, days int) Time
  • func (t Time) After(u Time) bool
  • func (t Time) Before(u Time) bool
  • func (t Time) Clock() (hour, min, sec int)
  • func (t Time) Date() (year int, month Month, day int)
  • func (t Time) Day() int
  • func (t Time) Equal(u Time) bool
  • func (t Time) Format(layout string) string
  • func (t *Time) GobDecode(buf []byte) error
  • func (t Time) GobEncode() ([]byte, error)
  • func (t Time) Hour() int
  • func (t Time) ISOWeek() (year, week int)
  • func (t Time) In(loc *Location) Time
  • func (t Time) IsZero() bool
  • func (t Time) Local() Time
  • func (t Time) Location() *Location
  • func (t Time) MarshalJSON() ([]byte, error)
  • func (t Time) Minute() int
  • func (t Time) Month() Month
  • func (t Time) Nanosecond() int
  • func (t Time) Round(d Duration) Time
  • func (t Time) Second() int
  • func (t Time) String() string
  • func (t Time) Sub(u Time) Duration
  • func (t Time) Truncate(d Duration) Time
  • func (t Time) UTC() Time
  • func (t Time) Unix() int64
  • func (t Time) UnixNano() int64
  • func (t *Time) UnmarshalJSON(data []byte) (err error)
  • func (t Time) Weekday() Weekday
  • func (t Time) Year() int
  • func (t Time) YearDay() int
  • func (t Time) Zone() (name string, offset int)
• type Timer
  • func AfterFunc(d Duration, f func()) *Timer
  • func NewTimer(d Duration) *Timer
  • func (t *Timer) Reset(d Duration) bool
  • func (t *Timer) Stop() bool
• type Weekday
  • func (d Weekday) String() string

Examples

• After
• Date
• Duration
• Month
• Parse
• ParseInLocation
• Sleep
• Tick
• Time.Format
• Time.Round
• Time.Truncate

Package Files

format.go sleep.go sys_unix.go tick.go time.go zoneinfo.go zoneinfo_read.go zoneinfo_unix.go

1. 基本函数

func After

func After(d Duration) <-chan Time

在等待了d时间间隔后，向返回channel发送当前时间。与NewTimer(d).C等效。事例以下：

select {
case m := <-c:
    handle(m)
case <-time.After(5 * time.Minute):
    fmt.Println("timed out")
}

主要用于超时处理，以防死锁。

func Sleep

func Sleep(d Duration)

挂起当前goroutine，d时间间隔。

time.Sleep(100 * time.Millisecond)

func Tick

func Tick(d Duration) <-chan Time

Tick是NewTicker的一个封装，只用于访问ticking channel；用户不须要关闭ticker。示例：

c := time.Tick(1 * time.Minute)
for now := range c {
    fmt.Printf("%v %s\n", now, statusUpdate())
}

2. type Duration

type Duration

type Duration int64

Duration是两个纳秒时间标记之间的间隔，其表示的最大间隔是290年。

const (
    Nanosecond  Duration = 1
    Microsecond          = 1000 * Nanosecond
    Millisecond          = 1000 * Microsecond
    Second               = 1000 * Millisecond
    Minute               = 60 * Second
    Hour                 = 60 * Minute
)

上面的常量都是经常使用的duration，须要记住。

若是将一个整数转化成一个duration的话，须要这么作：

seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s

计算通过的时间间隔的示例以下，此示例很通用：

t0 := time.Now()
expensiveCall()
t1 := time.Now()
fmt.Printf("The call took %v to run.\n", t1.Sub(t0))

func Since

func Since(t Time) Duration

Since返回从时间t开始的已流逝时间，它是time.Now().Sub(t)的浓缩版。

3. type Month

type Month

type Month int

const (
    January Month = 1 + iota
    February
    March
    April
    May
    June
    July
    August
    September
    October
    November
    December
)

注意其写法。

4. type Ticker

type Ticker

type Ticker struct {
    C <-chan Time // The channel on which the ticks are delivered.
    // contains filtered or unexported fields
}

Ticker包含一个channel，此channel以固定间隔发送ticks。

func NewTicker

func NewTicker(d Duration) *Ticker

返回一个Ticker，此Ticker包含一个channel，此channel以给定的duration发送时间。duration d必须大于0.

func (*Ticker) Stop

func (t *Ticker) Stop()

用于关闭相应的Ticker，但并不关闭channel。

5. type Time

type Time

type Time struct {      // contains filtered or unexported fields }

Time以纳秒来表示一个时刻。程序应该存储或传递Time值，而不是指针，即time.Time，而非*time.Time。

6. type Timer

type Timer

type Timer struct {
    C <-chan Time
    // contains filtered or unexported fields
}

Timer type表明了一个事件，若是不是被AfterFunc建立的Timer，当Timer过时，当前时间将发送到C。

func AfterFunc

func AfterFunc(d Duration, f func()) *Timer

AfterFunc等待duration耗尽后，在当前的goroutine中调用f函数。它返回一个Timer，利用此Timer的Stop方法，能够取消调用f函数。