clock

Documentation

Overview

Package clock provides extensions to the time package.

Index

• func ContextWithDeadline(ctx context.Context, deadline time.Time, timeSource TimeSource) (context.Context, context.CancelFunc)
• func ContextWithTimeout(ctx context.Context, timeout time.Duration, timeSource TimeSource) (context.Context, context.CancelFunc)
• type EventTimeSource
  • func NewEventTimeSource() *EventTimeSource
  • func (ts *EventTimeSource) Advance(d time.Duration)
  • func (ts *EventTimeSource) AfterFunc(d time.Duration, f func()) Timer
  • func (ts *EventTimeSource) NewTimer(d time.Duration) (<-chan time.Time, Timer)
  • func (ts *EventTimeSource) Now() time.Time
  • func (ts *EventTimeSource) NumTimers() int
  • func (ts *EventTimeSource) Update(now time.Time) *EventTimeSource
• type RealTimeSource
  • func NewRealTimeSource() RealTimeSource
  • func (ts RealTimeSource) AfterFunc(d time.Duration, f func()) Timer
  • func (ts RealTimeSource) NewTimer(d time.Duration) (<-chan time.Time, Timer)
  • func (ts RealTimeSource) Now() time.Time
• type TimeSource
• type Timer

Examples

• EventTimeSource

Functions

func ContextWithDeadline

func ContextWithDeadline(
	ctx context.Context,
	deadline time.Time,
	timeSource TimeSource,
) (context.Context, context.CancelFunc)

func ContextWithTimeout

func ContextWithTimeout(
	ctx context.Context,
	timeout time.Duration,
	timeSource TimeSource,
) (context.Context, context.CancelFunc)

Types

type EventTimeSource

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

EventTimeSource is a fake TimeSource. Unlike other fake clock implementations, the methods are synchronous, so when you call Advance or Update, all triggered timers from AfterFunc will fire before the method returns, in the same goroutine.

Example

package main

import (
	"fmt"
	"time"

	"go.temporal.io/server/common/clock"
)

func main() {
	// Create a new fake timeSource.
	source := clock.NewEventTimeSource()

	// Create a timer which fires after 1 second.
	source.AfterFunc(time.Second, func() {
		fmt.Println("timer fired")
	})

	// Advance the time source by 1 second.
	fmt.Println("advancing time source by 1 second")
	source.Advance(time.Second)
	fmt.Println("time source advanced")

}

Output:

advancing time source by 1 second
timer fired
time source advanced

func NewEventTimeSource

func NewEventTimeSource() *EventTimeSource

NewEventTimeSource returns a EventTimeSource with the current time set to Unix zero: 1970-01-01 00:00:00 +0000 UTC.

func (*EventTimeSource) Advance

func (ts *EventTimeSource) Advance(d time.Duration)

Advance the timer by the specified duration.

func (*EventTimeSource) AfterFunc

func (ts *EventTimeSource) AfterFunc(d time.Duration, f func()) Timer

AfterFunc return a timer that will fire after the specified duration. It is important to note that the timeSource is locked while the callback is called. This means that you must be cautious about calling any other mutating methods on the timeSource from within the callback. Doing so will probably result in a deadlock. To avoid this, you may want to wrap all such calls in a goroutine. If the duration is non-positive, the callback will fire immediately before AfterFunc returns.

func (*EventTimeSource) NewTimer

func (ts *EventTimeSource) NewTimer(d time.Duration) (<-chan time.Time, Timer)

NewTimer creates a Timer that will send the current time on a channel after at least duration d. It returns the channel and the Timer.

func (*EventTimeSource) Now

func (ts *EventTimeSource) Now() time.Time

Now return the current time.

func (*EventTimeSource) NumTimers

func (ts *EventTimeSource) NumTimers() int

NumTimers returns the number of outstanding timers.

func (*EventTimeSource) Update

func (ts *EventTimeSource) Update(now time.Time) *EventTimeSource

Update the fake current time. It returns the timeSource so that you can chain calls like this: timeSource := NewEventTimeSource().Update(time.Now())

type RealTimeSource

type RealTimeSource struct{}

RealTimeSource is a timeSource that uses the real wall timeSource time. The zero value is valid.

func NewRealTimeSource

func NewRealTimeSource() RealTimeSource

NewRealTimeSource returns a timeSource that uses the real wall timeSource time.

func (RealTimeSource) AfterFunc

func (ts RealTimeSource) AfterFunc(d time.Duration, f func()) Timer

AfterFunc is a pass-through to time.AfterFunc.

func (RealTimeSource) NewTimer

func (ts RealTimeSource) NewTimer(d time.Duration) (<-chan time.Time, Timer)

NewTimer is a pass-through to time.NewTimer.

func (RealTimeSource) Now

func (ts RealTimeSource) Now() time.Time

Now returns the current time, with the location set to UTC.

type TimeSource

type TimeSource interface {
	Now() time.Time
	AfterFunc(d time.Duration, f func()) Timer
	NewTimer(d time.Duration) (<-chan time.Time, Timer)
}

TimeSource is an interface to make it easier to test code that uses time.

type Timer

type Timer interface {
	// Reset changes the expiration time of the timer. It returns true if the timer had been active, false if the
	// timer had expired or been stopped.
	Reset(d time.Duration) bool
	// Stop prevents the Timer from firing. It returns true if the call stops the timer, false if the timer has
	// already expired or been stopped.
	Stop() bool
}

Timer is a timer returned by TimeSource.AfterFunc. Unlike the timers returned by time.NewTimer or time.Ticker, this timer does not have a channel. That is because the callback already reacts to the timer firing.