go.mway.dev/chrono@v0.6.1-0.20240126030049-189c5aef20d2/clock/ticker.go (about)

     1  // Copyright (c) 2023 Matt Way
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to
     5  // deal in the Software without restriction, including without limitation the
     6  // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
     7  // sell copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    18  // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
    19  // IN THE THE SOFTWARE.
    20  
    21  package clock
    22  
    23  import (
    24  	"errors"
    25  	"time"
    26  )
    27  
    28  // A Ticker is functionally equivalent to a [time.Ticker]. A Ticker must be
    29  // created by [Clock.NewTicker].
    30  type Ticker struct {
    31  	C      <-chan time.Time
    32  	ticker *time.Ticker
    33  	fake   *fakeTimer
    34  }
    35  
    36  // Reset stops a ticker and resets its period to the specified duration. The
    37  // next tick will arrive after the new period elapses. The duration d must be
    38  // greater than zero; if not, Reset will panic.
    39  func (t *Ticker) Reset(d time.Duration) {
    40  	if t.ticker != nil {
    41  		t.ticker.Reset(d)
    42  		return
    43  	}
    44  
    45  	if d <= 0 {
    46  		panic(errors.New("non-positive interval for Ticker.Reset"))
    47  	}
    48  
    49  	t.fake.resetTimer(d)
    50  }
    51  
    52  // Stop turns off a ticker. After Stop, no more ticks will be sent. Stop does
    53  // not close the channel, to prevent a concurrent goroutine reading from the
    54  // channel from seeing an erroneous "tick".
    55  func (t *Ticker) Stop() {
    56  	if t.ticker != nil {
    57  		t.ticker.Stop()
    58  		return
    59  	}
    60  
    61  	t.fake.removeTimer()
    62  }