github.com/letsencrypt/trillian@v1.1.2-0.20180615153820-ae375a99d36a/util/time.go (about)

     1  // Copyright 2018 Google Inc. All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package util
    16  
    17  import (
    18  	"context"
    19  	"time"
    20  )
    21  
    22  // Sleep sleeps for at least the specified duration. Returns false iff done is
    23  // closed before the timer fires.
    24  func Sleep(done <-chan struct{}, dur time.Duration) bool {
    25  	timer := time.NewTimer(dur)
    26  	defer timer.Stop()
    27  	select {
    28  	case <-timer.C:
    29  		return true
    30  	case <-done:
    31  		return false
    32  	}
    33  }
    34  
    35  // SleepContext sleeps for at least the specified duration. Returns ctx.Err()
    36  // iff the context is canceled before the timer fires.
    37  func SleepContext(ctx context.Context, dur time.Duration) error {
    38  	if !Sleep(ctx.Done(), dur) {
    39  		return ctx.Err()
    40  	}
    41  	return nil
    42  }