go.uber.org/yarpc@v1.72.1/internal/testtime/scale.go (about)

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    20  
    21  // Package testtime provides ways to scale time for tests running on CPU
    22  // starved systems.
    23  package testtime
    24  
    25  import (
    26  	"fmt"
    27  	"os"
    28  	"strconv"
    29  	"time"
    30  )
    31  
    32  var (
    33  	// X is the multiplier from the TEST_TIME_SCALE environment variable.
    34  	X = 1.0
    35  	// Millisecond is a millisecond dilated into test time by TEST_TIME_SCALE.
    36  	Millisecond = time.Millisecond
    37  	// Second is a second dilated into test time by TEST_TIME_SCALE.
    38  	Second = time.Second
    39  )
    40  
    41  func init() {
    42  	if v := os.Getenv("TEST_TIME_SCALE"); v != "" {
    43  		fv, err := strconv.ParseFloat(v, 64)
    44  		if err != nil {
    45  			panic(err)
    46  		}
    47  		X = fv
    48  		fmt.Fprintln(os.Stderr, "Scaling test time by factor", X)
    49  	}
    50  
    51  	Millisecond = Scale(time.Millisecond)
    52  	Second = Scale(time.Second)
    53  }
    54  
    55  // Scale returns the timeout multiplied by any set multiplier.
    56  func Scale(timeout time.Duration) time.Duration {
    57  	return time.Duration(X * float64(timeout))
    58  }
    59  
    60  // Sleep sleeps the given duration in test time scale.
    61  func Sleep(duration time.Duration) {
    62  	time.Sleep(Scale(duration))
    63  }