k8s.io/apiserver@v0.29.3/pkg/storage/cacher/time_budget_test.go (about)

     1  /*
     2  Copyright 2016 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package cacher
    18  
    19  import (
    20  	"testing"
    21  	"time"
    22  
    23  	testingclock "k8s.io/utils/clock/testing"
    24  )
    25  
    26  func TestTimeBudget(t *testing.T) {
    27  	fakeClock := testingclock.NewFakeClock(time.Now())
    28  
    29  	budget := &timeBudgetImpl{
    30  		clock:     fakeClock,
    31  		budget:    time.Duration(0),
    32  		maxBudget: 200 * time.Millisecond,
    33  		refresh:   50 * time.Millisecond,
    34  		last:      fakeClock.Now(),
    35  	}
    36  	if res := budget.takeAvailable(); res != time.Duration(0) {
    37  		t.Errorf("Expected: %v, got: %v", time.Duration(0), res)
    38  	}
    39  
    40  	// wait for longer than the maxBudget
    41  	nextTime := time.Now().Add(10 * time.Second)
    42  	fakeClock.SetTime(nextTime)
    43  	if res := budget.takeAvailable(); res != budget.maxBudget {
    44  		t.Errorf("Expected: %v, got: %v", budget.maxBudget, res)
    45  	}
    46  	// add two refresh intervals to accumulate 2*refresh durations
    47  	nextTime = nextTime.Add(2 * time.Second)
    48  	fakeClock.SetTime(nextTime)
    49  	if res := budget.takeAvailable(); res != 2*budget.refresh {
    50  		t.Errorf("Expected: %v, got: %v", 2*budget.refresh, res)
    51  	}
    52  	// return one refresh duration to have only one refresh duration available
    53  	// we didn't advanced on time yet
    54  	budget.returnUnused(budget.refresh)
    55  	if res := budget.takeAvailable(); res != budget.refresh {
    56  		t.Errorf("Expected: %v, got: %v", budget.refresh, res)
    57  	}
    58  
    59  	// return a negative value to the budget
    60  	// we didn't advanced on time yet
    61  	budget.returnUnused(-time.Duration(50))
    62  	if res := budget.takeAvailable(); res != time.Duration(0) {
    63  		t.Errorf("Expected: %v, got: %v", time.Duration(0), res)
    64  	}
    65  	// handle back in time problem with an empty budget
    66  	nextTime = nextTime.Add(-2 * time.Minute)
    67  	fakeClock.SetTime(nextTime)
    68  	if res := budget.takeAvailable(); res != time.Duration(0) {
    69  		t.Errorf("Expected: %v, got: %v", time.Duration(0), res)
    70  	}
    71  	// wait for longer than the maxBudget
    72  	// verify that adding a negative value didn't affected
    73  	nextTime = nextTime.Add(10 * time.Minute)
    74  	fakeClock.SetTime(nextTime)
    75  	if res := budget.takeAvailable(); res != budget.maxBudget {
    76  		t.Errorf("Expected: %v, got: %v", budget.maxBudget, res)
    77  	}
    78  
    79  	// handle back in time problem with time on the budget
    80  	budget.returnUnused(10 * time.Second)
    81  	nextTime = nextTime.Add(-2 * time.Minute)
    82  	fakeClock.SetTime(nextTime)
    83  	if res := budget.takeAvailable(); res != budget.maxBudget {
    84  		t.Errorf("Expected: %v, got: %v", budget.maxBudget, res)
    85  	}
    86  }