k8s.io/kubernetes@v1.31.0-alpha.0.0.20240520171757-56147500dadc/plugin/pkg/admission/eventratelimit/cache_test.go (about)

     1  /*
     2  Copyright 2017 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 eventratelimit
    18  
    19  import (
    20  	"testing"
    21  
    22  	"k8s.io/client-go/util/flowcontrol"
    23  	"k8s.io/utils/lru"
    24  )
    25  
    26  func TestSingleCache(t *testing.T) {
    27  	rateLimiter := flowcontrol.NewTokenBucketRateLimiter(1., 1)
    28  	cache := singleCache{
    29  		rateLimiter: rateLimiter,
    30  	}
    31  	cases := []interface{}{nil, "key1", "key2"}
    32  	for _, tc := range cases {
    33  		actual := cache.get(tc)
    34  		if e, a := rateLimiter, actual; e != a {
    35  			t.Errorf("unexpected entry in cache for key %v: expected %v, got %v", tc, e, a)
    36  		}
    37  	}
    38  }
    39  
    40  func TestLRUCache(t *testing.T) {
    41  	rateLimiters := []flowcontrol.RateLimiter{
    42  		flowcontrol.NewTokenBucketRateLimiter(1., 1),
    43  		flowcontrol.NewTokenBucketRateLimiter(2., 2),
    44  		flowcontrol.NewTokenBucketRateLimiter(3., 3),
    45  		flowcontrol.NewTokenBucketRateLimiter(4., 4),
    46  	}
    47  	nextRateLimiter := 0
    48  	rateLimiterFactory := func() flowcontrol.RateLimiter {
    49  		rateLimiter := rateLimiters[nextRateLimiter]
    50  		nextRateLimiter++
    51  		return rateLimiter
    52  	}
    53  	underlyingCache := lru.New(2)
    54  	cache := lruCache{
    55  		rateLimiterFactory: rateLimiterFactory,
    56  		cache:              underlyingCache,
    57  	}
    58  	cases := []struct {
    59  		name     string
    60  		key      int
    61  		expected flowcontrol.RateLimiter
    62  	}{
    63  		{
    64  			name:     "first added",
    65  			key:      0,
    66  			expected: rateLimiters[0],
    67  		},
    68  		{
    69  			name:     "first obtained",
    70  			key:      0,
    71  			expected: rateLimiters[0],
    72  		},
    73  		{
    74  			name:     "second added",
    75  			key:      1,
    76  			expected: rateLimiters[1],
    77  		},
    78  		{
    79  			name:     "second obtained",
    80  			key:      1,
    81  			expected: rateLimiters[1],
    82  		},
    83  		{
    84  			name:     "first obtained second time",
    85  			key:      0,
    86  			expected: rateLimiters[0],
    87  		},
    88  		{
    89  			name:     "third added",
    90  			key:      2,
    91  			expected: rateLimiters[2],
    92  		},
    93  		{
    94  			name:     "third obtained",
    95  			key:      2,
    96  			expected: rateLimiters[2],
    97  		},
    98  		{
    99  			name:     "first obtained third time",
   100  			key:      0,
   101  			expected: rateLimiters[0],
   102  		},
   103  		{
   104  			name:     "second re-added after eviction",
   105  			key:      1,
   106  			expected: rateLimiters[3],
   107  		},
   108  	}
   109  	for _, tc := range cases {
   110  		actual := cache.get(tc.key)
   111  		if e, a := tc.expected, actual; e != a {
   112  			t.Errorf("%v: unexpected entry in cache for key %v: expected %v, got %v", tc.name, tc.key, e, a)
   113  		}
   114  	}
   115  }