1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
package cache
import (
"context"
"errors"
"sync"
"sync/atomic"
"testing"
"time"
"github.com/stretchr/testify/require"
"gitlab.com/gitlab-org/gitlab-pages/internal/source/gitlab/api"
)
type client struct {
counter uint64
lookups chan uint64
domain chan string
failure error
}
func (c *client) GetLookup(ctx context.Context, _ string) api.Lookup {
lookup := api.Lookup{}
if c.failure == nil {
lookup.Name = <-c.domain
} else {
lookup.Error = c.failure
}
c.lookups <- atomic.AddUint64(&c.counter, 1)
return lookup
}
func (c *client) Status() error {
return nil
}
func withTestCache(config resolverConfig, cacheConfig *cacheConfig, block func(*Cache, *client)) {
var chanSize int
if config.buffered {
chanSize = 1
} else {
chanSize = 0
}
resolver := &client{
domain: make(chan string, chanSize),
lookups: make(chan uint64, 100),
failure: config.failure,
}
cache := NewCache(resolver, cacheConfig)
block(cache, resolver)
}
func (cache *Cache) withTestEntry(config entryConfig, block func(*Entry)) {
domain := "my.gitlab.com"
if len(config.domain) > 0 {
domain = config.domain
}
entry := cache.store.LoadOrCreate(domain)
if config.retrieved {
entry.setResponse(api.Lookup{Name: domain})
}
if config.expired {
entry.created = time.Now().Add(-time.Hour)
}
block(entry)
}
type resolverConfig struct {
buffered bool
failure error
}
type entryConfig struct {
domain string
expired bool
retrieved bool
}
func TestResolve(t *testing.T) {
t.Run("when item is not cached", func(t *testing.T) {
withTestCache(resolverConfig{buffered: true}, nil, func(cache *Cache, resolver *client) {
require.Equal(t, 0, len(resolver.lookups))
resolver.domain <- "my.gitlab.com"
lookup := cache.Resolve(context.Background(), "my.gitlab.com")
require.NoError(t, lookup.Error)
require.Equal(t, "my.gitlab.com", lookup.Name)
require.Equal(t, uint64(1), <-resolver.lookups)
})
})
t.Run("when item is not cached and accessed multiple times", func(t *testing.T) {
withTestCache(resolverConfig{}, nil, func(cache *Cache, resolver *client) {
wg := &sync.WaitGroup{}
ctx := context.Background()
receiver := func() {
defer wg.Done()
cache.Resolve(ctx, "my.gitlab.com")
}
wg.Add(3)
go receiver()
go receiver()
go receiver()
require.Equal(t, 0, len(resolver.lookups))
resolver.domain <- "my.gitlab.com"
wg.Wait()
require.Equal(t, uint64(1), <-resolver.lookups)
})
})
t.Run("when item is in short cache", func(t *testing.T) {
withTestCache(resolverConfig{}, nil, func(cache *Cache, resolver *client) {
cache.withTestEntry(entryConfig{expired: false, retrieved: true}, func(*Entry) {
lookup := cache.Resolve(context.Background(), "my.gitlab.com")
require.Equal(t, "my.gitlab.com", lookup.Name)
require.Equal(t, 0, len(resolver.lookups))
})
})
})
t.Run("when a non-retrieved new item is in short cache", func(t *testing.T) {
withTestCache(resolverConfig{}, nil, func(cache *Cache, resolver *client) {
cache.withTestEntry(entryConfig{expired: false, retrieved: false}, func(*Entry) {
lookup := make(chan *api.Lookup, 1)
go func() {
lookup <- cache.Resolve(context.Background(), "my.gitlab.com")
}()
require.Equal(t, 0, len(resolver.lookups))
resolver.domain <- "my.gitlab.com"
<-lookup
require.Equal(t, uint64(1), <-resolver.lookups)
})
})
})
t.Run("when item is in long cache only", func(t *testing.T) {
withTestCache(resolverConfig{buffered: false}, nil, func(cache *Cache, resolver *client) {
cache.withTestEntry(entryConfig{expired: true, retrieved: true}, func(*Entry) {
lookup := cache.Resolve(context.Background(), "my.gitlab.com")
require.Equal(t, "my.gitlab.com", lookup.Name)
require.Equal(t, 0, len(resolver.lookups))
resolver.domain <- "my.gitlab.com"
require.Equal(t, uint64(1), <-resolver.lookups)
})
})
})
t.Run("when item in long cache is requested multiple times", func(t *testing.T) {
withTestCache(resolverConfig{}, nil, func(cache *Cache, resolver *client) {
cache.withTestEntry(entryConfig{expired: true, retrieved: true}, func(*Entry) {
cache.Resolve(context.Background(), "my.gitlab.com")
cache.Resolve(context.Background(), "my.gitlab.com")
cache.Resolve(context.Background(), "my.gitlab.com")
require.Equal(t, 0, len(resolver.lookups))
resolver.domain <- "my.gitlab.com"
require.Equal(t, uint64(1), <-resolver.lookups)
})
})
})
t.Run("when retrieval failed with an error", func(t *testing.T) {
cc := defaultCacheConfig
cc.maxRetrievalInterval = 0
err := errors.New("500 error")
withTestCache(resolverConfig{failure: err}, &cc, func(cache *Cache, resolver *client) {
lookup := cache.Resolve(context.Background(), "my.gitlab.com")
require.Equal(t, 3, len(resolver.lookups))
require.EqualError(t, lookup.Error, "500 error")
})
})
t.Run("when retrieval failed because of an internal retriever context timeout", func(t *testing.T) {
cc := defaultCacheConfig
cc.retrievalTimeout = 0
withTestCache(resolverConfig{}, &cc, func(cache *Cache, resolver *client) {
lookup := cache.Resolve(context.Background(), "my.gitlab.com")
require.Equal(t, 0, len(resolver.lookups))
require.EqualError(t, lookup.Error, "retrieval context done")
})
})
t.Run("when retrieval failed because of resolution context being canceled", func(t *testing.T) {
withTestCache(resolverConfig{}, nil, func(cache *Cache, resolver *client) {
cache.withTestEntry(entryConfig{expired: false, retrieved: false}, func(entry *Entry) {
ctx, cancel := context.WithCancel(context.Background())
cancel()
lookup := cache.Resolve(ctx, "my.gitlab.com")
resolver.domain <- "err.gitlab.com"
require.Equal(t, "my.gitlab.com", lookup.Name)
require.EqualError(t, lookup.Error, "context done")
})
})
})
}
|