Function TestCacheEviction

groupcache_test.go:189–227

(t *testing.T)

}

func TestCacheEviction(t *testing.T) {
	once.Do(testSetup)
	testKey := "TestCacheEviction-key"
	getTestKey := func() {
		var res string
		for i := 0; i < 10; i++ {
			if err := stringGroup.Get(dummyCtx, testKey, StringSink(&res)); err != nil {
				t.Fatal(err)
			}
		}
	}
	fills := countFills(getTestKey)
	if fills != 1 {
		t.Fatalf("expected 1 cache fill; got %d", fills)
	}

	g := stringGroup.(*Group)
	evict0 := g.mainCache.nevict

	// Trash the cache with other keys.
	var bytesFlooded int64
	// cacheSize/len(testKey) is approximate
	for bytesFlooded < cacheSize+1024 {
		var res string
		key := fmt.Sprintf("dummy-key-%d", bytesFlooded)
		stringGroup.Get(dummyCtx, key, StringSink(&res))
		bytesFlooded += int64(len(key) + len(res))
	}
	evicts := g.mainCache.nevict - evict0
	if evicts <= 0 {
		t.Errorf("evicts = %v; want more than 0", evicts)
	}

	// Test that the key is gone.
	fills = countFills(getTestKey)
	if fills != 1 {
		t.Fatalf("expected 1 cache fill after cache trashing; got %d", fills)
	}
}

type fakePeer struct {
	hits int