add dynamic options for cache (#4894)

* add dynamic options for cache

* fixed bugs based on unit-test

* add doc for cache

* make cache implements be private

* Change simpleCache name to InMemoryCache

Signed-off-by: Wenhao Zhou <wenhaozhou@yunify.com>

* Remove fake cache and replacing to in memory cache with default parameter

Signed-off-by: Wenhao Zhou <wenhaozhou@yunify.com>

Signed-off-by: Wenhao Zhou <wenhaozhou@yunify.com>

pkg/simple/client/cache/inmemory_cache_test.go

@@ -0,0 +1,140 @@
+/*
+Copyright 2019 The KubeSphere Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cache
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+var dataSet = map[string]string{
+	"foo1": "val1",
+	"foo2": "val2",
+	"foo3": "val3",
+	"bar1": "val1",
+	"bar2": "val2",
+}
+
+// load dataset into cache
+func load(client Interface, data map[string]string) error {
+	for k, v := range data {
+		err := client.Set(k, v, NeverExpire)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// dump retrieve all data in simple into a map
+func dump(client Interface) (map[string]string, error) {
+	keys, err := client.Keys("*")
+	if err != nil {
+		return nil, err
+	}
+
+	snapshot := make(map[string]string)
+	for _, key := range keys {
+		val, err := client.Get(key)
+		if err != nil {
+			continue
+		}
+		snapshot[key] = val
+	}
+
+	return snapshot, nil
+}
+
+func TestDeleteAndExpireCache(t *testing.T) {
+	var testCases = []struct {
+		description    string
+		deleteKeys     sets.String
+		expireKeys     sets.String
+		expireDuration time.Duration // never use a 0(NeverExpires) duration with expireKeys, recommend time.Millisecond * 500.
+		expected       map[string]string
+	}{
+		{
+			description: "Should get all keys",
+			expected: map[string]string{
+				"foo1": "val1",
+				"foo2": "val2",
+				"foo3": "val3",
+				"bar1": "val1",
+				"bar2": "val2",
+			},
+		},
+		{
+			description: "Test delete should get only keys start with foo",
+			expected: map[string]string{
+				"foo1": "val1",
+				"foo2": "val2",
+				"foo3": "val3",
+			},
+			deleteKeys: sets.NewString("bar1", "bar2"),
+		},
+		{
+			description: "Should get only keys start with bar",
+			expected: map[string]string{
+				"bar1": "val1",
+				"bar2": "val2",
+			},
+			expireDuration: time.Millisecond * 500,
+			expireKeys:     sets.NewString("foo1", "foo2", "foo3"),
+		},
+	}
+
+	for _, testCase := range testCases {
+		cacheClient, _ := NewInMemoryCache(nil, nil)
+
+		t.Run(testCase.description, func(t *testing.T) {
+			err := load(cacheClient, dataSet)
+			if err != nil {
+				t.Fatalf("Unable to load dataset, got error %v", err)
+			}
+
+			if len(testCase.deleteKeys) != 0 {
+				err = cacheClient.Del(testCase.deleteKeys.List()...)
+				if err != nil {
+					t.Fatalf("Error delete keys, %v", err)
+				}
+			}
+
+			if len(testCase.expireKeys) != 0 && testCase.expireDuration != 0 {
+				for _, key := range testCase.expireKeys.List() {
+					err = cacheClient.Expire(key, testCase.expireDuration)
+					if err != nil {
+						t.Fatalf("Error expire keys, %v", err)
+					}
+				}
+				time.Sleep(testCase.expireDuration)
+			}
+
+			got, err := dump(cacheClient)
+			if err != nil {
+				t.Fatalf("Error dump data, %v", err)
+			}
+
+			if diff := cmp.Diff(got, testCase.expected); len(diff) != 0 {
+				t.Errorf("%T differ (-got, +expected) %v", testCase.expected, diff)
+			}
+		})
+	}
+}