1. move cloneBytes from geecache.go to byteview.go 2. add more tests

README.md

@@ -27,8 +27,8 @@
 [GeeCache](https://geektutu.com/post/geecache.html) 是一个模仿 [groupcache](https://github.com/golang/groupcache) 实现的分布式缓存系统
 
 - [第一天：LRU 缓存淘汰策略](https://geektutu.com/post/geecache-day1.html) | [Code](gee-cache/day1-lru)
-- 第二天：单机并发缓存 | [Code](gee-cache/day2-single-node)
-- 第三天：HTTP 服务端 | [Code](gee-cache/day3-http-server)
+- [第二天：单机并发缓存](https://geektutu.com/post/geecache-day2.html) | [Code](gee-cache/day2-single-node)
+- [第三天：HTTP 服务端](https://geektutu.com/post/geecache-day3.html) | [Code](gee-cache/day3-http-server)
 - 第四天：一致性哈希(Hash) | [Code](gee-cache/day4-consistent-hash)
 - 第五天：分布式节点 | [Code](gee-cache/day5-multi-nodes)
 - 第六天：防止缓存击穿 | [Code](gee-cache/day6-single-flight)

gee-cache/day2-single-node/geecache/byteview.go

@@ -19,3 +19,9 @@ func (v ByteView) ByteSlice() []byte {
 func (v ByteView) String() string {
 	return string(v.b)
 }
+
+func cloneBytes(b []byte) []byte {
+	c := make([]byte, len(b))
+	copy(c, b)
+	return c
+}

gee-cache/day2-single-node/geecache/geecache.go

@@ -70,12 +70,6 @@ func (g *Group) Get(key string) (ByteView, error) {
 	return g.load(key)
 }
 
-func cloneBytes(b []byte) []byte {
-	c := make([]byte, len(b))
-	copy(c, b)
-	return c
-}
-
 func (g *Group) load(key string) (value ByteView, err error) {
 	return g.getLocally(key)
 }

gee-cache/day2-single-node/geecache/geecache_test.go

@@ -3,6 +3,7 @@ package geecache
 import (
 	"fmt"
 	"log"
+	"reflect"
 	"testing"
 )
 
@@ -12,21 +13,39 @@ var db = map[string]string{
 	"Sam":  "567",
 }
 
+func TestGetter(t *testing.T) {
+	var f Getter = GetterFunc(func(key string) ([]byte, error) {
+		return []byte(key), nil
+	})
+
+	expect := []byte("key")
+	if v, _ := f.Get("key"); !reflect.DeepEqual(v, expect) {
+		t.Fatal("callback failed")
+	}
+}
+
 func TestGet(t *testing.T) {
+	loadCounts := make(map[string]int, len(db))
 	gee := NewGroup("scores", 2<<10, GetterFunc(
 		func(key string) ([]byte, error) {
 			log.Println("[SlowDB] search key", key)
 			if v, ok := db[key]; ok {
+				if _, ok := loadCounts[key]; !ok {
+					loadCounts[key] = 0
+				}
+				loadCounts[key]++
 				return []byte(v), nil
 			}
 			return nil, fmt.Errorf("%s not exist", key)
 		}))
 
 	for k, v := range db {
-		view, err := gee.Get(k)
-		if err != nil || view.String() != v {
+		if view, err := gee.Get(k); err != nil || view.String() != v {
 			t.Fatal("failed to get value of Tom")
 		}
+		if _, err := gee.Get(k); err != nil || loadCounts[k] > 1 {
+			t.Fatalf("cache %s miss", k)
+		}
 	}
 
 	if view, err := gee.Get("unknown"); err == nil {

gee-cache/day3-http-server/geecache/byteview.go

@@ -19,3 +19,9 @@ func (v ByteView) ByteSlice() []byte {
 func (v ByteView) String() string {
 	return string(v.b)
 }
+
+func cloneBytes(b []byte) []byte {
+	c := make([]byte, len(b))
+	copy(c, b)
+	return c
+}

gee-cache/day3-http-server/geecache/geecache.go

@@ -70,12 +70,6 @@ func (g *Group) Get(key string) (ByteView, error) {
 	return g.load(key)
 }
 
-func cloneBytes(b []byte) []byte {
-	c := make([]byte, len(b))
-	copy(c, b)
-	return c
-}
-
 func (g *Group) load(key string) (value ByteView, err error) {
 	return g.getLocally(key)
 }

gee-cache/day3-http-server/geecache/geecache_test.go

@@ -3,6 +3,7 @@ package geecache
 import (
 	"fmt"
 	"log"
+	"reflect"
 	"testing"
 )
 
@@ -12,21 +13,39 @@ var db = map[string]string{
 	"Sam":  "567",
 }
 
+func TestGetter(t *testing.T) {
+	var f Getter = GetterFunc(func(key string) ([]byte, error) {
+		return []byte(key), nil
+	})
+
+	expect := []byte("key")
+	if v, _ := f.Get("key"); !reflect.DeepEqual(v, expect) {
+		t.Fatal("callback failed")
+	}
+}
+
 func TestGet(t *testing.T) {
+	loadCounts := make(map[string]int, len(db))
 	gee := NewGroup("scores", 2<<10, GetterFunc(
 		func(key string) ([]byte, error) {
 			log.Println("[SlowDB] search key", key)
 			if v, ok := db[key]; ok {
+				if _, ok := loadCounts[key]; !ok {
+					loadCounts[key] = 0
+				}
+				loadCounts[key]++
 				return []byte(v), nil
 			}
 			return nil, fmt.Errorf("%s not exist", key)
 		}))
 
 	for k, v := range db {
-		view, err := gee.Get(k)
-		if err != nil || view.String() != v {
+		if view, err := gee.Get(k); err != nil || view.String() != v {
 			t.Fatal("failed to get value of Tom")
 		}
+		if _, err := gee.Get(k); err != nil || loadCounts[k] > 1 {
+			t.Fatalf("cache %s miss", k)
+		}
 	}
 
 	if view, err := gee.Get("unknown"); err == nil {

gee-cache/day3-http-server/geecache/http.go

@@ -16,7 +16,7 @@ type HTTPPool struct {
 	basePath string
 }
 
-// NewHTTPPool initializes an HTTP pool of peers, and registers itself as a PeerPicker.
+// NewHTTPPool initializes an HTTP pool of peers.
 func NewHTTPPool(self string) *HTTPPool {
 	return &HTTPPool{
 		self:     self,

gee-cache/day4-consistent-hash/geecache/byteview.go

@@ -19,3 +19,9 @@ func (v ByteView) ByteSlice() []byte {
 func (v ByteView) String() string {
 	return string(v.b)
 }
+
+func cloneBytes(b []byte) []byte {
+	c := make([]byte, len(b))
+	copy(c, b)
+	return c
+}

gee-cache/day4-consistent-hash/geecache/geecache.go

@@ -70,12 +70,6 @@ func (g *Group) Get(key string) (ByteView, error) {
 	return g.load(key)
 }
 
-func cloneBytes(b []byte) []byte {
-	c := make([]byte, len(b))
-	copy(c, b)
-	return c
-}
-
 func (g *Group) load(key string) (value ByteView, err error) {
 	return g.getLocally(key)
 }

gee-cache/day4-consistent-hash/geecache/geecache_test.go

@@ -3,6 +3,7 @@ package geecache
 import (
 	"fmt"
 	"log"
+	"reflect"
 	"testing"
 )
 
@@ -12,21 +13,39 @@ var db = map[string]string{
 	"Sam":  "567",
 }
 
+func TestGetter(t *testing.T) {
+	var f Getter = GetterFunc(func(key string) ([]byte, error) {
+		return []byte(key), nil
+	})
+
+	expect := []byte("key")
+	if v, _ := f.Get("key"); !reflect.DeepEqual(v, expect) {
+		t.Fatal("callback failed")
+	}
+}
+
 func TestGet(t *testing.T) {
+	loadCounts := make(map[string]int, len(db))
 	gee := NewGroup("scores", 2<<10, GetterFunc(
 		func(key string) ([]byte, error) {
 			log.Println("[SlowDB] search key", key)
 			if v, ok := db[key]; ok {
+				if _, ok := loadCounts[key]; !ok {
+					loadCounts[key] = 0
+				}
+				loadCounts[key]++
 				return []byte(v), nil
 			}
 			return nil, fmt.Errorf("%s not exist", key)
 		}))
 
 	for k, v := range db {
-		view, err := gee.Get(k)
-		if err != nil || view.String() != v {
+		if view, err := gee.Get(k); err != nil || view.String() != v {
 			t.Fatal("failed to get value of Tom")
 		}
+		if _, err := gee.Get(k); err != nil || loadCounts[k] > 1 {
+			t.Fatalf("cache %s miss", k)
+		}
 	}
 
 	if view, err := gee.Get("unknown"); err == nil {

gee-cache/day4-consistent-hash/geecache/http.go

@@ -16,7 +16,7 @@ type HTTPPool struct {
 	basePath string
 }
 
-// NewHTTPPool initializes an HTTP pool of peers, and registers itself as a PeerPicker.
+// NewHTTPPool initializes an HTTP pool of peers.
 func NewHTTPPool(self string) *HTTPPool {
 	return &HTTPPool{
 		self:     self,

gee-cache/day5-multi-nodes/geecache/byteview.go

@@ -19,3 +19,9 @@ func (v ByteView) ByteSlice() []byte {
 func (v ByteView) String() string {
 	return string(v.b)
 }
+
+func cloneBytes(b []byte) []byte {
+	c := make([]byte, len(b))
+	copy(c, b)
+	return c
+}

gee-cache/day5-multi-nodes/geecache/geecache.go

@@ -79,12 +79,6 @@ func (g *Group) RegisterPeers(peers PeerPicker) {
 	g.peers = peers
 }
 
-func cloneBytes(b []byte) []byte {
-	c := make([]byte, len(b))
-	copy(c, b)
-	return c
-}
-
 func (g *Group) load(key string) (value ByteView, err error) {
 	if g.peers != nil {
 		if peer, ok := g.peers.PickPeer(key); ok {

gee-cache/day5-multi-nodes/geecache/geecache_test.go

@@ -3,6 +3,7 @@ package geecache
 import (
 	"fmt"
 	"log"
+	"reflect"
 	"testing"
 )
 
@@ -12,21 +13,39 @@ var db = map[string]string{
 	"Sam":  "567",
 }
 
+func TestGetter(t *testing.T) {
+	var f Getter = GetterFunc(func(key string) ([]byte, error) {
+		return []byte(key), nil
+	})
+
+	expect := []byte("key")
+	if v, _ := f.Get("key"); !reflect.DeepEqual(v, expect) {
+		t.Fatal("callback failed")
+	}
+}
+
 func TestGet(t *testing.T) {
+	loadCounts := make(map[string]int, len(db))
 	gee := NewGroup("scores", 2<<10, GetterFunc(
 		func(key string) ([]byte, error) {
 			log.Println("[SlowDB] search key", key)
 			if v, ok := db[key]; ok {
+				if _, ok := loadCounts[key]; !ok {
+					loadCounts[key] = 0
+				}
+				loadCounts[key]++
 				return []byte(v), nil
 			}
 			return nil, fmt.Errorf("%s not exist", key)
 		}))
 
 	for k, v := range db {
-		view, err := gee.Get(k)
-		if err != nil || view.String() != v {
+		if view, err := gee.Get(k); err != nil || view.String() != v {
 			t.Fatal("failed to get value of Tom")
 		}
+		if _, err := gee.Get(k); err != nil || loadCounts[k] > 1 {
+			t.Fatalf("cache %s miss", k)
+		}
 	}
 
 	if view, err := gee.Get("unknown"); err == nil {

gee-cache/day5-multi-nodes/geecache/http.go

@@ -26,7 +26,7 @@ type HTTPPool struct {
 	httpGetters map[string]*httpGetter // keyed by e.g. "http://10.0.0.2:8008"
 }
 
-// NewHTTPPool initializes an HTTP pool of peers, and registers itself as a PeerPicker.
+// NewHTTPPool initializes an HTTP pool of peers.
 func NewHTTPPool(self string) *HTTPPool {
 	return &HTTPPool{
 		self:     self,

gee-cache/day6-single-flight/geecache/byteview.go

@@ -19,3 +19,9 @@ func (v ByteView) ByteSlice() []byte {
 func (v ByteView) String() string {
 	return string(v.b)
 }
+
+func cloneBytes(b []byte) []byte {
+	c := make([]byte, len(b))
+	copy(c, b)
+	return c
+}

gee-cache/day6-single-flight/geecache/geecache.go

@@ -84,12 +84,6 @@ func (g *Group) RegisterPeers(peers PeerPicker) {
 	g.peers = peers
 }
 
-func cloneBytes(b []byte) []byte {
-	c := make([]byte, len(b))
-	copy(c, b)
-	return c
-}
-
 func (g *Group) load(key string) (value ByteView, err error) {
 	// each key is only fetched once (either locally or remotely)
 	// regardless of the number of concurrent callers.