From f55701b374c78e4fc7057dd8489d93cd334c3b3e Mon Sep 17 00:00:00 2001
From: Asim Aslam <asim@aslam.me>
Date: Sun, 23 Aug 2020 13:59:19 +0100
Subject: [PATCH] Strip cache from the client. Its only used externally in a
 wrapper

---
 client/cache.go      | 66 -------------------------------------
 client/cache_test.go | 77 --------------------------------------------
 client/options.go    | 14 --------
 3 files changed, 157 deletions(-)
 delete mode 100644 client/cache.go
 delete mode 100644 client/cache_test.go

diff --git a/client/cache.go b/client/cache.go
deleted file mode 100644
index dfcff812..00000000
--- a/client/cache.go
+++ /dev/null
@@ -1,66 +0,0 @@
-package client
-
-import (
-	"context"
-	"encoding/json"
-	"fmt"
-	"hash/fnv"
-	"time"
-
-	"github.com/micro/go-micro/v3/metadata"
-	cache "github.com/patrickmn/go-cache"
-)
-
-// NewCache returns an initialised cache.
-func NewCache() *Cache {
-	return &Cache{
-		cache: cache.New(cache.NoExpiration, 30*time.Second),
-	}
-}
-
-// Cache for responses
-type Cache struct {
-	cache *cache.Cache
-}
-
-// Get a response from the cache
-func (c *Cache) Get(ctx context.Context, req Request) (interface{}, bool) {
-	return c.cache.Get(key(ctx, req))
-}
-
-// Set a response in the cache
-func (c *Cache) Set(ctx context.Context, req Request, rsp interface{}, expiry time.Duration) {
-	c.cache.Set(key(ctx, req), rsp, expiry)
-}
-
-// List the key value pairs in the cache
-func (c *Cache) List() map[string]string {
-	items := c.cache.Items()
-
-	rsp := make(map[string]string, len(items))
-	for k, v := range items {
-		bytes, _ := json.Marshal(v.Object)
-		rsp[k] = string(bytes)
-	}
-
-	return rsp
-}
-
-// key returns a hash for the context and request
-func key(ctx context.Context, req Request) string {
-	ns, _ := metadata.Get(ctx, "Micro-Namespace")
-
-	bytes, _ := json.Marshal(map[string]interface{}{
-		"namespace": ns,
-		"request": map[string]interface{}{
-			"service":  req.Service(),
-			"endpoint": req.Endpoint(),
-			"method":   req.Method(),
-			"body":     req.Body(),
-		},
-	})
-
-	h := fnv.New64()
-	h.Write(bytes)
-	return fmt.Sprintf("%x", h.Sum(nil))
-}
diff --git a/client/cache_test.go b/client/cache_test.go
deleted file mode 100644
index 8125e67e..00000000
--- a/client/cache_test.go
+++ /dev/null
@@ -1,77 +0,0 @@
-package client
-
-import (
-	"context"
-	"testing"
-	"time"
-
-	"github.com/micro/go-micro/v3/metadata"
-)
-
-func TestCache(t *testing.T) {
-	ctx := context.TODO()
-	req := &testRequest{service: "go.micro.service.foo", method: "Foo.Bar"}
-
-	t.Run("CacheMiss", func(t *testing.T) {
-		if _, ok := NewCache().Get(ctx, req); ok {
-			t.Errorf("Expected to get no result from Get")
-		}
-	})
-
-	t.Run("CacheHit", func(t *testing.T) {
-		c := NewCache()
-
-		rsp := "theresponse"
-		c.Set(ctx, req, rsp, time.Minute)
-
-		if res, ok := c.Get(ctx, req); !ok {
-			t.Errorf("Expected a result, got nothing")
-		} else if res != rsp {
-			t.Errorf("Expected '%v' result, got '%v'", rsp, res)
-		}
-	})
-}
-
-func TestCacheKey(t *testing.T) {
-	ctx := context.TODO()
-
-	req1 := &testRequest{service: "go.micro.service.foo", method: "Foo.Bar"}
-	req2 := &testRequest{service: "go.micro.service.foo", method: "Foo.Baz"}
-	req3 := &testRequest{service: "go.micro.service.foo", method: "Foo.Bar", body: "customquery"}
-
-	t.Run("IdenticalRequests", func(t *testing.T) {
-		key1 := key(ctx, req1)
-		key2 := key(ctx, req1)
-		if key1 != key2 {
-			t.Errorf("Expected the keys to match for identical requests and context")
-		}
-	})
-
-	t.Run("DifferentRequestEndpoints", func(t *testing.T) {
-		key1 := key(ctx, req1)
-		key2 := key(ctx, req2)
-
-		if key1 == key2 {
-			t.Errorf("Expected the keys to differ for different request endpoints")
-		}
-	})
-
-	t.Run("DifferentRequestBody", func(t *testing.T) {
-		key1 := key(ctx, req2)
-		key2 := key(ctx, req3)
-
-		if key1 == key2 {
-			t.Errorf("Expected the keys to differ for different request bodies")
-		}
-	})
-
-	t.Run("DifferentMetadata", func(t *testing.T) {
-		mdCtx := metadata.Set(context.TODO(), "Micro-Namespace", "bar")
-		key1 := key(mdCtx, req1)
-		key2 := key(ctx, req1)
-
-		if key1 == key2 {
-			t.Errorf("Expected the keys to differ for different metadata")
-		}
-	})
-}
diff --git a/client/options.go b/client/options.go
index 4328c8e0..94f8fe94 100644
--- a/client/options.go
+++ b/client/options.go
@@ -36,9 +36,6 @@ type Options struct {
 	PoolSize int
 	PoolTTL  time.Duration
 
-	// Response cache
-	Cache *Cache
-
 	// Middleware for client
 	Wrappers []Wrapper
 
@@ -55,8 +52,6 @@ type CallOptions struct {
 	Address []string
 	// Backoff func
 	Backoff BackoffFunc
-	// Duration to cache the response for
-	CacheExpiry time.Duration
 	// Transport Dial Timeout
 	DialTimeout time.Duration
 	// Number of Call attempts
@@ -109,7 +104,6 @@ type RequestOptions struct {
 
 func NewOptions(options ...Option) Options {
 	opts := Options{
-		Cache:       NewCache(),
 		Context:     context.Background(),
 		ContentType: "application/protobuf",
 		Codecs:      make(map[string]codec.NewCodec),
@@ -357,14 +351,6 @@ func WithAuthToken() CallOption {
 	}
 }
 
-// WithCache is a CallOption which sets the duration the response
-// shoull be cached for
-func WithCache(c time.Duration) CallOption {
-	return func(o *CallOptions) {
-		o.CacheExpiry = c
-	}
-}
-
 // WithNetwork is a CallOption which sets the network attribute
 func WithNetwork(n string) CallOption {
 	return func(o *CallOptions) {