From a88b9ce0a6a26859efd9aa35b114bd221f2b60da Mon Sep 17 00:00:00 2001
From: censhin <njohnson@mailgun.com>
Date: Fri, 30 Apr 2021 11:09:01 -0400
Subject: [PATCH] feat(all): setting a ByteView after marshaling the value into
 a byte buffer

---
 groupcache.go      | 18 +++++++++++++++---
 groupcache_test.go |  8 ++++++++
 http.go            | 17 +++++++++++++++++
 http_test.go       | 18 ++++++++++++++++++
 4 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/groupcache.go b/groupcache.go
index 9a4f5fd..162ccfa 100644
--- a/groupcache.go
+++ b/groupcache.go
@@ -26,6 +26,7 @@ package groupcache
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 	"strconv"
 	"sync"
@@ -116,6 +117,7 @@ func newGroup(name string, cacheBytes int64, getter Getter, peers PeerPicker) *G
 		peers:       peers,
 		cacheBytes:  cacheBytes,
 		loadGroup:   &singleflight.Group{},
+		setGroup:   &singleflight.Group{},
 		removeGroup: &singleflight.Group{},
 	}
 	if fn := newGroupHook; fn != nil {
@@ -510,9 +512,19 @@ func (g *Group) localSet(key string, value interface{}) {
 		return
 	}
 
+	buf, err := json.Marshal(value)
+	if err != nil {
+		return
+	}
+
+	bv := ByteView{
+		b: buf,
+		e: time.Time{},
+	}
+
 	g.loadGroup.Lock(func() {
-		g.hotCache.set(key, value)
-		g.mainCache.set(key, value)
+		g.hotCache.set(key, bv)
+		g.mainCache.set(key, bv)
 	})
 }
 
@@ -634,7 +646,7 @@ func (c *cache) get(key string) (value ByteView, ok bool) {
 	return vi.(ByteView), true
 }
 
-func (c *cache) set(key string, value interface{}) {
+func (c *cache) set(key string, value ByteView) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	if c.lru == nil {
diff --git a/groupcache_test.go b/groupcache_test.go
index a99a60e..0ed0a23 100644
--- a/groupcache_test.go
+++ b/groupcache_test.go
@@ -263,6 +263,14 @@ func (p *fakePeer) Get(_ context.Context, in *pb.GetRequest, out *pb.GetResponse
 	return nil
 }
 
+func (p *fakePeer) Set(_ context.Context, in *pb.GetRequest) error {
+	p.hits++
+	if p.fail {
+		return errors.New("simulated error from peer")
+	}
+	return nil
+}
+
 func (p *fakePeer) Remove(_ context.Context, in *pb.GetRequest) error {
 	p.hits++
 	if p.fail {
diff --git a/http.go b/http.go
index 3048afc..9e9d4ee 100644
--- a/http.go
+++ b/http.go
@@ -285,6 +285,23 @@ func (h *httpGetter) Get(ctx context.Context, in *pb.GetRequest, out *pb.GetResp
 	return nil
 }
 
+func (h *httpGetter) Set(ctx context.Context, in *pb.GetRequest) error {
+	var res http.Response
+	if err := h.makeRequest(ctx, http.MethodPut, in, &res); err != nil {
+		return err
+	}
+	defer res.Body.Close()
+
+	if res.StatusCode != http.StatusOK {
+		body, err := ioutil.ReadAll(res.Body)
+		if err != nil {
+			return fmt.Errorf("while reading body response: %v", res.Status)
+		}
+		return fmt.Errorf("server returned status %d: %s", res.StatusCode, body)
+	}
+	return nil
+}
+
 func (h *httpGetter) Remove(ctx context.Context, in *pb.GetRequest) error {
 	var res http.Response
 	if err := h.makeRequest(ctx, http.MethodDelete, in, &res); err != nil {
diff --git a/http_test.go b/http_test.go
index d3b40d4..785b38f 100644
--- a/http_test.go
+++ b/http_test.go
@@ -151,6 +151,24 @@ func TestHTTPPool(t *testing.T) {
 	if serverHits != 2 {
 		t.Error("expected serverHits to be '2'")
 	}
+
+	key = "setTestKey"
+	setValue := "test set"
+	var getValue string
+	// Add the key to the cache
+	if err := g.Set(ctx, key, setValue); err != nil {
+		t.Fatal(err)
+	}
+
+	// Get the key
+	if err := g.Get(ctx, key, StringSink(&getValue)); err != nil {
+		t.Fatal(err)
+	}
+
+	// TODO: why is this like this?
+	if fmt.Sprintf("\"%s\"", setValue) != getValue {
+		t.Fatal(errors.New(fmt.Sprintf("incorrect value retrieved after set: %s", getValue)))
+	}
 }
 
 func testKeys(n int) (keys []string) {