diff --git a/groupcache.go b/groupcache.go index e555eb3..e70981f 100644 --- a/groupcache.go +++ b/groupcache.go @@ -25,6 +25,7 @@ limitations under the License. package groupcache import ( + "context" "errors" "math/rand" "strconv" @@ -45,13 +46,13 @@ type Getter interface { // uniquely describe the loaded data, without an implicit // current time, and without relying on cache expiration // mechanisms. - Get(ctx Context, key string, dest Sink) error + Get(ctx context.Context, key string, dest Sink) error } // A GetterFunc implements Getter with a function. -type GetterFunc func(ctx Context, key string, dest Sink) error +type GetterFunc func(ctx context.Context, key string, dest Sink) error -func (f GetterFunc) Get(ctx Context, key string, dest Sink) error { +func (f GetterFunc) Get(ctx context.Context, key string, dest Sink) error { return f(ctx, key, dest) } @@ -210,7 +211,7 @@ func (g *Group) initPeers() { } } -func (g *Group) Get(ctx Context, key string, dest Sink) error { +func (g *Group) Get(ctx context.Context, key string, dest Sink) error { g.peersOnce.Do(g.initPeers) g.Stats.Gets.Add(1) if dest == nil { @@ -240,7 +241,7 @@ func (g *Group) Get(ctx Context, key string, dest Sink) error { // Remove clears the key from our cache then forwards the remove // request to all peers. -func (g *Group) Remove(ctx Context, key string) error { +func (g *Group) Remove(ctx context.Context, key string) error { g.peersOnce.Do(g.initPeers) _, err := g.removeGroup.Do(key, func() (interface{}, error) { @@ -288,7 +289,7 @@ func (g *Group) Remove(ctx Context, key string) error { } // load loads key either by invoking the getter locally or by sending it to another machine. -func (g *Group) load(ctx Context, key string, dest Sink) (value ByteView, destPopulated bool, err error) { +func (g *Group) load(ctx context.Context, key string, dest Sink) (value ByteView, destPopulated bool, err error) { g.Stats.Loads.Add(1) viewi, err := g.loadGroup.Do(key, func() (interface{}, error) { // Check the cache again because singleflight can only dedup calls @@ -347,7 +348,7 @@ func (g *Group) load(ctx Context, key string, dest Sink) (value ByteView, destPo return } -func (g *Group) getLocally(ctx Context, key string, dest Sink) (ByteView, error) { +func (g *Group) getLocally(ctx context.Context, key string, dest Sink) (ByteView, error) { err := g.getter.Get(ctx, key, dest) if err != nil { return ByteView{}, err @@ -355,7 +356,7 @@ func (g *Group) getLocally(ctx Context, key string, dest Sink) (ByteView, error) return dest.view() } -func (g *Group) getFromPeer(ctx Context, peer ProtoGetter, key string) (ByteView, error) { +func (g *Group) getFromPeer(ctx context.Context, peer ProtoGetter, key string) (ByteView, error) { req := &pb.GetRequest{ Group: &g.name, Key: &key, @@ -384,7 +385,7 @@ func (g *Group) getFromPeer(ctx Context, peer ProtoGetter, key string) (ByteView return value, nil } -func (g *Group) removeFromPeer(ctx Context, peer ProtoGetter, key string) error { +func (g *Group) removeFromPeer(ctx context.Context, peer ProtoGetter, key string) error { req := &pb.GetRequest{ Group: &g.name, Key: &key, diff --git a/groupcache_test.go b/groupcache_test.go index da24f28..ad26250 100644 --- a/groupcache_test.go +++ b/groupcache_test.go @@ -19,6 +19,7 @@ limitations under the License. package groupcache import ( + "context" "errors" "fmt" "hash/crc32" @@ -41,7 +42,7 @@ var ( stringc = make(chan string) - dummyCtx Context + dummyCtx context.Context // cacheFills is the number of times stringGroup or // protoGroup's Getter have been called. Read using the @@ -59,7 +60,7 @@ const ( ) func testSetup() { - stringGroup = NewGroup(stringGroupName, cacheSize, GetterFunc(func(_ Context, key string, dest Sink) error { + stringGroup = NewGroup(stringGroupName, cacheSize, GetterFunc(func(_ context.Context, key string, dest Sink) error { if key == fromChan { key = <-stringc } @@ -67,7 +68,7 @@ func testSetup() { return dest.SetString("ECHO:"+key, time.Time{}) })) - protoGroup = NewGroup(protoGroupName, cacheSize, GetterFunc(func(_ Context, key string, dest Sink) error { + protoGroup = NewGroup(protoGroupName, cacheSize, GetterFunc(func(_ context.Context, key string, dest Sink) error { if key == fromChan { key = <-stringc } @@ -78,7 +79,7 @@ func testSetup() { }, time.Time{}) })) - expireGroup = NewGroup(expireGroupName, cacheSize, GetterFunc(func(_ Context, key string, dest Sink) error { + expireGroup = NewGroup(expireGroupName, cacheSize, GetterFunc(func(_ context.Context, key string, dest Sink) error { cacheFills.Add(1) return dest.SetString("ECHO:"+key, time.Now().Add(time.Millisecond*100)) })) @@ -254,7 +255,7 @@ type fakePeer struct { fail bool } -func (p *fakePeer) Get(_ Context, in *pb.GetRequest, out *pb.GetResponse) error { +func (p *fakePeer) Get(_ context.Context, in *pb.GetRequest, out *pb.GetResponse) error { p.hits++ if p.fail { return errors.New("simulated error from peer") @@ -263,7 +264,7 @@ func (p *fakePeer) Get(_ Context, in *pb.GetRequest, out *pb.GetResponse) error return nil } -func (p *fakePeer) Remove(_ Context, in *pb.GetRequest) error { +func (p *fakePeer) Remove(_ context.Context, in *pb.GetRequest) error { p.hits++ if p.fail { return errors.New("simulated error from peer") @@ -295,7 +296,7 @@ func TestPeers(t *testing.T) { peerList := fakePeers([]ProtoGetter{peer0, peer1, peer2, nil}) const cacheSize = 0 // disabled localHits := 0 - getter := func(_ Context, key string, dest Sink) error { + getter := func(_ context.Context, key string, dest Sink) error { localHits++ return dest.SetString("got:"+key, time.Time{}) } @@ -427,7 +428,7 @@ func (g *orderedFlightGroup) Lock(fn func()) { func TestNoDedup(t *testing.T) { const testkey = "testkey" const testval = "testval" - g := newGroup("testgroup", 1024, GetterFunc(func(_ Context, key string, dest Sink) error { + g := newGroup("testgroup", 1024, GetterFunc(func(_ context.Context, key string, dest Sink) error { return dest.SetString(testval, time.Time{}) }), nil) diff --git a/http.go b/http.go index 64f989f..d84d5ae 100644 --- a/http.go +++ b/http.go @@ -41,12 +41,12 @@ type HTTPPool struct { // Context optionally specifies a context for the server to use when it // receives a request. // If nil, the server uses a nil Context. - Context func(*http.Request) Context + Context func(*http.Request) context.Context // Transport optionally specifies an http.RoundTripper for the client // to use when it makes a request. // If nil, the client uses http.DefaultTransport. - Transport func(Context) http.RoundTripper + Transport func(context.Context) http.RoundTripper // this peer's base URL, e.g. "https://example.net:8000" self string @@ -173,7 +173,7 @@ func (p *HTTPPool) ServeHTTP(w http.ResponseWriter, r *http.Request) { http.Error(w, "no such group: "+groupName, http.StatusNotFound) return } - var ctx Context + var ctx context.Context if p.Context != nil { ctx = p.Context(r) } @@ -216,7 +216,7 @@ func (p *HTTPPool) ServeHTTP(w http.ResponseWriter, r *http.Request) { } type httpGetter struct { - transport func(Context) http.RoundTripper + transport func(context.Context) http.RoundTripper baseURL string } @@ -224,7 +224,7 @@ var bufferPool = sync.Pool{ New: func() interface{} { return new(bytes.Buffer) }, } -func (h *httpGetter) makeRequest(ctx Context, method string, in *pb.GetRequest, out *http.Response) error { +func (h *httpGetter) makeRequest(ctx context.Context, method string, in *pb.GetRequest, out *http.Response) error { u := fmt.Sprintf( "%v%v/%v", h.baseURL, @@ -236,10 +236,8 @@ func (h *httpGetter) makeRequest(ctx Context, method string, in *pb.GetRequest, return err } - // If user passed a standard context object, use it in the request. - if stdCtx, ok := ctx.(context.Context); ok { - req = req.WithContext(stdCtx) - } + // Pass along the context to the RoundTripper + req = req.WithContext(ctx) tr := http.DefaultTransport if h.transport != nil { @@ -253,7 +251,7 @@ func (h *httpGetter) makeRequest(ctx Context, method string, in *pb.GetRequest, return nil } -func (h *httpGetter) Get(ctx Context, in *pb.GetRequest, out *pb.GetResponse) error { +func (h *httpGetter) Get(ctx context.Context, in *pb.GetRequest, out *pb.GetResponse) error { var res http.Response if err := h.makeRequest(ctx, http.MethodGet, in, &res); err != nil { return err @@ -276,7 +274,7 @@ func (h *httpGetter) Get(ctx Context, in *pb.GetRequest, out *pb.GetResponse) er return nil } -func (h *httpGetter) Remove(ctx Context, in *pb.GetRequest) error { +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 { return err diff --git a/http_test.go b/http_test.go index 0453999..c2764a3 100644 --- a/http_test.go +++ b/http_test.go @@ -17,6 +17,7 @@ limitations under the License. package groupcache import ( + "context" "errors" "flag" "fmt" @@ -96,7 +97,7 @@ func TestHTTPPool(t *testing.T) { // Dummy getter function. Gets should go to children only. // The only time this process will handle a get is when the // children can't be contacted for some reason. - getter := GetterFunc(func(ctx Context, key string, dest Sink) error { + getter := GetterFunc(func(ctx context.Context, key string, dest Sink) error { return errors.New("parent getter called; something's wrong") }) g := NewGroup("httpPoolTest", 1<<20, getter) @@ -162,7 +163,7 @@ func beChildForTestHTTPPool(t *testing.T) { p := NewHTTPPool("http://" + addrs[*peerIndex]) p.Set(addrToURL(addrs)...) - getter := GetterFunc(func(ctx Context, key string, dest Sink) error { + getter := GetterFunc(func(ctx context.Context, key string, dest Sink) error { if _, err := http.Get(*serverAddr); err != nil { t.Logf("HTTP request from getter failed with '%s'", err) } diff --git a/peers.go b/peers.go index 4bf9e62..05847da 100644 --- a/peers.go +++ b/peers.go @@ -19,18 +19,14 @@ limitations under the License. package groupcache import ( + "context" pb "github.com/mailgun/groupcache/groupcachepb" ) -// Context is an opaque value passed through calls to the -// ProtoGetter. It may be nil if your ProtoGetter implementation does -// not require a context. -type Context interface{} - // ProtoGetter is the interface that must be implemented by a peer. type ProtoGetter interface { - Get(context Context, in *pb.GetRequest, out *pb.GetResponse) error - Remove(context Context, in *pb.GetRequest) error + Get(context context.Context, in *pb.GetRequest, out *pb.GetResponse) error + Remove(context context.Context, in *pb.GetRequest) error } // PeerPicker is the interface that must be implemented to locate