add module invalidation via DELETE request

pkg/api/api.go

@@ -158,6 +158,10 @@ func (api *api) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 				version = m[2]
 			}
 			module = decodeBangs(module)
+			if r.Method == http.MethodDelete && version != "" {
+				api.delete(w, r, module, version)
+				return
+			}
 			httpRequests.Add(route.id, 1)
 			defer func() {
 				v := &expvar.Float{}
@@ -288,3 +292,12 @@ func (api *api) zip(w http.ResponseWriter, r *http.Request, module, version stri
 	}
 	io.Copy(w, bytes.NewReader(b))
 }
+
+func (api *api) delete(w http.ResponseWriter, r *http.Request, module, version string) {
+	for _, store := range api.stores {
+		if err := store.Del(r.Context(), module, vcs.Version(version)); err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+	}
+}

pkg/store/disk.go

@@ -47,4 +47,15 @@ func (d disk) Get(ctx context.Context, module string, version vcs.Version) (Snap
 	return s, err
 }
 
+func (d disk) Del(ctx context.Context, module string, version vcs.Version) error {
+	dir := string(d)
+	s := Snapshot{Module: module, Version: version}
+	err := os.Remove(filepath.Join(dir, s.Key()+".time"))
+	if err != nil {
+		return err
+	}
+	err = os.Remove(filepath.Join(dir, s.Key()+".zip"))
+	return err
+}
+
 func (d disk) Close() error { return nil }

pkg/store/mem.go

@@ -45,17 +45,41 @@ func (m *memory) Put(ctx context.Context, snapshot Snapshot) error {
 func (m *memory) Get(ctx context.Context, module string, version vcs.Version) (Snapshot, error) {
 	m.Lock()
 	defer m.Unlock()
-	return m.lookup(module, version)
+	item, err := m.lookup(module, version)
+	if err != nil {
+		return Snapshot{}, err
+	}
+	return item.Snapshot, nil
 }
 
-func (m *memory) lookup(module string, version vcs.Version) (Snapshot, error) {
+func (m *memory) Del(ctx context.Context, module string, version vcs.Version) error {
+	m.Lock()
+	defer m.Unlock()
+	item, err := m.lookup(module, version)
+	if err != nil {
+		return err
+	}
+	if item.prev == nil {
+		m.head = item.next
+	} else {
+		item.prev.next = item.next
+	}
+	if item.next == nil {
+		m.tail = item.prev
+	} else {
+		item.next.prev = item.prev
+	}
+	return nil
+}
+
+func (m *memory) lookup(module string, version vcs.Version) (*lruItem, error) {
 	for item := m.head; item != nil; item = item.next {
 		if item.Module == module && item.Version == version {
 			m.update(item)
-			return item.Snapshot, nil
+			return item, nil
 		}
 	}
-	return Snapshot{}, errors.New("not found")
+	return nil, errors.New("not found")
 }
 
 func (m *memory) insert(item *lruItem) {

pkg/store/store.go

@@ -14,6 +14,7 @@ type logger = func(...interface{})
 type Store interface {
 	Put(ctx context.Context, snapshot Snapshot) error
 	Get(ctx context.Context, module string, version vcs.Version) (Snapshot, error)
+	Del(ctx context.Context, module string, version vcs.Version) error
 	Close() error
 }