From 5750f47a0d201196504576faa64973403111cea8 Mon Sep 17 00:00:00 2001
From: Ishank Arora <ishank011@gmail.com>
Date: Mon, 8 Nov 2021 19:13:48 +0100
Subject: [PATCH] Cache whether a user home was created or not

---
 .../unreleased/gateway-create-home-cache.md   |  7 +++++
 .../grpc/services/gateway/authprovider.go     | 31 +++++++++++--------
 internal/grpc/services/gateway/gateway.go     | 23 +++++++++-----
 3 files changed, 40 insertions(+), 21 deletions(-)
 create mode 100644 changelog/unreleased/gateway-create-home-cache.md

diff --git a/changelog/unreleased/gateway-create-home-cache.md b/changelog/unreleased/gateway-create-home-cache.md
new file mode 100644
index 0000000000..9ae99099e0
--- /dev/null
+++ b/changelog/unreleased/gateway-create-home-cache.md
@@ -0,0 +1,7 @@
+Enhancement: Cache whether a user home was created or not
+
+Previously, on every call, we used to stat the user home to make sure that it
+existed. Now we cache it for a given amount of time so as to avoid repeated
+calls.
+
+https://github.com/cs3org/reva/pull/2248
\ No newline at end of file
diff --git a/internal/grpc/services/gateway/authprovider.go b/internal/grpc/services/gateway/authprovider.go
index 6a2eb5ae3e..81156facd8 100644
--- a/internal/grpc/services/gateway/authprovider.go
+++ b/internal/grpc/services/gateway/authprovider.go
@@ -154,20 +154,25 @@ func (s *svc) Authenticate(ctx context.Context, req *gateway.AuthenticateRequest
 	ctx = metadata.AppendToOutgoingContext(ctx, ctxpkg.TokenHeader, token) // TODO(jfd): hardcoded metadata key. use  PerRPCCredentials?
 
 	// create home directory
-	createHomeRes, err := s.CreateHome(ctx, &storageprovider.CreateHomeRequest{})
-	if err != nil {
-		log.Err(err).Msg("error calling CreateHome")
-		return &gateway.AuthenticateResponse{
-			Status: status.NewInternal(ctx, err, "error creating user home"),
-		}, nil
-	}
+	if _, err = s.createHomeCache.Get(res.User.Id.OpaqueId); err != nil {
+		createHomeRes, err := s.CreateHome(ctx, &storageprovider.CreateHomeRequest{})
+		if err != nil {
+			log.Err(err).Msg("error calling CreateHome")
+			return &gateway.AuthenticateResponse{
+				Status: status.NewInternal(ctx, err, "error creating user home"),
+			}, nil
+		}
 
-	if createHomeRes.Status.Code != rpc.Code_CODE_OK {
-		err := status.NewErrorFromCode(createHomeRes.Status.Code, "gateway")
-		log.Err(err).Msg("error calling Createhome")
-		return &gateway.AuthenticateResponse{
-			Status: status.NewInternal(ctx, err, "error creating user home"),
-		}, nil
+		if createHomeRes.Status.Code != rpc.Code_CODE_OK {
+			err := status.NewErrorFromCode(createHomeRes.Status.Code, "gateway")
+			log.Err(err).Msg("error calling Createhome")
+			return &gateway.AuthenticateResponse{
+				Status: status.NewInternal(ctx, err, "error creating user home"),
+			}, nil
+		}
+		if s.c.CreateHomeCacheTTL > 0 {
+			_ = s.createHomeCache.Set(res.User.Id.OpaqueId, true)
+		}
 	}
 
 	gwRes := &gateway.AuthenticateResponse{
diff --git a/internal/grpc/services/gateway/gateway.go b/internal/grpc/services/gateway/gateway.go
index 6908174e16..0de4137d89 100644
--- a/internal/grpc/services/gateway/gateway.go
+++ b/internal/grpc/services/gateway/gateway.go
@@ -69,6 +69,7 @@ type config struct {
 	HomeMapping         string                            `mapstructure:"home_mapping"`
 	TokenManagers       map[string]map[string]interface{} `mapstructure:"token_managers"`
 	EtagCacheTTL        int                               `mapstructure:"etag_cache_ttl"`
+	CreateHomeCacheTTL  int                               `mapstructure:"create_home_cache_ttl"`
 }
 
 // sets defaults
@@ -116,10 +117,11 @@ func (c *config) init() {
 }
 
 type svc struct {
-	c              *config
-	dataGatewayURL url.URL
-	tokenmgr       token.Manager
-	etagCache      *ttlcache.Cache `mapstructure:"etag_cache"`
+	c               *config
+	dataGatewayURL  url.URL
+	tokenmgr        token.Manager
+	etagCache       *ttlcache.Cache `mapstructure:"etag_cache"`
+	createHomeCache *ttlcache.Cache `mapstructure:"create_home_cache"`
 }
 
 // New creates a new gateway svc that acts as a proxy for any grpc operation.
@@ -148,11 +150,16 @@ func New(m map[string]interface{}, ss *grpc.Server) (rgrpc.Service, error) {
 	_ = etagCache.SetTTL(time.Duration(c.EtagCacheTTL) * time.Second)
 	etagCache.SkipTTLExtensionOnHit(true)
 
+	createHomeCache := ttlcache.NewCache()
+	_ = createHomeCache.SetTTL(time.Duration(c.CreateHomeCacheTTL) * time.Second)
+	createHomeCache.SkipTTLExtensionOnHit(true)
+
 	s := &svc{
-		c:              c,
-		dataGatewayURL: *u,
-		tokenmgr:       tokenManager,
-		etagCache:      etagCache,
+		c:               c,
+		dataGatewayURL:  *u,
+		tokenmgr:        tokenManager,
+		etagCache:       etagCache,
+		createHomeCache: createHomeCache,
 	}
 
 	return s, nil