From 222024dabbaf1aaa8c87f5ff4129fd5d0a972979 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ferdinand=20M=C3=BCtsch?= <ferdinand@muetsch.io>
Date: Thu, 17 Feb 2022 10:34:33 +0100
Subject: [PATCH] chore: cache avatars in memory

---
 go.mod               |  1 +
 go.sum               |  2 ++
 routes/api/avatar.go | 24 +++++++++++++++++-------
 utils/fs/exists.go   | 13 +++++++++----
 4 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/go.mod b/go.mod
index f9c6624..ce255d7 100644
--- a/go.mod
+++ b/go.mod
@@ -17,6 +17,7 @@ require (
 	github.com/gorilla/mux v1.8.0
 	github.com/gorilla/schema v1.2.0
 	github.com/gorilla/securecookie v1.1.1
+	github.com/hashicorp/golang-lru v0.5.4
 	github.com/jackc/pgx/v4 v4.14.1 // indirect
 	github.com/jinzhu/configor v1.2.1
 	github.com/jinzhu/now v1.1.4 // indirect
diff --git a/go.sum b/go.sum
index 5d316f7..862ccf0 100644
--- a/go.sum
+++ b/go.sum
@@ -109,6 +109,8 @@ github.com/gorilla/securecookie v1.1.1 h1:miw7JPhV+b/lAHSXz4qd/nN9jRiAFV5FwjeKyC
 github.com/gorilla/securecookie v1.1.1/go.mod h1:ra0sb63/xPlUeL+yeDciTfxMRAA+MP+HVt/4epWDjd4=
 github.com/gorilla/websocket v1.4.1/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/hashicorp/go-version v1.2.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
+github.com/hashicorp/golang-lru v0.5.4 h1:YDjusn29QI/Das2iO9M0BHnIbxPeyuCHsjMW+lJfyTc=
+github.com/hashicorp/golang-lru v0.5.4/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/imkira/go-interpol v1.1.0/go.mod h1:z0h2/2T3XF8kyEPpRgJ3kmNv+C43p+I/CoI+jC3w2iA=
diff --git a/routes/api/avatar.go b/routes/api/avatar.go
index f5e3818..5faf49b 100644
--- a/routes/api/avatar.go
+++ b/routes/api/avatar.go
@@ -3,16 +3,26 @@ package api
 import (
 	"codeberg.org/Codeberg/avatars"
 	"github.com/gorilla/mux"
+	lru "github.com/hashicorp/golang-lru"
 	conf "github.com/muety/wakapi/config"
 	"net/http"
 )
 
 type AvatarHandler struct {
 	config *conf.Config
+	cache  *lru.Cache
 }
 
 func NewAvatarHandler() *AvatarHandler {
-	return &AvatarHandler{config: conf.Get()}
+	cache, err := lru.New(1 * 1000 * 64) // assuming an avatar is 1 kb, allocate up to 64 mb of memory for avatars cache
+	if err != nil {
+		panic(err)
+	}
+
+	return &AvatarHandler{
+		config: conf.Get(),
+		cache:  cache,
+	}
 }
 
 func (h *AvatarHandler) RegisterRoutes(router *mux.Router) {
@@ -21,15 +31,15 @@ func (h *AvatarHandler) RegisterRoutes(router *mux.Router) {
 }
 
 func (h *AvatarHandler) Get(w http.ResponseWriter, r *http.Request) {
-	vars := mux.Vars(r)
+	hash := mux.Vars(r)["hash"]
 
-	if vars["hash"] == "" {
-		w.WriteHeader(http.StatusNotFound)
-		w.Write([]byte{})
-		return
+	if !h.cache.Contains(hash) {
+		h.cache.Add(hash, avatars.MakeMaleAvatar(hash))
 	}
+	data, _ := h.cache.Get(hash)
 
 	w.Header().Set("Content-Type", "image/svg+xml")
+	w.Header().Set("Cache-Control", "max-age=2592000")
 	w.WriteHeader(http.StatusOK)
-	w.Write([]byte(avatars.MakeMaleAvatar(vars["hash"])))
+	w.Write([]byte(data.(string)))
 }
diff --git a/utils/fs/exists.go b/utils/fs/exists.go
index 08c256d..a0b0d6d 100644
--- a/utils/fs/exists.go
+++ b/utils/fs/exists.go
@@ -1,23 +1,28 @@
 package fs
 
 import (
-	"github.com/patrickmn/go-cache"
+	lru "github.com/hashicorp/golang-lru"
 	"io/fs"
 	"net/http"
 	"strings"
 )
 
 func NewExistsFS(fs fs.FS) ExistsFS {
+	cache, err := lru.New(1 << 24)
+	if err != nil {
+		panic(err)
+	}
+
 	return ExistsFS{
 		FS:    fs,
-		cache: cache.New(cache.NoExpiration, cache.NoExpiration),
+		cache: cache,
 	}
 }
 
 type ExistsFS struct {
 	fs.FS
 	UseCache bool
-	cache    *cache.Cache
+	cache    *lru.Cache
 }
 
 func (efs ExistsFS) WithCache(withCache bool) ExistsFS {
@@ -34,7 +39,7 @@ func (efs ExistsFS) Exists(name string) bool {
 	_, err := fs.Stat(efs.FS, name)
 	result := err == nil
 	if efs.UseCache {
-		efs.cache.SetDefault(name, result)
+		efs.cache.Add(name, result)
 	}
 	return result
 }