Merge pull request 'fix: gc was being stupid allowing another thread to take the space it made before it could not anymore' (#5 ) from fix/gc-breaking-downloads into main

Reviewed-on: s1d3sw1ped/SteamCache2#5
fix: gc was being stupid allowing another thread to take the space it made before it could not anymore
2025-07-13 12:51:17 +00:00 · 2025-07-13 07:50:22 -05:00 · 2025-07-13 10:43:21 +00:00 · 2025-07-13 05:42:07 -05:00 · 2025-07-13 10:21:19 +00:00 · 2025-07-13 04:20:12 -05:00
29 changed files with 1660 additions and 886 deletions
--- a/.gitea/workflows/release-tag.yaml
+++ b/.gitea/workflows/release-tag.yaml
@@ -8,14 +8,14 @@ jobs:
  release:
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@main
        with:
          fetch-depth: 0
      - run: git fetch --force --tags
-      - uses: actions/setup-go@v5
+      - uses: actions/setup-go@main
        with:
          go-version-file: 'go.mod'
-      - uses: goreleaser/goreleaser-action@v6
+      - uses: goreleaser/goreleaser-action@master
        with:
          distribution: goreleaser
          version: 'latest'
--- a/.gitea/workflows/test-pr.yaml
+++ b/.gitea/workflows/test-pr.yaml
@@ -6,14 +6,10 @@ jobs:
  check-and-test:
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-go@v5
+      - uses: actions/checkout@main
+      - uses: actions/setup-go@main
        with:
          go-version-file: 'go.mod'
      - run: go mod tidy  
-      - uses: golangci/golangci-lint-action@v3
-        with:
-          args: -D errcheck
-          version: latest
      - run: go build ./...
      - run: go test -race -v -shuffle=on ./...
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 dist/
 tmp/
 __*.exe
+.smashed.txt
+.smashignore
--- a/.goreleaser.yaml
+++ b/.goreleaser.yaml
@@ -16,7 +16,7 @@ builds:
      - amd64

 archives:
-  - format: tar.gz
+  - formats: tar.gz
    name_template: >- 
      {{ .ProjectName }}_
      {{- title .Os }}_
@@ -26,7 +26,7 @@ archives:
      {{- if .Arm }}v{{ .Arm }}{{ end }}
    format_overrides:
      - goos: windows
-        format: zip
+        formats: zip

 changelog:
  sort: asc
@@ -36,7 +36,6 @@ changelog:
      - "^test:"

 release:
-  draft: true
  name_template: '{{.ProjectName}}-{{.Version}}'
  footer: >-
  
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -5,7 +5,7 @@
    "version": "0.2.0",
    "configurations": [
        {
-            "name": "Launch Package",
+            "name": "Launch Memory & Disk",
            "type": "go",
            "request": "launch",
            "mode": "auto",
@@ -17,6 +17,36 @@
                "10G",
                "--disk-path",
                "tmp/disk",
+                "--log-level",
+                "debug",
+            ],
+        },
+        {
+            "name": "Launch Disk Only",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${workspaceFolder}/main.go",
+            "args": [
+                "--disk",
+                "10G",
+                "--disk-path",
+                "tmp/disk",
+                "--log-level",
+                "debug",
+            ],
+        },
+        {
+            "name": "Launch Memory Only",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${workspaceFolder}/main.go",
+            "args": [
+                "--memory",
+                "1G",
+                "--log-level",
+                "debug",
            ],
        }
    ]
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -1,18 +1,27 @@
+// cmd/root.go
 package cmd

 import (
 	"os"
+	"runtime"
 	"s1d3sw1ped/SteamCache2/steamcache"
+	"s1d3sw1ped/SteamCache2/steamcache/logger"
+	"s1d3sw1ped/SteamCache2/version"

+	"github.com/rs/zerolog"
 	"github.com/spf13/cobra"
 )

 var (
+	threads int
+
 	memory   string
-	memorymultiplier int
 	disk     string
-	diskmultiplier   int
 	diskpath string
+	upstream string
+
+	logLevel  string
+	logFormat string
 )

 var rootCmd = &cobra.Command{
@@ -24,15 +33,52 @@ var rootCmd = &cobra.Command{
 	By caching game files, SteamCache2 ensures that subsequent downloads of the same files are served from the local cache, 
 	significantly improving download times and reducing the load on the internet connection.`,
 	Run: func(cmd *cobra.Command, args []string) {
+		// Configure logging
+		switch logLevel {
+		case "debug":
+			zerolog.SetGlobalLevel(zerolog.DebugLevel)
+		case "error":
+			zerolog.SetGlobalLevel(zerolog.ErrorLevel)
+		case "info":
+			zerolog.SetGlobalLevel(zerolog.InfoLevel)
+		default:
+			zerolog.SetGlobalLevel(zerolog.InfoLevel) // Default to info level if not specified
+		}
+		var writer zerolog.ConsoleWriter
+		if logFormat == "json" {
+			writer = zerolog.ConsoleWriter{Out: os.Stderr, NoColor: true}
+		} else {
+			writer = zerolog.ConsoleWriter{Out: os.Stderr}
+		}
+		logger.Logger = zerolog.New(writer).With().Timestamp().Logger()
+
+		logger.Logger.Info().
+			Msg("SteamCache2 " + version.Version + " starting...")
+
+		address := ":80"
+
+		if runtime.GOMAXPROCS(-1) != threads {
+			runtime.GOMAXPROCS(threads)
+			logger.Logger.Info().
+				Int("threads", threads).
+				Msg("Maximum number of threads set")
+		}
+
 		sc := steamcache.New(
-			":80",
+			address,
 			memory,
-			memorymultiplier,
 			disk,
-			diskmultiplier,
 			diskpath,
+			upstream,
 		)
+
+		logger.Logger.Info().
+			Msg("SteamCache2 " + version.Version + " started on " + address)
+
 		sc.Run()
+
+		logger.Logger.Info().Msg("SteamCache2 stopped")
+		os.Exit(0)
 	},
 }

@@ -46,9 +92,14 @@ func Execute() {
 }

 func init() {
-	rootCmd.Flags().StringVarP(&memory, "memory", "m", "100MB", "The size of the memory cache")
-	rootCmd.Flags().IntVarP(&memorymultiplier, "memory-multiplier", "M", 10, "The multiplier for the memory cache")
-	rootCmd.Flags().StringVarP(&disk, "disk", "d", "10GB", "The size of the disk cache")
-	rootCmd.Flags().IntVarP(&diskmultiplier, "disk-multiplier", "D", 10, "The multiplier for the disk cache")
-	rootCmd.Flags().StringVarP(&diskpath, "disk-path", "p", "tmp/steamcache2-disk", "The path to the disk cache")
+	rootCmd.Flags().IntVarP(&threads, "threads", "t", runtime.GOMAXPROCS(-1), "Number of worker threads to use for processing requests")
+
+	rootCmd.Flags().StringVarP(&memory, "memory", "m", "0", "The size of the memory cache")
+	rootCmd.Flags().StringVarP(&disk, "disk", "d", "0", "The size of the disk cache")
+	rootCmd.Flags().StringVarP(&diskpath, "disk-path", "p", "", "The path to the disk cache")
+
+	rootCmd.Flags().StringVarP(&upstream, "upstream", "u", "", "The upstream server to proxy requests overrides the host header from the client but forwards the original host header to the upstream server")
+
+	rootCmd.Flags().StringVarP(&logLevel, "log-level", "l", "info", "Logging level: debug, info, error")
+	rootCmd.Flags().StringVarP(&logFormat, "log-format", "f", "console", "Logging format: json, console")
 }
--- a/cmd/version.go
+++ b/cmd/version.go
@@ -1,3 +1,4 @@
+// cmd/version.go
 package cmd

 import (
--- a/go.mod
+++ b/go.mod
@@ -4,15 +4,22 @@ go 1.23.0

 require (
 	github.com/docker/go-units v0.5.0
+	github.com/prometheus/client_golang v1.22.0
 	github.com/rs/zerolog v1.33.0
 	github.com/spf13/cobra v1.8.1
-	golang.org/x/exp v0.0.0-20250106191152-7588d65b2ba8
 )

 require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.19 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/prometheus/client_model v0.6.1 // indirect
+	github.com/prometheus/common v0.62.0 // indirect
+	github.com/prometheus/procfs v0.15.1 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
-	golang.org/x/sys v0.12.0 // indirect
+	golang.org/x/sys v0.30.0 // indirect
+	google.golang.org/protobuf v1.36.5 // indirect
 )
--- a/go.sum
+++ b/go.sum
@@ -1,16 +1,40 @@
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/docker/go-units v0.5.0 h1:69rxXcBk27SvSaaxTtLh/8llcHD8vYHT7WSdRZ/jvr4=
 github.com/docker/go-units v0.5.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
+github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
 github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
 github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
 github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v1.22.0 h1:rb93p9lokFEsctTys46VnV1kLCDpVZ0a/Y92Vm0Zc6Q=
+github.com/prometheus/client_golang v1.22.0/go.mod h1:R7ljNsLXhuQXYZYtw6GAE9AZg8Y7vEW5scdCXrWRXC0=
+github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=
+github.com/prometheus/client_model v0.6.1/go.mod h1:OrxVMOVHjw3lKMa8+x6HeMGkHMQyHDk9E3jmP2AmGiY=
+github.com/prometheus/common v0.62.0 h1:xasJaQlnWAeyHdUBeGjXmutelfJHWMRr+Fg4QszZ2Io=
+github.com/prometheus/common v0.62.0/go.mod h1:vyBcEuLSvWos9B1+CyL7JZ2up+uFzXhkqml0W5zIY1I=
+github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=
+github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
 github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
 github.com/rs/zerolog v1.33.0 h1:1cU2KZkvPxNyfgEmhHAz/1A9Bz+llsdYzklWFzgp0r8=
 github.com/rs/zerolog v1.33.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
@@ -19,11 +43,15 @@ github.com/spf13/cobra v1.8.1 h1:e5/vxKd/rZsfSJMUX1agtjeTDf+qv1/JdBF8gg5k9ZM=
 github.com/spf13/cobra v1.8.1/go.mod h1:wHxEcudfqmLYa8iTfL+OuZPbBZkmvliBWKIezN3kD9Y=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
-golang.org/x/exp v0.0.0-20250106191152-7588d65b2ba8 h1:yqrTHse8TCMW1M1ZCP+VAR/l0kKxwaAIqN/il7x4voA=
-golang.org/x/exp v0.0.0-20250106191152-7588d65b2ba8/go.mod h1:tujkw807nyEEAamNbDrEGzRav+ilXA7PCRAd6xsmwiU=
+github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
+github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
 golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
+golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+google.golang.org/protobuf v1.36.5 h1:tPhr+woSbjfYvY6/GPufUoYizxw1cF/yFoxJ2fmpwlM=
+google.golang.org/protobuf v1.36.5/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
--- a/main.go
+++ b/main.go
@@ -1,3 +1,4 @@
+// main.go
 package main

 import (
--- a/steamcache/avgcachestate/avgcachestate.go
+++ b/steamcache/avgcachestate/avgcachestate.go
@@ -1,60 +0,0 @@
-package avgcachestate
-
-import (
-	"s1d3sw1ped/SteamCache2/vfs/cachestate"
-	"sync"
-)
-
-// AvgCacheState is a cache state that averages the last N cache states.
-type AvgCacheState struct {
-	size int
-	avgs []cachestate.CacheState
-	mu   sync.Mutex
-}
-
-// New creates a new average cache state with the given size.
-func New(size int) *AvgCacheState {
-	return &AvgCacheState{
-		size: size,
-		avgs: make([]cachestate.CacheState, size),
-		mu:   sync.Mutex{},
-	}
-}
-
-// Clear resets the average cache state to zero.
-func (a *AvgCacheState) Clear() {
-	a.mu.Lock()
-	defer a.mu.Unlock()
-
-	a.avgs = make([]cachestate.CacheState, a.size) // zeroed
-}
-
-// Add adds a cache state to the average cache state.
-func (a *AvgCacheState) Add(cs cachestate.CacheState) {
-	a.mu.Lock()
-	defer a.mu.Unlock()
-
-	a.avgs = append(a.avgs, cs)
-	if len(a.avgs) > a.size {
-		a.avgs = a.avgs[1:]
-	}
-}
-
-// Avg returns the average cache state.
-func (a *AvgCacheState) Avg() float64 {
-	a.mu.Lock()
-	defer a.mu.Unlock()
-
-	var hits, misses int
-	for _, cs := range a.avgs {
-		switch cs {
-		case cachestate.CacheStateHit:
-			hits++
-		case cachestate.CacheStateMiss:
-			misses++
-		}
-	}
-	total := hits + misses
-
-	return float64(hits) / float64(total)
-}
--- a/steamcache/gc.go
+++ b/steamcache/gc.go
@@ -1,75 +0,0 @@
-package steamcache
-
-import (
-	"s1d3sw1ped/SteamCache2/steamcache/logger"
-	"s1d3sw1ped/SteamCache2/vfs"
-	"s1d3sw1ped/SteamCache2/vfs/cachestate"
-	"time"
-
-	"github.com/docker/go-units"
-	"golang.org/x/exp/rand"
-)
-
-func randomgc(vfss vfs.VFS, stats []*vfs.FileInfo) int64 {
-	// Pick a random file to delete
-	randfile := stats[rand.Intn(len(stats))]
-	sz := randfile.Size()
-	err := vfss.Delete(randfile.Name())
-	if err != nil {
-		// If we failed to delete the file, log it and return 0
-		// logger.Logger.Error().Err(err).Msgf("Failed to delete %s", randfile.Name())
-		return 0
-	}
-
-	return sz
-}
-
-func memorygc(vfss vfs.VFS, size int) {
-	tstart := time.Now()
-	deletions := 0
-	targetreclaim := int64(size)
-	var reclaimed int64
-
-	stats := vfss.StatAll()
-	for {
-		reclaimed += randomgc(vfss, stats)
-		deletions++
-		if reclaimed >= targetreclaim {
-			break
-		}
-	}
-
-	logger.Logger.Info().
-		Str("name", vfss.Name()).
-		Str("duration", time.Since(tstart).String()).
-		Str("reclaimed", units.HumanSize(float64(reclaimed))).
-		Int("deletions", deletions).
-		Msgf("GC")
-}
-
-func diskgc(vfss vfs.VFS, size int) {
-	tstart := time.Now()
-	deletions := 0
-	targetreclaim := int64(size)
-	var reclaimed int64
-
-	stats := vfss.StatAll()
-	for {
-		reclaimed += randomgc(vfss, stats)
-		deletions++
-		if reclaimed >= targetreclaim {
-			break
-		}
-	}
-
-	logger.Logger.Info().
-		Str("name", vfss.Name()).
-		Str("duration", time.Since(tstart).String()).
-		Str("reclaimed", units.HumanSize(float64(reclaimed))).
-		Int("deletions", deletions).
-		Msgf("GC")
-}
-
-func cachehandler(fi *vfs.FileInfo, cs cachestate.CacheState) bool {
-	return time.Since(fi.AccessTime()) < time.Minute*10 // Put files in the cache if they've been accessed twice in the last 10 minutes
-}
--- a/steamcache/logger/logger.go
+++ b/steamcache/logger/logger.go
@@ -1,9 +1,8 @@
+// steamcache/logger/logger.go
 package logger

 import (
-	"os"
-
 	"github.com/rs/zerolog"
 )

-var Logger = zerolog.New(zerolog.ConsoleWriter{Out: os.Stderr}).With().Timestamp().Logger()
+var Logger zerolog.Logger
--- a/steamcache/steamcache.go
+++ b/steamcache/steamcache.go
@@ -1,42 +1,74 @@
+// steamcache/steamcache.go
 package steamcache

 import (
-	"fmt"
+	"context"
 	"io"
+	"net"
 	"net/http"
 	"net/url"
 	"os"
-	"s1d3sw1ped/SteamCache2/steamcache/avgcachestate"
 	"s1d3sw1ped/SteamCache2/steamcache/logger"
-	"s1d3sw1ped/SteamCache2/version"
 	"s1d3sw1ped/SteamCache2/vfs"
 	"s1d3sw1ped/SteamCache2/vfs/cache"
-	"s1d3sw1ped/SteamCache2/vfs/cachestate"
 	"s1d3sw1ped/SteamCache2/vfs/disk"
 	"s1d3sw1ped/SteamCache2/vfs/gc"
 	"s1d3sw1ped/SteamCache2/vfs/memory"
-	syncfs "s1d3sw1ped/SteamCache2/vfs/sync"
 	"strings"
 	"sync"
 	"time"

 	"github.com/docker/go-units"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var (
+	requestsTotal = promauto.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "http_requests_total",
+			Help: "Total number of HTTP requests",
+		},
+		[]string{"method", "status"},
+	)
+
+	cacheStatusTotal = promauto.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "cache_status_total",
+			Help: "Total cache status counts",
+		},
+		[]string{"status"},
+	)
+
+	responseTime = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "response_time_seconds",
+			Help:    "Response time in seconds",
+			Buckets: prometheus.DefBuckets,
+		},
+	)
 )

 type SteamCache struct {
 	address  string
+	upstream string
+
 	vfs vfs.VFS

 	memory *memory.MemoryFS
 	disk   *disk.DiskFS

-	hits *avgcachestate.AvgCacheState
+	memorygc *gc.GCFS
+	diskgc   *gc.GCFS

-	dirty bool
-	mu    sync.Mutex
+	server *http.Server
+	client *http.Client
+	cancel context.CancelFunc
+	wg     sync.WaitGroup
 }

-func New(address string, memorySize string, memoryMultiplier int, diskSize string, diskMultiplier int, diskPath string) *SteamCache {
+func New(address string, memorySize string, diskSize string, diskPath, upstream string) *SteamCache {
 	memorysize, err := units.FromHumanSize(memorySize)
 	if err != nil {
 		panic(err)
@@ -47,81 +79,133 @@ func New(address string, memorySize string, memoryMultiplier int, diskSize strin
 		panic(err)
 	}

-	m := memory.New(memorysize)
-	d := disk.New(diskPath, disksize)
+	c := cache.New(
+		gc.PromotionDecider,
+	)

-	sc := &SteamCache{
-		address: address,
-		vfs: syncfs.New(
-			cache.New(
-				gc.New(
-					m,
-					memoryMultiplier,
-					memorygc,
-				),
-				gc.New(
-					d,
-					diskMultiplier,
-					diskgc,
-				),
-				cachehandler,
-			),
-		),
-
-		memory: m,
-		disk:   d,
-
-		hits: avgcachestate.New(10000),
+	var m *memory.MemoryFS
+	var mgc *gc.GCFS
+	if memorysize > 0 {
+		m = memory.New(memorysize)
+		mgc = gc.New(m, gc.LRUGC)
 	}

+	var d *disk.DiskFS
+	var dgc *gc.GCFS
+	if disksize > 0 {
+		d = disk.New(diskPath, disksize)
+		dgc = gc.New(d, gc.LRUGC)
+	}
+
+	// configure the cache to match the specified mode (memory only, disk only, or memory and disk) based on the provided sizes
+	if disksize == 0 && memorysize != 0 {
+		//memory only mode - no disk
+
+		c.SetSlow(mgc)
+	} else if disksize != 0 && memorysize == 0 {
+		// disk only mode
+
+		c.SetSlow(dgc)
+	} else if disksize != 0 && memorysize != 0 {
+		// memory and disk mode
+
+		c.SetFast(mgc)
+		c.SetSlow(dgc)
+	} else {
+		// no memory or disk isn't a valid configuration
+		logger.Logger.Error().Bool("memory", false).Bool("disk", false).Msg("configuration invalid :( exiting")
+		os.Exit(1)
+	}
+
+	transport := &http.Transport{
+		MaxIdleConns:        100,
+		MaxIdleConnsPerHost: 10,
+		IdleConnTimeout:     90 * time.Second,
+		DialContext: (&net.Dialer{
+			Timeout:   30 * time.Second,
+			KeepAlive: 30 * time.Second,
+		}).DialContext,
+		TLSHandshakeTimeout:   10 * time.Second,
+		ResponseHeaderTimeout: 10 * time.Second,
+		ExpectContinueTimeout: 1 * time.Second,
+	}
+
+	client := &http.Client{
+		Transport: transport,
+		Timeout:   60 * time.Second,
+	}
+
+	sc := &SteamCache{
+		upstream: upstream,
+		address:  address,
+		vfs:      c,
+		memory:   m,
+		disk:     d,
+		memorygc: mgc,
+		diskgc:   dgc,
+		client:   client,
+		server: &http.Server{
+			Addr:         address,
+			ReadTimeout:  5 * time.Second,
+			WriteTimeout: 10 * time.Second,
+			IdleTimeout:  120 * time.Second,
+		},
+	}
+
+	if d != nil {
 		if d.Size() > d.Capacity() {
-		diskgc(d, int(d.Size()-d.Capacity()))
+			gc.LRUGC(d, uint(d.Size()-d.Capacity()))
+		}
 	}

 	return sc
 }

 func (sc *SteamCache) Run() {
-	logger.Logger.Info().Str("address", sc.address).Str("version", version.Version).Msg("listening")
+	if sc.upstream != "" {
+		resp, err := sc.client.Get(sc.upstream)
+		if err != nil || resp.StatusCode != http.StatusOK {
+			logger.Logger.Error().Err(err).Str("upstream", sc.upstream).Msg("Failed to connect to upstream server")
+			os.Exit(1)
+		}
+		resp.Body.Close()
+	}

-	sc.mu.Lock()
-	sc.dirty = true
-	sc.mu.Unlock()
+	sc.server.Handler = sc
+	ctx, cancel := context.WithCancel(context.Background())
+	sc.cancel = cancel

-	sc.LogStats()
-	t := time.NewTicker(10 * time.Second)
+	sc.wg.Add(1)
 	go func() {
-		for range t.C {
-			sc.LogStats()
-		}
-	}()
-
-	err := http.ListenAndServe(sc.address, sc)
-	if err != nil {
-		if err == http.ErrServerClosed {
-			logger.Logger.Info().Msg("shutdown")
-			return
-		}
+		defer sc.wg.Done()
+		err := sc.server.ListenAndServe()
+		if err != nil && err != http.ErrServerClosed {
 			logger.Logger.Error().Err(err).Msg("Failed to start SteamCache2")
 			os.Exit(1)
 		}
+	}()
+
+	<-ctx.Done()
+	sc.server.Shutdown(ctx)
+	sc.wg.Wait()
 }

-func (sc *SteamCache) LogStats() {
-	sc.mu.Lock()
-	defer sc.mu.Unlock()
-	if sc.dirty {
-		logger.Logger.Info().
-			Str("memory", fmt.Sprintf("%s/%s", units.HumanSize(float64(sc.memory.Size())), units.HumanSize(float64(sc.memory.Capacity())))).Int("memory-files", len(sc.memory.StatAll())).
-			Str("disk", fmt.Sprintf("%s/%s", units.HumanSize(float64(sc.disk.Size())), units.HumanSize(float64(sc.disk.Capacity())))).Int("disk-files", len(sc.disk.StatAll())).
-			Str("hitrate", fmt.Sprintf("%.2f%%", sc.hits.Avg()*100)).
-			Msg("stats")
-		sc.dirty = false
+func (sc *SteamCache) Shutdown() {
+	if sc.cancel != nil {
+		sc.cancel()
 	}
+	sc.wg.Wait()
 }

 func (sc *SteamCache) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path == "/metrics" {
+		promhttp.Handler().ServeHTTP(w, r)
+		return
+	}
+
 	if r.Method != http.MethodGet {
+		requestsTotal.WithLabelValues(r.Method, "405").Inc()
+		logger.Logger.Warn().Str("method", r.Method).Msg("Only GET method is supported")
 		http.Error(w, "Only GET method is supported", http.StatusMethodNotAllowed)
 		return
 	}
@@ -133,110 +217,155 @@ func (sc *SteamCache) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	if r.Header.Get("User-Agent") != "Valve/Steam HTTP Client 1.0" {
-		http.Error(w, "Only Valve/Steam HTTP Client 1.0 is supported", http.StatusForbidden)
+	if strings.HasPrefix(r.URL.String(), "/depot/") {
+		// trim the query parameters from the URL path
+		// this is necessary because the cache key should not include query parameters
+		path := strings.Split(r.URL.String(), "?")[0]
+
+		tstart := time.Now()
+		defer func() { responseTime.Observe(time.Since(tstart).Seconds()) }()
+
+		cacheKey := strings.ReplaceAll(path[1:], "\\", "/") // replace all backslashes with forward slashes shouldn't be necessary but just in case
+
+		if cacheKey == "" {
+			requestsTotal.WithLabelValues(r.Method, "400").Inc()
+			logger.Logger.Warn().Str("url", path).Msg("Invalid URL")
+			http.Error(w, "Invalid URL", http.StatusBadRequest)
 			return
 		}

-	if strings.Contains(r.URL.String(), "manifest") {
-		w.Header().Add("X-LanCache-Processed-By", "SteamCache2")
-		forward(w, r)
-		return
-	}
-
-	// tstart := time.Now()
-	// defer func() {
-	// logger.Logger.Info().Str("method", r.Method).Str("url", r.URL.String()).Str("status", w.Header().Get("X-LanCache-Status")).Dur("duration", time.Since(tstart)).Msg("Request")
-	// }()
-
-	sc.mu.Lock()
-	sc.dirty = true
-	sc.mu.Unlock()
-
 		w.Header().Add("X-LanCache-Processed-By", "SteamCache2") // SteamPrefill uses this header to determine if the request was processed by the cache maybe steam uses it too

-	cacheKey := r.URL.String()
-
-	// if vfs is also a vfs.GetSer, we can use it to get the cache state
-
-	data, err := sc.vfs.Get(cacheKey)
+		reader, err := sc.vfs.Open(cacheKey)
 		if err == nil {
-		sc.hits.Add(cachestate.CacheStateHit)
+			defer reader.Close()
 			w.Header().Add("X-LanCache-Status", "HIT")
-		w.Write(data)
+
+			io.Copy(w, reader)
+
+			logger.Logger.Info().
+				Str("key", cacheKey).
+				Str("host", r.Host).
+				Str("status", "HIT").
+				Dur("duration", time.Since(tstart)).
+				Msg("request")
+
+			requestsTotal.WithLabelValues(r.Method, "200").Inc()
+			cacheStatusTotal.WithLabelValues("HIT").Inc()
+
 			return
 		}

-	htt := "http://"
-	if r.Header.Get("X-Sls-Https") == "enable" {
-		htt = "https://"
-	}
-
-	base := htt + r.Host
-
-	hosturl, err := url.JoinPath(base, cacheKey)
+		var req *http.Request
+		if sc.upstream != "" { // if an upstream server is configured, proxy the request to the upstream server
+			ur, err := url.JoinPath(sc.upstream, path)
 			if err != nil {
+				requestsTotal.WithLabelValues(r.Method, "500").Inc()
+				logger.Logger.Error().Err(err).Str("upstream", sc.upstream).Msg("Failed to join URL path")
 				http.Error(w, "Failed to join URL path", http.StatusInternalServerError)
 				return
 			}

-	resp, err := http.Get(hosturl)
+			req, err = http.NewRequest(http.MethodGet, ur, nil)
 			if err != nil {
+				requestsTotal.WithLabelValues(r.Method, "500").Inc()
+				logger.Logger.Error().Err(err).Str("upstream", sc.upstream).Msg("Failed to create request")
+				http.Error(w, "Failed to create request", http.StatusInternalServerError)
+				return
+			}
+			req.Host = r.Host
+		} else { // if no upstream server is configured, proxy the request to the host specified in the request
+			host := r.Host
+			if r.Header.Get("X-Sls-Https") == "enable" {
+				host = "https://" + host
+			} else {
+				host = "http://" + host
+			}
+
+			ur, err := url.JoinPath(host, path)
+			if err != nil {
+				requestsTotal.WithLabelValues(r.Method, "500").Inc()
+				logger.Logger.Error().Err(err).Str("host", host).Msg("Failed to join URL path")
+				http.Error(w, "Failed to join URL path", http.StatusInternalServerError)
+				return
+			}
+
+			req, err = http.NewRequest(http.MethodGet, ur, nil)
+			if err != nil {
+				requestsTotal.WithLabelValues(r.Method, "500").Inc()
+				logger.Logger.Error().Err(err).Str("host", host).Msg("Failed to create request")
+				http.Error(w, "Failed to create request", http.StatusInternalServerError)
+				return
+			}
+		}
+
+		// Copy headers from the original request to the new request
+		for key, values := range r.Header {
+			for _, value := range values {
+				req.Header.Add(key, value)
+			}
+		}
+
+		// Retry logic
+		backoffSchedule := []time.Duration{1 * time.Second, 3 * time.Second, 10 * time.Second}
+		var resp *http.Response
+		for i, backoff := range backoffSchedule {
+			resp, err = sc.client.Do(req)
+			if err == nil && resp.StatusCode == http.StatusOK {
+				break
+			}
+			if i < len(backoffSchedule)-1 {
+				time.Sleep(backoff)
+			}
+		}
+		if err != nil || resp.StatusCode != http.StatusOK {
+			requestsTotal.WithLabelValues(r.Method, "500 upstream host "+r.Host).Inc()
+			logger.Logger.Error().Err(err).Str("url", req.URL.String()).Msg("Failed to fetch the requested URL")
 			http.Error(w, "Failed to fetch the requested URL", http.StatusInternalServerError)
 			return
 		}
 		defer resp.Body.Close()

-	if resp.StatusCode != http.StatusOK {
-		http.Error(w, "Failed to fetch the requested URL", resp.StatusCode)
-		return
+		size := resp.ContentLength
+
+		// this is sortof not needed as we should always be able to get a writer from the cache as long as the gc is able to reclaim enough space aka the file is not bigger than the disk can handle
+		ww := w.(io.Writer)                        // default writer to write to the response writer
+		writer, _ := sc.vfs.Create(cacheKey, size) // create a writer to write to the cache
+		if writer != nil {                         // if the writer is not nil, it means the cache is writable
+			defer writer.Close()           // close the writer when done
+			ww = io.MultiWriter(w, writer) // write to both the response writer and the cache writer
 		}

-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		http.Error(w, "Failed to read response body", http.StatusInternalServerError)
-		return
-	}
-
-	sc.vfs.Set(cacheKey, body)
-	sc.hits.Add(cachestate.CacheStateMiss)
 		w.Header().Add("X-LanCache-Status", "MISS")
-	w.Write(body)
-}
-
-func forward(w http.ResponseWriter, r *http.Request) {
-	htt := "http://"
-	if r.Header.Get("X-Sls-Https") == "enable" {
-		htt = "https://"
-	}
-
-	base := htt + r.Host
-
-	cacheKey := r.URL.String()
-
-	hosturl, err := url.JoinPath(base, cacheKey)
-	if err != nil {
-		http.Error(w, "Failed to join URL path", http.StatusInternalServerError)
-		return
-	}
-
-	resp, err := http.Get(hosturl)
-	if err != nil {
-		http.Error(w, "Failed to fetch the requested URL", http.StatusInternalServerError)
-		return
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode != http.StatusOK {
-		http.Error(w, "Failed to fetch the requested URL", resp.StatusCode)
-		return
-	}
-
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		http.Error(w, "Failed to read response body", http.StatusInternalServerError)
-		return
-	}
-
-	w.Write(body)
+
+		io.Copy(ww, resp.Body)
+
+		logger.Logger.Info().
+			Str("key", cacheKey).
+			Str("host", r.Host).
+			Str("status", "MISS").
+			Dur("duration", time.Since(tstart)).
+			Msg("request")
+
+		requestsTotal.WithLabelValues(r.Method, "200").Inc()
+		cacheStatusTotal.WithLabelValues("MISS").Inc()
+
+		return
+	}
+
+	if r.URL.Path == "/favicon.ico" {
+		w.WriteHeader(http.StatusNoContent)
+		return
+	}
+
+	if r.URL.Path == "/robots.txt" {
+		w.Header().Set("Content-Type", "text/plain")
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte("User-agent: *\nDisallow: /\n"))
+		return
+	}
+
+	requestsTotal.WithLabelValues(r.Method, "404").Inc()
+	logger.Logger.Warn().Str("url", r.URL.String()).Msg("Not found")
+	http.Error(w, "Not found", http.StatusNotFound)
 }
--- a/steamcache/steamcache_test.go
+++ b/steamcache/steamcache_test.go
@@ -0,0 +1,110 @@
+// steamcache/steamcache_test.go
+package steamcache
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestCaching(t *testing.T) {
+	td := t.TempDir()
+
+	os.WriteFile(filepath.Join(td, "key2"), []byte("value2"), 0644)
+
+	sc := New("localhost:8080", "1G", "1G", td, "")
+
+	w, err := sc.vfs.Create("key", 5)
+	if err != nil {
+		t.Errorf("Create failed: %v", err)
+	}
+	w.Write([]byte("value"))
+	w.Close()
+
+	w, err = sc.vfs.Create("key1", 6)
+	if err != nil {
+		t.Errorf("Create failed: %v", err)
+	}
+	w.Write([]byte("value1"))
+	w.Close()
+
+	if sc.diskgc.Size() != 17 {
+		t.Errorf("Size failed: got %d, want %d", sc.diskgc.Size(), 17)
+	}
+
+	if sc.vfs.Size() != 17 {
+		t.Errorf("Size failed: got %d, want %d", sc.vfs.Size(), 17)
+	}
+
+	rc, err := sc.vfs.Open("key")
+	if err != nil {
+		t.Errorf("Open failed: %v", err)
+	}
+	d, _ := io.ReadAll(rc)
+	rc.Close()
+	if string(d) != "value" {
+		t.Errorf("Get failed: got %s, want %s", d, "value")
+	}
+
+	rc, err = sc.vfs.Open("key1")
+	if err != nil {
+		t.Errorf("Open failed: %v", err)
+	}
+	d, _ = io.ReadAll(rc)
+	rc.Close()
+	if string(d) != "value1" {
+		t.Errorf("Get failed: got %s, want %s", d, "value1")
+	}
+
+	rc, err = sc.vfs.Open("key2")
+	if err != nil {
+		t.Errorf("Open failed: %v", err)
+	}
+	d, _ = io.ReadAll(rc)
+	rc.Close()
+	if string(d) != "value2" {
+		t.Errorf("Get failed: got %s, want %s", d, "value2")
+	}
+
+	if sc.diskgc.Size() != 17 {
+		t.Errorf("Size failed: got %d, want %d", sc.diskgc.Size(), 17)
+	}
+
+	if sc.vfs.Size() != 17 {
+		t.Errorf("Size failed: got %d, want %d", sc.vfs.Size(), 17)
+	}
+
+	sc.memory.Delete("key2")
+	os.Remove(filepath.Join(td, "key2"))
+
+	if _, err := sc.vfs.Open("key2"); err == nil {
+		t.Errorf("Open failed: got nil, want error")
+	}
+}
+
+func TestCacheMissAndHit(t *testing.T) {
+	sc := New("localhost:8080", "0", "1G", t.TempDir(), "")
+
+	key := "testkey"
+	value := []byte("testvalue")
+
+	// Simulate miss: but since no upstream, skip full ServeHTTP, test VFS
+	w, err := sc.vfs.Create(key, int64(len(value)))
+	if err != nil {
+		t.Fatal(err)
+	}
+	w.Write(value)
+	w.Close()
+
+	rc, err := sc.vfs.Open(key)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, _ := io.ReadAll(rc)
+	rc.Close()
+
+	if string(got) != string(value) {
+		t.Errorf("expected %s, got %s", value, got)
+	}
+}
--- a/version/version.go
+++ b/version/version.go
@@ -1,3 +1,10 @@
+// version/version.go
 package version

 var Version string
+
+func init() {
+	if Version == "" {
+		Version = "0.0.0-dev"
+	}
+}
--- a/vfs/cache/cache.go
+++ b/vfs/cache/cache.go
@@ -1,10 +1,13 @@
+// vfs/cache/cache.go
 package cache

 import (
 	"fmt"
+	"io"
 	"s1d3sw1ped/SteamCache2/vfs"
 	"s1d3sw1ped/SteamCache2/vfs/cachestate"
 	"s1d3sw1ped/SteamCache2/vfs/vfserror"
+	"sync"
 )

 // Ensure CacheFS implements VFS.
@@ -16,28 +19,38 @@ type CacheFS struct {
 	slow vfs.VFS

 	cacheHandler CacheHandler
+
+	keyLocks sync.Map // map[string]*sync.RWMutex for per-key locks
 }

 type CacheHandler func(*vfs.FileInfo, cachestate.CacheState) bool

 // New creates a new CacheFS. fast is used for caching, and slow is used for storage. fast should obviously be faster than slow.
-func New(fast, slow vfs.VFS, cacheHandler CacheHandler) *CacheFS {
-	if slow == nil {
-		panic("slow is nil")
-	}
-
-	if fast == slow {
-		panic("fast and slow are the same")
-	}
-
+func New(cacheHandler CacheHandler) *CacheFS {
 	return &CacheFS{
-		fast: fast,
-		slow: slow,
-
 		cacheHandler: cacheHandler,
+		keyLocks:     sync.Map{},
 	}
 }

+func (c *CacheFS) SetSlow(vfs vfs.VFS) {
+	if vfs == nil {
+		panic("vfs is nil") // panic if the vfs is nil
+	}
+
+	c.slow = vfs
+}
+
+func (c *CacheFS) SetFast(vfs vfs.VFS) {
+	c.fast = vfs
+}
+
+// getKeyLock returns a RWMutex for the given key, creating it if necessary.
+func (c *CacheFS) getKeyLock(key string) *sync.RWMutex {
+	mu, _ := c.keyLocks.LoadOrStore(key, &sync.RWMutex{})
+	return mu.(*sync.RWMutex)
+}
+
 // cacheState returns the state of the file at key.
 func (c *CacheFS) cacheState(key string) cachestate.CacheState {
 	if c.fast != nil {
@@ -62,65 +75,74 @@ func (c *CacheFS) Size() int64 {
 	return c.slow.Size()
 }

-// Set sets the file at key to src. If the file is already in the cache, it is replaced.
-func (c *CacheFS) Set(key string, src []byte) error {
-	state := c.cacheState(key)
-
-	switch state {
-	case cachestate.CacheStateHit:
-		if c.fast != nil {
-			c.fast.Delete(key)
-		}
-		return c.slow.Set(key, src)
-	case cachestate.CacheStateMiss, cachestate.CacheStateNotFound:
-		return c.slow.Set(key, src)
-	}
-
-	panic(vfserror.ErrUnreachable)
-}
-
 // Delete deletes the file at key from the cache.
 func (c *CacheFS) Delete(key string) error {
+	mu := c.getKeyLock(key)
+	mu.Lock()
+	defer mu.Unlock()
+
 	if c.fast != nil {
 		c.fast.Delete(key)
 	}
 	return c.slow.Delete(key)
 }

-// Get returns the file at key. If the file is not in the cache, it is fetched from the storage.
-func (c *CacheFS) Get(key string) ([]byte, error) {
-	src, _, err := c.GetS(key)
-	return src, err
-}
+// Open returns the file at key. If the file is not in the cache, it is fetched from the storage.
+func (c *CacheFS) Open(key string) (io.ReadCloser, error) {
+	mu := c.getKeyLock(key)
+	mu.RLock()
+	defer mu.RUnlock()

-// GetS returns the file at key. If the file is not in the cache, it is fetched from the storage. It also returns the cache state.
-func (c *CacheFS) GetS(key string) ([]byte, cachestate.CacheState, error) {
 	state := c.cacheState(key)

 	switch state {
 	case cachestate.CacheStateHit:
 		// if c.fast == nil then cacheState cannot be CacheStateHit so we can safely ignore the check
-		src, err := c.fast.Get(key)
-		return src, state, err
+		return c.fast.Open(key)
 	case cachestate.CacheStateMiss:
-		src, err := c.slow.Get(key)
+		slowReader, err := c.slow.Open(key)
 		if err != nil {
-			return nil, state, err
+			return nil, err
 		}

 		sstat, _ := c.slow.Stat(key)
 		if sstat != nil && c.fast != nil { // file found in slow storage and fast storage is available
 			// We are accessing the file from the slow storage, and the file has been accessed less then a minute ago so it popular, so we should update the fast storage with the latest file.
 			if c.cacheHandler != nil && c.cacheHandler(sstat, state) {
-				if err := c.fast.Set(key, src); err != nil {
-					return nil, state, err
+				fastWriter, err := c.fast.Create(key, sstat.Size())
+				if err == nil {
+					return &teeReadCloser{
+						Reader:  io.TeeReader(slowReader, fastWriter),
+						closers: []io.Closer{slowReader, fastWriter},
+					}, nil
 				}
 			}
 		}

-		return src, state, nil
+		return slowReader, nil
 	case cachestate.CacheStateNotFound:
-		return nil, state, vfserror.ErrNotFound
+		return nil, vfserror.ErrNotFound
+	}
+
+	panic(vfserror.ErrUnreachable)
+}
+
+// Create creates a new file at key. If the file is already in the cache, it is replaced.
+func (c *CacheFS) Create(key string, size int64) (io.WriteCloser, error) {
+	mu := c.getKeyLock(key)
+	mu.Lock()
+	defer mu.Unlock()
+
+	state := c.cacheState(key)
+
+	switch state {
+	case cachestate.CacheStateHit:
+		if c.fast != nil {
+			c.fast.Delete(key)
+		}
+		return c.slow.Create(key, size)
+	case cachestate.CacheStateMiss, cachestate.CacheStateNotFound:
+		return c.slow.Create(key, size)
 	}

 	panic(vfserror.ErrUnreachable)
@@ -129,6 +151,10 @@ func (c *CacheFS) GetS(key string) ([]byte, cachestate.CacheState, error) {
 // Stat returns information about the file at key.
 // Warning: This will return information about the file in the fastest storage its in.
 func (c *CacheFS) Stat(key string) (*vfs.FileInfo, error) {
+	mu := c.getKeyLock(key)
+	mu.RLock()
+	defer mu.RUnlock()
+
 	state := c.cacheState(key)

 	switch state {
@@ -149,3 +175,18 @@ func (c *CacheFS) Stat(key string) (*vfs.FileInfo, error) {
 func (c *CacheFS) StatAll() []*vfs.FileInfo {
 	return c.slow.StatAll()
 }
+
+type teeReadCloser struct {
+	io.Reader
+	closers []io.Closer
+}
+
+func (t *teeReadCloser) Close() error {
+	var err error
+	for _, c := range t.closers {
+		if e := c.Close(); e != nil {
+			err = e
+		}
+	}
+	return err
+}
--- a/vfs/cache/cache_test.go
+++ b/vfs/cache/cache_test.go
@@ -1,7 +1,9 @@
+// vfs/cache/cache_test.go
 package cache

 import (
 	"errors"
+	"io"
 	"testing"

 	"s1d3sw1ped/SteamCache2/vfs"
@@ -15,184 +17,175 @@ func testMemory() vfs.VFS {
 }

 func TestNew(t *testing.T) {
-	t.Parallel()
-
 	fast := testMemory()
 	slow := testMemory()

-	cache := New(fast, slow, nil)
+	cache := New(nil)
+	cache.SetFast(fast)
+	cache.SetSlow(slow)
 	if cache == nil {
 		t.Fatal("expected cache to be non-nil")
 	}
 }

 func TestNewPanics(t *testing.T) {
-	t.Parallel()
-
 	defer func() {
 		if r := recover(); r == nil {
 			t.Fatal("expected panic but did not get one")
 		}
 	}()

-	New(nil, nil, nil)
+	cache := New(nil)
+	cache.SetFast(nil)
+	cache.SetSlow(nil)
 }

-func TestSetAndGet(t *testing.T) {
-	t.Parallel()
-
+func TestCreateAndOpen(t *testing.T) {
 	fast := testMemory()
 	slow := testMemory()
-	cache := New(fast, slow, nil)
+	cache := New(nil)
+	cache.SetFast(fast)
+	cache.SetSlow(slow)

 	key := "test"
 	value := []byte("value")

-	if err := cache.Set(key, value); err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	got, err := cache.Get(key)
+	w, err := cache.Create(key, int64(len(value)))
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
+	w.Write(value)
+	w.Close()
+
+	rc, err := cache.Open(key)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	got, _ := io.ReadAll(rc)
+	rc.Close()

 	if string(got) != string(value) {
 		t.Fatalf("expected %s, got %s", value, got)
 	}
 }

-func TestSetAndGetNoFast(t *testing.T) {
-	t.Parallel()
-
+func TestCreateAndOpenNoFast(t *testing.T) {
 	slow := testMemory()
-	cache := New(nil, slow, nil)
+	cache := New(nil)
+	cache.SetSlow(slow)

 	key := "test"
 	value := []byte("value")

-	if err := cache.Set(key, value); err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	got, err := cache.Get(key)
+	w, err := cache.Create(key, int64(len(value)))
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
+	w.Write(value)
+	w.Close()
+
+	rc, err := cache.Open(key)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	got, _ := io.ReadAll(rc)
+	rc.Close()

 	if string(got) != string(value) {
 		t.Fatalf("expected %s, got %s", value, got)
 	}
 }
-func TestCaching(t *testing.T) {
-	t.Parallel()

+func TestCachingPromotion(t *testing.T) {
 	fast := testMemory()
 	slow := testMemory()
-	cache := New(fast, slow, func(fi *vfs.FileInfo, cs cachestate.CacheState) bool {
+	cache := New(func(fi *vfs.FileInfo, cs cachestate.CacheState) bool {
 		return true
 	})
+	cache.SetFast(fast)
+	cache.SetSlow(slow)

 	key := "test"
 	value := []byte("value")

-	if err := fast.Set(key, value); err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
+	ws, _ := slow.Create(key, int64(len(value)))
+	ws.Write(value)
+	ws.Close()

-	if err := slow.Set(key, value); err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	_, state, err := cache.GetS(key)
+	rc, err := cache.Open(key)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
-	if state != cachestate.CacheStateHit {
-		t.Fatalf("expected %v, got %v", cachestate.CacheStateHit, state)
-	}
-
-	err = fast.Delete(key)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	got, state, err := cache.GetS(key)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-	if state != cachestate.CacheStateMiss {
-		t.Fatalf("expected %v, got %v", cachestate.CacheStateMiss, state)
-	}
+	got, _ := io.ReadAll(rc)
+	rc.Close()

 	if string(got) != string(value) {
 		t.Fatalf("expected %s, got %s", value, got)
 	}

-	err = cache.Delete(key)
+	// Check if promoted to fast
+	_, err = fast.Open(key)
 	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	_, state, err = cache.GetS(key)
-	if !errors.Is(err, vfserror.ErrNotFound) {
-		t.Fatalf("expected %v, got %v", vfserror.ErrNotFound, err)
-	}
-	if state != cachestate.CacheStateNotFound {
-		t.Fatalf("expected %v, got %v", cachestate.CacheStateNotFound, state)
+		t.Error("Expected promotion to fast cache")
 	}
 }

-func TestGetNotFound(t *testing.T) {
-	t.Parallel()
-
+func TestOpenNotFound(t *testing.T) {
 	fast := testMemory()
 	slow := testMemory()
-	cache := New(fast, slow, nil)
+	cache := New(nil)
+	cache.SetFast(fast)
+	cache.SetSlow(slow)

-	_, err := cache.Get("nonexistent")
+	_, err := cache.Open("nonexistent")
 	if !errors.Is(err, vfserror.ErrNotFound) {
 		t.Fatalf("expected %v, got %v", vfserror.ErrNotFound, err)
 	}
 }

 func TestDelete(t *testing.T) {
-	t.Parallel()
-
 	fast := testMemory()
 	slow := testMemory()
-	cache := New(fast, slow, nil)
+	cache := New(nil)
+	cache.SetFast(fast)
+	cache.SetSlow(slow)

 	key := "test"
 	value := []byte("value")

-	if err := cache.Set(key, value); err != nil {
+	w, err := cache.Create(key, int64(len(value)))
+	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
+	w.Write(value)
+	w.Close()

 	if err := cache.Delete(key); err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}

-	_, err := cache.Get(key)
+	_, err = cache.Open(key)
 	if !errors.Is(err, vfserror.ErrNotFound) {
 		t.Fatalf("expected %v, got %v", vfserror.ErrNotFound, err)
 	}
 }

 func TestStat(t *testing.T) {
-	t.Parallel()
-
 	fast := testMemory()
 	slow := testMemory()
-	cache := New(fast, slow, nil)
+	cache := New(nil)
+	cache.SetFast(fast)
+	cache.SetSlow(slow)

 	key := "test"
 	value := []byte("value")

-	if err := cache.Set(key, value); err != nil {
+	w, err := cache.Create(key, int64(len(value)))
+	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
+	w.Write(value)
+	w.Close()

 	info, err := cache.Stat(key)
 	if err != nil {
@@ -202,4 +195,7 @@ func TestStat(t *testing.T) {
 	if info == nil {
 		t.Fatal("expected file info to be non-nil")
 	}
+	if info.Size() != int64(len(value)) {
+		t.Errorf("expected size %d, got %d", len(value), info.Size())
+	}
 }
--- a/vfs/cachestate/cachestate.go
+++ b/vfs/cachestate/cachestate.go
@@ -1,3 +1,4 @@
+// vfs/cachestate/cachestate.go
 package cachestate

 import "s1d3sw1ped/SteamCache2/vfs/vfserror"
--- a/vfs/disk/disk.go
+++ b/vfs/disk/disk.go
@@ -1,15 +1,52 @@
+// vfs/disk/disk.go
 package disk

 import (
+	"container/list"
+	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 	"s1d3sw1ped/SteamCache2/steamcache/logger"
 	"s1d3sw1ped/SteamCache2/vfs"
 	"s1d3sw1ped/SteamCache2/vfs/vfserror"
+	"strings"
 	"sync"
 	"time"

 	"github.com/docker/go-units"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	diskCapacityBytes = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "disk_cache_capacity_bytes",
+			Help: "Total capacity of the disk cache in bytes",
+		},
+	)
+
+	diskSizeBytes = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "disk_cache_size_bytes",
+			Help: "Total size of the disk cache in bytes",
+		},
+	)
+
+	diskReadBytes = promauto.NewCounter(
+		prometheus.CounterOpts{
+			Name: "disk_cache_read_bytes_total",
+			Help: "Total number of bytes read from the disk cache",
+		},
+	)
+
+	diskWriteBytes = promauto.NewCounter(
+		prometheus.CounterOpts{
+			Name: "disk_cache_write_bytes_total",
+			Help: "Total number of bytes written to the disk cache",
+		},
+	)
 )

 // Ensure DiskFS implements VFS.
@@ -21,24 +58,92 @@ type DiskFS struct {

 	info     map[string]*vfs.FileInfo
 	capacity int64
-	mu       sync.Mutex
-	sg       sync.WaitGroup
+	size     int64
+	mu       sync.RWMutex
+	keyLocks sync.Map // map[string]*sync.RWMutex
+	LRU      *lruList
+}
+
+// lruList for LRU eviction
+type lruList struct {
+	list *list.List
+	elem map[string]*list.Element
+}
+
+func newLruList() *lruList {
+	return &lruList{
+		list: list.New(),
+		elem: make(map[string]*list.Element),
+	}
+}
+
+func (l *lruList) MoveToFront(key string) {
+	if e, ok := l.elem[key]; ok {
+		l.list.MoveToFront(e)
+	}
+}
+
+func (l *lruList) Add(key string, fi *vfs.FileInfo) *list.Element {
+	e := l.list.PushFront(fi)
+	l.elem[key] = e
+	return e
+}
+
+func (l *lruList) Remove(key string) {
+	if e, ok := l.elem[key]; ok {
+		l.list.Remove(e)
+		delete(l.elem, key)
+	}
+}
+
+func (l *lruList) Back() *vfs.FileInfo {
+	if e := l.list.Back(); e != nil {
+		return e.Value.(*vfs.FileInfo)
+	}
+	return nil
 }

 // New creates a new DiskFS.
 func new(root string, capacity int64, skipinit bool) *DiskFS {
+	if capacity <= 0 {
+		panic("disk capacity must be greater than 0") // panic if the capacity is less than or equal to 0
+	}
+
+	if root == "" {
+		panic("disk root must not be empty") // panic if the root is empty
+	}
+
+	fi, err := os.Stat(root)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			panic(err) // panic if the error is something other than not found
+		}
+		os.Mkdir(root, 0755)    // create the root directory if it does not exist
+		fi, err = os.Stat(root) // re-stat to get the file info
+		if err != nil {
+			panic(err) // panic if the re-stat fails
+		}
+	}
+	if !fi.IsDir() {
+		panic("disk root must be a directory") // panic if the root is not a directory
+	}
+
 	dfs := &DiskFS{
 		root:     root,
 		info:     make(map[string]*vfs.FileInfo),
 		capacity: capacity,
-		mu:       sync.Mutex{},
-		sg:       sync.WaitGroup{},
+		mu:       sync.RWMutex{},
+		keyLocks: sync.Map{},
+		LRU:      newLruList(),
 	}

 	os.MkdirAll(dfs.root, 0755)

+	diskCapacityBytes.Set(float64(dfs.capacity))
+
 	if !skipinit {
 		dfs.init()
+		diskSizeBytes.Set(float64(dfs.Size()))
 	}

 	return dfs
@@ -53,43 +158,39 @@ func NewSkipInit(root string, capacity int64) *DiskFS {
 }

 func (d *DiskFS) init() {
-	// logger.Logger.Info().Str("name", d.Name()).Str("root", d.root).Str("capacity", units.HumanSize(float64(d.capacity))).Msg("init")
-
 	tstart := time.Now()

-	d.walk(d.root)
-	d.sg.Wait()
-
-	logger.Logger.Info().Str("name", d.Name()).Str("root", d.root).Str("capacity", units.HumanSize(float64(d.capacity))).Str("duration", time.Since(tstart).String()).Msg("init")
-}
-
-func (d *DiskFS) walk(path string) {
-	d.sg.Add(1)
-	go func() {
-		defer d.sg.Done()
-		filepath.Walk(path, func(npath string, info os.FileInfo, err error) error {
-			if path == npath {
-				return nil
-			}
-
+	err := filepath.Walk(d.root, func(npath string, info os.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}

 		if info.IsDir() {
-				d.walk(npath)
-				return filepath.SkipDir
+			return nil
 		}

 		d.mu.Lock()
-			k := npath[len(d.root)+1:]
-			d.info[k] = vfs.NewFileInfoFromOS(info, k)
+		k := strings.ReplaceAll(npath[len(d.root)+1:], "\\", "/")
+		fi := vfs.NewFileInfoFromOS(info, k)
+		d.info[k] = fi
+		d.LRU.Add(k, fi)
+		d.size += info.Size()
 		d.mu.Unlock()

-			// logger.Logger.Debug().Str("name", d.Name()).Str("root", d.root).Str("capacity", units.HumanSize(float64(d.capacity))).Str("path", npath).Msg("init")
 		return nil
 	})
-	}()
+	if err != nil {
+		logger.Logger.Error().Err(err).Msg("Walk failed")
+	}
+
+	logger.Logger.Info().
+		Str("name", d.Name()).
+		Str("root", d.root).
+		Str("capacity", units.HumanSize(float64(d.capacity))).
+		Str("size", units.HumanSize(float64(d.Size()))).
+		Str("files", fmt.Sprint(len(d.info))).
+		Str("duration", time.Since(tstart).String()).
+		Msg("init")
 }

 func (d *DiskFS) Capacity() int64 {
@@ -101,108 +202,259 @@ func (d *DiskFS) Name() string {
 }

 func (d *DiskFS) Size() int64 {
-	var size int64
-	d.mu.Lock()
-	defer d.mu.Unlock()
-	for _, v := range d.info {
-		size += v.Size()
-	}
-	return size
+	d.mu.RLock()
+	defer d.mu.RUnlock()
+	return d.size
 }

-func (d *DiskFS) Set(key string, src []byte) error {
+func (d *DiskFS) getKeyLock(key string) *sync.RWMutex {
+	mu, _ := d.keyLocks.LoadOrStore(key, &sync.RWMutex{})
+	return mu.(*sync.RWMutex)
+}
+
+func (d *DiskFS) Create(key string, size int64) (io.WriteCloser, error) {
+	if key == "" {
+		return nil, vfserror.ErrInvalidKey
+	}
+	if key[0] == '/' {
+		return nil, vfserror.ErrInvalidKey
+	}
+
+	// Sanitize key to prevent path traversal
+	key = filepath.Clean(key)
+	key = strings.ReplaceAll(key, "\\", "/") // Ensure forward slashes for consistency
+	if strings.Contains(key, "..") {
+		return nil, vfserror.ErrInvalidKey
+	}
+
+	d.mu.RLock()
 	if d.capacity > 0 {
-		if size := d.Size() + int64(len(src)); size > d.capacity {
-			return vfserror.ErrDiskFull
+		if d.size+size > d.capacity {
+			d.mu.RUnlock()
+			return nil, vfserror.ErrDiskFull
 		}
 	}
+	d.mu.RUnlock()

-	if _, err := d.Stat(key); err == nil {
-		d.Delete(key)
-	}
+	keyMu := d.getKeyLock(key)
+	keyMu.Lock()
+	defer keyMu.Unlock()

+	// Check again after lock
 	d.mu.Lock()
-	defer d.mu.Unlock()
-	os.MkdirAll(filepath.Join(d.root, filepath.Dir(key)), 0755)
-	if err := os.WriteFile(filepath.Join(d.root, key), src, 0644); err != nil {
+	if fi, exists := d.info[key]; exists {
+		d.size -= fi.Size()
+		d.LRU.Remove(key)
+		delete(d.info, key)
+		path := filepath.Join(d.root, key)
+		os.Remove(path) // Ignore error, as file might not exist or other issues
+	}
+	d.mu.Unlock()
+
+	path := filepath.Join(d.root, key)
+	path = strings.ReplaceAll(path, "\\", "/") // Ensure forward slashes for consistency
+	dir := filepath.Dir(path)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return nil, err
+	}
+
+	file, err := os.Create(path)
+	if err != nil {
+		return nil, err
+	}
+
+	return &diskWriteCloser{
+		Writer: file,
+		onClose: func(n int64) error {
+			fi, err := os.Stat(path)
+			if err != nil {
+				os.Remove(path)
 				return err
 			}

-	fi, err := os.Stat(filepath.Join(d.root, key))
-	if err != nil {
-		panic(err)
-	}
+			d.mu.Lock()
+			finfo := vfs.NewFileInfoFromOS(fi, key)
+			d.info[key] = finfo
+			d.LRU.Add(key, finfo)
+			d.size += n
+			d.mu.Unlock()

-	d.info[key] = vfs.NewFileInfoFromOS(fi, key)
+			diskWriteBytes.Add(float64(n))
+			diskSizeBytes.Set(float64(d.Size()))

 			return nil
+		},
+		key:  key,
+		file: file,
+	}, nil
+}
+
+type diskWriteCloser struct {
+	io.Writer
+	onClose func(int64) error
+	n       int64
+	key     string
+	file    *os.File
+}
+
+func (wc *diskWriteCloser) Write(p []byte) (int, error) {
+	n, err := wc.Writer.Write(p)
+	wc.n += int64(n)
+	return n, err
+}
+
+func (wc *diskWriteCloser) Close() error {
+	err := wc.file.Close()
+	if e := wc.onClose(wc.n); e != nil {
+		os.Remove(wc.file.Name())
+		return e
+	}
+	return err
 }

 // Delete deletes the value of key.
 func (d *DiskFS) Delete(key string) error {
-	_, err := d.Stat(key)
-	if err != nil {
+	if key == "" {
+		return vfserror.ErrInvalidKey
+	}
+	if key[0] == '/' {
+		return vfserror.ErrInvalidKey
+	}
+
+	// Sanitize key to prevent path traversal
+	key = filepath.Clean(key)
+	key = strings.ReplaceAll(key, "\\", "/") // Ensure forward slashes for consistency
+	if strings.Contains(key, "..") {
+		return vfserror.ErrInvalidKey
+	}
+
+	keyMu := d.getKeyLock(key)
+	keyMu.Lock()
+	defer keyMu.Unlock()
+
+	d.mu.Lock()
+	fi, exists := d.info[key]
+	if !exists {
+		d.mu.Unlock()
+		return vfserror.ErrNotFound
+	}
+	d.size -= fi.Size()
+	d.LRU.Remove(key)
+	delete(d.info, key)
+	d.mu.Unlock()
+
+	path := filepath.Join(d.root, key)
+	path = strings.ReplaceAll(path, "\\", "/") // Ensure forward slashes for consistency
+	if err := os.Remove(path); err != nil {
 		return err
 	}

-	d.mu.Lock()
-	defer d.mu.Unlock()
-	delete(d.info, key)
-	if err := os.Remove(filepath.Join(d.root, key)); err != nil {
-		return err
-	}
+	diskSizeBytes.Set(float64(d.Size()))

 	return nil
 }

-// Get gets the value of key and returns it.
-func (d *DiskFS) Get(key string) ([]byte, error) {
-	_, err := d.Stat(key)
-	if err != nil {
-		return nil, err
+// Open opens the file at key and returns it.
+func (d *DiskFS) Open(key string) (io.ReadCloser, error) {
+	if key == "" {
+		return nil, vfserror.ErrInvalidKey
 	}
+	if key[0] == '/' {
+		return nil, vfserror.ErrInvalidKey
+	}
+
+	// Sanitize key to prevent path traversal
+	key = filepath.Clean(key)
+	key = strings.ReplaceAll(key, "\\", "/") // Ensure forward slashes for consistency
+	if strings.Contains(key, "..") {
+		return nil, vfserror.ErrInvalidKey
+	}
+
+	keyMu := d.getKeyLock(key)
+	keyMu.RLock()
+	defer keyMu.RUnlock()

 	d.mu.Lock()
-	defer d.mu.Unlock()
+	fi, exists := d.info[key]
+	if !exists {
+		d.mu.Unlock()
+		return nil, vfserror.ErrNotFound
+	}
+	fi.ATime = time.Now()
+	d.LRU.MoveToFront(key)
+	d.mu.Unlock()

-	data, err := os.ReadFile(filepath.Join(d.root, key))
+	path := filepath.Join(d.root, key)
+	path = strings.ReplaceAll(path, "\\", "/") // Ensure forward slashes for consistency
+	file, err := os.Open(path)
 	if err != nil {
 		return nil, err
 	}

-	return data, nil
+	// Update metrics on close
+	return &readCloser{
+		ReadCloser: file,
+		onClose: func(n int64) {
+			diskReadBytes.Add(float64(n))
+		},
+	}, nil
+}
+
+type readCloser struct {
+	io.ReadCloser
+	onClose func(int64)
+	n       int64
+}
+
+func (rc *readCloser) Read(p []byte) (int, error) {
+	n, err := rc.ReadCloser.Read(p)
+	rc.n += int64(n)
+	return n, err
+}
+
+func (rc *readCloser) Close() error {
+	err := rc.ReadCloser.Close()
+	rc.onClose(rc.n)
+	return err
 }

 // Stat returns the FileInfo of key. If key is not found in the cache, it will stat the file on disk. If the file is not found on disk, it will return vfs.ErrNotFound.
 func (d *DiskFS) Stat(key string) (*vfs.FileInfo, error) {
-	d.mu.Lock()
-	fi, ok := d.info[key]
-	d.mu.Unlock() // unlock before statting the file
+	if key == "" {
+		return nil, vfserror.ErrInvalidKey
+	}
+	if key[0] == '/' {
+		return nil, vfserror.ErrInvalidKey
+	}

-	if !ok {
-		fii, err := os.Stat(filepath.Join(d.root, key))
-		if err != nil {
+	// Sanitize key to prevent path traversal
+	key = filepath.Clean(key)
+	key = strings.ReplaceAll(key, "\\", "/") // Ensure forward slashes for consistency
+	if strings.Contains(key, "..") {
+		return nil, vfserror.ErrInvalidKey
+	}
+
+	keyMu := d.getKeyLock(key)
+	keyMu.RLock()
+	defer keyMu.RUnlock()
+
+	d.mu.RLock()
+	defer d.mu.RUnlock()
+
+	if fi, ok := d.info[key]; !ok {
 		return nil, vfserror.ErrNotFound
-		}
-
-		d.mu.Lock()         // relock to update the info map
-		defer d.mu.Unlock() // nothing else needs to unlock before returning
-
-		d.info[key] = vfs.NewFileInfoFromOS(fii, key)
-		fi = d.info[key]
-		// fallthrough to return fi with shiny new info
-	}
-
+	} else {
 		return fi, nil
+	}
 }

-func (m *DiskFS) StatAll() []*vfs.FileInfo {
-	m.mu.Lock()
-	defer m.mu.Unlock()
+func (d *DiskFS) StatAll() []*vfs.FileInfo {
+	d.mu.RLock()
+	defer d.mu.RUnlock()

 	// hard copy the file info to prevent modification of the original file info or the other way around
-	files := make([]*vfs.FileInfo, 0, len(m.info))
-	for _, v := range m.info {
+	files := make([]*vfs.FileInfo, 0, len(d.info))
+	for _, v := range d.info {
 		fi := *v
 		files = append(files, &fi)
 	}
--- a/vfs/disk/disk_test.go
+++ b/vfs/disk/disk_test.go
@@ -1,87 +1,181 @@
+// vfs/disk/disk_test.go
 package disk

 import (
+	"errors"
 	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 	"s1d3sw1ped/SteamCache2/vfs/vfserror"
 	"testing"
 )

-func TestAllDisk(t *testing.T) {
-	t.Parallel()
-
+func TestCreateAndOpen(t *testing.T) {
 	m := NewSkipInit(t.TempDir(), 1024)
-	if err := m.Set("key", []byte("value")); err != nil {
-		t.Errorf("Set failed: %v", err)
-	}
+	key := "key"
+	value := []byte("value")

-	if err := m.Set("key", []byte("value1")); err != nil {
-		t.Errorf("Set failed: %v", err)
+	w, err := m.Create(key, int64(len(value)))
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
 	}
+	w.Write(value)
+	w.Close()

-	if d, err := m.Get("key"); err != nil {
-		t.Errorf("Get failed: %v", err)
-	} else if string(d) != "value1" {
-		t.Errorf("Get failed: got %s, want %s", d, "value1")
+	rc, err := m.Open(key)
+	if err != nil {
+		t.Fatalf("Open failed: %v", err)
 	}
+	got, _ := io.ReadAll(rc)
+	rc.Close()

-	if err := m.Delete("key"); err != nil {
-		t.Errorf("Delete failed: %v", err)
-	}
-
-	if _, err := m.Get("key"); err == nil {
-		t.Errorf("Get failed: got nil, want %v", vfserror.ErrNotFound)
-	}
-
-	if err := m.Delete("key"); err == nil {
-		t.Errorf("Delete failed: got nil, want %v", vfserror.ErrNotFound)
-	}
-
-	if _, err := m.Stat("key"); err == nil {
-		t.Errorf("Stat failed: got nil, want %v", vfserror.ErrNotFound)
-	}
-
-	if err := m.Set("key", []byte("value")); err != nil {
-		t.Errorf("Set failed: %v", err)
-	}
-
-	if _, err := m.Stat("key"); err != nil {
-		t.Errorf("Stat failed: %v", err)
+	if string(got) != string(value) {
+		t.Fatalf("expected %s, got %s", value, got)
 	}
 }

-func TestLimited(t *testing.T) {
-	t.Parallel()
+func TestOverwrite(t *testing.T) {
+	m := NewSkipInit(t.TempDir(), 1024)
+	key := "key"
+	value1 := []byte("value1")
+	value2 := []byte("value2")

+	w, err := m.Create(key, int64(len(value1)))
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
+	}
+	w.Write(value1)
+	w.Close()
+
+	w, err = m.Create(key, int64(len(value2)))
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
+	}
+	w.Write(value2)
+	w.Close()
+
+	rc, err := m.Open(key)
+	if err != nil {
+		t.Fatalf("Open failed: %v", err)
+	}
+	got, _ := io.ReadAll(rc)
+	rc.Close()
+
+	if string(got) != string(value2) {
+		t.Fatalf("expected %s, got %s", value2, got)
+	}
+}
+
+func TestDelete(t *testing.T) {
+	m := NewSkipInit(t.TempDir(), 1024)
+	key := "key"
+	value := []byte("value")
+
+	w, err := m.Create(key, int64(len(value)))
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
+	}
+	w.Write(value)
+	w.Close()
+
+	if err := m.Delete(key); err != nil {
+		t.Fatalf("Delete failed: %v", err)
+	}
+
+	_, err = m.Open(key)
+	if !errors.Is(err, vfserror.ErrNotFound) {
+		t.Fatalf("expected %v, got %v", vfserror.ErrNotFound, err)
+	}
+}
+
+func TestCapacityLimit(t *testing.T) {
 	m := NewSkipInit(t.TempDir(), 10)
 	for i := 0; i < 11; i++ {
-		if err := m.Set(fmt.Sprintf("key%d", i), []byte("1")); err != nil && i < 10 {
-			t.Errorf("Set failed: %v", err)
+		w, err := m.Create(fmt.Sprintf("key%d", i), 1)
+		if err != nil && i < 10 {
+			t.Errorf("Create failed: %v", err)
 		} else if i == 10 && err == nil {
-			t.Errorf("Set succeeded: got nil, want %v", vfserror.ErrDiskFull)
+			t.Errorf("Create succeeded: got nil, want %v", vfserror.ErrDiskFull)
+		}
+		if i < 10 {
+			w.Write([]byte("1"))
+			w.Close()
 		}
 	}
 }

-func TestInit(t *testing.T) {
-	t.Parallel()
-
+func TestInitExistingFiles(t *testing.T) {
 	td := t.TempDir()

 	path := filepath.Join(td, "test", "key")
-
 	os.MkdirAll(filepath.Dir(path), 0755)
-
 	os.WriteFile(path, []byte("value"), 0644)

 	m := New(td, 10)
-	if _, err := m.Get("test/key"); err != nil {
-		t.Errorf("Get failed: %v", err)
+	rc, err := m.Open("test/key")
+	if err != nil {
+		t.Fatalf("Open failed: %v", err)
+	}
+	got, _ := io.ReadAll(rc)
+	rc.Close()
+
+	if string(got) != "value" {
+		t.Errorf("expected value, got %s", got)
 	}

-	s, _ := m.Stat("test/key")
-	if s.Name() != "test/key" {
-		t.Errorf("Stat failed: got %s, want %s", s.Name(), "key")
+	s, err := m.Stat("test/key")
+	if err != nil {
+		t.Fatalf("Stat failed: %v", err)
+	}
+	if s == nil {
+		t.Error("Stat returned nil")
+	}
+	if s != nil && s.Name() != "test/key" {
+		t.Errorf("Stat failed: got %s, want %s", s.Name(), "test/key")
+	}
+}
+
+func TestSizeConsistency(t *testing.T) {
+	td := t.TempDir()
+	os.WriteFile(filepath.Join(td, "key2"), []byte("value2"), 0644)
+
+	m := New(td, 1024)
+	if m.Size() != 6 {
+		t.Errorf("Size failed: got %d, want 6", m.Size())
+	}
+
+	w, err := m.Create("key", 5)
+	if err != nil {
+		t.Errorf("Create failed: %v", err)
+	}
+	w.Write([]byte("value"))
+	w.Close()
+
+	w, err = m.Create("key1", 6)
+	if err != nil {
+		t.Errorf("Create failed: %v", err)
+	}
+	w.Write([]byte("value1"))
+	w.Close()
+
+	assumedSize := int64(6 + 5 + 6)
+	if assumedSize != m.Size() {
+		t.Errorf("Size failed: got %d, want %d", m.Size(), assumedSize)
+	}
+
+	rc, err := m.Open("key")
+	if err != nil {
+		t.Errorf("Open failed: %v", err)
+	}
+	d, _ := io.ReadAll(rc)
+	rc.Close()
+	if string(d) != "value" {
+		t.Errorf("Get failed: got %s, want value", d)
+	}
+
+	m = New(td, 1024)
+	if assumedSize != m.Size() {
+		t.Errorf("Size failed: got %d, want %d", m.Size(), assumedSize)
 	}
 }
--- a/vfs/fileinfo.go
+++ b/vfs/fileinfo.go
@@ -1,3 +1,4 @@
+// vfs/fileinfo.go
 package vfs

 import (
@@ -12,9 +13,9 @@ type FileInfo struct {
 	ATime time.Time
 }

-func NewFileInfo(name string, size int64, modTime time.Time) *FileInfo {
+func NewFileInfo(key string, size int64, modTime time.Time) *FileInfo {
 	return &FileInfo{
-		name:  name,
+		name:  key,
 		size:  size,
 		MTime: modTime,
 		ATime: time.Now(),
--- a/vfs/gc/gc.go
+++ b/vfs/gc/gc.go
@@ -1,42 +1,108 @@
+// vfs/gc/gc.go
 package gc

 import (
 	"fmt"
+	"io"
+	"s1d3sw1ped/SteamCache2/steamcache/logger"
 	"s1d3sw1ped/SteamCache2/vfs"
+	"s1d3sw1ped/SteamCache2/vfs/cachestate"
+	"s1d3sw1ped/SteamCache2/vfs/disk"
+	"s1d3sw1ped/SteamCache2/vfs/memory"
 	"s1d3sw1ped/SteamCache2/vfs/vfserror"
+	"time"
 )

+var (
+	// ErrInsufficientSpace is returned when there are no files to delete in the VFS.
+	ErrInsufficientSpace = fmt.Errorf("no files to delete")
+)
+
+// LRUGC deletes files in LRU order until enough space is reclaimed.
+func LRUGC(vfss vfs.VFS, size uint) error {
+	logger.Logger.Debug().Uint("target", size).Msg("Attempting to reclaim space using LRU GC")
+
+	var reclaimed uint // reclaimed space in bytes
+
+	for {
+		switch fs := vfss.(type) {
+		case *disk.DiskFS:
+			fi := fs.LRU.Back()
+			if fi == nil {
+				return ErrInsufficientSpace // No files to delete
+			}
+			sz := uint(fi.Size())
+			err := fs.Delete(fi.Name())
+			if err != nil {
+				continue // If delete fails, try the next file
+			}
+			reclaimed += sz
+		case *memory.MemoryFS:
+			fi := fs.LRU.Back()
+			if fi == nil {
+				return ErrInsufficientSpace // No files to delete
+			}
+			sz := uint(fi.Size())
+			err := fs.Delete(fi.Name())
+			if err != nil {
+				continue // If delete fails, try the next file
+			}
+			reclaimed += sz
+		default:
+			panic("unreachable: unsupported VFS type for LRU GC") // panic if the VFS is not disk or memory
+		}
+
+		if reclaimed >= size {
+			logger.Logger.Debug().Uint("target", size).Uint("achieved", reclaimed).Msg("Reclaimed enough space using LRU GC")
+			return nil // stop if enough space is reclaimed
+		}
+	}
+}
+
+func PromotionDecider(fi *vfs.FileInfo, cs cachestate.CacheState) bool {
+	return time.Since(fi.AccessTime()) < time.Second*60 // Put hot files in the fast vfs if equipped
+}
+
 // Ensure GCFS implements VFS.
 var _ vfs.VFS = (*GCFS)(nil)

 // GCFS is a virtual file system that calls a GC handler when the disk is full. The GC handler is responsible for freeing up space on the disk. The GCFS is a wrapper around another VFS.
 type GCFS struct {
 	vfs.VFS
-	multiplier   int
+
 	gcHanderFunc GCHandlerFunc
 }

 // GCHandlerFunc is a function that is called when the disk is full and the GCFS needs to free up space. It is passed the VFS and the size of the file that needs to be written. Its up to the implementation to free up space. How much space is freed is also up to the implementation.
-type GCHandlerFunc func(vfs vfs.VFS, size int)
+type GCHandlerFunc func(vfs vfs.VFS, size uint) error

-func New(vfs vfs.VFS, multiplier int, gcHandlerFunc GCHandlerFunc) *GCFS {
+func New(vfs vfs.VFS, gcHandlerFunc GCHandlerFunc) *GCFS {
 	return &GCFS{
 		VFS:          vfs,
-		multiplier:   multiplier,
 		gcHanderFunc: gcHandlerFunc,
 	}
 }

-// Set overrides the Set method of the VFS interface. It tries to set the key and src, if it fails due to disk full error, it calls the GC handler and tries again. If it still fails it returns the error.
-func (g *GCFS) Set(key string, src []byte) error {
-	err := g.VFS.Set(key, src) // try to set the key and src
-
-	if err == vfserror.ErrDiskFull && g.gcHanderFunc != nil { // if the error is disk full and there is a GC handler
-		g.gcHanderFunc(g.VFS, len(src)*g.multiplier) // call the GC handler
-		err = g.VFS.Set(key, src)                    // try again after GC if it still fails return the error
+// Create overrides the Create method of the VFS interface. It tries to create the key, if it fails due to disk full error, it calls the GC handler and tries again. If it still fails it returns the error.
+func (g *GCFS) Create(key string, size int64) (io.WriteCloser, error) {
+	w, err := g.VFS.Create(key, size)                          // try to create the key
+	for err == vfserror.ErrDiskFull && g.gcHanderFunc != nil { // if the error is disk full and there is a GC handler
+		errr := g.gcHanderFunc(g.VFS, uint(size)) // call the GC handler
+		if errr == ErrInsufficientSpace {
+			return nil, errr // if the GC handler returns no files to delete, return the error
+		}
+		w, err = g.VFS.Create(key, size)
 	}

-	return err
+	if err != nil {
+		if err == vfserror.ErrDiskFull {
+			logger.Logger.Error().Str("key", key).Int64("size", size).Msg("Failed to create file due to disk full, even after GC")
+		} else {
+			logger.Logger.Error().Str("key", key).Int64("size", size).Err(err).Msg("Failed to create file")
+		}
+	}
+
+	return w, err
 }

 func (g *GCFS) Name() string {
--- a/vfs/gc/gc_test.go
+++ b/vfs/gc/gc_test.go
@@ -1,111 +1,72 @@
+// vfs/gc/gc_test.go
 package gc

 import (
+	"errors"
 	"fmt"
-	"s1d3sw1ped/SteamCache2/vfs"
 	"s1d3sw1ped/SteamCache2/vfs/memory"
-	"sort"
 	"testing"
-	"time"
-
-	"golang.org/x/exp/rand"
 )

-func TestGCSmallRandom(t *testing.T) {
-	t.Parallel()
+func TestGCOnFull(t *testing.T) {
+	m := memory.New(10)
+	gc := New(m, LRUGC)

-	m := memory.New(1024 * 1024 * 16)
-	gc := New(m, 10, func(vfs vfs.VFS, size int) {
-		tstart := time.Now()
-		deletions := 0
-		targetreclaim := int64(size)
-		var reclaimed int64
-
-		t.Logf("GC starting to reclaim %d bytes", targetreclaim)
-
-		stats := vfs.StatAll()
-		sort.Slice(stats, func(i, j int) bool {
-			// Sort by access time so we can remove the oldest files first.
-			return stats[i].AccessTime().Before(stats[j].AccessTime())
-		})
-
-		// Delete the oldest files until we've reclaimed enough space.
-		for _, s := range stats {
-			sz := s.Size() // Get the size of the file
-			err := vfs.Delete(s.Name())
+	for i := 0; i < 5; i++ {
+		w, err := gc.Create(fmt.Sprintf("key%d", i), 2)
 		if err != nil {
-				panic(err)
-			}
-			reclaimed += sz // Track how much space we've reclaimed
-			deletions++     // Track how many files we've deleted
-
-			// t.Logf("GC deleting %s, %v", s.Name(), s.AccessTime().Format(time.RFC3339Nano))
-
-			if reclaimed >= targetreclaim { // We've reclaimed enough space
-				break
+			t.Fatalf("Create failed: %v", err)
 		}
+		w.Write([]byte("ab"))
+		w.Close()
 	}

-		t.Logf("GC took %v to reclaim %d bytes by deleting %d files", time.Since(tstart), reclaimed, deletions)
-	})
-
-	for i := 0; i < 10000; i++ {
-		if err := gc.Set(fmt.Sprintf("key:%d", i), genRandomData(1024*1, 1024*4)); err != nil {
-			t.Errorf("Set failed: %v", err)
+	// Cache full at 10 bytes
+	w, err := gc.Create("key5", 2)
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
 	}
+	w.Write([]byte("cd"))
+	w.Close()
+
+	if gc.Size() > 10 {
+		t.Errorf("Size exceeded: %d > 10", gc.Size())
 	}

-	if gc.Size() > 1024*1024*16 {
-		t.Errorf("MemoryFS size is %d, want <= 1024", m.Size())
+	// Check if older keys were evicted
+	_, err = m.Open("key0")
+	if err == nil {
+		t.Error("Expected key0 to be evicted")
 	}
 }

-func genRandomData(min int, max int) []byte {
-	data := make([]byte, rand.Intn(max-min)+min)
-	rand.Read(data)
-	return data
-}
+func TestNoGCNeeded(t *testing.T) {
+	m := memory.New(20)
+	gc := New(m, LRUGC)

-func TestGCLargeRandom(t *testing.T) {
-	t.Parallel()
-
-	m := memory.New(1024 * 1024 * 16) // 16MB
-	gc := New(m, 10, func(vfs vfs.VFS, size int) {
-		tstart := time.Now()
-		deletions := 0
-		targetreclaim := int64(size)
-		var reclaimed int64
-
-		t.Logf("GC starting to reclaim %d bytes", targetreclaim)
-
-		stats := vfs.StatAll()
-		sort.Slice(stats, func(i, j int) bool {
-			// Sort by access time so we can remove the oldest files first.
-			return stats[i].AccessTime().Before(stats[j].AccessTime())
-		})
-
-		// Delete the oldest files until we've reclaimed enough space.
-		for _, s := range stats {
-			sz := s.Size() // Get the size of the file
-			vfs.Delete(s.Name())
-			reclaimed += sz // Track how much space we've reclaimed
-			deletions++     // Track how many files we've deleted
-
-			if reclaimed >= targetreclaim { // We've reclaimed enough space
-				break
+	for i := 0; i < 5; i++ {
+		w, err := gc.Create(fmt.Sprintf("key%d", i), 2)
+		if err != nil {
+			t.Fatalf("Create failed: %v", err)
 		}
+		w.Write([]byte("ab"))
+		w.Close()
 	}

-		t.Logf("GC took %v to reclaim %d bytes by deleting %d files", time.Since(tstart), reclaimed, deletions)
-	})
-
-	for i := 0; i < 10000; i++ {
-		if err := gc.Set(fmt.Sprintf("key:%d", i), genRandomData(1024, 1024*1024)); err != nil {
-			t.Errorf("Set failed: %v", err)
-		}
-	}
-
-	if gc.Size() > 1024*1024*16 {
-		t.Errorf("MemoryFS size is %d, want <= 1024", m.Size())
+	if gc.Size() != 10 {
+		t.Errorf("Size: got %d, want 10", gc.Size())
+	}
+}
+
+func TestGCInsufficientSpace(t *testing.T) {
+	m := memory.New(5)
+	gc := New(m, LRUGC)
+
+	w, err := gc.Create("key0", 10)
+	if err == nil {
+		w.Close()
+		t.Error("Expected ErrDiskFull")
+	} else if !errors.Is(err, ErrInsufficientSpace) {
+		t.Errorf("Unexpected error: %v", err)
 	}
 }
--- a/vfs/memory/memory.go
+++ b/vfs/memory/memory.go
@@ -1,10 +1,49 @@
+// vfs/memory/memory.go
 package memory

 import (
+	"bytes"
+	"container/list"
+	"io"
+	"s1d3sw1ped/SteamCache2/steamcache/logger"
 	"s1d3sw1ped/SteamCache2/vfs"
 	"s1d3sw1ped/SteamCache2/vfs/vfserror"
 	"sync"
 	"time"
+
+	"github.com/docker/go-units"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	memoryCapacityBytes = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "memory_cache_capacity_bytes",
+			Help: "Total capacity of the memory cache in bytes",
+		},
+	)
+
+	memorySizeBytes = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "memory_cache_size_bytes",
+			Help: "Total size of the memory cache in bytes",
+		},
+	)
+
+	memoryReadBytes = promauto.NewCounter(
+		prometheus.CounterOpts{
+			Name: "memory_cache_read_bytes_total",
+			Help: "Total number of bytes read from the memory cache",
+		},
+	)
+
+	memoryWriteBytes = promauto.NewCounter(
+		prometheus.CounterOpts{
+			Name: "memory_cache_write_bytes_total",
+			Help: "Total number of bytes written to the memory cache",
+		},
+	)
 )

 // Ensure MemoryFS implements VFS.
@@ -20,16 +59,74 @@ type file struct {
 type MemoryFS struct {
 	files    map[string]*file
 	capacity int64
-	mu       sync.Mutex
+	size     int64
+	mu       sync.RWMutex
+	keyLocks sync.Map // map[string]*sync.RWMutex
+	LRU      *lruList
+}
+
+// lruList for LRU eviction
+type lruList struct {
+	list *list.List
+	elem map[string]*list.Element
+}
+
+func newLruList() *lruList {
+	return &lruList{
+		list: list.New(),
+		elem: make(map[string]*list.Element),
+	}
+}
+
+func (l *lruList) MoveToFront(key string) {
+	if e, ok := l.elem[key]; ok {
+		l.list.MoveToFront(e)
+	}
+}
+
+func (l *lruList) Add(key string, fi *vfs.FileInfo) *list.Element {
+	e := l.list.PushFront(fi)
+	l.elem[key] = e
+	return e
+}
+
+func (l *lruList) Remove(key string) {
+	if e, ok := l.elem[key]; ok {
+		l.list.Remove(e)
+		delete(l.elem, key)
+	}
+}
+
+func (l *lruList) Back() *vfs.FileInfo {
+	if e := l.list.Back(); e != nil {
+		return e.Value.(*vfs.FileInfo)
+	}
+	return nil
 }

 // New creates a new MemoryFS.
 func New(capacity int64) *MemoryFS {
-	return &MemoryFS{
+	if capacity <= 0 {
+		panic("memory capacity must be greater than 0") // panic if the capacity is less than or equal to 0
+	}
+
+	logger.Logger.Info().
+		Str("name", "MemoryFS").
+		Str("capacity", units.HumanSize(float64(capacity))).
+		Msg("init")
+
+	mfs := &MemoryFS{
 		files:    make(map[string]*file),
 		capacity: capacity,
-		mu:       sync.Mutex{},
+		mu:       sync.RWMutex{},
+		keyLocks: sync.Map{},
+		LRU:      newLruList(),
 	}
+
+	memoryCapacityBytes.Set(float64(capacity))
+	memorySizeBytes.Set(float64(mfs.Size()))
+
+	return mfs
 }

 func (m *MemoryFS) Capacity() int64 {
@@ -41,74 +138,118 @@ func (m *MemoryFS) Name() string {
 }

 func (m *MemoryFS) Size() int64 {
-	var size int64
-
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	for _, v := range m.files {
-		size += int64(len(v.data))
-	}
-
-	return size
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return m.size
 }

-func (m *MemoryFS) Set(key string, src []byte) error {
+func (m *MemoryFS) getKeyLock(key string) *sync.RWMutex {
+	mu, _ := m.keyLocks.LoadOrStore(key, &sync.RWMutex{})
+	return mu.(*sync.RWMutex)
+}
+
+func (m *MemoryFS) Create(key string, size int64) (io.WriteCloser, error) {
+	m.mu.RLock()
 	if m.capacity > 0 {
-		if size := m.Size() + int64(len(src)); size > m.capacity {
-			return vfserror.ErrDiskFull
+		if m.size+size > m.capacity {
+			m.mu.RUnlock()
+			return nil, vfserror.ErrDiskFull
 		}
 	}
+	m.mu.RUnlock()

+	keyMu := m.getKeyLock(key)
+	keyMu.Lock()
+	defer keyMu.Unlock()
+
+	buf := &bytes.Buffer{}
+
+	return &memWriteCloser{
+		Writer: buf,
+		onClose: func() error {
+			data := buf.Bytes()
 			m.mu.Lock()
-	defer m.mu.Unlock()
-
-	m.files[key] = &file{
-		fileinfo: vfs.NewFileInfo(
-			key,
-			int64(len(src)),
-			time.Now(),
-		),
-		data: make([]byte, len(src)),
+			if f, exists := m.files[key]; exists {
+				m.size -= int64(len(f.data))
+				m.LRU.Remove(key)
 			}
-	copy(m.files[key].data, src)
+			fi := vfs.NewFileInfo(key, int64(len(data)), time.Now())
+			m.files[key] = &file{
+				fileinfo: fi,
+				data:     data,
+			}
+			m.LRU.Add(key, fi)
+			m.size += int64(len(data))
+			m.mu.Unlock()
+
+			memoryWriteBytes.Add(float64(len(data)))
+			memorySizeBytes.Set(float64(m.Size()))

 			return nil
+		},
+	}, nil
+}
+
+type memWriteCloser struct {
+	io.Writer
+	onClose func() error
+}
+
+func (wc *memWriteCloser) Close() error {
+	return wc.onClose()
 }

 func (m *MemoryFS) Delete(key string) error {
-	_, err := m.Stat(key)
-	if err != nil {
-		return err
-	}
+	keyMu := m.getKeyLock(key)
+	keyMu.Lock()
+	defer keyMu.Unlock()

 	m.mu.Lock()
-	defer m.mu.Unlock()
-
+	f, exists := m.files[key]
+	if !exists {
+		m.mu.Unlock()
+		return vfserror.ErrNotFound
+	}
+	m.size -= int64(len(f.data))
+	m.LRU.Remove(key)
 	delete(m.files, key)
+	m.mu.Unlock()
+
+	memorySizeBytes.Set(float64(m.Size()))

 	return nil
 }

-func (m *MemoryFS) Get(key string) ([]byte, error) {
-	_, err := m.Stat(key)
-	if err != nil {
-		return nil, err
-	}
+func (m *MemoryFS) Open(key string) (io.ReadCloser, error) {
+	keyMu := m.getKeyLock(key)
+	keyMu.RLock()
+	defer keyMu.RUnlock()

 	m.mu.Lock()
-	defer m.mu.Unlock()
+	f, exists := m.files[key]
+	if !exists {
+		m.mu.Unlock()
+		return nil, vfserror.ErrNotFound
+	}
+	f.fileinfo.ATime = time.Now()
+	m.LRU.MoveToFront(key)
+	dataCopy := make([]byte, len(f.data))
+	copy(dataCopy, f.data)
+	m.mu.Unlock()

-	m.files[key].fileinfo.ATime = time.Now()
-	dst := make([]byte, len(m.files[key].data))
-	copy(dst, m.files[key].data)
+	memoryReadBytes.Add(float64(len(dataCopy)))
+	memorySizeBytes.Set(float64(m.Size()))

-	return dst, nil
+	return io.NopCloser(bytes.NewReader(dataCopy)), nil
 }

 func (m *MemoryFS) Stat(key string) (*vfs.FileInfo, error) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
+	keyMu := m.getKeyLock(key)
+	keyMu.RLock()
+	defer keyMu.RUnlock()
+
+	m.mu.RLock()
+	defer m.mu.RUnlock()

 	f, ok := m.files[key]
 	if !ok {
@@ -119,8 +260,8 @@ func (m *MemoryFS) Stat(key string) (*vfs.FileInfo, error) {
 }

 func (m *MemoryFS) StatAll() []*vfs.FileInfo {
-	m.mu.Lock()
-	defer m.mu.Unlock()
+	m.mu.RLock()
+	defer m.mu.RUnlock()

 	// hard copy the file info to prevent modification of the original file info or the other way around
 	files := make([]*vfs.FileInfo, 0, len(m.files))
--- a/vfs/memory/memory_test.go
+++ b/vfs/memory/memory_test.go
@@ -1,63 +1,129 @@
+// vfs/memory/memory_test.go
 package memory

 import (
+	"errors"
 	"fmt"
+	"io"
 	"s1d3sw1ped/SteamCache2/vfs/vfserror"
 	"testing"
 )

-func TestAllMemory(t *testing.T) {
-	t.Parallel()
-
+func TestCreateAndOpen(t *testing.T) {
 	m := New(1024)
-	if err := m.Set("key", []byte("value")); err != nil {
-		t.Errorf("Set failed: %v", err)
-	}
+	key := "key"
+	value := []byte("value")

-	if err := m.Set("key", []byte("value1")); err != nil {
-		t.Errorf("Set failed: %v", err)
+	w, err := m.Create(key, int64(len(value)))
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
 	}
+	w.Write(value)
+	w.Close()

-	if d, err := m.Get("key"); err != nil {
-		t.Errorf("Get failed: %v", err)
-	} else if string(d) != "value1" {
-		t.Errorf("Get failed: got %s, want %s", d, "value1")
+	rc, err := m.Open(key)
+	if err != nil {
+		t.Fatalf("Open failed: %v", err)
 	}
+	got, _ := io.ReadAll(rc)
+	rc.Close()

-	if err := m.Delete("key"); err != nil {
-		t.Errorf("Delete failed: %v", err)
-	}
-
-	if _, err := m.Get("key"); err == nil {
-		t.Errorf("Get failed: got nil, want %v", vfserror.ErrNotFound)
-	}
-
-	if err := m.Delete("key"); err == nil {
-		t.Errorf("Delete failed: got nil, want %v", vfserror.ErrNotFound)
-	}
-
-	if _, err := m.Stat("key"); err == nil {
-		t.Errorf("Stat failed: got nil, want %v", vfserror.ErrNotFound)
-	}
-
-	if err := m.Set("key", []byte("value")); err != nil {
-		t.Errorf("Set failed: %v", err)
-	}
-
-	if _, err := m.Stat("key"); err != nil {
-		t.Errorf("Stat failed: %v", err)
+	if string(got) != string(value) {
+		t.Fatalf("expected %s, got %s", value, got)
 	}
 }

-func TestLimited(t *testing.T) {
-	t.Parallel()
+func TestOverwrite(t *testing.T) {
+	m := New(1024)
+	key := "key"
+	value1 := []byte("value1")
+	value2 := []byte("value2")

+	w, err := m.Create(key, int64(len(value1)))
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
+	}
+	w.Write(value1)
+	w.Close()
+
+	w, err = m.Create(key, int64(len(value2)))
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
+	}
+	w.Write(value2)
+	w.Close()
+
+	rc, err := m.Open(key)
+	if err != nil {
+		t.Fatalf("Open failed: %v", err)
+	}
+	got, _ := io.ReadAll(rc)
+	rc.Close()
+
+	if string(got) != string(value2) {
+		t.Fatalf("expected %s, got %s", value2, got)
+	}
+}
+
+func TestDelete(t *testing.T) {
+	m := New(1024)
+	key := "key"
+	value := []byte("value")
+
+	w, err := m.Create(key, int64(len(value)))
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
+	}
+	w.Write(value)
+	w.Close()
+
+	if err := m.Delete(key); err != nil {
+		t.Fatalf("Delete failed: %v", err)
+	}
+
+	_, err = m.Open(key)
+	if !errors.Is(err, vfserror.ErrNotFound) {
+		t.Fatalf("expected %v, got %v", vfserror.ErrNotFound, err)
+	}
+}
+
+func TestCapacityLimit(t *testing.T) {
 	m := New(10)
 	for i := 0; i < 11; i++ {
-		if err := m.Set(fmt.Sprintf("key%d", i), []byte("1")); err != nil && i < 10 {
-			t.Errorf("Set failed: %v", err)
+		w, err := m.Create(fmt.Sprintf("key%d", i), 1)
+		if err != nil && i < 10 {
+			t.Errorf("Create failed: %v", err)
 		} else if i == 10 && err == nil {
-			t.Errorf("Set succeeded: got nil, want %v", vfserror.ErrDiskFull)
+			t.Errorf("Create succeeded: got nil, want %v", vfserror.ErrDiskFull)
+		}
+		if i < 10 {
+			w.Write([]byte("1"))
+			w.Close()
 		}
 	}
 }
+
+func TestStat(t *testing.T) {
+	m := New(1024)
+	key := "key"
+	value := []byte("value")
+
+	w, err := m.Create(key, int64(len(value)))
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
+	}
+	w.Write(value)
+	w.Close()
+
+	info, err := m.Stat(key)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if info == nil {
+		t.Fatal("expected file info to be non-nil")
+	}
+	if info.Size() != int64(len(value)) {
+		t.Errorf("expected size %d, got %d", len(value), info.Size())
+	}
+}
--- a/vfs/sync/sync.go
+++ b/vfs/sync/sync.go
@@ -1,76 +0,0 @@
-package sync
-
-import (
-	"fmt"
-	"s1d3sw1ped/SteamCache2/vfs"
-	"sync"
-)
-
-// Ensure SyncFS implements VFS.
-var _ vfs.VFS = (*SyncFS)(nil)
-
-type SyncFS struct {
-	vfs vfs.VFS
-	mu  sync.RWMutex
-}
-
-func New(vfs vfs.VFS) *SyncFS {
-	return &SyncFS{
-		vfs: vfs,
-		mu:  sync.RWMutex{},
-	}
-}
-
-// Name returns the name of the file system.
-func (sfs *SyncFS) Name() string {
-	return fmt.Sprintf("SyncFS(%s)", sfs.vfs.Name())
-}
-
-// Size returns the total size of all files in the file system.
-func (sfs *SyncFS) Size() int64 {
-	sfs.mu.RLock()
-	defer sfs.mu.RUnlock()
-
-	return sfs.vfs.Size()
-}
-
-// Set sets the value of key as src.
-// Setting the same key multiple times, the last set call takes effect.
-func (sfs *SyncFS) Set(key string, src []byte) error {
-	sfs.mu.Lock()
-	defer sfs.mu.Unlock()
-
-	return sfs.vfs.Set(key, src)
-}
-
-// Delete deletes the value of key.
-func (sfs *SyncFS) Delete(key string) error {
-	sfs.mu.Lock()
-	defer sfs.mu.Unlock()
-
-	return sfs.vfs.Delete(key)
-}
-
-// Get gets the value of key to dst, and returns dst no matter whether or not there is an error.
-func (sfs *SyncFS) Get(key string) ([]byte, error) {
-	sfs.mu.RLock()
-	defer sfs.mu.RUnlock()
-
-	return sfs.vfs.Get(key)
-}
-
-// Stat returns the FileInfo of key.
-func (sfs *SyncFS) Stat(key string) (*vfs.FileInfo, error) {
-	sfs.mu.RLock()
-	defer sfs.mu.RUnlock()
-
-	return sfs.vfs.Stat(key)
-}
-
-// StatAll returns the FileInfo of all keys.
-func (sfs *SyncFS) StatAll() []*vfs.FileInfo {
-	sfs.mu.RLock()
-	defer sfs.mu.RUnlock()
-
-	return sfs.vfs.StatAll()
-}
--- a/vfs/vfs.go
+++ b/vfs/vfs.go
@@ -1,5 +1,8 @@
+// vfs/vfs.go
 package vfs

+import "io"
+
 // VFS is the interface that wraps the basic methods of a virtual file system.
 type VFS interface {
 	// Name returns the name of the file system.
@@ -8,15 +11,14 @@ type VFS interface {
 	// Size returns the total size of all files in the file system.
 	Size() int64

-	// Set sets the value of key as src.
-	// Setting the same key multiple times, the last set call takes effect.
-	Set(key string, src []byte) error
+	// Create creates a new file at key with expected size.
+	Create(key string, size int64) (io.WriteCloser, error)

 	// Delete deletes the value of key.
 	Delete(key string) error

-	// Get gets the value of key to dst, and returns dst no matter whether or not there is an error.
-	Get(key string) ([]byte, error)
+	// Open opens the file at key.
+	Open(key string) (io.ReadCloser, error)

 	// Stat returns the FileInfo of key.
 	Stat(key string) (*FileInfo, error)
--- a/vfs/vfserror/vfserror.go
+++ b/vfs/vfserror/vfserror.go
@@ -1,8 +1,12 @@
+// vfs/vfserror/vfserror.go
 package vfserror

 import "errors"

 var (
+	// ErrInvalidKey is returned when a key is invalid.
+	ErrInvalidKey = errors.New("vfs: invalid key")
+
 	// ErrUnreachable is returned when a code path is unreachable.
 	ErrUnreachable = errors.New("unreachable")
Author	SHA1	Message	Date
s1d3sw1ped	00792d87a5	Merge pull request 'fix: gc was being stupid allowing another thread to take the space it made before it could not anymore' (#5 ) from fix/gc-breaking-downloads into main All checks were successful Release Tag / release (push) Successful in 13s Details Reviewed-on: s1d3sw1ped/SteamCache2#5	2025-07-13 12:51:17 +00:00
Justin Harms	3427b8f5bc	fix: gc was being stupid allowing another thread to take the space it made before it could not anymore All checks were successful PR Check / check-and-test (pull_request) Successful in 12s Details	2025-07-13 07:50:22 -05:00
s1d3sw1ped	7f744d04b0	Merge pull request 'fix: trim query parameters from URL path in ServeHTTP to ensure cache key correctness' (#4 ) from fix/query-params into main All checks were successful Release Tag / release (push) Successful in 17s Details Reviewed-on: s1d3sw1ped/SteamCache2#4	2025-07-13 10:43:21 +00:00
Justin Harms	6c98d03ae7	fix: trim query parameters from URL path in ServeHTTP to ensure cache key correctness All checks were successful PR Check / check-and-test (pull_request) Successful in 16s Details	2025-07-13 05:42:07 -05:00
s1d3sw1ped	17ff507c89	Merge pull request 'fix: redo the whole caching functionality to make it really 420 blaze it fast' (#3 ) from fix/blazing-sun-speed into main All checks were successful Release Tag / release (push) Successful in 26s Details Reviewed-on: s1d3sw1ped/SteamCache2#3	2025-07-13 10:21:19 +00:00
Justin Harms	539f14e8ec	refactor: moved the GC stuff around and corrected all tests All checks were successful PR Check / check-and-test (pull_request) Successful in 30s Details	2025-07-13 04:20:12 -05:00
Justin Harms	1673e9554a	Refactor VFS implementation to use Create and Open methods Some checks failed PR Check / check-and-test (pull_request) Failing after 11m4s Details - Updated disk_test.go to replace Set and Get with Create and Open methods for better clarity and functionality. - Modified fileinfo.go to include package comment. - Refactored gc.go to streamline garbage collection handling and removed unused statistics. - Updated gc_test.go to comment out large random tests for future implementation. - Enhanced memory.go to implement LRU caching and metrics for memory usage. - Updated memory_test.go to replace Set and Get with Create and Open methods. - Removed sync.go as it was redundant and not utilized. - Updated vfs.go to reflect changes in the VFS interface, replacing Set and Get with Create and Open. - Added package comments to vfserror.go for consistency.	2025-07-13 03:17:22 -05:00
Justin Harms	b83836f914	fix: update log message for server startup and improve request handling in ServeHTTP All checks were successful PR Check / check-and-test (pull_request) Successful in 1m6s Details	2025-07-12 09:48:06 -05:00
Justin Harms	745856f0f4	fix: correct format key to formats in .goreleaser.yaml All checks were successful PR Check / check-and-test (pull_request) Successful in 1m4s Details	2025-07-12 09:21:56 -05:00
Justin Harms	b4d2b1305e	fix: add logging for unsupported methods and error handling in ServeHTTP All checks were successful PR Check / check-and-test (pull_request) Successful in 1m6s Details	2025-07-12 08:50:34 -05:00
s1d3sw1ped	0d263be2ca	Merge pull request 'feat: update dependencies and improve caching mechanism' (#2 ) from feature/blazing-sun-speed into main All checks were successful Release Tag / release (push) Successful in 1m17s Details Reviewed-on: s1d3sw1ped/SteamCache2#2	2025-07-12 13:18:53 +00:00
Justin Harms	63a1c21861	fix: update action versions to use main branch for consistency All checks were successful PR Check / check-and-test (pull_request) Successful in 1m13s Details	2025-07-12 07:32:35 -05:00
Justin Harms	0a73e46f90	fix: remove golangci-lint-action from PR workflow All checks were successful PR Check / check-and-test (pull_request) Successful in 1m42s Details	2025-07-12 07:16:48 -05:00
Justin Harms	6f1158edeb	fix: update action versions to use main branch for consistency Some checks failed PR Check / check-and-test (pull_request) Failing after 1m4s Details	2025-07-12 07:10:14 -05:00
Justin Harms	93b682cfa5	chore: update action versions to latest in CI workflow Some checks failed PR Check / check-and-test (pull_request) Failing after 15s Details	2025-07-12 07:08:25 -05:00
Justin Harms	f378d0e81f	feat: update dependencies and improve caching mechanism Some checks failed PR Check / check-and-test (pull_request) Failing after 2m11s Details - Added Prometheus client library for metrics collection. - Refactored garbage collection strategy from random deletion to LRU (Least Recently Used) deletion. - Introduced per-key locking in cache to prevent race conditions. - Enhanced logging with structured log messages for cache hits and misses. - Implemented a retry mechanism for upstream requests with exponential backoff. - Updated Go modules and indirect dependencies for better compatibility and performance. - Removed unused sync filesystem implementation. - Added version initialization to ensure a default version string.	2025-07-12 06:43:00 -05:00
Justin Harms	8c1bb695b8	fix: enhance logging to handle empty upstream values All checks were successful Release Tag / release (push) Successful in 10s Details	2025-01-23 11:31:28 -06:00
Justin Harms	f58951fd92	fix: removed specific to my dev setup config	2025-01-23 11:31:13 -06:00
Justin Harms	70786da8c6	fix: improve logging readability and remove configuration messages All checks were successful Release Tag / release (push) Successful in 10s Details	2025-01-23 11:25:18 -06:00
Justin Harms	e24af47697	feat: add upstream and verbose flags to command line interface All checks were successful Release Tag / release (push) Successful in 13s Details feat: add upstream support allowing to chain cache servers if needed fix: tweaked garbage collection to be better	2025-01-23 11:14:39 -06:00
Justin Harms	931c43d7a8	fix: remove draft status from release configuration All checks were successful Release Tag / release (push) Successful in 9s Details	2025-01-22 21:01:35 -06:00
Justin Harms	6fe80c82ad	fix: reduce cache hits averaging size for improved performance All checks were successful Release Tag / release (push) Successful in 9s Details	2025-01-22 20:59:24 -06:00
Justin Harms	4a69c4ba66	fix: add empty line in logging for improved readability All checks were successful Release Tag / release (push) Successful in 9s Details	2025-01-22 20:51:32 -06:00
Justin Harms	2d0fe6571d	feat: enhance garbage collection logging with total GC time and improved stat formatting All checks were successful Release Tag / release (push) Successful in 9s Details	2025-01-22 20:48:05 -06:00
Justin Harms	550948951e	feat: implement enhanced garbage collection statistics logging All checks were successful Release Tag / release (push) Successful in 12s Details	2025-01-22 20:27:12 -06:00
Justin Harms	4a23eecae0	fix: reduce log interval to 1 second for more frequent statistics updates All checks were successful Release Tag / release (push) Successful in 28s Details	2025-01-22 19:37:30 -06:00
Justin Harms	fed9bbe218	fix: go back to the old averaging All checks were successful Release Tag / release (push) Successful in 12s Details	2025-01-22 19:35:17 -06:00
Justin Harms	7401c040dc	feat: add configurations for memory only, disk only, and memory & disk modes All checks were successful Release Tag / release (push) Successful in 14s Details	2025-01-22 19:28:45 -06:00
Justin Harms	ca069a20ee	fix: track cache hits and misses in average cache state	2025-01-22 18:43:07 -06:00
Justin Harms	3e8a92b865	fix: log memory statistics only if memory is enabled All checks were successful Release Tag / release (push) Successful in 9s Details	2025-01-22 18:29:19 -06:00
Justin Harms	b7652ed7cc	fix: initialize average cache state with cleared values All checks were successful Release Tag / release (push) Successful in 9s Details	2025-01-22 18:25:16 -06:00
Justin Harms	08b8d0ce3d	fix: enhance logging for memory and disk statistics in cache	2025-01-22 18:23:53 -06:00
Justin Harms	53847db0e9	fix: improve cache state clearing and average calculation logic	2025-01-22 18:23:47 -06:00