feat: add upstream and verbose flags to command line interface

feat: add upstream support allowing to chain cache servers if needed
fix: tweaked garbage collection to be better

.gitea/workflows/release-tag.yaml

@@ -1,4 +1,4 @@
-name: Release
+name: Release Tag
 on:
   push:
     tags:
@@ -6,7 +6,6 @@ on:
 
 jobs:
   release:
-    name: Build versioned release
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4

.gitea/workflows/test-pr.yaml

@@ -1,4 +1,4 @@
-name: CI
+name: PR Check
 on:
   - pull_request
 

.goreleaser.yaml

@@ -36,8 +36,9 @@ changelog:
       - "^test:"
 
 release:
+  name_template: '{{.ProjectName}}-{{.Version}}'
   footer: >-
-
+  
     ---
 
     Released by [GoReleaser](https://github.com/goreleaser/goreleaser).

.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 +17,39 @@
                 "10G",
                 "--disk-path",
                 "tmp/disk",
+                "--upstream",
+                "http://192.168.2.88:80",
+                "--verbose",
+            ],
+        },
+        {
+            "name": "Launch Disk Only",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${workspaceFolder}/main.go",
+            "args": [
+                "--disk",
+                "10G",
+                "--disk-path",
+                "tmp/disk",
+                "--upstream",
+                "http://192.168.2.88:80",
+                "--verbose",
+            ],
+        },
+        {
+            "name": "Launch Memory Only",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "${workspaceFolder}/main.go",
+            "args": [
+                "--memory",
+                "1G",
+                "--upstream",
+                "http://192.168.2.88:80",
+                "--verbose",
             ],
         }
     ]

cmd/root.go

@@ -4,6 +4,7 @@ import (
 	"os"
 	"s1d3sw1ped/SteamCache2/steamcache"
 
+	"github.com/rs/zerolog"
 	"github.com/spf13/cobra"
 )
 
@@ -13,6 +14,10 @@ var (
 	disk             string
 	diskmultiplier   int
 	diskpath         string
+	upstream         string
+
+	pprof   bool
+	verbose bool
 )
 
 var rootCmd = &cobra.Command{
@@ -24,6 +29,10 @@ 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) {
+		if verbose {
+			zerolog.SetGlobalLevel(zerolog.DebugLevel)
+		}
+
 		sc := steamcache.New(
 			":80",
 			memory,
@@ -31,6 +40,8 @@ var rootCmd = &cobra.Command{
 			disk,
 			diskmultiplier,
 			diskpath,
+			upstream,
+			pprof,
 		)
 		sc.Run()
 	},
@@ -46,9 +57,15 @@ func Execute() {
 }
 
 func init() {
-	rootCmd.Flags().StringVarP(&memory, "memory", "m", "100MB", "The size of the memory cache")
+	rootCmd.Flags().StringVarP(&memory, "memory", "m", "0", "The size of the memory cache")
-	rootCmd.Flags().IntVarP(&memorymultiplier, "memory-multiplier", "M", 10, "The multiplier for the memory cache")
+	rootCmd.Flags().IntVarP(&memorymultiplier, "memory-gc", "M", 10, "The gc value for the memory cache")
-	rootCmd.Flags().StringVarP(&disk, "disk", "d", "10GB", "The size of the disk cache")
+	rootCmd.Flags().StringVarP(&disk, "disk", "d", "0", "The size of the disk cache")
-	rootCmd.Flags().IntVarP(&diskmultiplier, "disk-multiplier", "D", 10, "The multiplier for the disk cache")
+	rootCmd.Flags().IntVarP(&diskmultiplier, "disk-gc", "D", 100, "The gc value for the disk cache")
-	rootCmd.Flags().StringVarP(&diskpath, "disk-path", "p", "tmp/steamcache2-disk", "The path to 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().BoolVarP(&pprof, "pprof", "P", false, "Enable pprof")
+	rootCmd.Flags().MarkHidden("pprof")
+	rootCmd.Flags().BoolVarP(&verbose, "verbose", "v", false, "Enable verbose logging")
 }

steamcache/avgcachestate/avgcachestate.go

@@ -14,11 +14,15 @@ type AvgCacheState struct {
 
 // New creates a new average cache state with the given size.
 func New(size int) *AvgCacheState {
-	return &AvgCacheState{
+	a := &AvgCacheState{
 		size: size,
 		avgs: make([]cachestate.CacheState, size),
 		mu:   sync.Mutex{},
 	}
+
+	a.Clear()
+
+	return a
 }
 
 // Clear resets the average cache state to zero.
@@ -26,7 +30,9 @@ func (a *AvgCacheState) Clear() {
 	a.mu.Lock()
 	defer a.mu.Unlock()
 
-	a.avgs = make([]cachestate.CacheState, a.size) // zeroed
+	for i := 0; i < len(a.avgs); i++ {
+		a.avgs[i] = cachestate.CacheStateMiss
+	}
 }
 
 // Add adds a cache state to the average cache state.
@@ -45,16 +51,13 @@ func (a *AvgCacheState) Avg() float64 {
 	a.mu.Lock()
 	defer a.mu.Unlock()
 
-	var hits, misses int
+	var hits int
+
 	for _, cs := range a.avgs {
-		switch cs {
+		if cs == cachestate.CacheStateHit {
-		case cachestate.CacheStateHit:
 			hits++
-		case cachestate.CacheStateMiss:
-			misses++
 		}
 	}
-	total := hits + misses
 
-	return float64(hits) / float64(total)
+	return float64(hits) / float64(len(a.avgs))
 }

steamcache/gc.go

@@ -1,75 +1,49 @@
 package steamcache
 
 import (
-	"s1d3sw1ped/SteamCache2/steamcache/logger"
+	"runtime/debug"
 	"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 {
+func init() {
-	// Pick a random file to delete
+	// Set the GC percentage to 50%. This is a good balance between performance and memory usage.
-	randfile := stats[rand.Intn(len(stats))]
+	debug.SetGCPercent(50)
-	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) {
+// RandomGC randomly deletes files until we've reclaimed enough space.
-	tstart := time.Now()
+func randomgc(vfss vfs.VFS, size uint) (uint, uint) {
+	// Randomly delete files until we've reclaimed enough space.
+	random := func(vfss vfs.VFS, stats []*vfs.FileInfo) int64 {
+		randfile := stats[rand.Intn(len(stats))]
+		sz := randfile.Size()
+		err := vfss.Delete(randfile.Name())
+		if err != nil {
+			return 0
+		}
+
+		return sz
+	}
+
 	deletions := 0
 	targetreclaim := int64(size)
 	var reclaimed int64
 
 	stats := vfss.StatAll()
 	for {
-		reclaimed += randomgc(vfss, stats)
-		deletions++
 		if reclaimed >= targetreclaim {
 			break
 		}
-	}
+		reclaimed += random(vfss, stats)
-
-	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().
+	return uint(reclaimed), uint(deletions)
-		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
+	return time.Since(fi.AccessTime()) < time.Second*10 // Put hot files in the fast vfs if equipped
 }

steamcache/logger/logger.go

@@ -6,4 +6,8 @@ import (
 	"github.com/rs/zerolog"
 )
 
+func init() {
+	zerolog.SetGlobalLevel(zerolog.InfoLevel)
+}
+
 var Logger = zerolog.New(zerolog.ConsoleWriter{Out: os.Stderr}).With().Timestamp().Logger()

steamcache/steamcache.go

@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"runtime"
 	"s1d3sw1ped/SteamCache2/steamcache/avgcachestate"
 	"s1d3sw1ped/SteamCache2/steamcache/logger"
 	"s1d3sw1ped/SteamCache2/version"
@@ -20,23 +21,31 @@ import (
 	"sync"
 	"time"
 
+	pprof "net/http/pprof"
+
 	"github.com/docker/go-units"
 )
 
 type SteamCache struct {
-	address string
+	pprof    bool
-	vfs     vfs.VFS
+	address  string
+	upstream string
+
+	vfs vfs.VFS
 
 	memory *memory.MemoryFS
 	disk   *disk.DiskFS
 
+	memorygc *gc.GCFS
+	diskgc   *gc.GCFS
+
 	hits *avgcachestate.AvgCacheState
 
 	dirty bool
 	mu    sync.Mutex
 }
 
-func New(address string, memorySize string, memoryMultiplier int, diskSize string, diskMultiplier int, diskPath string) *SteamCache {
+func New(address string, memorySize string, memoryMultiplier int, diskSize string, diskMultiplier int, diskPath, upstream string, pprof bool) *SteamCache {
 	memorysize, err := units.FromHumanSize(memorySize)
 	if err != nil {
 		panic(err)
@@ -47,35 +56,66 @@ func New(address string, memorySize string, memoryMultiplier int, diskSize strin
 		panic(err)
 	}
 
-	m := memory.New(memorysize)
+	c := cache.New(
-	d := disk.New(diskPath, disksize)
+		cachehandler,
+	)
+
+	var m *memory.MemoryFS
+	var mgc *gc.GCFS
+	if memorysize > 0 {
+		m = memory.New(memorysize)
+		mgc = gc.New(m, memoryMultiplier, randomgc)
+	}
+
+	var d *disk.DiskFS
+	var dgc *gc.GCFS
+	if disksize > 0 {
+		d = disk.New(diskPath, disksize)
+		dgc = gc.New(d, diskMultiplier, randomgc)
+	}
+
+	// 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)
+		logger.Logger.Info().Bool("memory", true).Bool("disk", false).Msg("configuration")
+	} else if disksize != 0 && memorysize == 0 {
+		// disk only mode
+
+		c.SetSlow(dgc)
+		logger.Logger.Info().Bool("memory", false).Bool("disk", true).Msg("configuration")
+	} else if disksize != 0 && memorysize != 0 {
+		// memory and disk mode
+
+		c.SetFast(mgc)
+		c.SetSlow(dgc)
+		logger.Logger.Info().Bool("memory", true).Bool("disk", true).Msg("configuration")
+	} 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)
+	}
 
 	sc := &SteamCache{
-		address: address,
+		pprof:    pprof,
-		vfs: syncfs.New(
+		upstream: upstream,
-			cache.New(
+		address:  address,
-				gc.New(
+		vfs:      syncfs.New(c),
-					m,
-					memoryMultiplier,
-					memorygc,
-				),
-				gc.New(
-					d,
-					diskMultiplier,
-					diskgc,
-				),
-				cachehandler,
-			),
-		),
 
 		memory: m,
 		disk:   d,
 
-		hits: avgcachestate.New(10000),
+		memorygc: mgc,
+		diskgc:   dgc,
+
+		hits: avgcachestate.New(100),
 	}
 
-	if d.Size() > d.Capacity() {
+	if d != nil {
-		diskgc(d, int(d.Size()-d.Capacity()))
+		if d.Size() > d.Capacity() {
+			randomgc(d, uint(d.Size()-d.Capacity()))
+		}
 	}
 
 	return sc
@@ -84,12 +124,21 @@ func New(address string, memorySize string, memoryMultiplier int, diskSize strin
 func (sc *SteamCache) Run() {
 	logger.Logger.Info().Str("address", sc.address).Str("version", version.Version).Msg("listening")
 
+	if sc.upstream != "" {
+		_, err := http.Get(sc.upstream)
+		if err != nil {
+			logger.Logger.Error().Err(err).Str("upstream", sc.upstream).Msg("Failed to connect to upstream server")
+			os.Exit(1)
+		}
+		logger.Logger.Info().Str("upstream", sc.upstream).Msg("connected")
+	}
+
 	sc.mu.Lock()
 	sc.dirty = true
 	sc.mu.Unlock()
 
 	sc.LogStats()
-	t := time.NewTicker(10 * time.Second)
+	t := time.NewTicker(1 * time.Second)
 	go func() {
 		for range t.C {
 			sc.LogStats()
@@ -111,16 +160,71 @@ func (sc *SteamCache) LogStats() {
 	sc.mu.Lock()
 	defer sc.mu.Unlock()
 	if sc.dirty {
+
+		logger.Logger.Info().Msg("") // empty line to separate log entries for better readability
+
+		if sc.memory != nil { // only log memory if memory is enabled
+			lifetimeBytes, lifetimeFiles, reclaimedBytes, deletedFiles, gcTime := sc.memorygc.Stats()
+
+			logger.Logger.Info().
+				Str("size", units.HumanSize(float64(sc.memory.Size()))).
+				Str("capacity", units.HumanSize(float64(sc.memory.Capacity()))).
+				Str("files", fmt.Sprintf("%d", len(sc.memory.StatAll()))).
+				Msg("memory")
+
+			logger.Logger.Info().
+				Str("data_total", units.HumanSize(float64(lifetimeBytes))).
+				Uint("files_total", lifetimeFiles).
+				Str("data", units.HumanSize(float64(reclaimedBytes))).
+				Uint("files", deletedFiles).
+				Str("gc_time", gcTime.String()).
+				Msg("memory_gc")
+		}
+
+		if sc.disk != nil { // only log disk if disk is enabled
+			lifetimeBytes, lifetimeFiles, reclaimedBytes, deletedFiles, gcTime := sc.diskgc.Stats()
+
+			logger.Logger.Info().
+				Str("size", units.HumanSize(float64(sc.disk.Size()))).
+				Str("capacity", units.HumanSize(float64(sc.disk.Capacity()))).
+				Str("files", fmt.Sprintf("%d", len(sc.disk.StatAll()))).
+				Msg("disk")
+
+			logger.Logger.Info().
+				Str("data_total", units.HumanSize(float64(lifetimeBytes))).
+				Uint("files_total", lifetimeFiles).
+				Str("data", units.HumanSize(float64(reclaimedBytes))).
+				Uint("files", deletedFiles).
+				Str("gc_time", gcTime.String()).
+				Msg("disk_gc")
+		}
+
+		// log golang Garbage Collection stats
+		var m runtime.MemStats
+		runtime.ReadMemStats(&m)
+
+		logger.Logger.Info().
+			Str("alloc", units.HumanSize(float64(m.Alloc))).
+			Str("sys", units.HumanSize(float64(m.Sys))).
+			Msg("go_gc")
+
 		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")
+			Msg("cache")
+
 		sc.dirty = false
 	}
 }
 
 func (sc *SteamCache) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if sc.pprof && r.URL.Path == "/debug/pprof/" {
+		pprof.Index(w, r)
+		return
+	} else if sc.pprof && strings.HasPrefix(r.URL.Path, "/debug/pprof/") {
+		pprof.Handler(strings.TrimPrefix(r.URL.Path, "/debug/pprof/")).ServeHTTP(w, r)
+		return
+	}
+
 	if r.Method != http.MethodGet {
 		http.Error(w, "Only GET method is supported", http.StatusMethodNotAllowed)
 		return
@@ -133,54 +237,68 @@ 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)
-		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()
+	cacheKey := strings.ReplaceAll(r.URL.String()[1:], "\\", "/") // replace all backslashes with forward slashes shouldn't be necessary but just in case
-
+	if cacheKey == "" {
-	// if vfs is also a vfs.GetSer, we can use it to get the cache state
+		http.Error(w, "Invalid URL", http.StatusBadRequest)
+		return
+	}
 
 	data, err := sc.vfs.Get(cacheKey)
 	if err == nil {
 		sc.hits.Add(cachestate.CacheStateHit)
 		w.Header().Add("X-LanCache-Status", "HIT")
 		w.Write(data)
+		logger.Logger.Debug().Str("key", r.URL.String()).Msg("cache")
 		return
 	}
 
-	htt := "http://"
+	var req *http.Request
-	if r.Header.Get("X-Sls-Https") == "enable" {
+	if sc.upstream != "" { // if an upstream server is configured, proxy the request to the upstream server
-		htt = "https://"
+		ur, err := url.JoinPath(sc.upstream, r.URL.String())
+		if err != nil {
+			http.Error(w, "Failed to join URL path", http.StatusInternalServerError)
+			return
+		}
+
+		req, err = http.NewRequest(http.MethodGet, ur, nil)
+		if err != nil {
+			http.Error(w, "Failed to create request", http.StatusInternalServerError)
+			return
+		}
+		req.Host = r.Host
+		logger.Logger.Debug().Str("key", cacheKey).Str("host", sc.upstream).Msg("upstream")
+	} 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, r.URL.String())
+		if err != nil {
+			http.Error(w, "Failed to join URL path", http.StatusInternalServerError)
+			return
+		}
+
+		req, err = http.NewRequest(http.MethodGet, ur, nil)
+		if err != nil {
+			http.Error(w, "Failed to create request", http.StatusInternalServerError)
+			return
+		}
+
+		logger.Logger.Debug().Str("key", cacheKey).Str("host", host).Msg("forward")
 	}
 
-	base := htt + r.Host
+	req.Header.Add("X-Sls-Https", r.Header.Get("X-Sls-Https"))
-
+	req.Header.Add("User-Agent", r.Header.Get("User-Agent"))
-	hosturl, err := url.JoinPath(base, cacheKey)
+	resp, err := http.DefaultClient.Do(req)
-	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
@@ -203,40 +321,3 @@ func (sc *SteamCache) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	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)
-}

steamcache/steamcache_test.go

@@ -0,0 +1,71 @@
+package steamcache
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestCaching(t *testing.T) {
+	t.Parallel()
+
+	td := t.TempDir()
+
+	os.WriteFile(filepath.Join(td, "key2"), []byte("value2"), 0644)
+
+	sc := New("localhost:8080", "1GB", 10, "1GB", 100, td, "", false)
+
+	sc.dirty = true
+	sc.LogStats()
+
+	if err := sc.vfs.Set("key", []byte("value")); err != nil {
+		t.Errorf("Set failed: %v", err)
+	}
+	if err := sc.vfs.Set("key1", []byte("value1")); err != nil {
+		t.Errorf("Set failed: %v", err)
+	}
+
+	sc.dirty = true
+	sc.LogStats()
+
+	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)
+	}
+
+	if d, err := sc.vfs.Get("key"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else if string(d) != "value" {
+		t.Errorf("Get failed: got %s, want %s", d, "value")
+	}
+
+	if d, err := sc.vfs.Get("key1"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else if string(d) != "value1" {
+		t.Errorf("Get failed: got %s, want %s", d, "value1")
+	}
+
+	if d, err := sc.vfs.Get("key2"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else 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.Get("key2"); err == nil {
+		t.Errorf("Get failed: got nil, want error")
+	}
+}

vfs/cache/cache.go

@@ -21,23 +21,24 @@ type CacheFS struct {
 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 {
+func New(cacheHandler CacheHandler) *CacheFS {
-	if slow == nil {
-		panic("slow is nil")
-	}
-
-	if fast == slow {
-		panic("fast and slow are the same")
-	}
-
 	return &CacheFS{
-		fast: fast,
-		slow: slow,
-
 		cacheHandler: cacheHandler,
 	}
 }
 
+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
+}
+
 // cacheState returns the state of the file at key.
 func (c *CacheFS) cacheState(key string) cachestate.CacheState {
 	if c.fast != nil {

vfs/cache/cache_test.go

@@ -20,7 +20,9 @@ func TestNew(t *testing.T) {
 	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")
 	}
@@ -35,7 +37,9 @@ func TestNewPanics(t *testing.T) {
 		}
 	}()
 
-	New(nil, nil, nil)
+	cache := New(nil)
+	cache.SetFast(nil)
+	cache.SetSlow(nil)
 }
 
 func TestSetAndGet(t *testing.T) {
@@ -43,7 +47,9 @@ func TestSetAndGet(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")
@@ -66,7 +72,8 @@ func TestSetAndGetNoFast(t *testing.T) {
 	t.Parallel()
 
 	slow := testMemory()
-	cache := New(nil, slow, nil)
+	cache := New(nil)
+	cache.SetSlow(slow)
 
 	key := "test"
 	value := []byte("value")
@@ -89,9 +96,11 @@ func TestCaching(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")
@@ -148,7 +157,9 @@ func TestGetNotFound(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")
 	if !errors.Is(err, vfserror.ErrNotFound) {
@@ -161,7 +172,9 @@ func TestDelete(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")
@@ -185,7 +198,9 @@ func TestStat(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")

vfs/disk/disk.go

@@ -1,11 +1,13 @@
 package disk
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"s1d3sw1ped/SteamCache2/steamcache/logger"
 	"s1d3sw1ped/SteamCache2/vfs"
 	"s1d3sw1ped/SteamCache2/vfs/vfserror"
+	"strings"
 	"sync"
 	"time"
 
@@ -27,6 +29,24 @@ type DiskFS struct {
 
 // 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
+		}
+	}
+	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),
@@ -60,7 +80,14 @@ func (d *DiskFS) init() {
 	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")
+	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) walk(path string) {
@@ -82,7 +109,8 @@ func (d *DiskFS) walk(path string) {
 			}
 
 			d.mu.Lock()
-			k := npath[len(d.root)+1:]
+			k := strings.ReplaceAll(npath[len(d.root)+1:], "\\", "/")
+			logger.Logger.Debug().Str("name", k).Str("root", d.root).Msg("walk")
 			d.info[k] = vfs.NewFileInfoFromOS(info, k)
 			d.mu.Unlock()
 
@@ -101,9 +129,10 @@ func (d *DiskFS) Name() string {
 }
 
 func (d *DiskFS) Size() int64 {
-	var size int64
 	d.mu.Lock()
 	defer d.mu.Unlock()
+
+	var size int64
 	for _, v := range d.info {
 		size += v.Size()
 	}
@@ -111,24 +140,34 @@ func (d *DiskFS) Size() int64 {
 }
 
 func (d *DiskFS) Set(key string, src []byte) error {
+	if key == "" {
+		return vfserror.ErrInvalidKey
+	}
+	if key[0] == '/' {
+		return vfserror.ErrInvalidKey
+	}
+
 	if d.capacity > 0 {
 		if size := d.Size() + int64(len(src)); size > d.capacity {
 			return vfserror.ErrDiskFull
 		}
 	}
 
+	logger.Logger.Debug().Str("name", key).Str("root", d.root).Msg("set")
+
 	if _, err := d.Stat(key); err == nil {
+		logger.Logger.Debug().Str("name", key).Str("root", d.root).Msg("delete")
 		d.Delete(key)
 	}
 
 	d.mu.Lock()
 	defer d.mu.Unlock()
-	os.MkdirAll(filepath.Join(d.root, filepath.Dir(key)), 0755)
+	os.MkdirAll(d.root+"/"+filepath.Dir(key), 0755)
-	if err := os.WriteFile(filepath.Join(d.root, key), src, 0644); err != nil {
+	if err := os.WriteFile(d.root+"/"+key, src, 0644); err != nil {
 		return err
 	}
 
-	fi, err := os.Stat(filepath.Join(d.root, key))
+	fi, err := os.Stat(d.root + "/" + key)
 	if err != nil {
 		panic(err)
 	}
@@ -140,6 +179,13 @@ func (d *DiskFS) Set(key string, src []byte) error {
 
 // Delete deletes the value of key.
 func (d *DiskFS) Delete(key string) error {
+	if key == "" {
+		return vfserror.ErrInvalidKey
+	}
+	if key[0] == '/' {
+		return vfserror.ErrInvalidKey
+	}
+
 	_, err := d.Stat(key)
 	if err != nil {
 		return err
@@ -147,6 +193,7 @@ func (d *DiskFS) Delete(key string) error {
 
 	d.mu.Lock()
 	defer d.mu.Unlock()
+
 	delete(d.info, key)
 	if err := os.Remove(filepath.Join(d.root, key)); err != nil {
 		return err
@@ -157,6 +204,13 @@ func (d *DiskFS) Delete(key string) error {
 
 // Get gets the value of key and returns it.
 func (d *DiskFS) Get(key string) ([]byte, error) {
+	if key == "" {
+		return nil, vfserror.ErrInvalidKey
+	}
+	if key[0] == '/' {
+		return nil, vfserror.ErrInvalidKey
+	}
+
 	_, err := d.Stat(key)
 	if err != nil {
 		return nil, err
@@ -175,25 +229,23 @@ func (d *DiskFS) Get(key string) ([]byte, error) {
 
 // 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()
+	if key == "" {
-	fi, ok := d.info[key]
+		return nil, vfserror.ErrInvalidKey
-	d.mu.Unlock() // unlock before statting the file
+	}
-
+	if key[0] == '/' {
-	if !ok {
+		return nil, vfserror.ErrInvalidKey
-		fii, err := os.Stat(filepath.Join(d.root, key))
-		if err != nil {
-			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
 	}
 
-	return fi, nil
+	logger.Logger.Debug().Str("name", key).Str("root", d.root).Msg("stat")
+
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if fi, ok := d.info[key]; !ok {
+		return nil, vfserror.ErrNotFound
+	} else {
+		return fi, nil
+	}
 }
 
 func (m *DiskFS) StatAll() []*vfs.FileInfo {

vfs/disk/disk_test.go

@@ -85,3 +85,62 @@ func TestInit(t *testing.T) {
 		t.Errorf("Stat failed: got %s, want %s", s.Name(), "key")
 	}
 }
+
+func TestDiskSizeDiscrepancy(t *testing.T) {
+	t.Parallel()
+	td := t.TempDir()
+
+	assumedSize := int64(6 + 5 + 6) // 6 + 5 + 6 bytes for key, key1, key2
+	os.WriteFile(filepath.Join(td, "key2"), []byte("value2"), 0644)
+
+	m := New(td, 1024)
+	if 6 != m.Size() {
+		t.Errorf("Size failed: got %d, want %d", m.Size(), 6)
+	}
+
+	if err := m.Set("key", []byte("value")); err != nil {
+		t.Errorf("Set failed: %v", err)
+	}
+
+	if err := m.Set("key1", []byte("value1")); err != nil {
+		t.Errorf("Set failed: %v", err)
+	}
+
+	if assumedSize != m.Size() {
+		t.Errorf("Size failed: got %d, want %d", m.Size(), assumedSize)
+	}
+
+	if d, err := m.Get("key"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else if string(d) != "value" {
+		t.Errorf("Get failed: got %s, want %s", d, "value")
+	}
+
+	if d, err := m.Get("key1"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else if string(d) != "value1" {
+		t.Errorf("Get failed: got %s, want %s", d, "value1")
+	}
+
+	m = New(td, 1024)
+
+	if assumedSize != m.Size() {
+		t.Errorf("Size failed: got %d, want %d", m.Size(), assumedSize)
+	}
+
+	if d, err := m.Get("key"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else if string(d) != "value" {
+		t.Errorf("Get failed: got %s, want %s", d, "value")
+	}
+
+	if d, err := m.Get("key1"); err != nil {
+		t.Errorf("Get failed: %v", err)
+	} else if string(d) != "value1" {
+		t.Errorf("Get failed: got %s, want %s", d, "value1")
+	}
+
+	if assumedSize != m.Size() {
+		t.Errorf("Size failed: got %d, want %d", m.Size(), assumedSize)
+	}
+}

vfs/fileinfo.go

@@ -12,9 +12,9 @@ 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(),

vfs/gc/gc.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"s1d3sw1ped/SteamCache2/vfs"
 	"s1d3sw1ped/SteamCache2/vfs/vfserror"
+	"sync"
+	"time"
 )
 
 // Ensure GCFS implements VFS.
@@ -12,14 +14,23 @@ 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
+	multiplier int
-	gcHanderFunc GCHandlerFunc
+
+	// protected by mu
+	gcHanderFunc                 GCHandlerFunc
+	lifetimeBytes, lifetimeFiles uint
+	reclaimedBytes, deletedFiles uint
+	gcTime                       time.Duration
+	mu                           sync.Mutex
 }
 
 // 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) (reclaimedBytes uint, deletedFiles uint)
 
 func New(vfs vfs.VFS, multiplier int, gcHandlerFunc GCHandlerFunc) *GCFS {
+	if multiplier <= 0 {
+		multiplier = 1 // if the multiplier is less than or equal to 0 set it to 1 will be slow but the user can set it to a higher value if they want
+	}
 	return &GCFS{
 		VFS:          vfs,
 		multiplier:   multiplier,
@@ -27,13 +38,44 @@ func New(vfs vfs.VFS, multiplier int, gcHandlerFunc GCHandlerFunc) *GCFS {
 	}
 }
 
+// Stats returns the lifetime bytes, lifetime files, reclaimed bytes and deleted files.
+// The lifetime bytes and lifetime files are the total bytes and files that have been freed up by the GC handler.
+// The reclaimed bytes and deleted files are the bytes and files that have been freed up by the GC handler since last call to Stats.
+// The gc time is the total time spent in the GC handler since last call to Stats.
+// The reclaimed bytes and deleted files and gc time are reset to 0 after the call to Stats.
+func (g *GCFS) Stats() (lifetimeBytes, lifetimeFiles, reclaimedBytes, deletedFiles uint, gcTime time.Duration) {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+
+	g.lifetimeBytes += g.reclaimedBytes
+	g.lifetimeFiles += g.deletedFiles
+
+	lifetimeBytes = g.lifetimeBytes
+	lifetimeFiles = g.lifetimeFiles
+	reclaimedBytes = g.reclaimedBytes
+	deletedFiles = g.deletedFiles
+	gcTime = g.gcTime
+
+	g.reclaimedBytes = 0
+	g.deletedFiles = 0
+	g.gcTime = time.Duration(0)
+
+	return
+}
+
 // 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 {
+	g.mu.Lock()
+	defer g.mu.Unlock()
 	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
+		tstart := time.Now()
-		err = g.VFS.Set(key, src)                    // try again after GC if it still fails return the error
+		reclaimedBytes, deletedFiles := g.gcHanderFunc(g.VFS, uint(len(src)*g.multiplier)) // call the GC handler
+		g.gcTime += time.Since(tstart)
+		g.reclaimedBytes += reclaimedBytes
+		g.deletedFiles += deletedFiles
+		err = g.VFS.Set(key, src) // try again after GC if it still fails return the error
 	}
 
 	return err

vfs/gc/gc_test.go

@@ -6,7 +6,6 @@ import (
 	"s1d3sw1ped/SteamCache2/vfs/memory"
 	"sort"
 	"testing"
-	"time"
 
 	"golang.org/x/exp/rand"
 )
@@ -15,13 +14,11 @@ func TestGCSmallRandom(t *testing.T) {
 	t.Parallel()
 
 	m := memory.New(1024 * 1024 * 16)
-	gc := New(m, 10, func(vfs vfs.VFS, size int) {
+	gc := New(m, 10, func(vfs vfs.VFS, size uint) (uint, uint) {
-		tstart := time.Now()
 		deletions := 0
-		targetreclaim := int64(size)
+		var reclaimed uint
-		var reclaimed int64
 
-		t.Logf("GC starting to reclaim %d bytes", targetreclaim)
+		t.Logf("GC starting to reclaim %d bytes", size)
 
 		stats := vfs.StatAll()
 		sort.Slice(stats, func(i, j int) bool {
@@ -31,7 +28,7 @@ func TestGCSmallRandom(t *testing.T) {
 
 		// Delete the oldest files until we've reclaimed enough space.
 		for _, s := range stats {
-			sz := s.Size() // Get the size of the file
+			sz := uint(s.Size()) // Get the size of the file
 			err := vfs.Delete(s.Name())
 			if err != nil {
 				panic(err)
@@ -41,12 +38,11 @@ func TestGCSmallRandom(t *testing.T) {
 
 			// t.Logf("GC deleting %s, %v", s.Name(), s.AccessTime().Format(time.RFC3339Nano))
 
-			if reclaimed >= targetreclaim { // We've reclaimed enough space
+			if reclaimed >= size { // We've reclaimed enough space
 				break
 			}
 		}
-
+		return uint(reclaimed), uint(deletions)
-		t.Logf("GC took %v to reclaim %d bytes by deleting %d files", time.Since(tstart), reclaimed, deletions)
 	})
 
 	for i := 0; i < 10000; i++ {
@@ -70,13 +66,11 @@ func TestGCLargeRandom(t *testing.T) {
 	t.Parallel()
 
 	m := memory.New(1024 * 1024 * 16) // 16MB
-	gc := New(m, 10, func(vfs vfs.VFS, size int) {
+	gc := New(m, 10, func(vfs vfs.VFS, size uint) (uint, uint) {
-		tstart := time.Now()
 		deletions := 0
-		targetreclaim := int64(size)
+		var reclaimed uint
-		var reclaimed int64
 
-		t.Logf("GC starting to reclaim %d bytes", targetreclaim)
+		t.Logf("GC starting to reclaim %d bytes", size)
 
 		stats := vfs.StatAll()
 		sort.Slice(stats, func(i, j int) bool {
@@ -86,17 +80,17 @@ func TestGCLargeRandom(t *testing.T) {
 
 		// Delete the oldest files until we've reclaimed enough space.
 		for _, s := range stats {
-			sz := s.Size() // Get the size of the file
+			sz := uint(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
+			if reclaimed >= size { // We've reclaimed enough space
 				break
 			}
 		}
 
-		t.Logf("GC took %v to reclaim %d bytes by deleting %d files", time.Since(tstart), reclaimed, deletions)
+		return uint(reclaimed), uint(deletions)
 	})
 
 	for i := 0; i < 10000; i++ {

vfs/memory/memory.go

@@ -25,6 +25,10 @@ type MemoryFS struct {
 
 // New creates a new MemoryFS.
 func New(capacity int64) *MemoryFS {
+	if capacity <= 0 {
+		panic("memory capacity must be greater than 0") // panic if the capacity is less than or equal to 0
+	}
+
 	return &MemoryFS{
 		files:    make(map[string]*file),
 		capacity: capacity,
@@ -69,9 +73,8 @@ func (m *MemoryFS) Set(key string, src []byte) error {
 			int64(len(src)),
 			time.Now(),
 		),
-		data: make([]byte, len(src)),
+		data: src,
 	}
-	copy(m.files[key].data, src)
 
 	return nil
 }

vfs/vfserror/vfserror.go

@@ -3,6 +3,9 @@ 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")