add LRU cache to fs retrieval

go.mod

@@ -3,11 +3,13 @@ module Moonshark
 go 1.24.1
 
 require (
+	git.sharkk.net/Go/LRU v1.0.0
 	git.sharkk.net/Sky/LuaJIT-to-Go v0.4.1
 	github.com/VictoriaMetrics/fastcache v1.12.4
 	github.com/alexedwards/argon2id v1.0.0
 	github.com/deneonet/benc v1.1.8
 	github.com/goccy/go-json v0.10.5
+	github.com/golang/snappy v1.0.0
 	github.com/matoous/go-nanoid/v2 v2.1.0
 	github.com/valyala/bytebufferpool v1.0.0
 	github.com/valyala/fasthttp v1.62.0
@@ -18,7 +20,6 @@ require (
 	github.com/andybalholm/brotli v1.1.1 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/dustin/go-humanize v1.0.1 // indirect
-	github.com/golang/snappy v1.0.0 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/klauspost/compress v1.18.0 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect

go.sum

@@ -1,3 +1,5 @@
+git.sharkk.net/Go/LRU v1.0.0 h1:/KqdRVhHldi23aVfQZ4ss6vhCWZqA3vFiQyf1MJPpQc=
+git.sharkk.net/Go/LRU v1.0.0/go.mod h1:8tdTyl85mss9a+KKwo+Wj9gKHOizhfLfpJhz1ltYz50=
 git.sharkk.net/Sky/LuaJIT-to-Go v0.4.1 h1:CAYt+C6Vgo4JxK876j0ApQ2GDFFvy9FKO0OoZBVD18k=
 git.sharkk.net/Sky/LuaJIT-to-Go v0.4.1/go.mod h1:HQz+D7AFxOfNbTIogjxP+shEBtz1KKrLlLucU+w07c8=
 github.com/VictoriaMetrics/fastcache v1.12.4 h1:2xvmwZBW+9QtHsXggfzAZRs1FZWCsBs8QDg22bMidf0=
@@ -107,8 +109,6 @@ modernc.org/fileutil v1.3.1 h1:8vq5fe7jdtEvoCf3Zf9Nm0Q05sH6kGx0Op2CPx1wTC8=
 modernc.org/fileutil v1.3.1/go.mod h1:HxmghZSZVAz/LXcMNwZPA/DRrQZEVP9VX0V4LQGQFOc=
 modernc.org/gc/v2 v2.6.5 h1:nyqdV8q46KvTpZlsw66kWqwXRHdjIlJOhG6kxiV/9xI=
 modernc.org/gc/v2 v2.6.5/go.mod h1:YgIahr1ypgfe7chRuJi2gD7DBQiKSLMPgBQe9oIiito=
-modernc.org/libc v1.65.7 h1:Ia9Z4yzZtWNtUIuiPuQ7Qf7kxYrxP1/jeHZzG8bFu00=
-modernc.org/libc v1.65.7/go.mod h1:011EQibzzio/VX3ygj1qGFt5kMjP0lHb0qCW5/D/pQU=
 modernc.org/libc v1.65.8 h1:7PXRJai0TXZ8uNA3srsmYzmTyrLoHImV5QxHeni108Q=
 modernc.org/libc v1.65.8/go.mod h1:011EQibzzio/VX3ygj1qGFt5kMjP0lHb0qCW5/D/pQU=
 modernc.org/mathutil v1.7.1 h1:GCZVGXdaN8gTqB1Mf/usp1Y/hSqgI2vAGGP4jZMCxOU=
@@ -125,7 +125,5 @@ modernc.org/strutil v1.2.1 h1:UneZBkQA+DX2Rp35KcM69cSsNES9ly8mQWD71HKlOA0=
 modernc.org/strutil v1.2.1/go.mod h1:EHkiggD70koQxjVdSBM3JKM7k6L0FbGE5eymy9i3B9A=
 modernc.org/token v1.1.0 h1:Xl7Ap9dKaEs5kLoOQeQmPWevfnk/DM5qcLcYlA8ys6Y=
 modernc.org/token v1.1.0/go.mod h1:UGzOrNV1mAFSEB63lOFHIpNRUVMvYTc6yu1SMY/XTDM=
-zombiezen.com/go/sqlite v1.4.0 h1:N1s3RIljwtp4541Y8rM880qgGIgq3fTD2yks1xftnKU=
-zombiezen.com/go/sqlite v1.4.0/go.mod h1:0w9F1DN9IZj9AcLS9YDKMboubCACkwYCGkzoy3eG5ik=
 zombiezen.com/go/sqlite v1.4.2 h1:KZXLrBuJ7tKNEm+VJcApLMeQbhmAUOKA5VWS93DfFRo=
 zombiezen.com/go/sqlite v1.4.2/go.mod h1:5Kd4taTAD4MkBzT25mQ9uaAlLjyR0rFhsR6iINO70jc=

runner/fs.go

@@ -6,15 +6,29 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"Moonshark/utils/logger"
 
+	lru "git.sharkk.net/Go/LRU"
 	luajit "git.sharkk.net/Sky/LuaJIT-to-Go"
+	"github.com/golang/snappy"
 )
 
 // Global filesystem path (set during initialization)
 var fsBasePath string
 
+// Global file cache with compressed data
+var fileCache *lru.LRUCache
+
+// Cache entry info for statistics/debugging
+type cacheStats struct {
+	hits   int64
+	misses int64
+}
+
+var stats cacheStats
+
 // InitFS initializes the filesystem with the given base path
 func InitFS(basePath string) error {
 	if basePath == "" {
@@ -33,13 +47,20 @@ func InitFS(basePath string) error {
 	}
 
 	fsBasePath = absPath
+
+	// Initialize file cache with 2000 entries (reasonable for most use cases)
+	fileCache = lru.NewLRUCache(2000)
+
 	logger.Server("Virtual filesystem initialized at: %s", fsBasePath)
 	return nil
 }
 
 // CleanupFS performs any necessary cleanup
 func CleanupFS() {
-	// Nothing to clean up currently
+	if fileCache != nil {
+		fileCache.Clear()
+		logger.Server("File cache cleared - Stats: hits=%d, misses=%d", stats.hits, stats.misses)
+	}
 }
 
 // ResolvePath resolves a given path relative to the filesystem base
@@ -79,6 +100,11 @@ func ResolvePath(path string) (string, error) {
 	return fullPath, nil
 }
 
+// getCacheKey creates a cache key from path and modification time
+func getCacheKey(fullPath string, modTime time.Time) string {
+	return fmt.Sprintf("%s:%d", fullPath, modTime.Unix())
+}
+
 // fsReadFile reads a file and returns its contents
 func fsReadFile(state *luajit.State) int {
 	if !state.IsString(1) {
@@ -93,12 +119,46 @@ func fsReadFile(state *luajit.State) int {
 		return -1
 	}
 
+	// Get file info for cache key and validation
+	info, err := os.Stat(fullPath)
+	if err != nil {
+		state.PushString("fs.read_file: " + err.Error())
+		return -1
+	}
+
+	// Create cache key with path and modification time
+	cacheKey := getCacheKey(fullPath, info.ModTime())
+
+	// Try to get from cache first
+	if fileCache != nil {
+		if cachedData, exists := fileCache.Get(cacheKey); exists {
+			if compressedData, ok := cachedData.([]byte); ok {
+				// Decompress cached data
+				data, err := snappy.Decode(nil, compressedData)
+				if err == nil {
+					stats.hits++
+					state.PushString(string(data))
+					return 1
+				}
+				// Cache corruption - continue to disk read
+			}
+		}
+	}
+
+	// Cache miss or error - read from disk
+	stats.misses++
 	data, err := os.ReadFile(fullPath)
 	if err != nil {
 		state.PushString("fs.read_file: " + err.Error())
 		return -1
 	}
 
+	// Compress and cache the data
+	if fileCache != nil {
+		compressedData := snappy.Encode(nil, data)
+		fileCache.Put(cacheKey, compressedData)
+	}
+
 	state.PushString(string(data))
 	return 1
 }
@@ -136,6 +196,12 @@ func fsWriteFile(state *luajit.State) int {
 		return -1
 	}
 
+	// Invalidate cache entries for this file path
+	if fileCache != nil {
+		// We can't easily iterate through cache keys, so we'll let the cache
+		// naturally expire old entries when the file is read again
+	}
+
 	state.PushBoolean(true)
 	return 1
 }