feat: update dependencies and improve caching mechanism

- 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.

vfs/sync/sync.go

@@ -1,76 +1,76 @@
 package sync
 
-import (
-	"fmt"
-	"s1d3sw1ped/SteamCache2/vfs"
-	"sync"
-)
+// import (
+// 	"fmt"
+// 	"s1d3sw1ped/SteamCache2/vfs"
+// 	"sync"
+// )
 
-// Ensure SyncFS implements VFS.
-var _ vfs.VFS = (*SyncFS)(nil)
+// // Ensure SyncFS implements VFS.
+// var _ vfs.VFS = (*SyncFS)(nil)
 
-type SyncFS struct {
-	vfs vfs.VFS
-	mu  sync.RWMutex
-}
+// type SyncFS struct {
+// 	vfs vfs.VFS
+// 	mu  sync.RWMutex
+// }
 
-func New(vfs vfs.VFS) *SyncFS {
-	return &SyncFS{
-		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())
-}
+// // 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()
+// // 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()
-}
+// 	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()
+// // 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)
-}
+// 	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()
+// // 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)
-}
+// 	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()
+// // 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)
-}
+// 	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()
+// // 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)
-}
+// 	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()
+// // StatAll returns the FileInfo of all keys.
+// func (sfs *SyncFS) StatAll() []*vfs.FileInfo {
+// 	sfs.mu.RLock()
+// 	defer sfs.mu.RUnlock()
 
-	return sfs.vfs.StatAll()
-}
+// 	return sfs.vfs.StatAll()
+// }