Add thread-local caches for file locks and handles in fd_pool

cpp/src/Public/sweepstore/utils/file_lock.h

@@ -25,6 +25,55 @@ private:
     Mode mode;
     bool locked = false;
 
+#ifdef _WIN32
+    // Thread-local HANDLE cache for Windows
+    static thread_local std::unordered_map<std::string, HANDLE> handleCache;
+
+    static HANDLE getOrOpenHandle(const std::string& path) {
+        auto it = handleCache.find(path);
+        if (it != handleCache.end()) {
+            return it->second;
+        }
+
+        HANDLE handle = CreateFileA(
+            path.c_str(),
+            GENERIC_READ | GENERIC_WRITE,
+            FILE_SHARE_READ | FILE_SHARE_WRITE,
+            NULL,
+            OPEN_EXISTING,
+            FILE_ATTRIBUTE_NORMAL,
+            NULL
+        );
+
+        if (handle == INVALID_HANDLE_VALUE) {
+            throw std::runtime_error("Failed to open file for locking: " + path);
+        }
+
+        handleCache[path] = handle;
+        return handle;
+    }
+
+    void acquire() {
+        HANDLE handle = getOrOpenHandle(filePath);
+        OVERLAPPED overlapped = {0};
+        DWORD flags = (mode == Mode::Exclusive) ? LOCKFILE_EXCLUSIVE_LOCK : 0;
+        flags |= LOCKFILE_FAIL_IMMEDIATELY;
+
+        if (!LockFileEx(handle, flags, 0, MAXDWORD, MAXDWORD, &overlapped)) {
+            throw std::runtime_error("Failed to acquire file lock");
+        }
+        locked = true;
+    }
+
+    void release() {
+        if (locked) {
+            HANDLE handle = getOrOpenHandle(filePath);
+            OVERLAPPED overlapped = {0};
+            UnlockFileEx(handle, 0, MAXDWORD, MAXDWORD, &overlapped);
+            locked = false;
+        }
+    }
+#else
     // Thread-local FD cache - each thread has its own FD per file
     static thread_local std::unordered_map<std::string, int> fdCache;
 
@@ -60,6 +109,7 @@ private:
             locked = false;
         }
     }
+#endif
 
 public:
     // Constructor accepts offset/length for API compatibility (unused with flock)
@@ -82,6 +132,21 @@ public:
 
     // Check if file is currently locked (non-blocking test)
     bool isLocked() const {
+#ifdef _WIN32
+        HANDLE handle = getOrOpenHandle(filePath);
+        OVERLAPPED overlapped = {0};
+        DWORD flags = (mode == Mode::Exclusive) ? LOCKFILE_EXCLUSIVE_LOCK : 0;
+        flags |= LOCKFILE_FAIL_IMMEDIATELY;
+
+        // Try non-blocking lock
+        if (!LockFileEx(handle, flags, 0, MAXDWORD, MAXDWORD, &overlapped)) {
+            return true; // Already locked
+        }
+
+        // Got the lock, release immediately
+        UnlockFileEx(handle, 0, MAXDWORD, MAXDWORD, &overlapped);
+        return false;
+#else
         int fd = getOrOpenFD(filePath);
         int operation = (mode == Mode::Exclusive) ? LOCK_EX : LOCK_SH;
 
@@ -93,6 +158,7 @@ public:
         // Got the lock, release immediately
         flock(fd, LOCK_UN);
         return false;
+#endif
     }
 
     // RAII helper for scoped locking