Function isLockFileStale

internal/cache/badger_cache.go:94–132

isLockFileStale checks if the lock file exists but no process is using it. This function attempts to determine if a BadgerDB lock file is stale by checking if the process that created it is still running.

(lockFilePath string)

// This function attempts to determine if a BadgerDB lock file is stale by
// checking if the process that created it is still running.
func isLockFileStale(lockFilePath string) (bool, error) {
	// Read the lock file to get the PID
	// #nosec G304 -- lockFilePath is constructed internally, not from user input
	data, err := os.ReadFile(lockFilePath)
	if err != nil {
		// Can't read the file, consider it not stale (safer default)
		return false, fmt.Errorf("failed to read lock file: %w", err)
	}

	// BadgerDB lock files typically contain just a PID
	// Try to parse it as an integer
	var pid int
	if _, err := fmt.Sscanf(string(data), "%d", &pid); err != nil {
		// Invalid lock file format, might be corrupted - consider it stale
		getCacheLogger().Debug("Lock file has invalid format, considering stale")
		return true, nil
	}

	// Check if the process exists by trying to find it
	process, err := os.FindProcess(pid)
	if err != nil {
		// Process doesn't exist (on some systems FindProcess always succeeds)
		getCacheLogger().Debug("Process %d not found, lock is stale", pid)
		return true, nil
	}

	// On Unix systems, send signal 0 to check if process is alive
	// Signal 0 doesn't actually send a signal, just checks if we can
	err = process.Signal(syscall.Signal(0))
	if err != nil {
		// Process doesn't exist or we don't have permission to signal it
		getCacheLogger().Debug("Cannot signal process %d: %v, lock is stale", pid, err)
		return true, nil
	}

	// Process exists and is running, lock is NOT stale
	getCacheLogger().Debug("Process %d is running, lock is valid", pid)
	return false, nil
}

// isErrorTemporarilyUnavailable checks if an error is due to a resource being temporarily unavailable.
func isErrorTemporarilyUnavailable(err error) bool {