Module write 

FCS file writing utilities

This module provides functionality to write FCS files to disk, including:

• Duplicating existing files
• Editing metadata and persisting changes
• Creating new FCS files with data modifications (filtering, concatenation, column addition)

Memory-Mapping Implications

Important: When writing FCS files, the original memory-mapped file is not modified. All write operations create new files. The original Fcs struct remains valid and can continue to access the original file via memory-mapping until it’s dropped.

When you call write_fcs_file() or any of the modification functions:

1. The data is read from the DataFrame (which is already in memory)
2. A new file is created on disk
3. The original memory-mapped file remains unchanged

This means:

• You can safely write modified versions without affecting the original
• The original Fcs struct can still be used after writing
• No special handling is needed to “close” or “unmap” before writing
• Multiple writes can happen concurrently from the same source file

Functions

add_column

Create a new FCS file by adding a column (parameter) to existing data

concatenate_events

Create a new FCS file by concatenating events from multiple files

duplicate_fcs_file

Duplicate an existing FCS file to a new path

edit_metadata_and_save

Edit metadata and persist changes to disk

filter_events

Create a new FCS file by filtering events

write_fcs_file

Write an FCS file to disk