Retrieve file count without walking through entire file system

I am on a vxworks 6.9 platform. I want to know how many files are in a folder. The file system is DOSFS (FAT). The only way I know how to do this is to simply loop through every file in the folder and count. This gets very expensive the more files in the folder. Is there a more sensible way to do this? Does there exist some internal database or count of all files in a folder?

The FAT filesystem does not keep track of the number of files it contains. What it does contain is:

• A boot sector
• A filesystem information sector (on FAT32) including:
  • Last number of known free clusters
  • Number of the most recently allocated cluster
• Two copies of the file allocation table
• An area for the root directory (on FAT12 and FAT16)
• Data clusters

You'll need to walk the directory tree to get a count.