applescript, folder action, move copied items fails, timing issue? - applescript

Question

Please help, I can't think of a fix for this.
A folder action is meant to do this for each file copied into a folder:
Derive a subfolder name, and a new filename.
Create subfolder.
Move file into it.
Rename subfolder and file.
Files are copied from a different volume and are usually 500…1500 MB.
Problem: The moving step (step 3) in the folder action script fails if the files are that large and their number is >1
and they are copied from a different volume.
The script works fine when copying: small files, or from the same volume, or only one file.
In a test, all of 200 Alias' were correctly processed, but only 23 of 512. This is not a problem, the number of added_items is usually <10 and unlikely to ever be >50. But it may help targeting the issue.
I suspected a timing issue, but all attempts to fix it using generous timeout's didn't work.
The script (note - before trying, set the regex in the do shell script lines to something workable):
on adding folder items to this_folder after receiving added_items
repeat with the_item in added_items
with timeout of 3600 seconds
tell application "Finder"
if kind of the_item is not "Folder" then
repeat -- wait until item is copied. Thanks to original coder on the WWW.
set {size:fileSize, busy status:Busy} to (info for (the_item))
if not Busy and (fileSize is greater than 0) then exit repeat
delay 1
end repeat
with timeout of 600 seconds
set new_folder_name to do shell script "echo '" & (name of the_item) ¬
& "' | sed -E 's/llooongRegex/replace/g'"
set new_item_name to do shell script "echo '" & (name of the_item) ¬
& "' | sed -E 's/otherRegex/replace/g'"
set new_folder to (make new folder at this_folder with properties {name:(new_folder_name & "-temp")}) as alias -- "-temp" in case new folder and file will have the same name
move file the_item to folder new_folder -- <== fails if ((added_items >1) AND (files big, tested with 0.5…1.5GB) AND (copied from different volume)) ==> Timing issue?
set name of (first item of (get contents of new_folder)) to new_item_name
set name of new_folder to new_folder_name
end timeout
end if
end tell
end timeout
end repeat
end adding folder items to
P.S.: is folder-action frequent enough for a tag?

Answer 1

After replacing the repeat -- wait until item is copied.... clause with a simple delay 60, the script works. So it is a timing problem.
Waiting for the target folder to stop changing size as describe here works as long as only 1 file copying (bunch of files dropped) is running. Two or more drag'n drops, and it hiccups again (nice word, #vadian!).
Ditto when checking for the size of individual added items to remain constant.