WitieFile API completiton progress

drjackool 956

hi in my app (win32 platform) i create a new file using CreateFile() then use SetFilePointer() to pre-allocate a big space for example 2GB then use SetEndOfFile() every thing is ok til here, then I call WriteFile() to write some data to the end of file; but issue is here writefile takes a long time to complete because system is allocating physical space for file, my question is, is there a way to calc/access the write operation progress completition value of the WiteFile()?

Such CopyFileEx() that has ProgressRoutine

Thanks

David Lowndes 2,345 Reputation points MVP

2023-06-10T22:44:48.8866667+00:00

Could you clarify what you're asking, I don't understand your specific question.

Information on sparse files that may be of interest to your situation.
drjackool 956 Reputation points

2023-06-11T04:52:12.77+00:00

is there a way to detect WriteFile() progress such CopyFileEx() that has ProgressRoutine
RLWA32 40,286 Reputation points

2023-06-11T06:45:14.87+00:00

If the issue is that WriteFile is blocking until the operation is complete you could look into using asynchronous IO instead.
Viorel 112.1K Reputation points

2023-06-11T17:39:24.3766667+00:00

Instead of using SetFilePointer, which later causes the delay until the disk space is allocated and cleared, and you do not want sparse files for some reasonable motives, maybe you can use a series of WriteFile (in a loop) that writes the gap to achieve the required file length. Then you can display the progress of this loop.
drjackool 956 Reputation points

2023-06-11T19:16:09.6366667+00:00

yes this possible, but i think this may take a few longer time than setfilepointer. Ishould test it. thanks
drjackool 956 Reputation points

2023-06-11T19:17:03.43+00:00

I currently working to create a marqee progress bar for it.
Xiaopo Yang - MSFT 11,496 Reputation points Microsoft Vendor

2023-06-13T06:09:32.5566667+00:00

@drjackool There is no such Win32 API. @Viorel 's workaround is a reasonable and applicable workaround.