Is there a way to directly query the file system device driver for listing out the files in a directory?
I'm currently using FindFirstFile, FindNextFile API to recursively iterate through directories for searching files based on a given criteria. I noticed that "dir /s" command gives better performance than my program. I'm tried checking out the events in process monitor and it looks like cmd.exe/dir command is directly querying the disk device driver. Is there any way I can achieve some thing similar with DeviceIOCo开发者_C百科ntrol() ?. I'm very new to device drivers though not new to programming. Attaching procmon output for reference:
Regards,
Use FindFirstFile
and FindNextFile
. That's the API, using DeviceIOControl
directly is either a mess or not possible (don't know exactly).
Have you tried FindFirstFileEx
and it's FIND_FIRST_EX_LARGE_FETCH
flag and FindExInfoBasic
info level?
You can call ZwQueryDirectoryFile directly. Going further down to the driver level would require sending a bunch of IRPs and would probably be an overkill.
"dir /s" is using FindFirst/Next. It doesn't do any special magic to enumerate the files.
QueryDirectory appears to be how Procmon exposes what FindFirst/Next does to get its data from the file system.
http://ntfs-search.sourceforge.net/
It works well. And faster.
It opens a volume, and parses directly.
But it only works on NTFS.
Profile your app, your bottleneck is likely to be elswhere. Some of these options are like taking out a shotgun to shoot a fly...
-scott
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