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detecting if a file is in use...a remote server and places them within a local directory. additionally, i have another thread that is running the FileSystemWatcher provided by .NET which notifies me when a file is created in that directory and then spins off another worker thread to perform some final processing on the new file. my problem is that my final worker thread that processes the file CANNOT begin to process the file UNTIL the file has been FULLY downloaded. yet i receive the event from FileSystemWatcher early when the file first appears (but often is still being written to). so, i was wondering if: 1) is there a way to determine if a file is in use (e.g. file handle count)? if so, then my worker thread can just wait until the file is no longer in use? 2) if not, can someone suggest a better alternative implementation to solving this issue? *please note that i cannot have the thread that is performing the download actually trigger the final worker thread itself when it is done writing the file to disk. this is because i also have the requirement that if a file is simply copied (e.g. by the user) from another location on the local computer, that it be picked up and processed by the FileSystemWatcher as well. therefore, i must use this FileSystemWatcher-based implementation. many thanks in advance, ben try/catch
-- Show quoteHTH, Kevin Spencer Microsoft MVP Professional Numbskull Show me your certification without works, and I'll show my certification *by* my works. "Ben Callister" <bcallister@community.nospam> wrote in message news:O6Kz0qlWGHA.1228@TK2MSFTNGP02.phx.gbl... >i have an application that has a background thread that downloads files >from a remote server and places them within a local directory. >additionally, i have another thread that is running the FileSystemWatcher >provided by .NET which notifies me when a file is created in that directory >and then spins off another worker thread to perform some final processing >on the new file. > > my problem is that my final worker thread that processes the file CANNOT > begin to process the file UNTIL the file has been FULLY downloaded. yet i > receive the event from FileSystemWatcher early when the file first appears > (but often is still being written to). > > so, i was wondering if: > > 1) is there a way to determine if a file is in use (e.g. file handle > count)? if so, then my worker thread can just wait until the file is no > longer in use? > 2) if not, can someone suggest a better alternative implementation to > solving this issue? > > *please note that i cannot have the thread that is performing the download > actually trigger the final worker thread itself when it is done writing > the file to disk. this is because i also have the requirement that if a > file is simply copied (e.g. by the user) from another location on the > local computer, that it be picked up and processed by the > FileSystemWatcher as well. therefore, i must use this > FileSystemWatcher-based implementation. > > many thanks in advance, > ben > > > Hi,
As I understand what you want to do, you could have the "download" module notify the "watcher" that it's about to download a file. The watcher module could then filter out it's watch on the file being downloaded until the download module notify that the file is completely downloaded. Best Regards, Etienne Lebeau It is really the same problem in both cases. The Create event only says the
directory *entry was created, not that it is done and closed. So you still need to wait for a close on a copy operation or a download as the stream is still opened in either case. So, you may want to refactor your protocol a little. All new files, both copy and download, goto a temp dir under your watch dir. When the file is done, you move (i.e. rename) the file into your "watched" dir (make sure DIRs are in same partition, othewise it would involve a copy across partitions and you would be back to first issue). Now just Watch for the Renamed event in your file system watcher and do your thing. hth -- Show quoteWilliam Stacey [MVP] "Ben Callister" <bcallister@community.nospam> wrote in message news:O6Kz0qlWGHA.1228@TK2MSFTNGP02.phx.gbl... |i have an application that has a background thread that downloads files from | a remote server and places them within a local directory. additionally, i | have another thread that is running the FileSystemWatcher provided by .NET | which notifies me when a file is created in that directory and then spins | off another worker thread to perform some final processing on the new file. | | my problem is that my final worker thread that processes the file CANNOT | begin to process the file UNTIL the file has been FULLY downloaded. yet i | receive the event from FileSystemWatcher early when the file first appears | (but often is still being written to). | | so, i was wondering if: | | 1) is there a way to determine if a file is in use (e.g. file handle count)? | if so, then my worker thread can just wait until the file is no longer in | use? | 2) if not, can someone suggest a better alternative implementation to | solving this issue? | | *please note that i cannot have the thread that is performing the download | actually trigger the final worker thread itself when it is done writing the | file to disk. this is because i also have the requirement that if a file is | simply copied (e.g. by the user) from another location on the local | computer, that it be picked up and processed by the FileSystemWatcher as | well. therefore, i must use this FileSystemWatcher-based implementation. | | many thanks in advance, | ben | | |  |
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