Would recommend to use a PHP or LC server-side front-end script to a MySQL or PostgreSQL SQL insert/update instruction instead. The SQL servers would manage this for you in a cleanest way than what can be done in using direct writes to flat files.
HTH, Le 22 août 2011 à 17:05, Gregory Lypny a écrit : > Hello everyone, > > I would appreciate your thoughts on how to avoid collisions on a server on > those presumably rare occasions when two or more visitors attempt to write to > a file at exactly the same time. In my case, it’s students writing via FTP > to a text log file, but the same situation can occur if visitors to a web > site, for example, submitting an entry to a guest book, do it at the same > time. I don’t know what the consequences of this are. > > My crude and imperfect attempt to minimize this possibility is to have a Busy > file that acts as a flag when the log file is being written to. It contains > just one line of data: > > False, the seconds > > If the first item is False, it means that the log file is not currently being > written to. A user about to write to the file invokes a handler that changes > this first item to True, and inserts a timestamp in the form of the seconds. > When they are finished writing to the file, the same handler sets the Busy > file to False and inserts a new timestamp. The purpose of the timestamp is > to cover for the possibility of the write process or the handler being > aborted, therefore failing to set the Busy file back to False. If the > timestamp is more than, say, four minutes old, the True flag can be > overridden. This method is obviously imperfect because it is possible that > two people might be writing to the Busy file at the same time! I’m curious > to know of other handler-based approaches that do not involve setting up > separate databases. > > > > Regards, > > Gregory > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode -- Pierre Sahores mobile : 06 03 95 77 70 www.sahores-conseil.com _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
