Sean Middleditch wrote: [...] > So far as implementation, this really is easy even with a (single) file- > based backend. Robustness might take some work, but the basics are > easy. You simply keep a list of all they keys that have been set, and > when the Commit command comes along, lock the file(s) in question and > modify them. On Rollback, just "forget" all the key changes that > haven't been committed yet. Basically the hard part for the simple file > backend is getting the commit to stay atomic on errors when you use > multiple files. If you have multiple files being changed, I don't > believe it's actually possible to be 100% atomic - you can reduce the > chances of something breaking, but there will always be various race > conditions in regards to when errors occur that could leave you in a > half-committed state. > rename is atomic. You can always use this fact if you need to.
