Re: Tips on Saving Data?
Re: Tips on Saving Data?
- Subject: Re: Tips on Saving Data?
- From: Matthew Cox <email@hidden>
- Date: Tue, 2 Dec 2003 20:50:11 -0500
On Tuesday, December 2, 2003, at 02:24 PM, Demitri Muna wrote:
Hello,
I had a question that I posted last week but got no responses for (may
have been the holidays). I'll recast it, but in a much shorter way.
Let's say you have an application like iTunes. What is the recommended
strategy for saving changes to the library (where there is no "Save"
command)? Presumably you would not save after every little change, but
how often is good? Is there a way to minimize drive/CPU time? It there
a file format that is preferable in this case?
You could log each change to a separate file, and then periodically
move the changes from the log into the master file; this is kind of
like journalling. This gives you several advantages:
-very fast to simply append data to the journal (no seeking within the
file)
-the disk cache will take care of this file automagically if its is
very active
-if your application crashes before the changes are written, you can
play back this file to restore the changes the user made (be sure to
check that an entry is sane before you apply it.
I can give you some pointers on crafting this scheme if you are
interested.
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