[Swift-devel] discussion for swift output file path

[Ben Clifford]

On Thu, 6 Nov 2008, Mihael Hategan wrote:

> It may also make sense to coalesce all the trees into one, such that
> data, info, and temporary job dirs are created in the same directory
> (e.g. (info/a/0, job/a/0) becomes (a/0/info, a/0/job)), since it will
> reduce the overall number of operations.

Perhaps does for info and job where the access/lock patterns are the same 
under both the info and job tree.

But the shared data tree needs to be hashed by something based on the file 
(eg a hash of the filename) rather than on something specific to a 
particular job.

Putting the shared directories under the same hash tree as info/ and job/ 
would reduce the number of directories in total but would increase lock 
contention on those directories, because cached data file accesses follow 
a different pattern from info/ and job/ accesses.
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