shave sub-second precision off modification time #251
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It seems like System.Directory's `getModificationTime` is now providing sub-second precision if it's available in the underlying system call, which it seems to be for most systems. The problem is that when the modification time is stored, the DiffTime, the number of seconds from midnight, has its sub-second precision shaved off, effectively becoming 0 the next time it's read. When a file is then checked to see if it has been modified, the file is _always_ deemed to have been modified because this time still includes the sub-second precision, which will almost always be later in time than 0, unless of course it happened to be 0 to begin with. This simply shaves the sub-second precision off of the time returned by `getModificationTime`, and thus no longer rebuilds every single file each time any one file is saved. Closes jaspervdj#250
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The error the Travis CI build ran into is related to this comment. It's unrelated to this fix. |
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Looks fine, but I wonder whether storing sub seconds when they're available
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I think that's a very good idea. I only chose to shave them off because that's what Hakyll was already doing. I'm closing this and submitting a new PR. |
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Re-submitted as PR #252 |
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It seems like System.Directory's
getModificationTimeis now providingsub-second precision if it's available in the underlying system call,
which it seems to be for most systems.
The problem is that when the modification time is stored, the DiffTime,
the number of seconds from midnight, has its sub-second precision
shaved off, effectively becoming 0 the next time it's read. When a
file is then checked to see if it has been modified, the file is
always deemed to have been modified because this time still includes
the sub-second precision, which will almost always be later in time
than 0, unless of course it happened to be 0 to begin with.
This simply shaves the sub-second precision off of the time returned by
getModificationTime, and thus no longer rebuilds every single fileeach time any one file is saved.
This closes #250
Update: I rebased some extra changes I made and pushed, doubt anyone will be affected. It added back an unrelated newline I removed from a different section of the file, as well as generalized the fix so that it works in both blocks regardless of the version of directory.