The experiment I tried was to have two jpegs in a directory, copying one or the other to picture.jpg, then using ctrl-L to reload, or using [menubar]->Tools->"Reload All Data" to confirm that metadata is not being reloaded.
It is being reloaded, however, so maybe there's something different that Ivar is doing. Interestingly, if I switch file, the metadata tab folds for a longer period than if the file is left alone. So it seems like there may be another cache which is involved.
I'm going to continue with the release, but I'll leave this ticket open until I talk to Ivar.
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I finally met with Ivar and we did verify that changing CDF files does not update. See sftp://draylax.physics.uiowa.edu:/home/jbf/ct/autoplot/u/2026/ivar/20260903/
cp ts1_l2_ace_def_20260401_v1.1.0.cdf to file.cdf
plot file.cdf?Epoch
cp ts2_l2_ace_def_20260401_v1.1.1.cdf to file.cdf
reload all data
The metadata tab does not update.
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The problem was the CDF reader had a feature that it would try to only read the attributes once, making it stateful when other codes expect them to be stateless. Reading the metadata takes less than a millisecond and is not worth caching.
However this showed me a potential error, where when the metadata was cached it would do actions which did not occur when reading for the first time. This needs further study.
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Note that any data source which maintains a state will potentially have this problem. A better solution might be to have "reload" create a new DataSource object.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
The experiment I tried was to have two jpegs in a directory, copying one or the other to picture.jpg, then using ctrl-L to reload, or using [menubar]->Tools->"Reload All Data" to confirm that metadata is not being reloaded.
It is being reloaded, however, so maybe there's something different that Ivar is doing. Interestingly, if I switch file, the metadata tab folds for a longer period than if the file is left alone. So it seems like there may be another cache which is involved.
I'm going to continue with the release, but I'll leave this ticket open until I talk to Ivar.
I finally met with Ivar and we did verify that changing CDF files does not update. See sftp://draylax.physics.uiowa.edu:/home/jbf/ct/autoplot/u/2026/ivar/20260903/
The metadata tab does not update.
The problem was the CDF reader had a feature that it would try to only read the attributes once, making it stateful when other codes expect them to be stateless. Reading the metadata takes less than a millisecond and is not worth caching.
However this showed me a potential error, where when the metadata was cached it would do actions which did not occur when reading for the first time. This needs further study.
I've fixed the CDF metadata as well.
Note that any data source which maintains a state will potentially have this problem. A better solution might be to have "reload" create a new DataSource object.