Change MerginProject constructor to force one instance per project #283
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mergin/merginproject.py
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| # directory paths to instances. | ||
| # The dictionary is a WeakValueDictionary so we don't cause memory leaks | ||
| # (when the instance is GC'd, the entry is deleted). | ||
| project_cache: weakref.WeakValueDictionary[str, "MerginProject"] = {} |
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I'm not sure if I understand... the type annotation is WeakValueDictionary - but doesn't project_cache become a normal dict if set it to {} ?
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Thanks, that's just me being an idiot, sorry. Though I wonder why my IDE didn't complain...
I've force-pushed a fix, since it's just one line.
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Hi @dvdkon , could you run tests with your version of code? You probably do not need to fork repo, instead of this -> use clone.
This is good idea to do it in this way. I'm wondering if this is not like 🩹 for buggy behavior in db-sync itself. In plugin are flying the MerginProject instances and no issues with that. Yeah, we could probably solve initialisation of Geodiff. @wonder-sk
mergin/merginproject.py
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| return instance | ||
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| instance = super().__new__(cls) | ||
| cls.project_cache[directory] = instance |
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Do we need to pass project_cache to class directly?
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No, it's already there since it's defined as a class property. cls.project_cache here is equivalent to MerginProject.project_cache.
Sadly I don't have the right (non-trial) account to run tests on the dev instance.
We could probably work around the desync issues by just being careful in |
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Currently there can be multiple instances of
MerginProjectin memory that represent a single project (directory). This is an issue, because doing an operation on one instance will desync metadata in the others, which caused syncing to fail indb-sync.This PR changes the MerginProject constructor to return the existing instance for a given directory, if one exists. It also bumps the library version, so I can make subsequent changes in
db-sync.