Update init_resource to not overwrite#1349
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I like this change, although it would be nice to change See #1186 for more discussion on this topic. Edit: I've made my own PR to solve this: #1352. |
alice-i-cecile
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alice-i-cecile
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I've looked over the codes changes themselves, and they're simple and sane 👍🏽
| { | ||
| let resource = R::from_resources(&self.app.resources); | ||
| self.app.resources.insert(resource); | ||
| if !self.resources().contains::<R>() { |
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This does "double hash" the type id. Resources don't currently have an "entry" api. And I don't think adding one is in scope for this pr. But can we add a // PERF: remove this double hash comment so it is discoverable?
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That would be difficult in this case, because we need to both be modifying self.resources() for the Entry, and reading it for the from_resources call - so without some gnarly unsafe code, I'm not sure this is feasible.
It's also worth noting that this is using the bevy_utils::HashMap, so the hashing is rather cheap.
Also this only happens at app startup time, so the cost doesn't matter too much. I've added a comment explaining this though
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makes sense. i added a "PERF" label here. I use those like TODO labels, but for places where we are knowingly leaving perf on the table.
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Well in that case, I think we'll all ready to merge. Message to future readers: Don't try and solve that perf thing, you're in for a world of unsafe pain. |
# Objective - The perf comments, added (by me) in bevyengine#1349, became outdated once the initialisation call started to take an exclusive reference, (presumably in bevyengine#1525). - They have been naïvely transferred along ever since ## Solution - Remove them
# Objective - The perf comments, added (by me) in bevyengine#1349, became outdated once the initialisation call started to take an exclusive reference, (presumably in bevyengine#1525). - They have been naïvely transferred along ever since ## Solution - Remove them
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The name init does not suggest it would overwrite an already created version.
We discussed this on discord and @cart has at one point been on board.