Hopper cache invalidation broken when inventory blocks are placed without block updates (WorldEdit)

[Fallen-Breath]

Instructions

If a inventory block with contents inside is placed without updates next to a hopper, the hopper will not pull / push items from / to the inventory block

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Version Information

• Minecraft 1.19.2
• fabric-carpet
• lithium-fabric-mc1.19.2-0.10.2

Reproduction Steps

1. Use /carpet fillUpdates false command to enable a carpet rule that removes block updates when during /setblock or /clone commands
2. Place hopper. Place a chest and put something inside the chest
3. Use /clone command to clone the placed chest to the top of the hopper

Expected Behavior

Hopper starts pulling items from the chest

Actual Behavior

Hopper does nothing and refuse to pull items from the chest. Seems like the hopper is not notified

Other Information

With /carpet fillUpdates false, using /setblock command to set a chest with inventory also doesn't make the hopper work

If you use worldedit and do //perf neighbors off to disable block updates from worldedit operation, then worldedit operations with inventory blocks also doesn't notify the hopper. Reproduced with worldedit 7.2.12 in mc1.19.2

lithium 0.10.2 for mc1.18.2 has this issue too

reloading the chunk fixes the "broken" hopper

[2No2Name]

This issue is caused by lithium assuming that the placement of an inventory block will send block updates to sourrounding hoppers. The block updates are used to invalidate the cached information which says that the hopper has no inventory block to interact with.
This probably also affects removal of composter blocks.

[2No2Name]

For a fix we probably have to check how carpet and world edit implement the update suppression. At some point we can probably get an update out of the block creation, however this might decrease the performance of large fills.

[Zifiv]

Hello @2No2Name,

Same issue on Farmer's Delight Fabric port, without Lithium, the cooking pot is working well, but if last version of Lithium is installed (I've not yet tested with older version), hoppers cannot pull or push items in the cooking pot until they are updated themself.

My first guess is that I'm doing something wrong in the code that break the interaction, but it work well without Lithium, and the code is the same than a furnace block.

If you need any information to understand what's wrong, I'm available.

This will maybe fixed by this action https://github.com/CaffeineMC/lithium-fabric/actions/runs/3504930287, so in next release, but I prefered notify that the bug.

[2No2Name]

Ideas how to fix update suppressed placement of inventories near hoppers not updating the hopper's caching:

1. Hook into some vanilla code that still runs (e.g. setblockstate), which won't be foolproof and might cause lag in other scenarios if not paying close attention to it
2. Hook into other mods's code
3. Provide an API to send updates to lithium's hoppers which the other mods can use

I think I will look into 1. as the other options are probably more work and less maintainable

[2No2Name]

@Zifiv please move to #423 , this issue about something different I believe

[2No2Name]

@Fallen-Breath I think the build at https://github.com/CaffeineMC/lithium-fabric/actions/runs/3554890604 might be able to fix the issue. If you test it, your feedback will be appreciated a lot.

[2No2Name]

The way it is fixed may or may not work with world edit, since I only read the fabric-carpet code in detail so far

[Fallen-Breath]

@Fallen-Breath I think the build at https://github.com/CaffeineMC/lithium-fabric/actions/runs/3554890604 might be able to fix the issue. If you test it, your feedback will be appreciated a lot.

The github action failed, might due to this client-side only import

https://github.com/CaffeineMC/lithium-fabric/blob/75223567aedc10294d6c75278ff357537dde5cd8/src/main/java/me/jellysquid/mods/lithium/mixin/block/hopper/WorldMixin.java#L21

[2No2Name]

Ugh, should have... tested it or waited for the build to finish.

[2No2Name]

Again, not testing before commenting:
https://github.com/CaffeineMC/lithium-fabric/actions/runs/3561253591

[Fallen-Breath]

Again, not testing before commenting: https://github.com/CaffeineMC/lithium-fabric/actions/runs/3561253591

Works for fabric carpet's /carpet fillUpdates false, but still doesn't work correctly with worldedit

For worldedit's implemetation, you can check these 2 classes. Basically worldedit directly sets block in chunk, and then performs side-effects by itself

https://github.com/EngineHub/WorldEdit/blob/master/worldedit-core/src/main/java/com/sk89q/worldedit/internal/wna/WorldNativeAccess.java

https://github.com/EngineHub/WorldEdit/blob/master/worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/internal/FabricWorldNativeAccess.java

[2No2Name]

Also included compatibility for worledit, but there is no general solution yet.