Make the lua function dgn.vault_at return a pointer - #4650
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gammafunk merged 1 commit intoJul 29, 2026
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The lua function dgn.vault_at was returning a copy of the vault_placemnt at a location. Unfortunately, it is slow to copy a vault_placement and because the object returned to lua is a wrapper around a c++ object lua doesn't know how big it is and won't trigger garbage collection until you have about 8000 of them (about 17 MB). The only place using dgn.vault_at is the disco Pan colour function which can work just fine with a pointer rather than a copy and runs considerably faster. This is also consistent with the c++ equivalent that returns a pointer.
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We saw a crash recently from particleface that illustrated the problem of this expensive copy, since it was an OOM: https://cbro.berotato.org/morgue/particleface/crash-particleface-20260728-135654.txt Hence it was a good time to take a closer look at this fix and merge. Using a pointer without the full copy seems great here. |
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The lua function dgn.vault_at was returning a copy of the vault_placemnt at a location. Unfortunately, it is slow to copy a vault_placement and because the object returned to lua is a wrapper around a c++ object lua doesn't know how big it is and won't trigger garbage collection until you have about 8000 of them (about 17 MB).
The only place using dgn.vault_at is the disco Pan colour function which can work just fine with a pointer rather than a copy and runs considerably faster.
This is also consistent with the c++ equivalent that returns a pointer.