llbsolver: Fix performance of recomputeDigests#3732
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Before this, in the case where nothing was mutated the visited memo would never be updated, thus causing exponential complexity. Now the memo is updated even when nothing is mutated, just setting old and new to be the same digest. Signed-off-by: Erik Sipsma <erik@sipsma.dev>
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Before this, in the case where nothing was mutated the visited memo would never be updated, thus causing exponential complexity.
Now the memo is updated even when nothing is mutated, just setting old and new to be the same digest.
This was causing real world performance regressions for dagger (due to the fact that dagger tries to by default propagate mount changes across every Exec, you can end up with fairly complicated LLB graphs pretty easily): dagger/dagger#4620