[backport 3.2] read view closing performance improvement#12123
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sergepetrenko merged 1 commit intorelease/3.2from Dec 9, 2025
Merged
[backport 3.2] read view closing performance improvement#12123sergepetrenko merged 1 commit intorelease/3.2from
sergepetrenko merged 1 commit intorelease/3.2from
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Inside `tuple_dictionary_delete_hash`, there was a loop that, on each iteration, searched for the first non-deleted element using `mh_first`, which has a complexity of `O(n)`, and deleted it using `mh_strnu32_del`. After the loop finished executing, `tuple_dictionary_delete_hash` immediately called `mh_strnu32_delete`. All elements are stored in the hashmap inplace, so `del` doesn't invoke any memory deallocation functions. `del` also doesn't call destructors for the elements; it merely sets a specific bit in the bitmap to 0. Immediately after the loop, `mh_strnu32_delete(hash)` will delete the hashmap `hash` along with the array `hash->p` containing all elements inplace. This commit simply removes this useless loop, which was causing significant performance issues when closing a read view. Closes tarantool/tarantool-ee#1043, #12115 NO_DOC=performance improvement NO_TEST=performance improvement (cherry picked from commit 4b72007)
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(This PR is a backport of #12019 to
release/3.2to a future3.2.4release.)Inside
tuple_dictionary_delete_hash, there was a loop that, on each iteration, searched for the first non-deleted element usingmh_first, which has a complexity ofO(n), and deleted it usingmh_strnu32_del. After the loop finished executing,tuple_dictionary_delete_hashimmediately calledmh_strnu32_delete.All elements are stored in the hashmap inplace, so
deldoesn't invoke any memory deallocation functions.delalso doesn't call destructors for the elements; it merely sets a specific bit in the bitmap to 0. Immediately after the loop,mh_strnu32_delete(hash)will delete the hashmaphashalong with the arrayhash->pcontaining all elements inplace.This PR simply removes this useless loop, which was causing significant performance issues when closing a read view.
Closes tarantool/tarantool-ee#1043, #12115
NO_DOC=performance improvement
NO_TEST=performance improvement