chore(flat): replace std::map with std::unordered_map for key_id_mapping#153
Open
longway-code wants to merge 1 commit intoalibaba:mainfrom
Open
chore(flat): replace std::map with std::unordered_map for key_id_mapping#153longway-code wants to merge 1 commit intoalibaba:mainfrom
longway-code wants to merge 1 commit intoalibaba:mainfrom
Conversation
…ing_ Reduces key lookup in get_id() from O(log N) to O(1) average, and index load time from O(N log N) to O(N). Also lowers per-entry memory usage by eliminating the three tree-node pointers (parent/left/right).
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
key_id_mapping_is only used for point lookups — no range scans, no ordering needed.std::unordered_mapis a better fit.get_id()lookup: O(log N) → O(1)nextpointer plus a bucket array; net ~12MB savings at N=1MMicrobenchmark — isolated
map::findvsunordered_map::find, random key order, all hits: