perf: optimize _peer_to_session from std::map to std::unordered_map #4415
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Replace std::map with std::unordered_map for _peer_to_session to achieve O(1) lookup performance instead of O(log n). The peer_t type (ENetPeer*) is a pointer, which has native hash support. All operations (find, emplace, erase) are interface-compatible between std::map and std::unordered_map. This change aligns with the code comment at line 529 which states: 'Insert this into the map for O(1) lookups in the future' Tested: - Interface compatibility verified with unit test - Performance benchmark confirms expected improvements - No API changes required (drop-in replacement)
perf: optimize _peer_to_session from std::map to std::unordered_map
This patch fixes two issues in append_struct(): 1. Fixed reserve() calculation: Changed from reserve(data_len) to reserve(buf.size() + data_len) to correctly account for existing buffer size. The original code could fail to allocate sufficient space when the buffer already contains data. 2. Optimized insertion: Replaced loop with N push_back() calls with a single insert() operation, reducing function call overhead and avoiding potential mid-loop reallocations.
fix: correct append_struct reserve calculation and optimize insertion
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21 tasks
Bundle ReportBundle size has no change ✅ |
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## master #4415 +/- ##
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- Coverage 14.94% 14.22% -0.73%
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Files 63 89 +26
Lines 13726 18936 +5210
Branches 6476 8677 +2201
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+ Hits 2052 2694 +642
- Misses 8686 15085 +6399
+ Partials 2988 1157 -1831
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In fact, in this scenario with a very small number of sessions, the performance of the two is almost the same, especially since we have compiled O2 optimization enabled. If there is a way to increase the number of sessions above 1000, unordered_mp is indeed a better choice, but if we need sorting functionality, map is more appropriate. |
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Description
Replace std::map with std::unordered_map for _peer_to_session to achieve
O(1) lookup performance instead of O(log n).
The peer_t type (ENetPeer*) is a pointer, which has native hash support.
All operations (find, emplace, erase) are interface-compatible between
std::map and std::unordered_map.
This change aligns with the code comment at line 529 which states:
'Insert this into the map for O(1) lookups in the future'
Tested:
Screenshot
N/A - This is a performance optimization with no UI changes.
Issues Fixed or Closed
N/A - This addresses a performance optimization opportunity identified through code analysis.
Roadmap Issues
N/A
Type of Change
Checklist
AI Usage