2009363 - Improve identifier search performance

Status: NEW

(Webtools :: Searchfox, task)

Description

[Nicolas Guichard]

While looking for test queries for 1794004, I found a query in the logs that takes a significant amount of time in identifier_search: searching for "MOZ_":

2026-01-09 10:28:19.711493/pid=38457 - request(handled by 38458) /firefox-main/search?q=MOZ_&path=&case=false&regexp=false
2026-01-09 10:28:19.713360/pid=38458 - QUERY line: "MOZ_", fold_case: true, 
2026-01-09 10:28:19.740916/pid=38458 -   codesearch result with 4006 line matches across 63 paths - 0.027674 : re2_time: 1, git_time: 42, exit_reason: MATCH_LIMIT, total_time: 7, 
2026-01-09 10:28:19.757116/pid=38458 -   search_files "MOZ_" - 0.016029
2026-01-09 10:28:25.691964/pid=38458 -   identifier_search "MOZ_" - 5.934788
2026-01-09 10:28:26.712158/pid=38458 - WORK LIMIT HIT
2026-01-09 10:28:26.718721/pid=38458 -   search.get() - 1.026377
2026-01-09 10:28:27.046444/pid=38457 - finish pid 38458 - 7.334631

The identifier lookup itself seems fast enough, it's the following loop that does crossref lookups and demangling for every hit that makes this query slow.