Improve performance and code readibility

[Nyeriah]

Module is heavy on per-tick overhead and the code is cluttered with dead debug comments, redundant map lookups, and deep nesting.

MythicmodeInstanceData map bloat

Every read via operator[] silently inserts a default entry for missing keys, growing the map unboundedly:

// Before: inserts false for every instanceId ever queried
bool isMythic = sZoneDifficulty->MythicmodeInstanceData[instanceId];

// After: no insertion on read
bool isMythic = sZoneDifficulty->IsInstanceMythic(instanceId);

Added IsInstanceMythic() helper using find(), replaced all ~12 read-only accesses.

OnAllCreatureUpdate — runs every tick for every creature

• Moved phase-match check before base health computation (early out before GetCreatureBaseStats/GenerateHealth)
• Replaced full modifier chain comparison (GetMaxHealth() == scaledHealth computing 3 modifier values) with direct BASE_VALUE comparison
• Used iterator from CreatureOverrides.find() instead of find-then-bracket double lookup

Double map lookups throughout hot paths

Replaced find() != end() followed by operator[] with single iterator-based access in all damage/heal modifier hooks, OverrideModeMatches, HasCompletedFullTier, SaveMythicmodeInstanceData, GetLowestMatchingPhase, OnPlayerLogin, etc.

// Before: two O(log n) lookups
if (sZoneDifficulty->SpellNerfOverrides.find(spellInfo->Id) != sZoneDifficulty->SpellNerfOverrides.end())
    heal = heal * sZoneDifficulty->SpellNerfOverrides[spellInfo->Id][mapId].NerfPct;

// After: single lookup
auto spellIt = sZoneDifficulty->SpellNerfOverrides.find(spellInfo->Id);
if (spellIt != sZoneDifficulty->SpellNerfOverrides.end()) { ... }

Other fixes

• VectorContainsUint32 now takes const std::vector<uint32>& instead of by value
• Cached ShouldNerfInDuels() result where it was called twice in ModifyHealReceived
• OnInstanceIdRemoved: removed redundant find-before-erase (erase on missing key is a no-op)
• OverrideModeMatches: rewrote to use find() for both SpellNerfOverrides and MythicmodeInstanceData instead of operator[]

Readability

• Removed ~30 commented-out LOG_INFO lines and /* debug ... end debug */ blocks
• Removed empty if (IsDebugInfoEnabled) { /* only comments */ } blocks
• Reduced nesting in ModifyHealReceived, OnAfterUpdateEncounterState
• Merged duplicate gossip close handlers
• Used local references to avoid repeated deep map chains like sZoneDifficulty->NerfInfo[mapId][matchingPhase].SpellDamageBuffPct

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[Copilot]

Pull request overview

This PR reduces per-tick overhead and map growth in the zone difficulty module by replacing operator[] reads with find()-based access patterns, flattening control flow, and removing dead debug/comment blocks.

Changes:

• Added ZoneDifficulty::IsInstanceMythic() and replaced read-only MythicmodeInstanceData[instanceId] access to avoid accidental inserts.
• Reduced redundant map lookups and nesting in several hot paths (heal/damage modifiers, creature update tick, instance encounter hooks).
• Cleaned up dead debug logging/comment blocks and simplified gossip handlers.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 5 comments.

File	Description
src/mod_zone_difficulty_scripts.cpp	Reworks hot-path hooks to avoid operator[] insertions/double lookups, adds early-outs, and cleans dead debug code.
src/mod_zone_difficulty_handler.cpp	Adds IsInstanceMythic(), rewrites lookups to iterator-based access, and refactors phase/override checks.
src/ZoneDifficulty.h	Exposes IsInstanceMythic() and updates helper signatures for safer/cheaper calls.
.gitignore	Ignores CodeQL detected source root marker file.

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[Copilot]

Pull request overview

Copilot reviewed 3 out of 4 changed files in this pull request and generated 1 comment.

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