From 20b0954aaf54bc3189f18825b9ad2c618612ddd9 Mon Sep 17 00:00:00 2001
From: Alexander Borsuk <me@alex.bio>
Date: Thu, 8 Aug 2024 22:17:31 +0200
Subject: [PATCH] Avoid temporary std::string for brands searching

Signed-off-by: Alexander Borsuk <me@alex.bio>
---
 indexer/brands_holder.hpp | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/indexer/brands_holder.hpp b/indexer/brands_holder.hpp
index f41463536a..877f75822e 100644
--- a/indexer/brands_holder.hpp
+++ b/indexer/brands_holder.hpp
@@ -40,7 +40,7 @@ public:
 
   std::set<std::string> const & GetKeys() const { return m_keys; }
 
-  template <class FnT> void ForEachNameByKey(std::string const & key, FnT && fn) const
+  template <class FnT> void ForEachNameByKey(std::string_view key, FnT && fn) const
   {
     auto const it = m_keyToName.find(key);
     if (it == m_keyToName.end())
@@ -57,7 +57,17 @@ private:
   void LoadFromStream(std::istream & s);
   void AddBrand(Brand & brand, std::string const & key);
 
-  std::unordered_map<std::string, std::shared_ptr<Brand>> m_keyToName;
+  struct StringViewHash
+  {
+    using hash_type = std::hash<std::string_view>;
+    using is_transparent = void;
+
+    // std::size_t operator()(const char* str) const        { return hash_type{}(str); }
+    std::size_t operator()(std::string_view str) const   { return hash_type{}(str); }
+    std::size_t operator()(std::string const & str) const { return hash_type{}(str); }
+  };
+
+  std::unordered_map<std::string, std::shared_ptr<Brand>, StringViewHash, std::equal_to<>> m_keyToName;
   std::set<std::string> m_keys;
 };
 
@@ -67,9 +77,8 @@ BrandsHolder const & GetDefaultBrands();
 template <class FnT> void ForEachLocalizedBrands(std::string_view brand, FnT && fn)
 {
   bool processed = false;
-  /// @todo Remove temporary string with the new cpp standard.
   /// Localized brands are not working as expected now because we store raw names from OSM, not brand IDs.
-  GetDefaultBrands().ForEachNameByKey(std::string(brand), [&fn, &processed](auto const & name)
+  GetDefaultBrands().ForEachNameByKey(brand, [&fn, &processed](auto const & name)
   {
     fn(name);
     processed = true;