From f6e9ba4eb206c6e23db24f6f0ba5375009b8efba Mon Sep 17 00:00:00 2001
From: Eric Wasylishen <ewasylishen@gmail.com>
Date: Wed, 6 Oct 2021 18:26:25 -0600
Subject: [PATCH] qbsp: drop mapentity_t::epair_order and std::map for epairs

just store as a std::vector of pairs. Lookups aren't done much in qbsp
so linear search performance should be fine.

epair_order approach gets messy because we sometimes add epairs
---
 include/qbsp/map.hh |  7 +++----
 qbsp/map.cc         | 29 +++++++++++++++++------------
 2 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/include/qbsp/map.hh b/include/qbsp/map.hh
index 6e811f0d..39d12887 100644
--- a/include/qbsp/map.hh
+++ b/include/qbsp/map.hh
@@ -26,6 +26,7 @@
 
 #include <optional>
 #include <vector>
+#include <utility>
 #include <unordered_map>
 
 struct mapface_t
@@ -92,10 +93,8 @@ public:
     brush_t *solid = nullptr, *sky = nullptr, *detail = nullptr, *detail_illusionary = nullptr, *detail_fence = nullptr,
             *liquid = nullptr;
 
-    // tree of key/value pairs
-    std::map<std::string, std::string, case_insensitive_less> epairs;
-    // order of parse
-    std::vector<std::string> epair_order;
+    // key/value pairs in the order they were parsed
+    std::vector<std::pair<std::string, std::string>> epairs;
 
     aabb3d bounds;
     brush_t *brushes = nullptr; /* NULL terminated list */
diff --git a/qbsp/map.cc b/qbsp/map.cc
index 40a187b5..efedeb83 100644
--- a/qbsp/map.cc
+++ b/qbsp/map.cc
@@ -495,7 +495,8 @@ static void ParseEpair(parser_t &parser, mapentity_t *entity)
             goto parse_error;
 
         {
-            std::string &value = (entity->epairs[key] = parser.token);
+            std::string value = parser.token;
+            SetKeyValue(entity, key.c_str(), value.c_str());
 
             if (!Q_strcasecmp(key.c_str(), "origin")) {
                 GetVectorForKey(entity, key.c_str(), entity->origin);
@@ -514,8 +515,6 @@ static void ParseEpair(parser_t &parser, mapentity_t *entity)
                 }
             }
 
-            entity->epair_order.push_back(std::move(key));
-
             return;
         }
     }
@@ -2186,8 +2185,8 @@ static void ConvertEntity(std::ofstream &f, const mapentity_t *entity, const con
 {
     f << "{\n";
 
-    for (const auto &key : entity->epair_order) {
-        fmt::print(f, "\"{}\" \"{}\"\n", key, entity->epairs.at(key));
+    for (const auto &[key, value] : entity->epairs) {
+        fmt::print(f, "\"{}\" \"{}\"\n", key, value);
     }
 
     for (int i = 0; i < entity->nummapbrushes; i++) {
@@ -2235,17 +2234,23 @@ void PrintEntity(const mapentity_t *entity)
 
 const char *ValueForKey(const mapentity_t *entity, const char *key)
 {
-    auto it = entity->epairs.find(key);
-
-    if (it == entity->epairs.end())
-        return "";
-
-    return it->second.c_str();
+    for (auto &epair : entity->epairs) {
+        if (!Q_strcasecmp(key, epair.first.c_str())) {
+            return epair.second.c_str();
+        }
+    }
+    return "";
 }
 
 void SetKeyValue(mapentity_t *entity, const char *key, const char *value)
 {
-    entity->epairs[key] = value;
+    for (auto &epair : entity->epairs) {
+        if (!Q_strcasecmp(key, epair.first.c_str())) {
+            epair.second = value;
+            return;
+        }
+    }
+    entity->epairs.emplace_back(key, value);
 }
 
 /**