Add a new HashMap implementation

Adds a new, cleaned up, HashMap implementation.

* Uses Robin Hood Hashing (https://en.wikipedia.org/wiki/Hash_table#Robin_Hood_hashing).
* Keeps elements in a double linked list for simpler, ordered, iteration.
* Allows keeping iterators for later use in removal (Unlike Map<>, it does not do much
  for performance vs keeping the key, but helps replace old code).
* Uses a more modern C++ iterator API, deprecates the old one.
* Supports custom allocator (in case there is a wish to use a paged one).

This class aims to unify all the associative template usage and replace it by this one:
* Map<> (whereas key order does not matter, which is 99% of cases)
* HashMap<>
* OrderedHashMap<>
* OAHashMap<>

1 files changed, 13 insertions, 27 deletions

diff --git a/core/string/translation_po.cpp b/core/string/translation_po.cpp
index 3f94e064ec..fa656b634d 100644
--- a/core/string/translation_po.cpp
+++ b/core/string/translation_po.cpp
@@ -70,21 +70,14 @@ Dictionary TranslationPO::_get_messages() const {
 
 	Dictionary d;
 
-	List<StringName> context_l;
-	translation_map.get_key_list(&context_l);
-	for (const StringName &ctx : context_l) {
-		const HashMap<StringName, Vector<StringName>> &id_str_map = translation_map[ctx];
-
+	for (const KeyValue<StringName, HashMap<StringName, Vector<StringName>>> &E : translation_map) {
 		Dictionary d2;
-		List<StringName> id_l;
-		id_str_map.get_key_list(&id_l);
-		// Save list of id and strs associated with a context in a temporary dictionary.
-		for (List<StringName>::Element *E2 = id_l.front(); E2; E2 = E2->next()) {
-			StringName id = E2->get();
-			d2[id] = id_str_map[id];
+
+		for (const KeyValue<StringName, Vector<StringName>> &E2 : E.value) {
+			d2[E2.key] = E2.value;
 		}
 
-		d[ctx] = d2;
+		d[E.key] = d2;
 	}
 
 	return d;
@@ -274,31 +267,24 @@ void TranslationPO::get_message_list(List<StringName> *r_messages) const {
 	// OptimizedTranslation uses this function to get the list of msgid.
 	// Return all the keys of translation_map under "" context.
 
-	List<StringName> context_l;
-	translation_map.get_key_list(&context_l);
-
-	for (const StringName &E : context_l) {
-		if (String(E) != "") {
+	for (const KeyValue<StringName, HashMap<StringName, Vector<StringName>>> &E : translation_map) {
+		if (E.key != StringName()) {
 			continue;
 		}
 
-		List<StringName> msgid_l;
-		translation_map[E].get_key_list(&msgid_l);
-
-		for (List<StringName>::Element *E2 = msgid_l.front(); E2; E2 = E2->next()) {
-			r_messages->push_back(E2->get());
+		for (const KeyValue<StringName, Vector<StringName>> &E2 : E.value) {
+			r_messages->push_back(E2.key);
 		}
 	}
 }
 
 int TranslationPO::get_message_count() const {
-	List<StringName> context_l;
-	translation_map.get_key_list(&context_l);
-
 	int count = 0;
-	for (const StringName &E : context_l) {
-		count += translation_map[E].size();
+
+	for (const KeyValue<StringName, HashMap<StringName, Vector<StringName>>> &E : translation_map) {
+		count += E.value.size();
 	}
+
 	return count;
 }