LibUnicode: Generate unique time zone structures

Each of the 374 locales contain 156 time zone structures. Of these
58,344 structures, 13,578 are unique.

Meta/Lagom/Tools/CodeGenerators/LibUnicode/GenerateUnicodeDateTimeFormat.cpp

@@ -55,6 +55,9 @@ constexpr auto s_calendar_symbols_list_index_type = "u8"sv;
 using CalendarIndexType = u8;
 constexpr auto s_calendar_index_type = "u8"sv;
 
+using TimeZoneIndexType = u16;
+constexpr auto s_time_zone_index_type = "u16"sv;
+
 struct CalendarPattern : public Unicode::CalendarPattern {
     bool contains_only_date_fields() const
     {
@@ -367,11 +370,43 @@ struct AK::Traits<Calendar> : public GenericTraits<Calendar> {
 };
 
 struct TimeZone {
+    unsigned hash() const
+    {
+        auto hash = int_hash(time_zone);
+        hash = pair_int_hash(hash, long_name);
+        hash = pair_int_hash(hash, short_name);
+        return hash;
+    }
+
+    bool operator==(TimeZone const& other) const
+    {
+        return (time_zone == other.time_zone)
+            && (long_name == other.long_name)
+            && (short_name == other.short_name);
+    }
+
     StringIndexType time_zone { 0 };
     StringIndexType long_name { 0 };
     StringIndexType short_name { 0 };
 };
 
+template<>
+struct AK::Formatter<TimeZone> : Formatter<FormatString> {
+    ErrorOr<void> format(FormatBuilder& builder, TimeZone const& time_zone)
+    {
+        return Formatter<FormatString>::format(builder,
+            "{{ {}, {}, {} }}",
+            time_zone.time_zone,
+            time_zone.long_name,
+            time_zone.short_name);
+    }
+};
+
+template<>
+struct AK::Traits<TimeZone> : public GenericTraits<TimeZone> {
+    static unsigned hash(TimeZone const& t) { return t.hash(); }
+};
+
 struct DayPeriod {
     Unicode::DayPeriod day_period {};
     u8 begin { 0 };
@@ -380,7 +415,7 @@ struct DayPeriod {
 
 struct Locale {
     HashMap<String, CalendarIndexType> calendars;
-    HashMap<String, TimeZone> time_zones;
+    HashMap<String, TimeZoneIndexType> time_zones;
     Vector<DayPeriod> day_periods;
 };
 
@@ -395,6 +430,7 @@ struct UnicodeLocaleData {
     UniqueStorage<CalendarSymbols, CalendarSymbolsIndexType> unique_calendar_symbols;
     UniqueStorage<CalendarSymbolsList, CalendarSymbolsListIndexType> unique_calendar_symbols_lists;
     UniqueStorage<Calendar, CalendarIndexType> unique_calendars;
+    UniqueStorage<TimeZone, TimeZoneIndexType> unique_time_zones;
 
     HashMap<String, Locale> locales;
 
@@ -1282,7 +1318,8 @@ static ErrorOr<void> parse_time_zone_names(String locale_time_zone_names_path, U
         if (!locale_data.time_zones.contains_slow(time_zone_name))
             locale_data.time_zones.append(time_zone_name);
 
-        locale.time_zones.set(time_zone_name, move(time_zone));
+        auto time_zone_index = locale_data.unique_time_zones.ensure(move(time_zone));
+        locale.time_zones.set(time_zone_name, time_zone_index);
     };
 
     meta_zone_object.as_object().for_each_member([&](auto const& meta_zone, JsonValue const& value) {
@@ -1465,6 +1502,7 @@ static void generate_unicode_locale_implementation(Core::File& file, UnicodeLoca
     generator.set("calendar_symbols_index_type"sv, s_calendar_symbols_index_type);
     generator.set("calendar_symbols_list_index_type"sv, s_calendar_symbols_list_index_type);
     generator.set("calendar_index_type"sv, s_calendar_index_type);
+    generator.set("time_zone_index_type"sv, s_time_zone_index_type);
 
     generator.append(R"~~~(
 #include <AK/Array.h>
@@ -1633,6 +1671,7 @@ struct DayPeriodData {
     locale_data.unique_calendar_symbols.generate(generator, "CalendarSymbols"sv, "s_calendar_symbols"sv, 10);
     locale_data.unique_calendar_symbols_lists.generate(generator, s_calendar_symbols_index_type, "s_calendar_symbol_lists"sv);
     locale_data.unique_calendars.generate(generator, "CalendarData"sv, "s_calendars"sv, 10);
+    locale_data.unique_time_zones.generate(generator, "TimeZoneData"sv, "s_time_zones"sv, 30);
 
     auto append_calendars = [&](String name, auto const& calendars) {
         generator.set("name", name);
@@ -1658,35 +1697,18 @@ static constexpr Array<@calendar_index_type@, @size@> @name@ { {)~~~");
         generator.set("size", String::number(locale_data.time_zones.size()));
 
         generator.append(R"~~~(
-static constexpr Array<TimeZoneData, @size@> @name@ { {)~~~");
-
-        constexpr size_t max_values_per_row = 20;
-        size_t values_in_current_row = 0;
+static constexpr Array<@time_zone_index_type@, @size@> @name@ { {)~~~");
 
+        bool first = true;
         for (auto const& time_zone_key : locale_data.time_zones) {
-            auto time_zone = time_zones.find(time_zone_key);
-
-            if (values_in_current_row++ > 0)
-                generator.append(" ");
-
-            if (time_zone == time_zones.end()) {
-                generator.append("{},");
-            } else {
-                generator.set("time_zone", String::number(time_zone->value.time_zone));
-                generator.set("long_name", String::number(time_zone->value.long_name));
-                generator.set("short_name", String::number(time_zone->value.short_name));
-                generator.append("{ @time_zone@, @long_name@, @short_name@ },");
-            }
+            auto time_zone = time_zones.get(time_zone_key).value_or(0);
 
-            if (values_in_current_row == max_values_per_row) {
-                values_in_current_row = 0;
-                generator.append("\n    ");
-            }
+            generator.append(first ? " " : ", ");
+            generator.append(String::number(time_zone));
+            first = false;
         }
 
-        generator.append(R"~~~(
-} };
-)~~~");
+        generator.append(" } };");
     };
 
     auto append_day_periods = [&](String name, auto const& day_periods) {
@@ -1724,7 +1746,7 @@ static constexpr Array<u8, @size@> @name@ { { )~~~");
     };
 
     generate_mapping(generator, locale_data.locales, s_calendar_index_type, "s_locale_calendars"sv, "s_calendars_{}", [&](auto const& name, auto const& value) { append_calendars(name, value.calendars); });
-    generate_mapping(generator, locale_data.locales, "TimeZoneData"sv, "s_time_zones"sv, "s_time_zones_{}", [&](auto const& name, auto const& value) { append_time_zones(name, value.time_zones); });
+    generate_mapping(generator, locale_data.locales, s_time_zone_index_type, "s_locale_time_zones"sv, "s_time_zones_{}", [&](auto const& name, auto const& value) { append_time_zones(name, value.time_zones); });
     generate_mapping(generator, locale_data.locales, "DayPeriodData"sv, "s_day_periods"sv, "s_day_periods_{}", [&](auto const& name, auto const& value) { append_day_periods(name, value.day_periods); });
     generate_mapping(generator, locale_data.hour_cycle_regions, "u8"sv, "s_hour_cycles"sv, "s_hour_cycles_{}", [&](auto const& name, auto const& value) { append_hour_cycles(name, value); });
 
@@ -1973,10 +1995,12 @@ static TimeZoneData const* find_time_zone_data(StringView locale, StringView tim
         return nullptr;
 
     auto locale_index = to_underlying(*locale_value) - 1; // Subtract 1 because 0 == Locale::None.
-    auto time_zone_index = to_underlying(*time_zone_value);
+    size_t time_zone_index = to_underlying(*time_zone_value);
+
+    auto const& time_zone_indices = s_locale_time_zones.at(locale_index);
+    time_zone_index = time_zone_indices.at(time_zone_index);
 
-    auto const& time_zones = s_time_zones.at(locale_index);
-    return &time_zones[time_zone_index];
+    return &s_time_zones[time_zone_index];
 }
 
 Optional<StringView> get_time_zone_name(StringView locale, StringView time_zone, CalendarPatternStyle style)