time: Make TimeZoneRule blittable and avoid copies (#3361)

* time: Make TimeZoneRule blittable and avoid copies

This drastically reduce overhead of using TimeZoneRule around the
codebase.

Effect on games is unknown

* Add missing Box type

* Ensure we clean the structure still

This doesn't perform any copies

* Address gdkchan's comments

* Simplify Box

2 files changed, 18 insertions, 15 deletions

diff --git a/Ryujinx.HLE/HOS/Services/Time/StaticService/ITimeZoneServiceForGlue.cs b/Ryujinx.HLE/HOS/Services/Time/StaticService/ITimeZoneServiceForGlue.cs
index 98d4b617..265cec5d 100644
--- a/Ryujinx.HLE/HOS/Services/Time/StaticService/ITimeZoneServiceForGlue.cs
+++ b/Ryujinx.HLE/HOS/Services/Time/StaticService/ITimeZoneServiceForGlue.cs
@@ -2,7 +2,10 @@ using Ryujinx.Common.Logging;
 using Ryujinx.Cpu;
 using Ryujinx.HLE.HOS.Services.Time.TimeZone;
 using Ryujinx.HLE.Utilities;
+using Ryujinx.Memory;
 using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Text;
 
 namespace Ryujinx.HLE.HOS.Services.Time.StaticService
@@ -100,15 +103,12 @@ namespace Ryujinx.HLE.HOS.Services.Time.StaticService
 
             string locationName = StringUtils.ReadInlinedAsciiString(context.RequestData, 0x24);
 
-            ResultCode resultCode = _timeZoneContentManager.LoadTimeZoneRule(out TimeZoneRule rules, locationName);
-
-            // Write TimeZoneRule if success
-            if (resultCode == ResultCode.Success)
+            using (WritableRegion region = context.Memory.GetWritableRegion(bufferPosition, Unsafe.SizeOf<TimeZoneRule>()))
             {
-                MemoryHelper.Write(context.Memory, bufferPosition, rules);
-            }
+                ref TimeZoneRule rules = ref MemoryMarshal.Cast<byte, TimeZoneRule>(region.Memory.Span)[0];
 
-            return resultCode;
+                return _timeZoneContentManager.LoadTimeZoneRule(ref rules, locationName);
+            }
         }
 
         [CommandHipc(100)]
diff --git a/Ryujinx.HLE/HOS/Services/Time/StaticService/ITimeZoneServiceForPsc.cs b/Ryujinx.HLE/HOS/Services/Time/StaticService/ITimeZoneServiceForPsc.cs
index 202099b0..24032999 100644
--- a/Ryujinx.HLE/HOS/Services/Time/StaticService/ITimeZoneServiceForPsc.cs
+++ b/Ryujinx.HLE/HOS/Services/Time/StaticService/ITimeZoneServiceForPsc.cs
@@ -4,9 +4,12 @@ using Ryujinx.Cpu;
 using Ryujinx.HLE.HOS.Services.Time.Clock;
 using Ryujinx.HLE.HOS.Services.Time.TimeZone;
 using Ryujinx.HLE.Utilities;
+using Ryujinx.Memory;
 using System;
 using System.Diagnostics;
 using System.IO;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 
 namespace Ryujinx.HLE.HOS.Services.Time.StaticService
 {
@@ -165,11 +168,11 @@ namespace Ryujinx.HLE.HOS.Services.Time.StaticService
 
             using (MemoryStream timeZoneBinaryStream = new MemoryStream(temp))
             {
-                result = _timeZoneManager.ParseTimeZoneRuleBinary(out TimeZoneRule timeZoneRule, timeZoneBinaryStream);
-
-                if (result == ResultCode.Success)
+                using (WritableRegion region = context.Memory.GetWritableRegion(timeZoneRuleBufferPosition, Unsafe.SizeOf<TimeZoneRule>()))
                 {
-                    MemoryHelper.Write(context.Memory, timeZoneRuleBufferPosition, timeZoneRule);
+                    ref TimeZoneRule rule = ref MemoryMarshal.Cast<byte, TimeZoneRule>(region.Memory.Span)[0];
+
+                    result = _timeZoneManager.ParseTimeZoneRuleBinary(ref rule, timeZoneBinaryStream);
                 }
             }
 
@@ -199,9 +202,9 @@ namespace Ryujinx.HLE.HOS.Services.Time.StaticService
                 throw new InvalidOperationException();
             }
 
-            TimeZoneRule rules = MemoryHelper.Read<TimeZoneRule>(context.Memory, bufferPosition);
+            ReadOnlySpan<TimeZoneRule> rules = MemoryMarshal.Cast<byte, TimeZoneRule>(context.Memory.GetSpan(bufferPosition, (int)bufferSize));
 
-            ResultCode resultCode = _timeZoneManager.ToCalendarTime(rules, posixTime, out CalendarInfo calendar);
+            ResultCode resultCode = _timeZoneManager.ToCalendarTime(in rules[0], posixTime, out CalendarInfo calendar);
 
             if (resultCode == 0)
             {
@@ -244,9 +247,9 @@ namespace Ryujinx.HLE.HOS.Services.Time.StaticService
                 throw new InvalidOperationException();
             }
 
-            TimeZoneRule rules = MemoryHelper.Read<TimeZoneRule>(context.Memory, inBufferPosition);
+            ReadOnlySpan<TimeZoneRule> rules = MemoryMarshal.Cast<byte, TimeZoneRule>(context.Memory.GetSpan(inBufferPosition, (int)inBufferSize));
 
-            ResultCode resultCode = _timeZoneManager.ToPosixTime(rules, calendarTime, out long posixTime);
+            ResultCode resultCode = _timeZoneManager.ToPosixTime(in rules[0], calendarTime, out long posixTime);
 
             if (resultCode == ResultCode.Success)
             {