Implement Bukkit#getTps

Note that this requires the caller to be on a ticking region
or the global region, otherwise it will throw
UnsupportedOperationException.

Now the function returns the TPS for the current region.

folia-server/paper-patches/features/0006-Add-TPS-From-Region.patch

@@ -5,10 +5,10 @@ Subject: [PATCH] Add TPS From Region
 
 
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
-index 20bcfeef39746d547ef17ccf2b66d44ce1e6e354..755527ed59b50c95aeca71d0fc5fea224731ff51 100644
+index b254cab566110c590ba22b0bd48cc165bfd7ae27..bcd17eba9798747010ed96903992939a284199df 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
-@@ -3333,4 +3333,68 @@ public final class CraftServer implements Server {
+@@ -3349,4 +3349,68 @@ public final class CraftServer implements Server {
          this.console.addPluginAllowingSleep(plugin.getName(), value);
      }
      // Paper end - API to check if the server is sleeping

folia-server/paper-patches/files/src/main/java/org/bukkit/craftbukkit/CraftServer.java.patch

@@ -91,6 +91,37 @@
          //Preconditions.checkState(!this.console.isIteratingOverLevels, "Cannot unload a world while worlds are being ticked"); // Paper - Cat - Temp disable. We'll see how this goes.
          if (world == null) {
              return false;
+@@ -3083,11 +_,27 @@
+
+     @Override
+     public double[] getTPS() {
++        // Folia start - region threading
++        ca.spottedleaf.concurrentutil.scheduler.SchedulerThreadPool.SchedulableTick task = io.papermc.paper.threadedregions.TickRegionScheduler.getCurrentTickingTask();
++        if (task == null) {
++            // might be on the shutdown thread, try retrieving the current region
++            if (io.papermc.paper.threadedregions.TickRegionScheduler.getCurrentRegion() != null) {
++                // we are on the shutdown thread
++                task = io.papermc.paper.threadedregions.TickRegionScheduler.getCurrentRegion().getData().getRegionSchedulingHandle();
++            }
++        }
++        if (!(task instanceof io.papermc.paper.threadedregions.TickRegionScheduler.RegionScheduleHandle tickHandle)) {
++            throw new UnsupportedOperationException("Not on any region");
++        }
++
++        // 1m, 5m, 15m
++        long currTime = System.nanoTime();
+         return new double[] {
+-            net.minecraft.server.MinecraftServer.getServer().tps1.getAverage(),
+-            net.minecraft.server.MinecraftServer.getServer().tps5.getAverage(),
+-            net.minecraft.server.MinecraftServer.getServer().tps15.getAverage()
++                tickHandle.getTickReport1m(currTime).tpsData().segmentAll().average(),
++                tickHandle.getTickReport5m(currTime).tpsData().segmentAll().average(),
++                tickHandle.getTickReport15m(currTime).tpsData().segmentAll().average(),
+         };
++        // Folia end - region threading
+     }
+
+     // Paper start - adventure sounds
 @@ -3258,7 +_,7 @@
 
      @Override