From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Mon, 20 Jan 2025 13:30:34 -0800
Subject: [PATCH] Flush regionfiles on save configuration option

The windows file system does not write metadata unless
the FileChannel is explicitly flushed with metaData=true.

Note: Setting SYNC (not DSYNC) on the FileChannel does not appear
to write the metadata.

Specifically, we are interested in writing the last modified
timestamp so that fs watchers can detect when RegionFiles are
modified.

diff --git a/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java b/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java
index 09320f243a54f855b29d3833089b096975ca0075..709df35246fb328cda21679b53d44d9f96206cb3 100644
--- a/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java
+++ b/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java
@@ -1258,6 +1258,14 @@ public final class MoonriseRegionFileIO {
 
             try {
                 this.regionDataController.finishWrite(this.chunkX, this.chunkZ, writeData);
+                // Paper start - flush regionfiles on save
+                if (this.world.paperConfig().chunks.flushRegionsOnSave) {
+                    final RegionFile regionFile = this.regionDataController.getCache().moonrise$getRegionFileIfLoaded(this.chunkX, this.chunkZ);
+                    if (regionFile != null) {
+                        regionFile.flush();
+                    } // else: evicted from cache, which should have called flush
+                }
+                // Paper end - flush regionfiles on save
             } catch (final Throwable thr) {
                 failedWrite = thr instanceof IOException;
                 LOGGER.error("Failed to write chunk data for task: " + this.toString(), thr);
