From 5518a806a70e7f40d5054a762ccda7d5e6b0d31c Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Tue, 30 Jan 2024 14:33:00 +0200
Subject: [PATCH] Make v0.6.0 work with Neon

Now that the WAL-logging happens as a separate step at the end of the
build, we need a few neon-specific hints to make it work.
---
 src/hnswbuild.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/hnswbuild.c b/src/hnswbuild.c
index 680789ba9044900eac9321844ee2a808a4a2ed12..41c5b709bcb2367ac8b8c498788ecac4c1148b74 100644
--- a/src/hnswbuild.c
+++ b/src/hnswbuild.c
@@ -1089,13 +1089,41 @@ BuildIndex(Relation heap, Relation index, IndexInfo *indexInfo,
 	SeedRandom(42);
 #endif

+#ifdef NEON_SMGR
+	smgr_start_unlogged_build(index->rd_smgr);
+#endif
+
 	InitBuildState(buildstate, heap, index, indexInfo, forkNum);

 	BuildGraph(buildstate, forkNum);

+#ifdef NEON_SMGR
+	smgr_finish_unlogged_build_phase_1(index->rd_smgr);
+#endif
+
 	if (RelationNeedsWAL(index))
+	{
 		log_newpage_range(index, forkNum, 0, RelationGetNumberOfBlocks(index), true);

+#ifdef NEON_SMGR
+		{
+#if PG_VERSION_NUM >= 160000
+			RelFileLocator rlocator = index->rd_smgr->smgr_rlocator.locator;
+#else
+			RelFileNode rlocator = index->rd_smgr->smgr_rnode.node;
+#endif
+
+			SetLastWrittenLSNForBlockRange(XactLastRecEnd, rlocator,
+										   MAIN_FORKNUM, 0, RelationGetNumberOfBlocks(index));
+			SetLastWrittenLSNForRelation(XactLastRecEnd, rlocator, MAIN_FORKNUM);
+		}
+#endif
+	}
+
+#ifdef NEON_SMGR
+	smgr_end_unlogged_build(index->rd_smgr);
+#endif
+
 	FreeBuildState(buildstate);
 }