From 51fe8aff02967920f1f09ce408d5a861886f7f28 Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Sun, 31 Jul 2022 20:48:15 -0700
Subject: [PATCH] Fixed unexpected data beyond EOF error - fixes #29

---
 CHANGELOG.md          |  4 ++++
 src/ivfinsert.c       | 49 ++++++++++++++++++++++++++-----------------
 test/t/007_inserts.pl | 33 +++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+), 19 deletions(-)
 create mode 100644 test/t/007_inserts.pl

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6e2158d..e61f436 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.2.7 (unreleased)
+
+- Fixed `unexpected data beyond EOF` error
+
 ## 0.2.6 (2022-05-22)
 
 - Improved performance of index creation for Postgres < 12
diff --git a/src/ivfinsert.c b/src/ivfinsert.c
index 449d141..9a0f68c 100644
--- a/src/ivfinsert.c
+++ b/src/ivfinsert.c
@@ -53,18 +53,6 @@ FindInsertPage(Relation rel, Datum *values, BlockNumber *insertPage, ListInfo *
 	}
 }
 
-/*
- * Prepare to insert an index tuple
- */
-static void
-LoadInsertPage(Relation index, Buffer *buf, Page *page, GenericXLogState **state, BlockNumber insertPage)
-{
-	*buf = ReadBuffer(index, insertPage);
-	LockBuffer(*buf, BUFFER_LOCK_EXCLUSIVE);
-	*state = GenericXLogStart(index);
-	*page = GenericXLogRegisterBuffer(*state, *buf, 0);
-}
-
 /*
  * Insert a tuple into the index
  */
@@ -87,11 +75,18 @@ InsertTuple(Relation rel, IndexTuple itup, Relation heapRel, Datum *values)
 	itemsz = MAXALIGN(IndexTupleSize(itup));
 	Assert(itemsz <= BLCKSZ - MAXALIGN(SizeOfPageHeaderData) - MAXALIGN(sizeof(IvfflatPageOpaqueData)));
 
-	LoadInsertPage(rel, &buf, &page, &state, insertPage);
-
 	/* Find a page to insert the item */
-	while (PageGetFreeSpace(page) < itemsz)
+	for (;;)
 	{
+		buf = ReadBuffer(rel, insertPage);
+		LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
+
+		state = GenericXLogStart(rel);
+		page = GenericXLogRegisterBuffer(state, buf, 0);
+
+		if (PageGetFreeSpace(page) >= itemsz)
+			break;
+
 		insertPage = IvfflatPageGetOpaque(page)->nextblkno;
 
 		if (BlockNumberIsValid(insertPage))
@@ -99,15 +94,31 @@ InsertTuple(Relation rel, IndexTuple itup, Relation heapRel, Datum *values)
 			/* Move to next page */
 			GenericXLogAbort(state);
 			UnlockReleaseBuffer(buf);
-
-			LoadInsertPage(rel, &buf, &page, &state, insertPage);
 		}
 		else
 		{
 			/* Add a new page */
-			IvfflatAppendPage(rel, &buf, &page, &state, MAIN_FORKNUM);
+			Buffer		newbuf = IvfflatNewBuffer(rel, MAIN_FORKNUM);
+			Page		newpage = GenericXLogRegisterBuffer(state, buf, GENERIC_XLOG_FULL_IMAGE);
 
-			insertPage = BufferGetBlockNumber(buf);
+			insertPage = BufferGetBlockNumber(newbuf);
+
+			/* Update previous buffer */
+			IvfflatPageGetOpaque(page)->nextblkno = insertPage;
+
+			/* Init page */
+			PageInit(newpage, BufferGetPageSize(newbuf), sizeof(IvfflatPageOpaqueData));
+			IvfflatPageGetOpaque(newpage)->nextblkno = InvalidBlockNumber;
+			IvfflatPageGetOpaque(newpage)->page_id = IVFFLAT_PAGE_ID;
+
+			/* Commit */
+			MarkBufferDirty(buf);
+			MarkBufferDirty(newbuf);
+			GenericXLogFinish(state);
+
+			/* Unlock */
+			UnlockReleaseBuffer(buf);
+			UnlockReleaseBuffer(newbuf);
 		}
 	}
 
diff --git a/test/t/007_inserts.pl b/test/t/007_inserts.pl
new file mode 100644
index 0000000..40681de
--- /dev/null
+++ b/test/t/007_inserts.pl
@@ -0,0 +1,33 @@
+use strict;
+use warnings;
+use PostgresNode;
+use TestLib;
+use Test::More tests => 3;
+
+# Initialize node
+my $node = get_new_node('node');
+$node->init;
+$node->start;
+
+# Create table and index
+$node->safe_psql("postgres", "CREATE EXTENSION vector;");
+$node->safe_psql("postgres", "CREATE TABLE tst (v vector(768));");
+$node->safe_psql("postgres",
+	"INSERT INTO tst SELECT (SELECT array_agg(random()) FROM generate_series(1, 768)) FROM generate_series(1, 10000) i;"
+);
+$node->safe_psql("postgres", "CREATE INDEX ON tst USING ivfflat (v);");
+
+$node->pgbench(
+	"--no-vacuum --client=5 --transactions=100",
+	0,
+	[qr{actually processed}],
+	[qr{^$}],
+	"concurrent INSERTs",
+	{
+		"007_concurrent" => q(
+			BEGIN;
+			INSERT INTO tst SELECT (SELECT array_agg(random()) FROM generate_series(1, 768)) FROM generate_series(1, 10) i;
+			COMMIT;
+		),
+	}
+);