0001-Add-test-for-read_stream_resume.patch

From 36668cc39dd8a6e249ece3ed53201cb3ea17073e Mon Sep 17 00:00:00 2001
From: Melanie Plageman <melanieplageman@gmail.com>
Date: Wed, 8 Apr 2026 13:40:16 -0400
Subject: [PATCH 1/2] Add test for read_stream_resume()

---
 .../modules/test_aio/t/004_read_stream.pl     | 22 ++++++
 src/test/modules/test_aio/test_aio--1.0.sql   |  9 +++
 src/test/modules/test_aio/test_aio.c          | 71 +++++++++++++++++++
 src/tools/pgindent/typedefs.list              |  1 +
 4 files changed, 103 insertions(+)

diff --git a/src/test/modules/test_aio/t/004_read_stream.pl b/src/test/modules/test_aio/t/004_read_stream.pl
index 32311c07ac0..28aedd7d163 100644
--- a/src/test/modules/test_aio/t/004_read_stream.pl
+++ b/src/test/modules/test_aio/t/004_read_stream.pl
@@ -115,6 +115,27 @@ sub test_repeated_blocks
 }
 
 
+sub test_read_stream_resume
+{
+	my $io_method = shift;
+	my $node = shift;
+
+	my $psql = $node->background_psql('postgres', on_error_stop => 0);
+
+	$psql->query_safe(
+		qq(
+CREATE TEMPORARY TABLE tmp_read_stream(data int not null);
+INSERT INTO tmp_read_stream SELECT generate_series(1, 10000);
+SELECT test_read_stream_resume('tmp_read_stream', 0);
+DROP TABLE tmp_read_stream;
+));
+
+	ok(1, "$io_method: read_stream_resume");
+
+	$psql->quit();
+}
+
+
 sub test_inject_foreign
 {
 	my $io_method = shift;
@@ -268,6 +289,7 @@ sub test_io_method
 		$io_method, "$io_method: io_method set correctly");
 
 	test_repeated_blocks($io_method, $node);
+	test_read_stream_resume($io_method, $node);
 
   SKIP:
 	{
diff --git a/src/test/modules/test_aio/test_aio--1.0.sql b/src/test/modules/test_aio/test_aio--1.0.sql
index 762ac29512f..48caad25bda 100644
--- a/src/test/modules/test_aio/test_aio--1.0.sql
+++ b/src/test/modules/test_aio/test_aio--1.0.sql
@@ -128,3 +128,12 @@ AS 'MODULE_PATHNAME' LANGUAGE C;
 CREATE FUNCTION inj_io_reopen_detach()
 RETURNS pg_catalog.void STRICT
 AS 'MODULE_PATHNAME' LANGUAGE C;
+
+
+
+/*
+ * Read stream related functions
+ */
+CREATE FUNCTION test_read_stream_resume(rel regclass, blockno int4)
+RETURNS pg_catalog.void STRICT
+AS 'MODULE_PATHNAME' LANGUAGE C;
diff --git a/src/test/modules/test_aio/test_aio.c b/src/test/modules/test_aio/test_aio.c
index 35efba1a5e3..9d2d32ad1a2 100644
--- a/src/test/modules/test_aio/test_aio.c
+++ b/src/test/modules/test_aio/test_aio.c
@@ -916,6 +916,77 @@ read_stream_for_blocks(PG_FUNCTION_ARGS)
 }
 
 
+typedef struct
+{
+	BlockNumber blkno;
+	int			count;
+} test_read_stream_resume_state;
+
+static BlockNumber
+test_read_stream_resume_cb(ReadStream *stream,
+						   void *callback_private_data,
+						   void *per_buffer_data)
+{
+	test_read_stream_resume_state *state = callback_private_data;
+
+	/* Periodic end-of-stream. */
+	if (++state->count % 3 == 0)
+		return read_stream_pause(stream);
+
+	return state->blkno;
+}
+
+/*
+ * Test read_stream_resume(), allowing a stream to end temporarily and then
+ * continue where it left off.
+ */
+PG_FUNCTION_INFO_V1(test_read_stream_resume);
+Datum
+test_read_stream_resume(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	BlockNumber blkno = PG_GETARG_UINT32(1);
+	Relation	rel;
+	Buffer		buf;
+	ReadStream *stream;
+	test_read_stream_resume_state state = {.blkno = blkno};
+
+	rel = relation_open(relid, AccessShareLock);
+	stream = read_stream_begin_relation(READ_STREAM_DEFAULT,
+										NULL,
+										rel,
+										MAIN_FORKNUM,
+										test_read_stream_resume_cb,
+										&state,
+										0);
+
+	for (int i = 0; i < 3; ++i)
+	{
+		/* Same block twice. */
+		buf = read_stream_next_buffer(stream, NULL);
+		Assert(BufferGetBlockNumber(buf) == blkno);
+		ReleaseBuffer(buf);
+		buf = read_stream_next_buffer(stream, NULL);
+		Assert(BufferGetBlockNumber(buf) == blkno);
+		ReleaseBuffer(buf);
+
+		/* End-of-stream. */
+		buf = read_stream_next_buffer(stream, NULL);
+		Assert(buf == InvalidBuffer);
+		buf = read_stream_next_buffer(stream, NULL);
+		Assert(buf == InvalidBuffer);
+
+		/* Resume. */
+		read_stream_resume(stream);
+	}
+
+	read_stream_end(stream);
+	relation_close(rel, NoLock);
+
+	PG_RETURN_VOID();
+}
+
+
 PG_FUNCTION_INFO_V1(handle_get);
 Datum
 handle_get(PG_FUNCTION_ARGS)
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index ea95e7984bc..4236afefa2d 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -4329,6 +4329,7 @@ teSection
 temp_tablespaces_extra
 test128
 test_re_flags
+test_read_stream_resume_state
 test_regex_ctx
 test_shm_mq_header
 test_spec
-- 
2.43.0