From 78b7bb5e30f7998b2701f5e967ec5d9c1849f7da Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Wed, 27 Mar 2024 16:46:42 -0400 Subject: [PATCH v6 5/6] Add read_stream_reset For rescan, we want to reuse the existing ReadStream and simply release the pinned buffers. --- src/backend/storage/aio/read_stream.c | 19 +++++++++++++++++++ src/include/storage/read_stream.h | 1 + 2 files changed, 20 insertions(+) diff --git a/src/backend/storage/aio/read_stream.c b/src/backend/storage/aio/read_stream.c index 4e293e0df65..0d855475959 100644 --- a/src/backend/storage/aio/read_stream.c +++ b/src/backend/storage/aio/read_stream.c @@ -731,3 +731,22 @@ read_stream_end(ReadStream *stream) /* Release memory. */ pfree(stream); } + + +/* + * Reset a read stream by releasing all of the buffers. + */ +void +read_stream_reset(ReadStream *stream) +{ + Buffer buffer; + + /* Stop looking ahead. */ + stream->distance = 0; + + /* Unpin anything that wasn't consumed. */ + while ((buffer = read_stream_next_buffer(stream, NULL)) != InvalidBuffer) + ReleaseBuffer(buffer); + + stream->distance = 1; +} diff --git a/src/include/storage/read_stream.h b/src/include/storage/read_stream.h index 9e5fa2acf15..dc1733a1594 100644 --- a/src/include/storage/read_stream.h +++ b/src/include/storage/read_stream.h @@ -58,5 +58,6 @@ extern ReadStream *read_stream_begin_relation(int flags, size_t per_buffer_data_size); extern Buffer read_stream_next_buffer(ReadStream *stream, void **per_buffer_private); extern void read_stream_end(ReadStream *stream); +extern void read_stream_reset(ReadStream *stream); #endif /* READ_STREAM_H */ -- 2.40.1