From 02af419b6884be3e36c12b0ae4e488f33f0327ad Mon Sep 17 00:00:00 2001
From: Michael Davis <mcrdavis@amazon.com>
Date: Tue, 3 Feb 2026 15:22:35 -0500
Subject: [PATCH] reader: Add committed_chunk_id/1 callback implementation

This adds an implementation for `osiris_log_reader:committed_chunk_id/1`
which was added upstream recently in
<https://redirect.github.com/rabbitmq/osiris/pull/203>.
The committed chunk ID is now a different concept than the committed
offset. The committed chunk Id is the first offset in the chunk which
is committed by a quorum. The committed offset is the last offset in
that chunk.

Here we do the same as `osiris_log`: read the values which are being
maintained in the `osiris_log_shared` atomic.
---
 src/rabbitmq_stream_s3_log_reader.erl | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/rabbitmq_stream_s3_log_reader.erl b/src/rabbitmq_stream_s3_log_reader.erl
index 3bc0e99..cd6f2b8 100644
--- a/src/rabbitmq_stream_s3_log_reader.erl
+++ b/src/rabbitmq_stream_s3_log_reader.erl
@@ -50,6 +50,7 @@
 -export([
     init_offset_reader/2,
     next_offset/1,
+    committed_chunk_id/1,
     committed_offset/1,
     close/1,
     send_file/3,
@@ -127,8 +128,13 @@ next_offset(#?MODULE{mode = #remote{next_offset = NextOffset}}) ->
 next_offset(#?MODULE{mode = Local}) ->
     osiris_log:next_offset(Local).
 
-committed_offset(#?MODULE{mode = #remote{shared = Shared}}) ->
+committed_chunk_id(#?MODULE{mode = #remote{shared = Shared}}) ->
     osiris_log_shared:committed_chunk_id(Shared);
+committed_chunk_id(#?MODULE{mode = Local}) ->
+    osiris_log:committed_chunk_id(Local).
+
+committed_offset(#?MODULE{mode = #remote{shared = Shared}}) ->
+    osiris_log_shared:committed_offset(Shared);
 committed_offset(#?MODULE{mode = Local}) ->
     osiris_log:committed_offset(Local).