From e8ef562d01240359c47c6e7e532ce63a6176ac77 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alicia=20Boya=20Garc=C3=ADa?= <aboya@igalia.com>
Date: Mon, 20 Jan 2025 18:48:11 +0100
Subject: [PATCH] tracers: log: Log buffer-chain

Commit de30de865cd added a hook for pad-chain-{pre,post} and
pad-chain-list-{pre,post}. As explained in that commit, hooking the
chain is helpful because it allows you to hook to buffer propagation in
both srcpads (pad-push) and sinkpads (pad-chain).

This patch uses the new hooks to log pad-chain in the log tracer.
Before, only pad-push was logged, so you could only follow the flow of
buffers through the srcpads.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8329>
---
 .../gstreamer/plugins/tracers/gstlog.c        | 46 +++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/subprojects/gstreamer/plugins/tracers/gstlog.c b/subprojects/gstreamer/plugins/tracers/gstlog.c
index bd89ea8be8..a36102f004 100644
--- a/subprojects/gstreamer/plugins/tracers/gstlog.c
+++ b/subprojects/gstreamer/plugins/tracers/gstlog.c
@@ -51,9 +51,11 @@
  *
  *  * `GST_DEBUG=GST_BUFFER:TRACE`
  *    * `pad-push-pre`, `pad-push-post`
+ *    * `pad-chain-pre`, `pad-chain-post`
  *    * `pad-pull-range-pre`, `pad-pull-range-post`
  *  * `GST_DEBUG=GST_BUFFER_LIST:TRACE`
  *    * `pad-push-list-pre`, `pad-push-list-post`
+ *    * `pad-chain-list-pre`, `pad-chain-list-post`
  *  * `GST_DEBUG=GST_EVENT:TRACE`
  *    * `pad-push-event-pre`, `pad-push-event-post`
  *  * `GST_DEBUG=GST_QUERY:TRACE`
@@ -188,6 +190,42 @@ do_push_buffer_list_post (GstTracer * self, guint64 ts, GstPad * pad,
       GST_TIME_ARGS (ts), pad, res);
 }
 
+static void
+do_chain_buffer_pre (GstTracer * self, guint64 ts, GstPad * pad,
+    GstFlowReturn res)
+{
+  do_log (GST_CAT_BUFFER, GST_FUNCTION, (GObject *) pad,
+      "%" GST_TIME_FORMAT ", pad=%" GST_PTR_FORMAT ", res=%d",
+      GST_TIME_ARGS (ts), pad, res);
+}
+
+static void
+do_chain_buffer_post (GstTracer * self, guint64 ts, GstPad * pad,
+    GstFlowReturn res)
+{
+  do_log (GST_CAT_BUFFER, GST_FUNCTION, (GObject *) pad,
+      "%" GST_TIME_FORMAT ", pad=%" GST_PTR_FORMAT ", res=%d",
+      GST_TIME_ARGS (ts), pad, res);
+}
+
+static void
+do_chain_buffer_list_pre (GstTracer * self, guint64 ts, GstPad * pad,
+    GstFlowReturn res)
+{
+  do_log (GST_CAT_BUFFER_LIST, GST_FUNCTION, (GObject *) pad,
+      "%" GST_TIME_FORMAT ", pad=%" GST_PTR_FORMAT ", res=%d",
+      GST_TIME_ARGS (ts), pad, res);
+}
+
+static void
+do_chain_buffer_list_post (GstTracer * self, guint64 ts, GstPad * pad,
+    GstFlowReturn res)
+{
+  do_log (GST_CAT_BUFFER_LIST, GST_FUNCTION, (GObject *) pad,
+      "%" GST_TIME_FORMAT ", pad=%" GST_PTR_FORMAT ", res=%d",
+      GST_TIME_ARGS (ts), pad, res);
+}
+
 static void
 do_pull_range_pre (GstTracer * self, guint64 ts, GstPad * pad, guint64 offset,
     guint size)
@@ -437,6 +475,14 @@ gst_log_tracer_init (GstLogTracer * self)
       G_CALLBACK (do_push_buffer_list_pre));
   gst_tracing_register_hook (tracer, "pad-push-list-post",
       G_CALLBACK (do_push_buffer_list_post));
+  gst_tracing_register_hook (tracer, "pad-chain-pre",
+      G_CALLBACK (do_chain_buffer_pre));
+  gst_tracing_register_hook (tracer, "pad-chain-post",
+      G_CALLBACK (do_chain_buffer_post));
+  gst_tracing_register_hook (tracer, "pad-chain-list-pre",
+      G_CALLBACK (do_chain_buffer_list_pre));
+  gst_tracing_register_hook (tracer, "pad-chain-list-post",
+      G_CALLBACK (do_chain_buffer_list_post));
   gst_tracing_register_hook (tracer, "pad-pull-range-pre",
       G_CALLBACK (do_pull_range_pre));
   gst_tracing_register_hook (tracer, "pad-pull-range-post",