From 1ebd0cbddbe6db114b44722bf3b30a9010905a89 Mon Sep 17 00:00:00 2001
From: ty <lastcanal@gmail.com>
Date: Wed, 18 Dec 2024 16:49:03 -0500
Subject: [PATCH 1/2] Get current segment number from  segment filename

The current implimentation is not smart enough to discover when
discontinuities have caused the segment number to increment, causing a
mis-match between the stored sequence numbers and the current
'preload-hint' partial.

It would be possible to get rid of Regex.named_captures by including the
segment number in the metadata send by Membrane.HTTPAdaptiveStream.Storage
---
 lib/algora/pipeline/storage.ex | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/lib/algora/pipeline/storage.ex b/lib/algora/pipeline/storage.ex
index c118ebf0..af2b37fa 100644
--- a/lib/algora/pipeline/storage.ex
+++ b/lib/algora/pipeline/storage.ex
@@ -40,6 +40,7 @@ defmodule Algora.Pipeline.Storage do
 
   @ets_cached_duration_in_segments 24
   @delta_manifest_suffix "_delta.m3u8"
+  @segment_from_filename ~r/^\w+_segment_+(?<segment>\d*)/
 
   @impl true
   def init(state) do
@@ -87,7 +88,7 @@ defmodule Algora.Pipeline.Storage do
 
     state =
       process_contents(parent_id, name, contents, metadata, ctx, state)
-      |> update_sequence_numbers(sequence_number, manifest_name)
+      |> update_sequence_numbers(sequence_number, name, manifest_name)
       |> add_partial(name, ctx, partial_name, contents, manifest_name)
 
     {:ok, state}
@@ -257,20 +258,24 @@ defmodule Algora.Pipeline.Storage do
   defp update_sequence_numbers(
          %{sequences: sequences} = state,
          new_partial_sn,
+         segment_name,
          manifest_name
        ) do
-    {segment_sn, partial_sn} = Map.get(sequences, manifest_name, {0, 0})
-    new_segment? = new_partial_sn < partial_sn
-    sequence = if new_segment? do
-      { segment_sn + 1, new_partial_sn }
-    else
-      { segment_sn, new_partial_sn }
-    end
+    {segment_sn, _partial_sn} = Map.get(sequences, manifest_name, {0, 0})
+    new_segment_sn =
+      case Regex.named_captures(@segment_from_filename, segment_name) do
+        %{"segment" => new_segment_sn} ->
+          String.to_integer(new_segment_sn)
+        _no_match ->
+          Membrane.Logger.error("failed extract segment number from filename #{inspect(segment_name)}")
+          segment_sn
+      end
+
     state = sequences
-      |> Map.put(manifest_name, sequence)
+      |> Map.put(manifest_name, {new_segment_sn, new_partial_sn})
       |> then(&Map.put(state, :sequences, &1))
       # If there is a new segment we want to remove partials that are too old from ets
-    if new_segment? do
+    if new_segment_sn > segment_sn do
       remove_partials(state, manifest_name)
     else
       state

From 36d73de61f3cb41a89d29de333f2c86db4e459ef Mon Sep 17 00:00:00 2001
From: ty <lastcanal@gmail.com>
Date: Wed, 18 Dec 2024 19:49:39 -0500
Subject: [PATCH 2/2] remove regex

---
 lib/algora/pipeline/storage.ex | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/lib/algora/pipeline/storage.ex b/lib/algora/pipeline/storage.ex
index af2b37fa..6912252e 100644
--- a/lib/algora/pipeline/storage.ex
+++ b/lib/algora/pipeline/storage.ex
@@ -40,7 +40,6 @@ defmodule Algora.Pipeline.Storage do
 
   @ets_cached_duration_in_segments 24
   @delta_manifest_suffix "_delta.m3u8"
-  @segment_from_filename ~r/^\w+_segment_+(?<segment>\d*)/
 
   @impl true
   def init(state) do
@@ -262,19 +261,12 @@ defmodule Algora.Pipeline.Storage do
          manifest_name
        ) do
     {segment_sn, _partial_sn} = Map.get(sequences, manifest_name, {0, 0})
-    new_segment_sn =
-      case Regex.named_captures(@segment_from_filename, segment_name) do
-        %{"segment" => new_segment_sn} ->
-          String.to_integer(new_segment_sn)
-        _no_match ->
-          Membrane.Logger.error("failed extract segment number from filename #{inspect(segment_name)}")
-          segment_sn
-      end
-
+    new_segment_sn = get_segment_number_from_name(segment_name)
     state = sequences
       |> Map.put(manifest_name, {new_segment_sn, new_partial_sn})
       |> then(&Map.put(state, :sequences, &1))
-      # If there is a new segment we want to remove partials that are too old from ets
+
+    # If there is a new segment we want to remove partials that are too old
     if new_segment_sn > segment_sn do
       remove_partials(state, manifest_name)
     else
@@ -386,4 +378,13 @@ defmodule Algora.Pipeline.Storage do
   defp process_contents(_parent_id, _name, _contents, _metadata, _ctx, state) do
     state
   end
+
+  # audio_segment_0_audio_master.m4s
+  defp get_segment_number_from_name(filename) do
+    filename
+    |> String.split("_")
+    |> Enum.drop(2)
+    |> List.first()
+    |> String.to_integer()
+  end
 end