From 76c7a402ebd7c779d332e230b3109260008c1de0 Mon Sep 17 00:00:00 2001
From: rlaphoenix <rlaphoenix@pm.me>
Date: Fri, 5 Aug 2022 07:35:34 +0100
Subject: [PATCH] PSSH: Optimize how overwrite_key_ids works with the repeated
 field

We can clear a repeated field with `del field[:]` and overwrite an entire field with `field[:] = [b"123", b"456"]`. So we can reduce this down to a single call operation.
---
 pywidevine/pssh.py | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/pywidevine/pssh.py b/pywidevine/pssh.py
index 8c3d0a5..229c8c8 100644
--- a/pywidevine/pssh.py
+++ b/pywidevine/pssh.py
@@ -270,13 +270,10 @@ class PSSH:
         init = WidevinePsshData()
         init.ParseFromString(box.init_data)
 
-        # TODO: Is there a better way to clear the Key IDs?
-        for _ in range(len(init.key_ids or [])):
-            init.key_ids.pop(0)
-
-        # TODO: Is there a .extend or a way to add all without a loop?
-        for key_id in key_ids:
-            init.key_ids.append(key_id.bytes)
+        init.key_ids[:] = [
+            key_id.bytes
+            for key_id in key_ids
+        ]
 
         box.init_data = init.SerializeToString()