Files
siftlode/backend/tests/test_download_deprioritize.py
T
peter 4aaaaa7860 chore(comments): drop epic, sprint and review-round ids from the code
The code cited its plan instead of saying why: `E28 review J4`, `(R6 S3b)`, `S1 justified…`,
`deep-review round 5`. That plan lives in the private ops repo, so for every reader of this one the
citation was noise, and a sentence whose subject was the plan step ("round 2 showed…") hid its
lesson behind an id. Each one is gone and the "why" kept: a bare citation is deleted, a sentence
carrying a lesson is reworded around it ("a later attempt showed…").

Measured (`scripts/audit_metrics.py`, product code): 652 lines in 270 files carried an epic code by
the definition the next commit holds (507 / 241 by the old, two-digit-only one) -> 0. Across all
code, tests, scripts and configs: ~1100 epic-code lines plus ~320 sprint/round ids.

Behaviour unchanged, checked mechanically: every changed .py file has the same AST once docstrings
are blanked; css/sh/toml/yml/json files are identical once comments are stripped; the only
non-comment changes in TS/JS are test titles, one description string in a contract table, and five
ESLint messages, whose text is all the gates snapshot diff holds. Not touched: Markdown (docs and
the changelog keep their history), Alembic migrations, TV episode notation (`S2 · E5`), DESIGN.md
ids (`C1`, `B4`, `S3h`), tracker ids (`SEC-16`, `DX-17`).

One stale claim fixed on the way: test_hls_reaper's docstring said the player checkpoints "every
10 s whether or not it is playing", which plex/stream.py calls wrong; it now says what the code does.
2026-10-05 00:19:39 +02:00

104 lines
4.4 KiB
Python

"""Worker-child resource de-prioritization: the encoder thread cap, the `-threads` flag on the
browser-safe re-encode, and the child's startup renice/ionice/OMP handicap. These keep a CPU-heavy
transcode from pegging every core on the box it shares with the API, Postgres, and Plex playback."""
import subprocess
import pytest
from app.config import settings
from app.downloads import edit as editmod
from app.downloads import runner
class TestEncodeThreadCap:
def test_pinned_setting_wins(self, monkeypatch):
monkeypatch.setattr(settings, "download_ffmpeg_threads", 3)
assert editmod.encode_thread_cap() == 3
def test_zero_reserves_one_core(self, monkeypatch):
monkeypatch.setattr(settings, "download_ffmpeg_threads", 0)
monkeypatch.setattr(editmod.os, "cpu_count", lambda: 8)
assert editmod.encode_thread_cap() == 7
def test_single_core_box_never_caps_below_one(self, monkeypatch):
monkeypatch.setattr(settings, "download_ffmpeg_threads", 0)
monkeypatch.setattr(editmod.os, "cpu_count", lambda: 1)
assert editmod.encode_thread_cap() == 1
def test_unknown_cpu_count_falls_back(self, monkeypatch):
monkeypatch.setattr(settings, "download_ffmpeg_threads", 0)
monkeypatch.setattr(editmod.os, "cpu_count", lambda: None)
assert editmod.encode_thread_cap() == 1 # max(1, 2 - 1)
class TestBrowserSafeThreads:
def test_threads_flag_added_when_capped(self):
cmd = editmod.build_browser_safe_cmd(
"/in.mkv", "/out.mp4", reencode_video=True, reencode_audio=False, threads=2
)
assert "-threads" in cmd
assert cmd[cmd.index("-threads") + 1] == "2"
# The cap precedes the output file, so it binds the encoder (not input decoding).
assert cmd.index("-threads") < cmd.index("/out.mp4")
@pytest.mark.parametrize("threads", [0, None])
def test_no_threads_flag_when_uncapped(self, threads):
cmd = editmod.build_browser_safe_cmd(
"/in.mkv", "/out.mp4", reencode_video=True, reencode_audio=False, threads=threads
)
assert "-threads" not in cmd
class TestDeprioritize:
def test_renices_by_configured_increment(self, monkeypatch):
monkeypatch.setattr(settings, "download_child_nice", 12)
monkeypatch.setattr(settings, "download_child_ionice_class", 0) # skip ionice branch
calls = []
monkeypatch.setattr(runner.os, "nice", lambda n: calls.append(n))
monkeypatch.setattr(runner.os, "environ", {})
runner._deprioritize()
assert calls == [12]
def test_nice_zero_does_not_renice(self, monkeypatch):
monkeypatch.setattr(settings, "download_child_nice", 0)
monkeypatch.setattr(settings, "download_child_ionice_class", 0)
calls = []
monkeypatch.setattr(runner.os, "nice", lambda n: calls.append(n))
monkeypatch.setattr(runner.os, "environ", {})
runner._deprioritize()
assert calls == []
def test_sets_omp_budget_to_thread_cap(self, monkeypatch):
monkeypatch.setattr(settings, "download_child_nice", 0)
monkeypatch.setattr(settings, "download_child_ionice_class", 0)
monkeypatch.setattr(settings, "download_ffmpeg_threads", 4)
env: dict = {}
monkeypatch.setattr(runner.os, "environ", env)
runner._deprioritize()
assert env["OMP_NUM_THREADS"] == "4"
def test_ionice_invoked_when_binary_present(self, monkeypatch):
monkeypatch.setattr(settings, "download_child_nice", 0)
monkeypatch.setattr(settings, "download_child_ionice_class", 3)
monkeypatch.setattr(runner.os, "environ", {})
monkeypatch.setattr(runner.shutil, "which", lambda name: "/usr/bin/ionice")
ran = []
monkeypatch.setattr(
runner.subprocess,
"run",
lambda cmd, **kw: ran.append(cmd) or subprocess.CompletedProcess(cmd, 0),
)
runner._deprioritize()
assert ran and ran[0][:3] == ["ionice", "-c", "3"]
def test_ionice_skipped_when_binary_absent(self, monkeypatch):
monkeypatch.setattr(settings, "download_child_nice", 0)
monkeypatch.setattr(settings, "download_child_ionice_class", 3)
monkeypatch.setattr(runner.os, "environ", {})
monkeypatch.setattr(runner.shutil, "which", lambda name: None)
ran = []
monkeypatch.setattr(runner.subprocess, "run", lambda cmd, **kw: ran.append(cmd))
runner._deprioritize()
assert ran == []