Files
paperless-ngx/profiling/harness.py
T
stumpylogandClaude Sonnet 5 0506dcad05 chore(profiling): add append_profiling_history function for persistent profiling records
Adds two new functions to harness.py:
- _current_git_ref(): Gets the current git short SHA
- append_profiling_history(): Appends JSON line to profiling/results/history.jsonl

This enables profiling numbers to persist across sessions/dates, with every run
appended to an immutable timeline rather than overwriting per-stage snapshots.

Also adds corresponding test to verify the function writes valid JSON lines.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-07-27 15:49:14 -07:00

124 lines
3.8 KiB
Python

# profiling/harness.py
from __future__ import annotations
import json
import subprocess
import time
from dataclasses import dataclass
from datetime import UTC
from datetime import datetime
from pathlib import Path
from typing import TYPE_CHECKING
from typing import Any
from typing import Generic
from typing import TypeVar
import pytest
from django.db import connection
from django.test.utils import CaptureQueriesContext
if TYPE_CHECKING:
from collections.abc import Callable
from django.db.models import QuerySet
from profiling.seed import ScaleProfile
T = TypeVar("T")
def require_postgres() -> None:
if connection.vendor != "postgresql":
pytest.skip(
"Profiling requires PostgreSQL to reflect production query "
"planning; SQLite does not reproduce the varchar-cast planner "
"pathology this work fixes.",
)
@dataclass(frozen=True, slots=True)
class ProfileResult(Generic[T]):
best_seconds: float
all_seconds: tuple[float, ...]
query_count: int
result: T
def run_profile(fn: Callable[[], T], *, repeat: int = 5) -> ProfileResult[T]:
require_postgres()
all_seconds: list[float] = []
result: T | None = None
query_count = 0
for i in range(repeat):
with CaptureQueriesContext(connection) as ctx:
start = time.perf_counter()
result = fn()
all_seconds.append(time.perf_counter() - start)
if i == repeat - 1:
query_count = len(ctx.captured_queries)
assert result is not None # repeat >= 1 guarantees at least one assignment
return ProfileResult(
best_seconds=min(all_seconds),
all_seconds=tuple(all_seconds),
query_count=query_count,
result=result,
)
def capture_explain_analyze(queryset: QuerySet[Any]) -> str:
if connection.vendor != "postgresql":
raise RuntimeError("EXPLAIN ANALYZE capture is Postgres-only")
sql, params = queryset.query.sql_with_params()
with connection.cursor() as cur:
cur.execute(f"EXPLAIN ANALYZE {sql}", params)
return "\n".join(row[0] for row in cur.fetchall())
def _current_git_ref() -> str:
result = subprocess.run(
["git", "rev-parse", "--short", "HEAD"],
capture_output=True,
text=True,
check=False,
)
return result.stdout.strip() or "unknown"
def append_profiling_history(
*,
stage: str,
scenario: str,
best_seconds: float,
query_count: int,
scale: ScaleProfile,
code_ref: str | None = None,
) -> None:
"""
Append one line to profiling/results/history.jsonl -- an append-only,
cross-session record of every profiling run. Unlike the per-stage
before/after snapshot JSON files (which the next run of the same stage
overwrites), this never gets clobbered, so a profiling effort picked
back up days later has a full timeline to resume from instead of only
the single most recent comparison.
``code_ref`` should identify the *production* code under test (a short
SHA on the feature branch, not this `profiling` branch) -- pass it
explicitly when known. Left as ``None``, it falls back to this repo's
current ``git rev-parse --short HEAD``, which is only meaningful if
you're actually running from a checkout where that reflects the code
being measured.
"""
results_dir = Path(__file__).parent / "results"
results_dir.mkdir(exist_ok=True)
entry = {
"timestamp": datetime.now(UTC).isoformat(),
"code_ref": code_ref or _current_git_ref(),
"stage": stage,
"scenario": scenario,
"scale": scale,
"best_seconds": best_seconds,
"query_count": query_count,
}
with (results_dir / "history.jsonl").open("a") as f:
f.write(json.dumps(entry) + "\n")