Init

ptdiag/result.py

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+"""Unique result-directory creation and JSON output."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from datetime import datetime
+import json
+import os
+from pathlib import Path
+import re
+from typing import Any, Mapping
+
+
+@dataclass(frozen=True)
+class ResultDirectory:
+	path: Path
+	metadata_path: Path
+	commands_path: Path
+
+
+def create_result_directory(
+	root: Path,
+	test_name: str,
+	started_at: datetime | None = None,
+) -> ResultDirectory:
+	name = _slug(test_name)
+	started = started_at or datetime.now().astimezone()
+	base_name = f"{started:%Y%m%d-%H%M%S}-{name}"
+	root.mkdir(parents=True, exist_ok=True)
+	path = _mkdir_unique(root, base_name)
+	metadata_path = path / "metadata.json"
+	commands_path = path / "commands.log"
+	commands_path.touch(exist_ok=False)
+	write_json(
+		metadata_path,
+		{
+			"test": name,
+			"started_at": started.isoformat(),
+			"result_directory": str(path),
+		},
+	)
+	return ResultDirectory(path, metadata_path, commands_path)
+
+
+def write_json(path: Path, value: Mapping[str, Any]) -> None:
+	path.parent.mkdir(parents=True, exist_ok=True)
+	temporary = path.with_name(f".{path.name}.{os.getpid()}.tmp")
+	with temporary.open("w", encoding="utf-8") as handle:
+		json.dump(value, handle, indent=2, sort_keys=True)
+		handle.write("\n")
+	temporary.replace(path)
+
+
+def _slug(value: str) -> str:
+	result = re.sub(r"[^a-z0-9]+", "-", value.casefold()).strip("-")
+	if not result:
+		raise ValueError("test_name must contain a letter or digit")
+	return result
+
+
+def _mkdir_unique(root: Path, base_name: str) -> Path:
+	for index in range(1000):
+		suffix = "" if index == 0 else f"-{index:02d}"
+		candidate = root / f"{base_name}{suffix}"
+		try:
+			candidate.mkdir()
+		except FileExistsError:
+			continue
+		return candidate
+	raise FileExistsError(f"Could not allocate a unique result directory for {base_name}")
+