Move runtimes to json journal store

CHANGELOG.md

@@ -7,7 +7,9 @@ releases are available on [PyPI](https://pypi.org/project/pytask) and
 
 ## Unreleased
 
-- Nothing yet.
+- {pull}`766` moves runtime profiling persistence from SQLite to a JSON snapshot plus
+  append-only journal in `.pytask/`, keeping runtime data resilient to crashes and
+  compacted on normal build exits.
 
 ## 0.5.8 - 2025-12-30
 

justfile

@@ -12,7 +12,7 @@ test-cov *FLAGS:
 
 # Run type checking
 typing:
-    uv run --group typing --group test --isolated ty check src/ tests/
+    uv run --group typing --group test --isolated ty check
 
 # Run linting
 lint:

pyproject.toml

@@ -24,6 +24,7 @@ dependencies = [
     "attrs>=21.3.0",
     "click>=8.1.8,!=8.2.0",
     "click-default-group>=1.2.4",
+    "msgspec>=0.18.6",
     "networkx>=2.4.0",
     "optree>=0.9.0",
     "packaging>=23.0.0",
@@ -178,6 +179,7 @@ include = [
 unused-ignore-comment = "ignore"
 
 [tool.ty.src]
+include = ["src", "tests"]
 exclude = ["src/_pytask/_hashlib.py"]
 
 [tool.ty.terminal]

src/_pytask/journal.py

@@ -0,0 +1,55 @@
+"""Helpers for append-only JSONL journals."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import TYPE_CHECKING
+from typing import Generic
+from typing import TypeVar
+
+import msgspec
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+T = TypeVar("T")
+
+
+@dataclass(frozen=True)
+class JsonlJournal(Generic[T]):
+    """Append-only JSONL journal with best-effort recovery."""
+
+    path: Path
+    type_: type[T]
+
+    def append(self, payload: msgspec.Struct) -> None:
+        """Append a JSON line to the journal."""
+        with self.path.open("ab") as journal_file:
+            journal_file.write(msgspec.json.encode(payload) + b"\n")
+
+    def read(self) -> list[T]:
+        """Read entries, keeping valid entries on decode errors."""
+        if not self.path.exists():
+            return []
+
+        entries: list[T] = []
+        data = self.path.read_bytes()
+        offset = 0
+        for line in data.splitlines(keepends=True):
+            stripped = line.strip()
+            if not stripped:
+                offset += len(line)
+                continue
+            try:
+                entries.append(msgspec.json.decode(stripped, type=self.type_))
+            except msgspec.DecodeError:
+                with self.path.open("rb+") as journal_file:
+                    journal_file.truncate(offset)
+                return entries
+            offset += len(line)
+        return entries
+
+    def delete(self) -> None:
+        """Delete the journal if it exists."""
+        if self.path.exists():
+            self.path.unlink()

src/_pytask/profile.py

@@ -8,21 +8,18 @@
 import sys
 import time
 from contextlib import suppress
+from dataclasses import dataclass
 from typing import TYPE_CHECKING
 from typing import Any
 
 import click
 from rich.table import Table
-from sqlalchemy.orm import Mapped
-from sqlalchemy.orm import mapped_column
 
 from _pytask.click import ColoredCommand
 from _pytask.click import EnumChoice
 from _pytask.console import console
 from _pytask.console import format_task_name
 from _pytask.dag import create_dag
-from _pytask.database_utils import BaseTable
-from _pytask.database_utils import DatabaseSession
 from _pytask.exceptions import CollectionError
 from _pytask.exceptions import ConfigurationError
 from _pytask.node_protocols import PPathNode
@@ -31,6 +28,7 @@
 from _pytask.outcomes import TaskOutcome
 from _pytask.pluginmanager import hookimpl
 from _pytask.pluginmanager import storage
+from _pytask.runtime_store import RuntimeState
 from _pytask.session import Session
 from _pytask.traceback import Traceback
 
@@ -48,16 +46,6 @@ class _ExportFormats(enum.Enum):
     CSV = "csv"
 
 
-class Runtime(BaseTable):
-    """Record of runtimes of tasks."""
-
-    __tablename__ = "runtime"
-
-    task: Mapped[str] = mapped_column(primary_key=True)
-    date: Mapped[float]
-    duration: Mapped[float]
-
-
 @hookimpl(tryfirst=True)
 def pytask_extend_command_line_interface(cli: click.Group) -> None:
     """Extend the command line interface."""
@@ -67,8 +55,10 @@ def pytask_extend_command_line_interface(cli: click.Group) -> None:
 @hookimpl
 def pytask_post_parse(config: dict[str, Any]) -> None:
     """Register the export option."""
+    runtime_state = RuntimeState.from_root(config["root"])
+    config["pm"].register(ProfilePlugin(runtime_state))
+    config["pm"].register(DurationNameSpace(runtime_state))
     config["pm"].register(ExportNameSpace)
-    config["pm"].register(DurationNameSpace)
     config["pm"].register(FileSizeNameSpace)
 
 
@@ -82,27 +72,50 @@ def pytask_execute_task(task: PTask) -> Generator[None, None, None]:
     return result
 
 
-@hookimpl
-def pytask_execute_task_process_report(report: ExecutionReport) -> None:
-    """Store runtime of successfully finishing tasks in database."""
-    task = report.task
-    duration = task.attributes.get("duration")
-    if report.outcome == TaskOutcome.SUCCESS and duration is not None:
-        _create_or_update_runtime(task.signature, *duration)
+@dataclass
+class ProfilePlugin:
+    """Collect and persist runtime profiling data."""
+
+    runtime_state: RuntimeState
+
+    @hookimpl
+    def pytask_execute_task_process_report(
+        self, session: Session, report: ExecutionReport
+    ) -> None:
+        """Store runtime of successfully finishing tasks."""
+        _ = session
+        task = report.task
+        duration = task.attributes.get("duration")
+        if report.outcome == TaskOutcome.SUCCESS and duration is not None:
+            self.runtime_state.update_task(task, *duration)
 
+    @hookimpl
+    def pytask_unconfigure(self, session: Session) -> None:
+        """Flush runtime information on normal build exits."""
+        if session.config.get("command") != "build":
+            return
+        if session.config.get("dry_run") or session.config.get("explain"):
+            return
+        self.runtime_state.flush()
 
-def _create_or_update_runtime(task_signature: str, start: float, end: float) -> None:
-    """Create or update a runtime entry."""
-    with DatabaseSession() as session:
-        runtime = session.get(Runtime, task_signature)
 
-        if not runtime:
-            session.add(Runtime(task=task_signature, date=start, duration=end - start))
-        else:
-            for attr, val in (("date", start), ("duration", end - start)):
-                setattr(runtime, attr, val)
+@dataclass
+class DurationNameSpace:
+    """A namespace for adding durations to the profile."""
+
+    def __init__(self, runtime_state: RuntimeState) -> None:
+        self.runtime_state = runtime_state
 
-        session.commit()
+    @hookimpl
+    def pytask_profile_add_info_on_task(
+        self, session: Session, tasks: list[PTask], profile: dict[str, dict[str, Any]]
+    ) -> None:
+        """Add the runtime for tasks to the profile."""
+        _ = session
+        for task in tasks:
+            duration = self.runtime_state.get_duration(task)
+            if duration is not None:
+                profile[task.name]["Duration (in s)"] = round(duration, 2)
 
 
 @click.command(cls=ColoredCommand)
@@ -183,29 +196,6 @@ def _print_profile_table(
         console.print("No information is stored on the collected tasks.")
 
 
-class DurationNameSpace:
-    """A namespace for adding durations to the profile."""
-
-    @staticmethod
-    @hookimpl
-    def pytask_profile_add_info_on_task(
-        tasks: list[PTask], profile: dict[str, dict[str, Any]]
-    ) -> None:
-        """Add the runtime for tasks to the profile."""
-        runtimes = _collect_runtimes(tasks)
-        for name, duration in runtimes.items():
-            profile[name]["Duration (in s)"] = round(duration, 2)
-
-
-def _collect_runtimes(tasks: list[PTask]) -> dict[str, float]:
-    """Collect runtimes."""
-    with DatabaseSession() as session:
-        runtimes = [session.get(Runtime, task.signature) for task in tasks]
-    return {
-        task.name: r.duration for task, r in zip(tasks, runtimes, strict=False) if r
-    }
-
-
 class FileSizeNameSpace:
     """A namespace for adding the total file size of products to a task."""
 

src/_pytask/runtime_store.py

@@ -0,0 +1,138 @@
+"""Runtime storage with an append-only journal."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from dataclasses import field
+from typing import TYPE_CHECKING
+
+import msgspec
+
+from _pytask.journal import JsonlJournal
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+    from _pytask.node_protocols import PTask
+
+
+class _RuntimeEntry(msgspec.Struct):
+    id: str
+    date: float
+    duration: float
+
+
+class _RuntimeFile(msgspec.Struct, forbid_unknown_fields=False):
+    task: list[_RuntimeEntry] = msgspec.field(default_factory=list)
+
+
+class _RuntimeJournalEntry(msgspec.Struct, forbid_unknown_fields=False):
+    id: str
+    date: float
+    duration: float
+
+
+def _read_runtimes(path: Path) -> _RuntimeFile | None:
+    if not path.exists():
+        return None
+    try:
+        data = msgspec.json.decode(path.read_bytes(), type=_RuntimeFile)
+    except msgspec.DecodeError:
+        path.unlink()
+        return None
+    return data
+
+
+def _write_runtimes(path: Path, runtimes: _RuntimeFile) -> None:
+    data = msgspec.json.encode(runtimes)
+    tmp = path.with_suffix(f"{path.suffix}.tmp")
+    tmp.write_bytes(data)
+    tmp.replace(path)
+
+
+def _read_journal(
+    journal: JsonlJournal[_RuntimeJournalEntry],
+) -> list[_RuntimeJournalEntry]:
+    return journal.read()
+
+
+def _apply_journal(
+    runtimes: _RuntimeFile, entries: list[_RuntimeJournalEntry]
+) -> _RuntimeFile:
+    if not entries:
+        return runtimes
+    index = {entry.id: entry for entry in runtimes.task}
+    for entry in entries:
+        index[entry.id] = _RuntimeEntry(
+            id=entry.id, date=entry.date, duration=entry.duration
+        )
+    return _RuntimeFile(
+        task=list(index.values()),
+    )
+
+
+@dataclass
+class RuntimeState:
+    path: Path
+    runtimes: _RuntimeFile
+    journal: JsonlJournal[_RuntimeJournalEntry]
+    _index: dict[str, _RuntimeEntry] = field(init=False, default_factory=dict)
+    _dirty: bool = field(init=False, default=False)
+
+    def __post_init__(self) -> None:
+        self._rebuild_index()
+
+    @classmethod
+    def from_root(cls, root: Path) -> RuntimeState:
+        path = root / ".pytask" / "runtimes.json"
+        journal = JsonlJournal(
+            path=path.with_suffix(".journal"), type_=_RuntimeJournalEntry
+        )
+        existing = _read_runtimes(path)
+        journal_entries = _read_journal(journal)
+        if existing is None:
+            runtimes = _RuntimeFile(
+                task=[],
+            )
+            runtimes = _apply_journal(runtimes, journal_entries)
+            state = cls(path=path, runtimes=runtimes, journal=journal)
+        else:
+            runtimes = _apply_journal(existing, journal_entries)
+            state = cls(path=path, runtimes=runtimes, journal=journal)
+
+        if journal_entries:
+            state._dirty = True
+        return state
+
+    def _rebuild_index(self) -> None:
+        self._index = {entry.id: entry for entry in self.runtimes.task}
+
+    def update_task(self, task: PTask, start: float, end: float) -> None:
+        task_id = task.name
+        entry = _RuntimeEntry(id=task_id, date=start, duration=end - start)
+        self._index[entry.id] = entry
+        self.runtimes = _RuntimeFile(
+            task=list(self._index.values()),
+        )
+        self._rebuild_index()
+        journal_entry = _RuntimeJournalEntry(
+            id=entry.id,
+            date=entry.date,
+            duration=entry.duration,
+        )
+        self.journal.append(journal_entry)
+        self._dirty = True
+
+    def get_duration(self, task: PTask) -> float | None:
+        task_id = task.name
+        entry = self._index.get(task_id)
+        if entry is None:
+            return None
+        return entry.duration
+
+    def flush(self) -> None:
+        if not self._dirty:
+            return
+        _write_runtimes(self.path, self.runtimes)
+        self.journal.delete()
+        self._dirty = False