feat: scaffold Focus export logging skeleton

litellm/integrations/focus/database.py

@@ -0,0 +1,22 @@
+"""Database access helpers for Focus export."""
+
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Optional
+
+import polars as pl
+
+
+class FocusLiteLLMDatabase:
+    """Retrieves LiteLLM usage data for Focus export workflows."""
+
+    async def get_usage_data(
+        self,
+        *,
+        limit: Optional[int] = None,
+        start_time_utc: Optional[datetime] = None,
+        end_time_utc: Optional[datetime] = None,
+    ) -> pl.DataFrame:
+        """Return usage data for the requested window."""
+        raise NotImplementedError

litellm/integrations/focus/destinations/__init__.py

@@ -0,0 +1,12 @@
+"""Destination implementations for Focus export."""
+
+from .base import FocusDestination, FocusTimeWindow
+from .factory import FocusDestinationFactory
+from .s3_destination import FocusS3Destination
+
+__all__ = [
+    "FocusDestination",
+    "FocusDestinationFactory",
+    "FocusTimeWindow",
+    "FocusS3Destination",
+]

litellm/integrations/focus/destinations/base.py

@@ -0,0 +1,30 @@
+"""Abstract destination interfaces for Focus export."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from datetime import datetime
+from typing import Protocol
+
+
+@dataclass(frozen=True)
+class FocusTimeWindow:
+    """Represents the span of data exported in a single batch."""
+
+    start_time: datetime
+    end_time: datetime
+    frequency: str
+
+
+class FocusDestination(Protocol):
+    """Protocol for anything that can receive Focus export files."""
+
+    async def deliver(
+        self,
+        *,
+        content: bytes,
+        time_window: FocusTimeWindow,
+        filename: str,
+    ) -> None:
+        """Persist the serialized export for the provided time window."""
+        ...

litellm/integrations/focus/destinations/factory.py

@@ -0,0 +1,21 @@
+"""Factory helpers for Focus export destinations."""
+
+from __future__ import annotations
+
+from typing import Optional
+
+from .base import FocusDestination
+
+
+class FocusDestinationFactory:
+    """Builds destination instances based on provider/config settings."""
+
+    @staticmethod
+    def create(
+        *,
+        provider: str,
+        prefix: str,
+        config: Optional[dict] = None,
+    ) -> FocusDestination:
+        """Return a destination implementation for the requested provider."""
+        raise NotImplementedError

litellm/integrations/focus/destinations/s3_destination.py

@@ -0,0 +1,32 @@
+"""S3 destination implementation for Focus export."""
+
+from __future__ import annotations
+
+from typing import Any, Optional
+
+from .base import FocusDestination, FocusTimeWindow
+
+
+class FocusS3Destination(FocusDestination):
+    """Handles uploading serialized exports to S3 buckets."""
+
+    def __init__(
+        self,
+        *,
+        prefix: str,
+        config: Optional[dict[str, Any]] = None,
+    ) -> None:
+        self.prefix = prefix.rstrip("/")
+        self.config = config or {}
+
+    async def deliver(
+        self,
+        *,
+        content: bytes,
+        time_window: FocusTimeWindow,
+        filename: str,
+    ) -> None:
+        raise NotImplementedError
+
+    def _build_object_key(self, *, time_window: FocusTimeWindow, filename: str) -> str:
+        raise NotImplementedError

litellm/integrations/focus/focus_export_logger.py

@@ -0,0 +1,129 @@
+"""Focus export logger orchestrating DB pull/transform/upload."""
+
+from __future__ import annotations
+
+import os
+from datetime import datetime, timedelta, timezone
+from typing import TYPE_CHECKING, Any, Optional
+
+import polars as pl
+
+from litellm.integrations.custom_logger import CustomLogger
+
+from .destinations import (
+    FocusDestination,
+    FocusDestinationFactory,
+    FocusTimeWindow,
+)
+from .serializers import FocusParquetSerializer, FocusSerializer
+from .transformer import FocusTransformer
+
+if TYPE_CHECKING:
+    from apscheduler.schedulers.asyncio import AsyncIOScheduler
+else:
+    AsyncIOScheduler = Any
+
+
+class FocusExportLogger(CustomLogger):
+    """Coordinates Focus export jobs across transformer/serializer/destination layers."""
+
+    def __init__(
+        self,
+        *,
+        provider: Optional[str] = None,
+        export_format: Optional[str] = None,
+        frequency: Optional[str] = None,
+        cron_offset_minute: Optional[int] = None,
+        interval_seconds: Optional[int] = None,
+        prefix: Optional[str] = None,
+        destination_config: Optional[dict[str, Any]] = None,
+        **kwargs: Any,
+    ) -> None:
+        super().__init__(**kwargs)
+        self.provider = (provider or os.getenv("FOCUS_EXPORT_PROVIDER") or "s3").lower()
+        self.export_format = (
+            export_format or os.getenv("FOCUS_EXPORT_FORMAT") or "parquet"
+        ).lower()
+        self.frequency = (
+            frequency or os.getenv("FOCUS_EXPORT_FREQUENCY") or "hourly"
+        ).lower()
+        self.cron_offset_minute = (
+            cron_offset_minute
+            if cron_offset_minute is not None
+            else int(os.getenv("FOCUS_EXPORT_CRON_OFFSET", "5"))
+        )
+        self.interval_seconds = (
+            interval_seconds
+            if interval_seconds is not None
+            else os.getenv("FOCUS_EXPORT_INTERVAL_SECONDS")
+        )
+        self.prefix = prefix or os.getenv("FOCUS_EXPORT_PREFIX", "focus_exports")
+
+        self._destination = self._init_destination(
+            destination_config=destination_config,
+        )
+        self._serializer = self._init_serializer()
+        self._transformer = FocusTransformer()
+
+    def _init_serializer(self) -> FocusSerializer:
+        """Return serializer implementation for requested format."""
+        if self.export_format != "parquet":
+            raise NotImplementedError("Only parquet export supported currently")
+        return FocusParquetSerializer()
+
+    def _init_destination(
+        self,
+        *,
+        destination_config: Optional[dict[str, Any]],
+    ) -> FocusDestination:
+        """Factory for destination implementations."""
+        resolved_config = self._resolve_destination_config(destination_config)
+        return FocusDestinationFactory.create(
+            provider=self.provider,
+            prefix=self.prefix,
+            config=resolved_config,
+        )
+
+    def _resolve_destination_config(
+        self,
+        destination_config: Optional[dict[str, Any]],
+    ) -> dict[str, Any]:
+        """Collect provider-specific configuration for destination creation."""
+        raise NotImplementedError
+
+    async def export_usage_data(self) -> None:
+        """Public hook to trigger export immediately."""
+        raise NotImplementedError
+
+    async def dry_run_export_usage_data(self) -> dict:
+        """Return transformed data without uploading."""
+        raise NotImplementedError
+
+    async def initialize_focus_export_job(self) -> None:
+        """Entry point for scheduler jobs to run export cycle with locking."""
+        raise NotImplementedError
+
+    @staticmethod
+    async def init_focus_export_background_job(
+        scheduler: AsyncIOScheduler,
+    ) -> None:
+        """Register the export cron/interval job with the provided scheduler."""
+        raise NotImplementedError
+
+    def _compute_time_window(self, now: datetime) -> FocusTimeWindow:
+        """Derive the time window to export based on configured frequency."""
+        raise NotImplementedError
+
+    def _serialize_and_upload(
+        self,
+        frame: pl.DataFrame,
+        window: FocusTimeWindow,
+    ) -> None:
+        """Helper stub for serializing and delegating to destination."""
+        raise NotImplementedError
+
+    def _build_filename(self) -> str:
+        """Return the canonical file name for exports."""
+        if not self._serializer.extension:
+            raise ValueError("Serializer must declare a file extension")
+        return f"usage.{self._serializer.extension}"

litellm/integrations/focus/serializers/__init__.py

@@ -0,0 +1,6 @@
+"""Serializer package exports for Focus integration."""
+
+from .base import FocusSerializer
+from .parquet import FocusParquetSerializer
+
+__all__ = ["FocusSerializer", "FocusParquetSerializer"]

litellm/integrations/focus/serializers/base.py

@@ -0,0 +1,18 @@
+"""Serializer abstractions for Focus export."""
+
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+
+import polars as pl
+
+
+class FocusSerializer(ABC):
+    """Base serializer turning Focus frames into bytes."""
+
+    extension: str = ""
+
+    @abstractmethod
+    def serialize(self, frame: pl.DataFrame) -> bytes:
+        """Convert the normalized Focus frame into the chosen format."""
+        raise NotImplementedError

litellm/integrations/focus/serializers/parquet.py

@@ -0,0 +1,16 @@
+"""Parquet serializer for Focus export."""
+
+from __future__ import annotations
+
+import polars as pl
+
+from .base import FocusSerializer
+
+
+class FocusParquetSerializer(FocusSerializer):
+    """Placeholder Parquet serializer implementation."""
+
+    extension = "parquet"
+
+    def serialize(self, frame: pl.DataFrame) -> bytes:
+        raise NotImplementedError

litellm/integrations/focus/transformer.py

@@ -0,0 +1,13 @@
+"""Focus export data transformer."""
+
+from __future__ import annotations
+
+import polars as pl
+
+
+class FocusTransformer:
+    """Transforms LiteLLM DB rows into Focus-compatible schema."""
+
+    def transform(self, frame: pl.DataFrame) -> pl.DataFrame:
+        """Return a normalized frame expected by downstream serializers."""
+        raise NotImplementedError