chore(rename): move llama_stack.distribution to llama_stack.core (#2975)

We would like to rename the term `template` to `distribution`. To
prepare for that, this is a precursor.

cc @leseb

llama_stack/core/routers/datasets.py

@@ -0,0 +1,73 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from typing import Any
+
+from llama_stack.apis.common.responses import PaginatedResponse
+from llama_stack.apis.datasetio import DatasetIO
+from llama_stack.apis.datasets import DatasetPurpose, DataSource
+from llama_stack.log import get_logger
+from llama_stack.providers.datatypes import RoutingTable
+
+logger = get_logger(name=__name__, category="core")
+
+
+class DatasetIORouter(DatasetIO):
+    def __init__(
+        self,
+        routing_table: RoutingTable,
+    ) -> None:
+        logger.debug("Initializing DatasetIORouter")
+        self.routing_table = routing_table
+
+    async def initialize(self) -> None:
+        logger.debug("DatasetIORouter.initialize")
+        pass
+
+    async def shutdown(self) -> None:
+        logger.debug("DatasetIORouter.shutdown")
+        pass
+
+    async def register_dataset(
+        self,
+        purpose: DatasetPurpose,
+        source: DataSource,
+        metadata: dict[str, Any] | None = None,
+        dataset_id: str | None = None,
+    ) -> None:
+        logger.debug(
+            f"DatasetIORouter.register_dataset: {purpose=} {source=} {metadata=} {dataset_id=}",
+        )
+        await self.routing_table.register_dataset(
+            purpose=purpose,
+            source=source,
+            metadata=metadata,
+            dataset_id=dataset_id,
+        )
+
+    async def iterrows(
+        self,
+        dataset_id: str,
+        start_index: int | None = None,
+        limit: int | None = None,
+    ) -> PaginatedResponse:
+        logger.debug(
+            f"DatasetIORouter.iterrows: {dataset_id}, {start_index=} {limit=}",
+        )
+        provider = await self.routing_table.get_provider_impl(dataset_id)
+        return await provider.iterrows(
+            dataset_id=dataset_id,
+            start_index=start_index,
+            limit=limit,
+        )
+
+    async def append_rows(self, dataset_id: str, rows: list[dict[str, Any]]) -> None:
+        logger.debug(f"DatasetIORouter.append_rows: {dataset_id}, {len(rows)} rows")
+        provider = await self.routing_table.get_provider_impl(dataset_id)
+        return await provider.append_rows(
+            dataset_id=dataset_id,
+            rows=rows,
+        )