feat(streaming): Streaming CSV uploads for over 100k records for constant memory usage (#35478)

superset/commands/chart/data/streaming_export_command.py

@@ -0,0 +1,80 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""Command for streaming CSV exports of chart data."""
+
+from __future__ import annotations
+
+from typing import Any, TYPE_CHECKING
+
+from superset.commands.streaming_export.base import BaseStreamingCSVExportCommand
+
+if TYPE_CHECKING:
+    from superset.common.query_context import QueryContext
+
+
+class StreamingCSVExportCommand(BaseStreamingCSVExportCommand):
+    """
+    Command to execute a streaming CSV export for chart data.
+
+    This command handles chart-specific logic:
+    - QueryContext validation
+    - Datasource preparation and SQL generation
+    - No row limit (exports all chart data)
+    """
+
+    def __init__(
+        self,
+        query_context: QueryContext,
+        chunk_size: int = 1000,
+    ):
+        """
+        Initialize the chart streaming export command.
+
+        Args:
+            query_context: The query context containing datasource and query details
+            chunk_size: Number of rows to fetch per database query (default: 1000)
+        """
+        super().__init__(chunk_size)
+        self._query_context = query_context
+
+    def validate(self) -> None:
+        """Validate permissions and query context."""
+        self._query_context.raise_for_access()
+
+    def _get_sql_and_database(self) -> tuple[str, Any]:
+        """
+        Get the SQL query and database for chart export.
+
+        Returns:
+            Tuple of (sql_query, database_object)
+        """
+        # Get datasource and generate SQL query
+        # Note: datasource should already be attached to a session from query_context
+        datasource = self._query_context.datasource
+        query_obj = self._query_context.queries[0]
+        sql_query = datasource.get_query_str(query_obj.to_dict())
+
+        return sql_query, datasource.database
+
+    def _get_row_limit(self) -> int | None:
+        """
+        Get the row limit for chart export.
+
+        Returns:
+            None (no limit for chart exports)
+        """
+        return None