Pyarrow direct loading

dlt/common/data_writers/writers.py

@@ -1,14 +1,14 @@
 import abc
-
 from dataclasses import dataclass
-from typing import Any, Dict, Sequence, IO, Type, Optional, List, cast
+from typing import IO, TYPE_CHECKING, Any, Dict, List, Optional, Sequence, Type, Union
 
 from dlt.common import json
-from dlt.common.typing import StrAny
-from dlt.common.schema.typing import TTableSchemaColumns
-from dlt.common.destination import TLoaderFileFormat, DestinationCapabilitiesContext
-from dlt.common.configuration import with_config, known_sections, configspec
+from dlt.common.configuration import configspec, known_sections, with_config
 from dlt.common.configuration.specs import BaseConfiguration
+from dlt.common.destination import DestinationCapabilitiesContext, TLoaderFileFormat
+from dlt.common.schema.typing import TTableSchemaColumns
+from dlt.common.typing import StrAny
+
 
 @dataclass
 class TFileFormatSpec:
@@ -70,6 +70,8 @@ def class_factory(file_format: TLoaderFileFormat) -> Type["DataWriter"]:
             return InsertValuesWriter
         elif file_format == "parquet":
             return ParquetDataWriter  # type: ignore
+        elif file_format == "arrow":
+            return ArrowWriter # type: ignore
         else:
             raise ValueError(file_format)
 
@@ -249,3 +251,37 @@ def write_footer(self) -> None:
     @classmethod
     def data_format(cls) -> TFileFormatSpec:
         return TFileFormatSpec("parquet", "parquet", True, False, requires_destination_capabilities=True, supports_compression=False)
+
+
+class ArrowWriter(ParquetDataWriter):
+    def write_header(self, columns_schema: TTableSchemaColumns) -> None:
+        # Schema will be written as-is from the arrow table
+        pass
+
+    def write_data(self, rows: Sequence[Any]) -> None:
+        from dlt.common.libs.pyarrow import pyarrow
+        rows = list(rows)
+        if not rows:
+            return
+        first = rows[0]
+        self.writer = self.writer or pyarrow.parquet.ParquetWriter(
+            self._f, first.schema, flavor=self.parquet_flavor, version=self.parquet_version, data_page_size=self.parquet_data_page_size
+        )
+        for row in rows:
+            if isinstance(row, pyarrow.Table):
+                self.writer.write_table(row)
+            elif isinstance(row, pyarrow.RecordBatch):
+                self.writer.write_batch(row)
+            else:
+                raise ValueError(f"Unsupported type {type(row)}")
+
+    @classmethod
+    def data_format(cls) -> TFileFormatSpec:
+        return TFileFormatSpec(
+            "arrow",
+            file_extension="parquet",
+            is_binary_format=True,
+            supports_schema_changes=False,
+            requires_destination_capabilities=False,
+            supports_compression=False,
+        )

dlt/common/destination/__init__.py

@@ -1,2 +1,2 @@
-from dlt.common.destination.capabilities import DestinationCapabilitiesContext, TLoaderFileFormat
-from dlt.common.destination.reference import DestinationReference, TDestinationReferenceArg
+from dlt.common.destination.capabilities import DestinationCapabilitiesContext, TLoaderFileFormat, ALL_SUPPORTED_FILE_FORMATS
+from dlt.common.destination.reference import DestinationReference, TDestinationReferenceArg

dlt/common/destination/capabilities.py

@@ -14,9 +14,10 @@
 # puae-jsonl - internal extract -> normalize format bases on jsonl
 # insert_values - insert SQL statements
 # sql - any sql statement
-TLoaderFileFormat = Literal["jsonl", "puae-jsonl", "insert_values", "sql", "parquet", "reference"]
+TLoaderFileFormat = Literal["jsonl", "puae-jsonl", "insert_values", "sql", "parquet", "reference", "arrow"]
+ALL_SUPPORTED_FILE_FORMATS: Set[TLoaderFileFormat] = set(get_args(TLoaderFileFormat))
 # file formats used internally by dlt
-INTERNAL_LOADER_FILE_FORMATS: Set[TLoaderFileFormat] = {"puae-jsonl", "sql", "reference"}
+INTERNAL_LOADER_FILE_FORMATS: Set[TLoaderFileFormat] = {"puae-jsonl", "sql", "reference", "arrow"}
 # file formats that may be chosen by the user
 EXTERNAL_LOADER_FILE_FORMATS: Set[TLoaderFileFormat] = set(get_args(TLoaderFileFormat)) - INTERNAL_LOADER_FILE_FORMATS
 

dlt/common/libs/pyarrow.py

@@ -1,9 +1,12 @@
-from typing import Any, Tuple, Optional
+from typing import Any, Tuple, Optional, Union
 from dlt import version
 from dlt.common.exceptions import MissingDependencyException
+from dlt.common.schema.typing import TTableSchemaColumns
 
 from dlt.common.destination.capabilities import DestinationCapabilitiesContext
 from dlt.common.schema.typing import TColumnType
+from dlt.common.data_types import TDataType
+from dlt.common.typing import TFileOrPath
 
 try:
     import pyarrow
@@ -12,6 +15,9 @@
     raise MissingDependencyException("DLT parquet Helpers", [f"{version.DLT_PKG_NAME}[parquet]"], "DLT Helpers for for parquet.")
 
 
+TAnyArrowItem = Union[pyarrow.Table, pyarrow.RecordBatch]
+
+
 def get_py_arrow_datatype(column: TColumnType, caps: DestinationCapabilitiesContext, tz: str) -> Any:
     column_type = column["data_type"]
     if column_type == "text":
@@ -82,3 +88,88 @@ def get_pyarrow_int(precision: Optional[int]) -> Any:
     elif precision <= 32:
         return pyarrow.int32()
     return pyarrow.int64()
+
+
+def _get_column_type_from_py_arrow(dtype: pyarrow.DataType) -> TColumnType:
+    """Returns (data_type, precision, scale) tuple from pyarrow.DataType
+    """
+    if pyarrow.types.is_string(dtype) or pyarrow.types.is_large_string(dtype):
+        return dict(data_type="text")
+    elif pyarrow.types.is_floating(dtype):
+        return dict(data_type="double")
+    elif pyarrow.types.is_boolean(dtype):
+        return dict(data_type="bool")
+    elif pyarrow.types.is_timestamp(dtype):
+        if dtype.unit == "s":
+            precision = 0
+        elif dtype.unit == "ms":
+            precision = 3
+        elif dtype.unit == "us":
+            precision = 6
+        else:
+            precision = 9
+        return dict(data_type="timestamp", precision=precision)
+    elif pyarrow.types.is_date(dtype):
+        return dict(data_type="date")
+    elif pyarrow.types.is_time(dtype):
+        # Time fields in schema are `DataType` instead of `Time64Type` or `Time32Type`
+        if dtype == pyarrow.time32("s"):
+            precision = 0
+        elif dtype == pyarrow.time32("ms"):
+            precision = 3
+        elif dtype == pyarrow.time64("us"):
+            precision = 6
+        else:
+            precision = 9
+        return dict(data_type="time", precision=precision)
+    elif pyarrow.types.is_integer(dtype):
+        result: TColumnType = dict(data_type="bigint")
+        if dtype.bit_width != 64: # 64bit is a default bigint
+            result["precision"] = dtype.bit_width
+        return result
+    elif pyarrow.types.is_fixed_size_binary(dtype):
+        return dict(data_type="binary", precision=dtype.byte_width)
+    elif pyarrow.types.is_binary(dtype) or pyarrow.types.is_large_binary(dtype):
+        return dict(data_type="binary")
+    elif pyarrow.types.is_decimal(dtype):
+        return dict(data_type="decimal", precision=dtype.precision, scale=dtype.scale)
+    elif pyarrow.types.is_nested(dtype):
+        return dict(data_type="complex")
+    else:
+        raise ValueError(dtype)
+
+
+def py_arrow_to_table_schema_columns(schema: pyarrow.Schema) -> TTableSchemaColumns:
+    """Convert a PyArrow schema to a table schema columns dict.
+
+    Args:
+        schema (pyarrow.Schema): pyarrow schema
+
+    Returns:
+        TTableSchemaColumns: table schema columns
+    """
+    result: TTableSchemaColumns = {}
+    for field in schema:
+        result[field.name] = {
+            "name": field.name,
+            "nullable": field.nullable,
+            **_get_column_type_from_py_arrow(field.type),
+        }
+    return result
+
+
+def get_row_count(parquet_file: TFileOrPath) -> int:
+    """Get the number of rows in a parquet file.
+
+    Args:
+        parquet_file (str): path to parquet file
+
+    Returns:
+        int: number of rows
+    """
+    with pyarrow.parquet.ParquetFile(parquet_file) as reader:
+        return reader.metadata.num_rows  # type: ignore[no-any-return]
+
+
+def is_arrow_item(item: Any) -> bool:
+    return isinstance(item, (pyarrow.Table, pyarrow.RecordBatch))

dlt/common/storages/data_item_storage.py

@@ -18,7 +18,7 @@ def get_writer(self, load_id: str, schema_name: str, table_name: str) -> Buffere
         writer_id = f"{load_id}.{schema_name}.{table_name}"
         writer = self.buffered_writers.get(writer_id, None)
         if not writer:
-            # assign a jsonl writer for each table
+            # assign a writer for each table
             path = self._get_data_item_path_template(load_id, schema_name, table_name)
             writer = BufferedDataWriter(self.loader_file_format, path)
             self.buffered_writers[writer_id] = writer

dlt/common/storages/file_storage.py

@@ -45,14 +45,19 @@ def save_atomic(storage_path: str, relative_path: str, data: Any, file_type: str
             raise
 
     @staticmethod
-    def copy_atomic(source_file_path: str, dest_folder_path: str) -> str:
+    def move_atomic_to_folder(source_file_path: str, dest_folder_path: str) -> str:
         file_name = os.path.basename(source_file_path)
         dest_file_path = os.path.join(dest_folder_path, file_name)
+        return FileStorage.move_atomic_to_file(source_file_path, dest_file_path)
+
+    @staticmethod
+    def move_atomic_to_file(source_file_path: str, dest_file_path: str) -> str:
         try:
             os.rename(source_file_path, dest_file_path)
         except OSError:
             # copy to local temp file
-            dest_temp_file = os.path.join(dest_folder_path, uniq_id())
+            folder_name = os.path.dirname(dest_file_path)
+            dest_temp_file = os.path.join(folder_name, uniq_id())
             try:
                 shutil.copyfile(source_file_path, dest_temp_file)
                 os.rename(dest_temp_file, dest_file_path)
@@ -63,6 +68,19 @@ def copy_atomic(source_file_path: str, dest_folder_path: str) -> str:
                 raise
         return dest_file_path
 
+    @staticmethod
+    def copy_atomic_to_file(source_file_path: str, dest_file_path: str) -> str:
+        folder_name = os.path.dirname(dest_file_path)
+        dest_temp_file = os.path.join(folder_name, uniq_id())
+        try:
+            shutil.copyfile(source_file_path, dest_temp_file)
+            os.rename(dest_temp_file, dest_file_path)
+        except Exception:
+            if os.path.isfile(dest_temp_file):
+                os.remove(dest_temp_file)
+            raise
+        return dest_file_path
+
     def load(self, relative_path: str) -> Any:
         # raises on file not existing
         with self.open_file(relative_path) as text_file:
@@ -144,6 +162,19 @@ def link_hard(self, from_relative_path: str, to_relative_path: str) -> None:
             self.make_full_path(to_relative_path)
         )
 
+    @staticmethod
+    def link_hard_with_fallback(external_file_path: str, to_file_path: str) -> None:
+        """Try to create a hardlink and fallback to copying when filesystem doesn't support links
+        """
+        try:
+            os.link(external_file_path, to_file_path)
+        except OSError as ex:
+            # Fallback to copy when fs doesn't support links or attempting to make a cross-device link
+            if ex.errno in (errno.EPERM, errno.EXDEV, errno.EMLINK):
+                FileStorage.copy_atomic_to_file(external_file_path, to_file_path)
+            else:
+                raise
+
     def atomic_rename(self, from_relative_path: str, to_relative_path: str) -> None:
         """Renames a path using os.rename which is atomic on POSIX, Windows and NFS v4.
 
@@ -195,11 +226,20 @@ def rename_tree_files(self, from_relative_path: str, to_relative_path: str) -> N
             if not os.listdir(root):
                 os.rmdir(root)
 
-    def atomic_import(self, external_file_path: str, to_folder: str) -> str:
-        """Moves a file at `external_file_path` into the `to_folder` effectively importing file into storage"""
-        return self.to_relative_path(FileStorage.copy_atomic(external_file_path, self.make_full_path(to_folder)))
-        # file_name = FileStorage.get_file_name_from_file_path(external_path)
-        # os.rename(external_path, os.path.join(self.make_full_path(to_folder), file_name))
+    def atomic_import(self, external_file_path: str, to_folder: str, new_file_name: Optional[str] = None) -> str:
+        """Moves a file at `external_file_path` into the `to_folder` effectively importing file into storage
+
+        Args:
+            external_file_path: Path to file to be imported
+            to_folder: Path to folder where file should be imported
+            new_file_name: Optional new file name for the imported file, otherwise the original file name is used
+
+        Returns:
+            Path to imported file relative to storage root
+        """
+        new_file_name = new_file_name or os.path.basename(external_file_path)
+        dest_file_path = os.path.join(self.make_full_path(to_folder), new_file_name)
+        return self.to_relative_path(FileStorage.move_atomic_to_file(external_file_path, dest_file_path))
 
     def in_storage(self, path: str) -> bool:
         assert path is not None

dlt/common/storages/load_storage.py

@@ -13,7 +13,8 @@
 from dlt.common.configuration.inject import with_config
 from dlt.common.typing import DictStrAny, StrAny
 from dlt.common.storages.file_storage import FileStorage
-from dlt.common.data_writers import TLoaderFileFormat, DataWriter
+from dlt.common.data_writers import DataWriter
+from dlt.common.destination import ALL_SUPPORTED_FILE_FORMATS, TLoaderFileFormat
 from dlt.common.configuration.accessors import config
 from dlt.common.exceptions import TerminalValueError
 from dlt.common.schema import Schema, TSchemaTables, TTableSchemaColumns
@@ -138,7 +139,7 @@ class LoadStorage(DataItemStorage, VersionedStorage):
     SCHEMA_FILE_NAME = "schema.json"  # package schema
     PACKAGE_COMPLETED_FILE_NAME = "package_completed.json"  # completed package marker file, currently only to store data with os.stat
 
-    ALL_SUPPORTED_FILE_FORMATS: Set[TLoaderFileFormat] = set(get_args(TLoaderFileFormat))
+    ALL_SUPPORTED_FILE_FORMATS = ALL_SUPPORTED_FILE_FORMATS
 
     @with_config(spec=LoadStorageConfiguration, sections=(known_sections.LOAD,))
     def __init__(
@@ -311,6 +312,11 @@ def add_new_job(self, load_id: str, job_file_path: str, job_state: TJobState = "
         """Adds new job by moving the `job_file_path` into `new_jobs` of package `load_id`"""
         self.storage.atomic_import(job_file_path, self._get_job_folder_path(load_id, job_state))
 
+    def atomic_import(self, external_file_path: str, to_folder: str) -> str:
+        """Copies or links a file at `external_file_path` into the `to_folder` effectively importing file into storage"""
+        # LoadStorage.parse_job_file_name
+        return self.storage.to_relative_path(FileStorage.move_atomic_to_folder(external_file_path, self.storage.make_full_path(to_folder)))
+
     def start_job(self, load_id: str, file_name: str) -> str:
         return self._move_job(load_id, LoadStorage.NEW_JOBS_FOLDER, LoadStorage.STARTED_JOBS_FOLDER, file_name)
 

dlt/common/storages/normalize_storage.py

@@ -1,4 +1,4 @@
-from typing import ClassVar, Sequence, NamedTuple
+from typing import ClassVar, Sequence, NamedTuple, Union
 from itertools import groupby
 from pathlib import Path
 
@@ -7,11 +7,14 @@
 from dlt.common.storages.file_storage import FileStorage
 from dlt.common.storages.configuration import NormalizeStorageConfiguration
 from dlt.common.storages.versioned_storage import VersionedStorage
+from dlt.common.destination import TLoaderFileFormat, ALL_SUPPORTED_FILE_FORMATS
+from dlt.common.exceptions import TerminalValueError
 
 class TParsedNormalizeFileName(NamedTuple):
     schema_name: str
     table_name: str
     file_id: str
+    file_format: TLoaderFileFormat
 
 
 class NormalizeStorage(VersionedStorage):
@@ -47,10 +50,13 @@ def build_extracted_file_stem(schema_name: str, table_name: str, file_id: str) -
     @staticmethod
     def parse_normalize_file_name(file_name: str) -> TParsedNormalizeFileName:
         # parse extracted file name and returns (events found, load id, schema_name)
-        if not file_name.endswith("jsonl"):
-            raise ValueError(file_name)
-
-        parts = Path(file_name).stem.split(".")
-        if len(parts) != 3:
-            raise ValueError(file_name)
-        return TParsedNormalizeFileName(*parts)
+        file_name_p: Path = Path(file_name)
+        parts = file_name_p.name.split(".")
+        ext = parts[-1]
+        if ext not in ALL_SUPPORTED_FILE_FORMATS:
+            raise TerminalValueError(f"File format {ext} not supported. Filename: {file_name}")
+        return TParsedNormalizeFileName(*parts)  # type: ignore[arg-type]
+
+    def delete_extracted_files(self, files: Sequence[str]) -> None:
+        for file_name in files:
+            self.storage.delete(file_name)

dlt/common/typing.py

@@ -1,8 +1,9 @@
 from collections.abc import Mapping as C_Mapping, Sequence as C_Sequence
 from datetime import datetime, date  # noqa: I251
 import inspect
+import os
 from re import Pattern as _REPattern
-from typing import Callable, Dict, Any, Final, Literal, List, Mapping, NewType, Optional, Tuple, Type, TypeVar, Generic, Protocol, TYPE_CHECKING, Union, runtime_checkable, get_args, get_origin
+from typing import Callable, Dict, Any, Final, Literal, List, Mapping, NewType, Optional, Tuple, Type, TypeVar, Generic, Protocol, TYPE_CHECKING, Union, runtime_checkable, get_args, get_origin, IO
 from typing_extensions import TypeAlias, ParamSpec, Concatenate
 
 from dlt.common.pendulum import timedelta, pendulum
@@ -44,6 +45,7 @@
 TVariantBase = TypeVar("TVariantBase", covariant=True)
 TVariantRV = Tuple[str, Any]
 VARIANT_FIELD_FORMAT = "v_%s"
+TFileOrPath = Union[str, os.PathLike, IO[Any]]
 
 @runtime_checkable
 class SupportsVariant(Protocol, Generic[TVariantBase]):