sdks/python/apache_beam/io/parquetio.py

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"""``PTransforms`` for reading from and writing to Parquet files.

Provides two read ``PTransform``\\s, ``ReadFromParquet`` and
``ReadAllFromParquet``, that produces a ``PCollection`` of records.
Each record of this ``PCollection`` will contain a single record read from
a Parquet file. Records that are of simple types will be mapped into
corresponding Python types. The actual parquet file operations are done by
pyarrow. Source splitting is supported at row group granularity.

Additionally, this module provides a write ``PTransform`` ``WriteToParquet``
that can be used to write a given ``PCollection`` of Python objects to a
Parquet file.
"""
# pytype: skip-file

from functools import partial
from typing import Iterator

from packaging import version

from apache_beam.io import filebasedsink
from apache_beam.io import filebasedsource
from apache_beam.io.filesystem import CompressionTypes
from apache_beam.io.filesystems import FileSystems
from apache_beam.io.iobase import RangeTracker
from apache_beam.io.iobase import Read
from apache_beam.io.iobase import Write
from apache_beam.portability.api import schema_pb2
from apache_beam.transforms import DoFn
from apache_beam.transforms import ParDo
from apache_beam.transforms import PTransform
from apache_beam.transforms import window
from apache_beam.typehints import schemas
from apache_beam.utils.windowed_value import WindowedValue

try:
  import pyarrow as pa
  paTable = pa.Table
  import pyarrow.parquet as pq

  # pylint: disable=ungrouped-imports
  from apache_beam.typehints import arrow_type_compatibility
except ImportError:
  pa = None
  paTable = None
  pq = None
  ARROW_MAJOR_VERSION = None
  arrow_type_compatibility = None
else:
  base_pa_version = version.parse(pa.__version__).base_version
  ARROW_MAJOR_VERSION, _, _ = map(int, base_pa_version.split('.'))

__all__ = [
    'ReadFromParquet',
    'ReadAllFromParquet',
    'ReadFromParquetBatched',
    'ReadAllFromParquetBatched',
    'WriteToParquet',
    'WriteToParquetBatched'
]


class _ArrowTableToRowDictionaries(DoFn):
  """ A DoFn that consumes an Arrow table and yields a python dictionary for
  each row in the table."""
  def process(self, table, with_filename=False):
    if with_filename:
      file_name = table[0]
      table = table[1]
    num_rows = table.num_rows
    data_items = table.to_pydict().items()
    for n in range(num_rows):
      row = {}
      for column, values in data_items:
        row[column] = values[n]
      if with_filename:
        yield (file_name, row)
      else:
        yield row


class _RowDictionariesToArrowTable(DoFn):
  """ A DoFn that consumes python dictionarys and yields a pyarrow table."""
  def __init__(
      self,
      schema,
      row_group_buffer_size=64 * 1024 * 1024,
      record_batch_size=1000):
    self._schema = schema
    self._row_group_buffer_size = row_group_buffer_size
    self._buffer = [[] for _ in range(len(schema.names))]
    self._buffer_size = record_batch_size
    self._record_batches = []
    self._record_batches_byte_size = 0
    self._window = None

  def process(self, row, w=DoFn.WindowParam, pane=DoFn.PaneInfoParam):
    self._window = w
    if len(self._buffer[0]) >= self._buffer_size:
      self._flush_buffer()

    if self._record_batches_byte_size >= self._row_group_buffer_size:
      table = self._create_table()
      yield table

    # reorder the data in columnar format.
    for i, n in enumerate(self._schema.names):
      # Handle missing nullable fields by using None as default value
      field = self._schema.field(i)
      if field.nullable and n not in row:
        self._buffer[i].append(None)
      else:
        self._buffer[i].append(row[n])

  def finish_bundle(self):
    if len(self._buffer[0]) > 0:
      self._flush_buffer()
    if self._record_batches_byte_size > 0:
      table = self._create_table()
      if self._window is None or isinstance(self._window, window.GlobalWindow):
        # bounded input
        yield window.GlobalWindows.windowed_value_at_end_of_window(table)
      else:
        # unbounded input
        yield WindowedValue(
            table,
            timestamp=self._window.
            end,  #or it could be max of timestamp of the rows processed
            windows=[self._window]  # TODO(pabloem) HOW DO WE GET THE PANE
        )

  def display_data(self):
    res = super().display_data()
    res['row_group_buffer_size'] = str(self._row_group_buffer_size)
    res['buffer_size'] = str(self._buffer_size)

    return res

  def _create_table(self):
    table = pa.Table.from_batches(self._record_batches, schema=self._schema)
    self._record_batches = []
    self._record_batches_byte_size = 0
    return table

  def _flush_buffer(self):
    arrays = [[] for _ in range(len(self._schema.names))]
    for x, y in enumerate(self._buffer):
      arrays[x] = pa.array(y, type=self._schema.types[x])
      self._buffer[x] = []
    rb = pa.RecordBatch.from_arrays(arrays, schema=self._schema)
    self._record_batches.append(rb)
    size = 0
    for x in arrays:
      for b in x.buffers():
        if b is not None:
          size = size + b.size
    self._record_batches_byte_size = self._record_batches_byte_size + size


class _ArrowTableToBeamRows(DoFn):
  def __init__(self, beam_type):
    self._beam_type = beam_type

  @DoFn.yields_batches
  def process(self, element) -> Iterator[paTable]:
    yield element

  def infer_output_type(self, input_type):
    return self._beam_type


class _BeamRowsToArrowTable(DoFn):
  @DoFn.yields_elements
  def process_batch(self, element: paTable) -> Iterator[paTable]:
    yield element


class ReadFromParquetBatched(PTransform):
  """A :class:`~apache_beam.transforms.ptransform.PTransform` for reading
     Parquet files as a `PCollection` of `pyarrow.Table`. This `PTransform` is
     currently experimental. No backward-compatibility guarantees."""
  def __init__(
      self, file_pattern=None, min_bundle_size=0, validate=True, columns=None):
    """ Initializes :class:`~ReadFromParquetBatched`

    An alternative to :class:`~ReadFromParquet` that yields each row group from
    the Parquet file as a `pyarrow.Table`.  These Table instances can be
    processed directly, or converted to a pandas DataFrame for processing.  For
    more information on supported types and schema, please see the pyarrow
    documentation.

    .. testcode::

      with beam.Pipeline() as p:
        dataframes = p \\
            | 'Read' >> beam.io.ReadFromParquetBatched('/mypath/mypqfiles*') \\
            | 'Convert to pandas' >> beam.Map(lambda table: table.to_pandas())

    .. NOTE: We're not actually interested in this error; but if we get here,
       it means that the way of calling this transform hasn't changed.

    .. testoutput::
      :hide:

      Traceback (most recent call last):
       ...
      OSError: No files found based on the file pattern

    See also: :class:`~ReadFromParquet`.

    Args:
      file_pattern (str): the file glob to read
      min_bundle_size (int): the minimum size in bytes, to be considered when
        splitting the input into bundles.
      validate (bool): flag to verify that the files exist during the pipeline
        creation time.
      columns (List[str]): list of columns that will be read from files.
        A column name may be a prefix of a nested field, e.g. 'a' will select
        'a.b', 'a.c', and 'a.d.e'
    """

    super().__init__()
    self._source = _ParquetSource(
        file_pattern,
        min_bundle_size,
        validate=validate,
        columns=columns,
    )

  def expand(self, pvalue):
    return pvalue.pipeline | Read(self._source)

  def display_data(self):
    return {'source_dd': self._source}


class ReadFromParquet(PTransform):
  """A `PTransform` for reading Parquet files."""
  def __init__(
      self,
      file_pattern=None,
      min_bundle_size=0,
      validate=True,
      columns=None,
      as_rows=False):
    """Initializes :class:`ReadFromParquet`.

    Uses source ``_ParquetSource`` to read a set of Parquet files defined by
    a given file pattern.

    If ``/mypath/myparquetfiles*`` is a file-pattern that points to a set of
    Parquet files, a :class:`~apache_beam.pvalue.PCollection` for the records in
    these Parquet files can be created in the following manner.

    .. testcode::

      with beam.Pipeline() as p:
        records = p | 'Read' >> beam.io.ReadFromParquet('/mypath/mypqfiles*')

    .. NOTE: We're not actually interested in this error; but if we get here,
       it means that the way of calling this transform hasn't changed.

    .. testoutput::
      :hide:

      Traceback (most recent call last):
       ...
      OSError: No files found based on the file pattern

    Each element of this :class:`~apache_beam.pvalue.PCollection` will contain
    a Python dictionary representing a single record. The keys will be of type
    :class:`str` and named after their corresponding column names. The values
    will be of the type defined in the corresponding Parquet schema. Records
    that are of simple types will be mapped into corresponding Python types.
    Records that are of complex types like list and struct will be mapped to
    Python list and dictionary respectively. For more information on supported
    types and schema, please see the pyarrow documentation.

    See also: :class:`~ReadFromParquetBatched`.

    Args:
      file_pattern (str): the file glob to read
      min_bundle_size (int): the minimum size in bytes, to be considered when
        splitting the input into bundles.
      validate (bool): flag to verify that the files exist during the pipeline
        creation time.
      columns (List[str]): list of columns that will be read from files.
        A column name may be a prefix of a nested field, e.g. 'a' will select
        'a.b', 'a.c', and 'a.d.e'
      as_rows (bool): whether to output a schema'd PCollection of Beam rows
        rather than Python dictionaries.
    """
    super().__init__()
    self._source = _ParquetSource(
        file_pattern,
        min_bundle_size,
        validate=validate,
        columns=columns,
    )
    if as_rows:
      if columns is None:
        filter_schema = lambda schema: schema
      else:
        top_level_columns = set(c.split('.')[0] for c in columns)
        filter_schema = lambda schema: schema_pb2.Schema(
            fields=[f for f in schema.fields if f.name in top_level_columns])
      path = FileSystems.match([file_pattern], [1])[0].metadata_list[0].path
      with FileSystems.open(path) as fin:
        self._schema = filter_schema(
            arrow_type_compatibility.beam_schema_from_arrow_schema(
                pq.read_schema(fin)))
    else:
      self._schema = None

  def expand(self, pvalue):
    arrow_batches = pvalue | Read(self._source)
    if self._schema is None:
      return arrow_batches | ParDo(_ArrowTableToRowDictionaries())
    else:
      return arrow_batches | ParDo(
          _ArrowTableToBeamRows(schemas.named_tuple_from_schema(self._schema)))

  def display_data(self):
    return {'source_dd': self._source}


class ReadAllFromParquetBatched(PTransform):
  """A ``PTransform`` for reading ``PCollection`` of Parquet files.

   Uses source ``_ParquetSource`` to read a ``PCollection`` of Parquet files or
   file patterns and produce a ``PCollection`` of ``pyarrow.Table``, one for
   each Parquet file row group. This ``PTransform`` is currently experimental.
   No backward-compatibility guarantees.
  """

  DEFAULT_DESIRED_BUNDLE_SIZE = 64 * 1024 * 1024  # 64MB

  def __init__(
      self,
      min_bundle_size=0,
      desired_bundle_size=DEFAULT_DESIRED_BUNDLE_SIZE,
      columns=None,
      with_filename=False,
      label='ReadAllFiles'):
    """Initializes ``ReadAllFromParquet``.

    Args:
      min_bundle_size: the minimum size in bytes, to be considered when
                       splitting the input into bundles.
      desired_bundle_size: the desired size in bytes, to be considered when
                       splitting the input into bundles.
      columns: list of columns that will be read from files. A column name
                       may be a prefix of a nested field, e.g. 'a' will select
                       'a.b', 'a.c', and 'a.d.e'
      with_filename: If True, returns a Key Value with the key being the file
        name and the value being the actual data. If False, it only returns
        the data.
    """
    super().__init__()
    source_from_file = partial(
        _ParquetSource, min_bundle_size=min_bundle_size, columns=columns)
    self._read_all_files = filebasedsource.ReadAllFiles(
        True,
        CompressionTypes.UNCOMPRESSED,
        desired_bundle_size,
        min_bundle_size,
        source_from_file,
        with_filename)

    self.label = label

  def expand(self, pvalue):
    return pvalue | self.label >> self._read_all_files


class ReadAllFromParquet(PTransform):
  def __init__(self, with_filename=False, **kwargs):
    self._with_filename = with_filename
    self._read_batches = ReadAllFromParquetBatched(
        with_filename=self._with_filename, **kwargs)

  def expand(self, pvalue):
    return pvalue | self._read_batches | ParDo(
        _ArrowTableToRowDictionaries(), with_filename=self._with_filename)


class _ParquetUtils(object):
  @staticmethod
  def find_first_row_group_index(pf, start_offset):
    for i in range(_ParquetUtils.get_number_of_row_groups(pf)):
      row_group_start_offset = _ParquetUtils.get_offset(pf, i)
      if row_group_start_offset >= start_offset:
        return i
    return -1

  @staticmethod
  def get_offset(pf, row_group_index):
    first_column_metadata =\
      pf.metadata.row_group(row_group_index).column(0)
    if first_column_metadata.has_dictionary_page:
      return first_column_metadata.dictionary_page_offset
    else:
      return first_column_metadata.data_page_offset

  @staticmethod
  def get_number_of_row_groups(pf):
    return pf.metadata.num_row_groups


class _ParquetSource(filebasedsource.FileBasedSource):
  """A source for reading Parquet files.
  """
  def __init__(
      self, file_pattern, min_bundle_size=0, validate=False, columns=None):
    super().__init__(
        file_pattern=file_pattern,
        min_bundle_size=min_bundle_size,
        validate=validate)
    self._columns = columns

  def read_records(self, file_name, range_tracker):
    next_block_start = -1

    def split_points_unclaimed(stop_position):
      if next_block_start >= stop_position:
        # Next block starts at or after the suggested stop position. Hence
        # there will not be split points to be claimed for the range ending at
        # suggested stop position.
        return 0
      return RangeTracker.SPLIT_POINTS_UNKNOWN

    range_tracker.set_split_points_unclaimed_callback(split_points_unclaimed)

    start_offset = range_tracker.start_position()
    if start_offset is None:
      start_offset = 0

    with self.open_file(file_name) as f:
      pf = pq.ParquetFile(f)

      # find the first dictionary page (or data page if there's no dictionary
      # page available) offset after the given start_offset. This offset is also
      # the starting offset of any row group since the Parquet specification
      # describes that the data pages always come first before the meta data in
      # each row group.
      index = _ParquetUtils.find_first_row_group_index(pf, start_offset)
      if index != -1:
        next_block_start = _ParquetUtils.get_offset(pf, index)
      else:
        next_block_start = range_tracker.stop_position()
      number_of_row_groups = _ParquetUtils.get_number_of_row_groups(pf)

      while range_tracker.try_claim(next_block_start):
        table = pf.read_row_group(index, self._columns)

        if index + 1 < number_of_row_groups:
          index = index + 1
          next_block_start = _ParquetUtils.get_offset(pf, index)
        else:
          next_block_start = range_tracker.stop_position()

        yield table


_create_parquet_source = _ParquetSource


class WriteToParquet(PTransform):
  """A ``PTransform`` for writing parquet files.
  """
  def __init__(
      self,
      file_path_prefix,
      schema=None,
      row_group_buffer_size=64 * 1024 * 1024,
      record_batch_size=1000,
      codec='none',
      use_deprecated_int96_timestamps=False,
      use_compliant_nested_type=False,
      file_name_suffix='',
      num_shards=0,
      shard_name_template=None,
      mime_type='application/x-parquet',
      triggering_frequency=None,
  ):
    """Initialize a WriteToParquet transform.

    Writes parquet files from a :class:`~apache_beam.pvalue.PCollection` of
    records. Each record is a dictionary with keys of a string type that
    represent column names. Schema must be specified like the example below.

    .. testsetup::

      from tempfile import NamedTemporaryFile
      import glob
      import os
      import pyarrow

      filename = NamedTemporaryFile(delete=False).name

    .. testcode::

      with beam.Pipeline() as p:
        records = p | 'Read' >> beam.Create(
            [{'name': 'foo', 'age': 10}, {'name': 'bar', 'age': 20}]
        )
        _ = records | 'Write' >> beam.io.WriteToParquet(filename,
            pyarrow.schema(
                [('name', pyarrow.binary()), ('age', pyarrow.int64())]
            )
        )

    .. testcleanup::

      for output in glob.glob('{}*'.format(filename)):
        os.remove(output)

    For more information on supported types and schema, please see the pyarrow
    document.

    Args:
      file_path_prefix: The file path to write to. The files written will begin
        with this prefix, followed by a shard identifier (see num_shards), and
        end in a common extension, if given by file_name_suffix. In most cases,
        only this argument is specified and num_shards, shard_name_template, and
        file_name_suffix use default values.
      schema: The schema to use, as type of ``pyarrow.Schema``.
      row_group_buffer_size: The byte size of the row group buffer. Note that
        this size is for uncompressed data on the memory and normally much
        bigger than the actual row group size written to a file.
      record_batch_size: The number of records in each record batch. Record
        batch is a basic unit used for storing data in the row group buffer.
        A higher record batch size implies low granularity on a row group buffer
        size. For configuring a row group size based on the number of records,
        set ``row_group_buffer_size`` to 1 and use ``record_batch_size`` to
        adjust the value.
      codec: The codec to use for block-level compression. Any string supported
        by the pyarrow specification is accepted.
      use_deprecated_int96_timestamps: Write nanosecond resolution timestamps to
        INT96 Parquet format. Defaults to False.
      use_compliant_nested_type: Write compliant Parquet nested type (lists).
      file_name_suffix: Suffix for the files written.
      num_shards: The number of files (shards) used for output. If not set, the
        service will decide on the optimal number of shards.
        Constraining the number of shards is likely to reduce
        the performance of a pipeline.  Setting this value is not recommended
        unless you require a specific number of output files.
      shard_name_template: A template string containing placeholders for
        the shard number and shard count. Currently only ``''``,
        ``'-SSSSS-of-NNNNN'``, ``'-W-SSSSS-of-NNNNN'`` and
        ``'-V-SSSSS-of-NNNNN'`` are patterns accepted by the service.
        When constructing a filename for a particular shard number, the
        upper-case letters ``S`` and ``N`` are replaced with the ``0``-padded
        shard number and shard count respectively.  This argument can be ``''``
        in which case it behaves as if num_shards was set to 1 and only one file
        will be generated. The default pattern used is ``'-SSSSS-of-NNNNN'`` for
        bounded PCollections and for ``'-W-SSSSS-of-NNNNN'`` unbounded 
        PCollections.
        W is used for windowed shard naming and is replaced with 
        ``[window.start, window.end)``
        V is used for windowed shard naming and is replaced with 
        ``[window.start.to_utc_datetime().strftime("%Y-%m-%dT%H-%M-%S"), 
        window.end.to_utc_datetime().strftime("%Y-%m-%dT%H-%M-%S")``
      mime_type: The MIME type to use for the produced files, if the filesystem
        supports specifying MIME types.
      triggering_frequency: (int) Every triggering_frequency duration, a window 
        will be triggered and all bundles in the window will be written.
        If set it overrides user windowing. Mandatory for GlobalWindow.

    Returns:
      A WriteToParquet transform usable for writing.
    """
    super().__init__()
    self._schema = schema
    self._row_group_buffer_size = row_group_buffer_size
    self._record_batch_size = record_batch_size

    self._sink = \
      _create_parquet_sink(
          file_path_prefix,
          schema,
          codec,
          use_deprecated_int96_timestamps,
          use_compliant_nested_type,
          file_name_suffix,
          num_shards,
          shard_name_template,
          mime_type,
          triggering_frequency
      )

  def expand(self, pcoll):
    if (not pcoll.is_bounded and self._sink.shard_name_template
        == filebasedsink.DEFAULT_SHARD_NAME_TEMPLATE):
      self._sink.shard_name_template = (
          filebasedsink.DEFAULT_WINDOW_SHARD_NAME_TEMPLATE)
      self._sink.shard_name_format = self._sink._template_to_format(
          self._sink.shard_name_template)
      self._sink.shard_name_glob_format = self._sink._template_to_glob_format(
          self._sink.shard_name_template)

    if self._schema is None:
      try:
        beam_schema = schemas.schema_from_element_type(pcoll.element_type)
      except TypeError as exn:
        raise ValueError(
            "A schema is required to write non-schema'd data.") from exn
      self._sink._schema = (
          arrow_type_compatibility.arrow_schema_from_beam_schema(beam_schema))
      convert_fn = _BeamRowsToArrowTable()
    else:
      convert_fn = _RowDictionariesToArrowTable(
          self._schema, self._row_group_buffer_size, self._record_batch_size)
    if pcoll.is_bounded:
      return pcoll | ParDo(convert_fn) | Write(self._sink)
    else:
      self._sink.convert_fn = convert_fn
      return pcoll | Write(self._sink)

  def display_data(self):
    return {
        'sink_dd': self._sink,
        'row_group_buffer_size': str(self._row_group_buffer_size)
    }


class WriteToParquetBatched(PTransform):
  """A ``PTransform`` for writing parquet files from a `PCollection` of
    `pyarrow.Table`.

    This ``PTransform`` is currently experimental. No backward-compatibility
    guarantees.
  """
  def __init__(
      self,
      file_path_prefix,
      schema=None,
      codec='none',
      use_deprecated_int96_timestamps=False,
      use_compliant_nested_type=False,
      file_name_suffix='',
      num_shards=0,
      shard_name_template=None,
      mime_type='application/x-parquet',
      triggering_frequency=None):
    """Initialize a WriteToParquetBatched transform.

    Writes parquet files from a :class:`~apache_beam.pvalue.PCollection` of
    records. Each record is a pa.Table Schema must be specified like the
    example below.

    .. testsetup:: batched

      from tempfile import NamedTemporaryFile
      import glob
      import os
      import pyarrow

      filename = NamedTemporaryFile(delete=False).name

    .. testcode:: batched

      table = pyarrow.Table.from_pylist([{'name': 'foo', 'age': 10},
                                         {'name': 'bar', 'age': 20}])
      with beam.Pipeline() as p:
        records = p | 'Read' >> beam.Create([table])
        _ = records | 'Write' >> beam.io.WriteToParquetBatched(filename,
            pyarrow.schema(
                [('name', pyarrow.string()), ('age', pyarrow.int64())]
            )
        )

    .. testcleanup:: batched

      for output in glob.glob('{}*'.format(filename)):
        os.remove(output)

    For more information on supported types and schema, please see the pyarrow
    document.

    Args:
      file_path_prefix: The file path to write to. The files written will begin
        with this prefix, followed by a shard identifier (see num_shards), and
        end in a common extension, if given by file_name_suffix. In most cases,
        only this argument is specified and num_shards, shard_name_template, and
        file_name_suffix use default values.
      schema: The schema to use, as type of ``pyarrow.Schema``.
      codec: The codec to use for block-level compression. Any string supported
        by the pyarrow specification is accepted.
      use_deprecated_int96_timestamps: Write nanosecond resolution timestamps to
        INT96 Parquet format. Defaults to False.
      use_compliant_nested_type: Write compliant Parquet nested type (lists).
      file_name_suffix: Suffix for the files written.
      num_shards: The number of files (shards) used for output. If not set, the
        service will decide on the optimal number of shards.
        Constraining the number of shards is likely to reduce
        the performance of a pipeline.  Setting this value is not recommended
        unless you require a specific number of output files.
      shard_name_template: A template string containing placeholders for
        the shard number and shard count. When constructing a filename for a
        particular shard number, the upper-case letters 'S' and 'N' are
        replaced with the 0-padded shard number and shard count respectively.
        W is used for windowed shard naming and is replaced with
        ``[window.start, window.end)``
        V is used for windowed shard naming and is replaced with
        ``[window.start.to_utc_datetime().isoformat(), 
        window.end.to_utc_datetime().isoformat()``
        This argument can be '' in which case it behaves as if num_shards was
        set to 1 and only one file will be generated. 
        The default pattern used is '-SSSSS-of-NNNNN' if None is passed as the 
        shard_name_template and the PCollection is bounded.
        The default pattern used is '-W-SSSSS-of-NNNNN' if None is passed as the
        shard_name_template and the PCollection is unbounded.
      mime_type: The MIME type to use for the produced files, if the filesystem
        supports specifying MIME types.
      triggering_frequency: (int) Every triggering_frequency duration, a window
        will be triggered and all bundles in the window will be written.

    Returns:
      A WriteToParquetBatched transform usable for writing.
    """
    super().__init__()
    self._sink = \
      _create_parquet_sink(
          file_path_prefix,
          schema,
          codec,
          use_deprecated_int96_timestamps,
          use_compliant_nested_type,
          file_name_suffix,
          num_shards,
          shard_name_template,
          mime_type,
          triggering_frequency
      )

  def expand(self, pcoll):
    if (not pcoll.is_bounded and self._sink.shard_name_template
        == filebasedsink.DEFAULT_SHARD_NAME_TEMPLATE):
      self._sink.shard_name_template = (
          filebasedsink.DEFAULT_WINDOW_SHARD_NAME_TEMPLATE)
      self._sink.shard_name_format = self._sink._template_to_format(
          self._sink.shard_name_template)
      self._sink.shard_name_glob_format = self._sink._template_to_glob_format(
          self._sink.shard_name_template)
    return pcoll | Write(self._sink)

  def display_data(self):
    return {'sink_dd': self._sink}


def _create_parquet_sink(
    file_path_prefix,
    schema,
    codec,
    use_deprecated_int96_timestamps,
    use_compliant_nested_type,
    file_name_suffix,
    num_shards,
    shard_name_template,
    mime_type,
    triggering_frequency=60):
  return \
    _ParquetSink(
        file_path_prefix,
        schema,
        codec,
        use_deprecated_int96_timestamps,
        use_compliant_nested_type,
        file_name_suffix,
        num_shards,
        shard_name_template,
        mime_type,
        triggering_frequency
    )


class _ParquetSink(filebasedsink.FileBasedSink):
  """A sink for parquet files from batches."""
  def __init__(
      self,
      file_path_prefix,
      schema,
      codec,
      use_deprecated_int96_timestamps,
      use_compliant_nested_type,
      file_name_suffix,
      num_shards,
      shard_name_template,
      mime_type,
      triggering_frequency):
    super().__init__(
        file_path_prefix,
        file_name_suffix=file_name_suffix,
        num_shards=num_shards,
        shard_name_template=shard_name_template,
        coder=None,
        mime_type=mime_type,
        # Compression happens at the block level using the supplied codec, and
        # not at the file level.
        compression_type=CompressionTypes.UNCOMPRESSED,
        triggering_frequency=triggering_frequency)
    self._schema = schema
    self._codec = codec
    if ARROW_MAJOR_VERSION == 1 and self._codec.lower() == "lz4":
      raise ValueError(
          "Due to ARROW-9424, writing with LZ4 compression is not supported in "
          "pyarrow 1.x, please use a different pyarrow version or a different "
          f"codec. Your pyarrow version: {pa.__version__}")
    self._use_deprecated_int96_timestamps = use_deprecated_int96_timestamps
    if use_compliant_nested_type and ARROW_MAJOR_VERSION < 4:
      raise ValueError(
          "With ARROW-11497, use_compliant_nested_type is only supported in "
          "pyarrow version >= 4.x, please use a different pyarrow version. "
          f"Your pyarrow version: {pa.__version__}")
    self._use_compliant_nested_type = use_compliant_nested_type
    self._file_handle = None

  def open(self, temp_path):
    self._file_handle = super().open(temp_path)
    if ARROW_MAJOR_VERSION < 4:
      return pq.ParquetWriter(
          self._file_handle,
          self._schema,
          compression=self._codec,
          use_deprecated_int96_timestamps=self._use_deprecated_int96_timestamps)
    return pq.ParquetWriter(
        self._file_handle,
        self._schema,
        compression=self._codec,
        use_deprecated_int96_timestamps=self._use_deprecated_int96_timestamps,
        use_compliant_nested_type=self._use_compliant_nested_type)

  def write_record(self, writer, table: paTable):
    writer.write_table(table)

  def close(self, writer):
    writer.close()
    if self._file_handle:
      self._file_handle.close()
      self._file_handle = None

  def display_data(self):
    res = super().display_data()
    res['codec'] = str(self._codec)
    res['schema'] = str(self._schema)
    return res