csharp/test/Apache.Arrow.Compression.Tests/generate_resources.py

# Licensed to the Apache Software Foundation (ASF) under one or more
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# 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
#
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"""
Generates files required for tests where it's not possible to generate
them with dotnet Arrow.
"""

import pyarrow as pa
from pathlib import Path


def write_compressed_ipc_file(path: Path, compression: str, stream: bool = False):
    schema = pa.schema([
        pa.field('integers', pa.int32()),
        pa.field('floats', pa.float32()),
    ])

    integers = pa.array(range(100), type=pa.int32())
    floats = pa.array((x * 0.1 for x in range(100)), type=pa.float32())
    batch = pa.record_batch([integers, floats], schema)

    options = pa.ipc.IpcWriteOptions(compression=compression)

    with pa.OSFile(path.as_posix(), 'wb') as sink:
        if stream:
            with pa.ipc.new_stream(sink, schema, options=options) as writer:
                writer.write(batch)
        else:
            with pa.ipc.new_file(sink, schema, options=options) as writer:
                writer.write(batch)


if __name__ == '__main__':
    resource_dir = Path(__file__).resolve().parent / 'Resources'

    write_compressed_ipc_file(resource_dir / 'ipc_lz4_compression.arrow', 'lz4')
    write_compressed_ipc_file(resource_dir / 'ipc_lz4_compression.arrow_stream', 'lz4', stream=True)
    write_compressed_ipc_file(resource_dir / 'ipc_zstd_compression.arrow', 'zstd')
    write_compressed_ipc_file(resource_dir / 'ipc_zstd_compression.arrow_stream', 'zstd', stream=True)