Function test_mock_output_stream

python/pyarrow/tests/test_io.py:1035–1066

()

def test_mock_output_stream():
    # Make sure that the MockOutputStream and the BufferOutputStream record the
    # same size

    # 10 bytes
    val = b'dataabcdef'

    f1 = pa.MockOutputStream()
    f2 = pa.BufferOutputStream()

    K = 1000
    for i in range(K):
        f1.write(val)
        f2.write(val)

    assert f1.size() == len(f2.getvalue())

    # Do the same test with a table
    record_batch = pa.RecordBatch.from_arrays([pa.array([1, 2, 3])], ['a'])

    f1 = pa.MockOutputStream()
    f2 = pa.BufferOutputStream()

    stream_writer1 = pa.RecordBatchStreamWriter(f1, record_batch.schema)
    stream_writer2 = pa.RecordBatchStreamWriter(f2, record_batch.schema)

    stream_writer1.write_batch(record_batch)
    stream_writer2.write_batch(record_batch)
    stream_writer1.close()
    stream_writer2.close()

    assert f1.size() == len(f2.getvalue())


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