Traktor/myenv/Lib/site-packages/fsspec/tests/test_compression.py
2024-05-23 01:57:24 +02:00

165 lines
5.1 KiB
Python

import pathlib
import pytest
import fsspec.core
from fsspec.compression import compr, register_compression
from fsspec.utils import compressions, infer_compression
def test_infer_custom_compression():
"""Inferred compression gets values from fsspec.compression.compr."""
assert infer_compression("fn.zip") == "zip"
assert infer_compression("fn.gz") == "gzip"
assert infer_compression("fn.unknown") is None
assert infer_compression("fn.test_custom") is None
assert infer_compression("fn.tst") is None
register_compression("test_custom", lambda f, **kwargs: f, "tst")
try:
assert infer_compression("fn.zip") == "zip"
assert infer_compression("fn.gz") == "gzip"
assert infer_compression("fn.unknown") is None
assert infer_compression("fn.test_custom") is None
assert infer_compression("fn.tst") == "test_custom"
# Duplicate registration in name or extension raises a value error.
with pytest.raises(ValueError):
register_compression("test_custom", lambda f, **kwargs: f, "tst")
with pytest.raises(ValueError):
register_compression("test_conflicting", lambda f, **kwargs: f, "tst")
assert "test_conflicting" not in compr
# ...but can be forced.
register_compression(
"test_conflicting", lambda f, **kwargs: f, "tst", force=True
)
assert infer_compression("fn.zip") == "zip"
assert infer_compression("fn.gz") == "gzip"
assert infer_compression("fn.unknown") is None
assert infer_compression("fn.test_custom") is None
assert infer_compression("fn.tst") == "test_conflicting"
finally:
del compr["test_custom"]
del compr["test_conflicting"]
del compressions["tst"]
def test_infer_uppercase_compression():
assert infer_compression("fn.ZIP") == "zip"
assert infer_compression("fn.GZ") == "gzip"
assert infer_compression("fn.UNKNOWN") is None
assert infer_compression("fn.TEST_UPPERCASE") is None
assert infer_compression("fn.TEST") is None
def test_lzma_compression_name():
pytest.importorskip("lzma")
assert infer_compression("fn.xz") == "xz"
assert infer_compression("fn.lzma") == "lzma"
def test_lz4_compression(tmpdir):
"""Infer lz4 compression for .lz4 files if lz4 is available."""
tmp_path = pathlib.Path(str(tmpdir))
lz4 = pytest.importorskip("lz4")
tmp_path.mkdir(exist_ok=True)
tdat = "foobar" * 100
with fsspec.core.open(
str(tmp_path / "out.lz4"), mode="wt", compression="infer"
) as outfile:
outfile.write(tdat)
compressed = (tmp_path / "out.lz4").open("rb").read()
assert lz4.frame.decompress(compressed).decode() == tdat
with fsspec.core.open(
str(tmp_path / "out.lz4"), mode="rt", compression="infer"
) as infile:
assert infile.read() == tdat
with fsspec.core.open(
str(tmp_path / "out.lz4"), mode="rt", compression="lz4"
) as infile:
assert infile.read() == tdat
def test_zstd_compression(tmpdir):
"""Infer zstd compression for .zst files if zstandard is available."""
tmp_path = pathlib.Path(str(tmpdir))
zstd = pytest.importorskip("zstandard")
tmp_path.mkdir(exist_ok=True)
tdat = "foobar" * 100
with fsspec.core.open(
str(tmp_path / "out.zst"), mode="wt", compression="infer"
) as outfile:
outfile.write(tdat)
compressed = (tmp_path / "out.zst").open("rb").read()
assert zstd.ZstdDecompressor().decompress(compressed, len(tdat)).decode() == tdat
with fsspec.core.open(
str(tmp_path / "out.zst"), mode="rt", compression="infer"
) as infile:
assert infile.read() == tdat
with fsspec.core.open(
str(tmp_path / "out.zst"), mode="rt", compression="zstd"
) as infile:
assert infile.read() == tdat
# fails in https://github.com/fsspec/filesystem_spec/issues/725
infile = fsspec.core.open(
str(tmp_path / "out.zst"), mode="rb", compression="infer"
).open()
infile.close()
def test_snappy_compression(tmpdir):
"""No registered compression for snappy, but can be specified."""
tmp_path = pathlib.Path(str(tmpdir))
snappy = pytest.importorskip("snappy")
tmp_path.mkdir(exist_ok=True)
tdat = "foobar" * 100
# Snappy isn't inferred.
with fsspec.core.open(
str(tmp_path / "out.snappy"), mode="wt", compression="infer"
) as outfile:
outfile.write(tdat)
assert (tmp_path / "out.snappy").open("rb").read().decode() == tdat
# but can be specified.
with fsspec.core.open(
str(tmp_path / "out.snappy"), mode="wt", compression="snappy"
) as outfile:
outfile.write(tdat)
compressed = (tmp_path / "out.snappy").open("rb").read()
assert snappy.StreamDecompressor().decompress(compressed).decode() == tdat
with fsspec.core.open(
str(tmp_path / "out.snappy"), mode="rb", compression="infer"
) as infile:
assert infile.read() == compressed
with fsspec.core.open(
str(tmp_path / "out.snappy"), mode="rt", compression="snappy"
) as infile:
assert infile.read() == tdat