This changes the calling convention for calling a Javascript function from Python so that any proxied arguments are automatically destroyed at the end of the function call. This is a breaking change. It should make it much more convenient to use the foreign function interface. 

The docs need to be updated to explain the new calling convention before this can be merged. We should put a link to the appropriate section in the docs into the error message emitted when a borrowed proxy is used after it is free so that people have an easy time learning the model by trial and error.
ENH Destroy proxies created in JsProxy.__call__ when done with call. This changes the calling convention for calling a Javascript function from Python so that any proxied arguments are automatically destroyed at the end of the function call. This is a breaking change. It should make it much more convenient to use the foreign function interface. 

The docs need to be updated to explain the new calling convention before this can be merged. We should put a link to the appropriate section in the docs into the error message emitted when a borrowed proxy is used after it is free so that people have an easy time learning the model by trial and error.
from pyodide_build.testing import run_in_pyodide


@run_in_pyodide(
    standalone=True,
    packages=["numcodecs", "numpy"],
    xfail_browsers={
        "chrome": "test_numcodecs triggers a recursion error in chrome",
    },
)
def test_blosc():
    import numpy as np
    from numcodecs.blosc import Blosc
    from numcodecs.zstd import Zstd
    from numcodecs.lz4 import LZ4
    from numcodecs.compat import ensure_bytes, ensure_ndarray
    from numpy.testing import assert_array_almost_equal, assert_array_equal
    import array

    def compare_arrays(arr, res, precision=None):
        # ensure numpy array with matching dtype
        res = ensure_ndarray(res).view(arr.dtype)

        # convert to correct shape
        if arr.flags.f_contiguous:
            order = "F"
        else:
            order = "C"
        res = res.reshape(arr.shape, order=order)

        # exact compare
        if precision is None:
            assert_array_equal(arr, res)

        # fuzzy compare
        else:
            assert_array_almost_equal(arr, res, decimal=precision)

    def check_encode_decode(arr, codec, precision=None):

        # N.B., watch out here with blosc compressor, if the itemsize of
        # the source buffer is different then the results of encoding
        # (i.e., compression) may be different. Hence we *do not* require that
        # the results of encoding be identical for all possible inputs, rather
        # we just require that the results of the encode/decode round-trip can
        # be compared to the original array.

        # encoding should support any object exporting the buffer protocol

        # test encoding of numpy array
        enc = codec.encode(arr)
        dec = codec.decode(enc)
        compare_arrays(arr, dec, precision=precision)

        # test encoding of bytes
        buf = arr.tobytes(order="A")
        enc = codec.encode(buf)
        dec = codec.decode(enc)
        compare_arrays(arr, dec, precision=precision)

        # test encoding of bytearray
        buf = bytearray(arr.tobytes(order="A"))
        enc = codec.encode(buf)
        dec = codec.decode(enc)
        compare_arrays(arr, dec, precision=precision)

        # test encoding of array.array
        buf = array.array("b", arr.tobytes(order="A"))
        enc = codec.encode(buf)
        dec = codec.decode(enc)
        compare_arrays(arr, dec, precision=precision)

        # decoding should support any object exporting the buffer protocol,

        # setup
        enc_bytes = ensure_bytes(enc)

        # test decoding of raw bytes
        dec = codec.decode(enc_bytes)
        compare_arrays(arr, dec, precision=precision)

        # test decoding of bytearray
        dec = codec.decode(bytearray(enc_bytes))
        compare_arrays(arr, dec, precision=precision)

        # test decoding of array.array
        buf = array.array("b", enc_bytes)
        dec = codec.decode(buf)
        compare_arrays(arr, dec, precision=precision)

        # test decoding of numpy array
        buf = np.frombuffer(enc_bytes, dtype="u1")
        dec = codec.decode(buf)
        compare_arrays(arr, dec, precision=precision)

        # test decoding directly into numpy array
        out = np.empty_like(arr)
        codec.decode(enc_bytes, out=out)
        compare_arrays(arr, out, precision=precision)

        # test decoding directly into bytearray
        out = bytearray(arr.nbytes)
        codec.decode(enc_bytes, out=out)
        # noinspection PyTypeChecker
        compare_arrays(arr, out, precision=precision)

    # mix of dtypes: integer, float, bool, string
    # mix of shapes: 1D, 2D, 3D
    # mix of orders: C, F
    arrays = [
        np.arange(1000, dtype="i4"),
        np.linspace(1000, 1001, 1000, dtype="f8"),
        np.random.normal(loc=1000, scale=1, size=(100, 10)),
        np.random.randint(0, 2, size=1000, dtype=bool).reshape(100, 10, order="F"),
        np.random.choice([b"a", b"bb", b"ccc"], size=1000).reshape(10, 10, 10),
        np.random.randint(0, 2 ** 60, size=1000, dtype="u8").view("M8[ns]"),
        np.random.randint(0, 2 ** 60, size=1000, dtype="u8").view("m8[ns]"),
        np.random.randint(0, 2 ** 25, size=1000, dtype="u8").view("M8[m]"),
        np.random.randint(0, 2 ** 25, size=1000, dtype="u8").view("m8[m]"),
        np.random.randint(-(2 ** 63), -(2 ** 63) + 20, size=1000, dtype="i8").view(
            "M8[ns]"
        ),
        np.random.randint(-(2 ** 63), -(2 ** 63) + 20, size=1000, dtype="i8").view(
            "m8[ns]"
        ),
        np.random.randint(-(2 ** 63), -(2 ** 63) + 20, size=1000, dtype="i8").view(
            "M8[m]"
        ),
        np.random.randint(-(2 ** 63), -(2 ** 63) + 20, size=1000, dtype="i8").view(
            "m8[m]"
        ),
    ]

    codecs = [
        LZ4(),
        LZ4(acceleration=-1),
        LZ4(acceleration=10),
        Zstd(),
        Zstd(level=-1),
        Zstd(level=10),
        Blosc(shuffle=Blosc.SHUFFLE),
        Blosc(clevel=0, shuffle=Blosc.SHUFFLE),
        Blosc(cname="lz4", shuffle=Blosc.SHUFFLE),
        Blosc(cname="lz4", clevel=1, shuffle=Blosc.NOSHUFFLE),
        Blosc(cname="lz4", clevel=5, shuffle=Blosc.SHUFFLE),
        Blosc(cname="lz4", clevel=9, shuffle=Blosc.BITSHUFFLE),
        Blosc(cname="zlib", clevel=1, shuffle=0),
        Blosc(cname="zstd", clevel=1, shuffle=1),
        Blosc(cname="blosclz", clevel=1, shuffle=2),
        Blosc(cname="snappy", clevel=1, shuffle=2),
        Blosc(shuffle=Blosc.SHUFFLE, blocksize=0),
        Blosc(shuffle=Blosc.SHUFFLE, blocksize=2 ** 8),
        Blosc(cname="lz4", clevel=1, shuffle=Blosc.NOSHUFFLE, blocksize=2 ** 8),
    ]
    for codec in codecs:
        for arr in arrays:
            check_encode_decode(arr, codec)

from pyodide_build.testing import run_in_pyodide


@run_in_pyodide(
    standalone=True,
    packages=["numcodecs", "numpy"],
    xfail_browsers={
        "chrome": "test_numcodecs triggers a recursion error in chrome",
    },
)
def test_blosc():
    import numpy as np
    from numcodecs.blosc import Blosc
    from numcodecs.zstd import Zstd
    from numcodecs.lz4 import LZ4
    from numcodecs.compat import ensure_bytes, ensure_ndarray
    from numpy.testing import assert_array_almost_equal, assert_array_equal
    import array

    def compare_arrays(arr, res, precision=None):
        # ensure numpy array with matching dtype
        res = ensure_ndarray(res).view(arr.dtype)

        # convert to correct shape
        if arr.flags.f_contiguous:
            order = "F"
        else:
            order = "C"
        res = res.reshape(arr.shape, order=order)

        # exact compare
        if precision is None:
            assert_array_equal(arr, res)

        # fuzzy compare
        else:
            assert_array_almost_equal(arr, res, decimal=precision)

    def check_encode_decode(arr, codec, precision=None):

        # N.B., watch out here with blosc compressor, if the itemsize of
        # the source buffer is different then the results of encoding
        # (i.e., compression) may be different. Hence we *do not* require that
        # the results of encoding be identical for all possible inputs, rather
        # we just require that the results of the encode/decode round-trip can
        # be compared to the original array.

        # encoding should support any object exporting the buffer protocol

        # test encoding of numpy array
        enc = codec.encode(arr)
        dec = codec.decode(enc)
        compare_arrays(arr, dec, precision=precision)

        # test encoding of bytes
        buf = arr.tobytes(order="A")
        enc = codec.encode(buf)
        dec = codec.decode(enc)
        compare_arrays(arr, dec, precision=precision)

        # test encoding of bytearray
        buf = bytearray(arr.tobytes(order="A"))
        enc = codec.encode(buf)
        dec = codec.decode(enc)
        compare_arrays(arr, dec, precision=precision)

        # test encoding of array.array
        buf = array.array("b", arr.tobytes(order="A"))
        enc = codec.encode(buf)
        dec = codec.decode(enc)
        compare_arrays(arr, dec, precision=precision)

        # decoding should support any object exporting the buffer protocol,

        # setup
        enc_bytes = ensure_bytes(enc)

        # test decoding of raw bytes
        dec = codec.decode(enc_bytes)
        compare_arrays(arr, dec, precision=precision)

        # test decoding of bytearray
        dec = codec.decode(bytearray(enc_bytes))
        compare_arrays(arr, dec, precision=precision)

        # test decoding of array.array
        buf = array.array("b", enc_bytes)
        dec = codec.decode(buf)
        compare_arrays(arr, dec, precision=precision)

        # test decoding of numpy array
        buf = np.frombuffer(enc_bytes, dtype="u1")
        dec = codec.decode(buf)
        compare_arrays(arr, dec, precision=precision)

        # test decoding directly into numpy array
        out = np.empty_like(arr)
        codec.decode(enc_bytes, out=out)
        compare_arrays(arr, out, precision=precision)

        # test decoding directly into bytearray
        out = bytearray(arr.nbytes)
        codec.decode(enc_bytes, out=out)
        # noinspection PyTypeChecker
        compare_arrays(arr, out, precision=precision)

    # mix of dtypes: integer, float, bool, string
    # mix of shapes: 1D, 2D, 3D
    # mix of orders: C, F
    arrays = [
        np.arange(1000, dtype="i4"),
        np.linspace(1000, 1001, 1000, dtype="f8"),
        np.random.normal(loc=1000, scale=1, size=(100, 10)),
        np.random.randint(0, 2, size=1000, dtype=bool).reshape(100, 10, order="F"),
        np.random.choice([b"a", b"bb", b"ccc"], size=1000).reshape(10, 10, 10),
        np.random.randint(0, 2 ** 60, size=1000, dtype="u8").view("M8[ns]"),
        np.random.randint(0, 2 ** 60, size=1000, dtype="u8").view("m8[ns]"),
        np.random.randint(0, 2 ** 25, size=1000, dtype="u8").view("M8[m]"),
        np.random.randint(0, 2 ** 25, size=1000, dtype="u8").view("m8[m]"),
        np.random.randint(-(2 ** 63), -(2 ** 63) + 20, size=1000, dtype="i8").view(
            "M8[ns]"
        ),
        np.random.randint(-(2 ** 63), -(2 ** 63) + 20, size=1000, dtype="i8").view(
            "m8[ns]"
        ),
        np.random.randint(-(2 ** 63), -(2 ** 63) + 20, size=1000, dtype="i8").view(
            "M8[m]"
        ),
        np.random.randint(-(2 ** 63), -(2 ** 63) + 20, size=1000, dtype="i8").view(
            "m8[m]"
        ),
    ]

    codecs = [
        LZ4(),
        LZ4(acceleration=-1),
        LZ4(acceleration=10),
        Zstd(),
        Zstd(level=-1),
        Zstd(level=10),
        Blosc(shuffle=Blosc.SHUFFLE),
        Blosc(clevel=0, shuffle=Blosc.SHUFFLE),
        Blosc(cname="lz4", shuffle=Blosc.SHUFFLE),
        Blosc(cname="lz4", clevel=1, shuffle=Blosc.NOSHUFFLE),
        Blosc(cname="lz4", clevel=5, shuffle=Blosc.SHUFFLE),
        Blosc(cname="lz4", clevel=9, shuffle=Blosc.BITSHUFFLE),
        Blosc(cname="zlib", clevel=1, shuffle=0),
        Blosc(cname="zstd", clevel=1, shuffle=1),
        Blosc(cname="blosclz", clevel=1, shuffle=2),
        Blosc(cname="snappy", clevel=1, shuffle=2),
        Blosc(shuffle=Blosc.SHUFFLE, blocksize=0),
        Blosc(shuffle=Blosc.SHUFFLE, blocksize=2 ** 8),
        Blosc(cname="lz4", clevel=1, shuffle=Blosc.NOSHUFFLE, blocksize=2 ** 8),
    ]
    for codec in codecs:
        for arr in arrays:
            check_encode_decode(arr, codec)
