Pillow

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"""
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Helper functions.
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"""
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from __future__ import annotations
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import logging
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import os
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import shutil
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import subprocess
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import sys
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import sysconfig
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import tempfile
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from collections.abc import Sequence
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from functools import lru_cache
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from io import BytesIO
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from typing import Any, Callable
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import pytest
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from packaging.version import parse as parse_version
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from PIL import Image, ImageFile, ImageMath, features
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logger = logging.getLogger(__name__)
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uploader = None
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if os.environ.get("SHOW_ERRORS"):
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    uploader = "show"
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elif "GITHUB_ACTIONS" in os.environ:
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    uploader = "github_actions"
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def upload(a: Image.Image, b: Image.Image) -> str | None:
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    if uploader == "show":
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        # local img.show for errors.
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        a.show()
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        b.show()
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    elif uploader == "github_actions":
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        dir_errors = os.path.join(os.path.dirname(__file__), "errors")
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        os.makedirs(dir_errors, exist_ok=True)
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        tmpdir = tempfile.mkdtemp(dir=dir_errors)
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        a.save(os.path.join(tmpdir, "a.png"))
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        b.save(os.path.join(tmpdir, "b.png"))
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        return tmpdir
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    return None
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def convert_to_comparable(
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    a: Image.Image, b: Image.Image
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) -> tuple[Image.Image, Image.Image]:
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    new_a, new_b = a, b
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    if a.mode == "P":
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        new_a = Image.new("L", a.size)
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        new_b = Image.new("L", b.size)
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        new_a.putdata(a.getdata())
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        new_b.putdata(b.getdata())
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    elif a.mode == "I;16":
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        new_a = a.convert("I")
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        new_b = b.convert("I")
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    return new_a, new_b
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def assert_deep_equal(a: Any, b: Any, msg: str | None = None) -> None:
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    try:
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        assert len(a) == len(b), msg or f"got length {len(a)}, expected {len(b)}"
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    except Exception:
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        assert a == b, msg
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def assert_image(
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    im: Image.Image, mode: str, size: tuple[int, int], msg: str | None = None
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) -> None:
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    if mode is not None:
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        assert im.mode == mode, (
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            msg or f"got mode {repr(im.mode)}, expected {repr(mode)}"
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        )
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    if size is not None:
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        assert im.size == size, (
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            msg or f"got size {repr(im.size)}, expected {repr(size)}"
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        )
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def assert_image_equal(a: Image.Image, b: Image.Image, msg: str | None = None) -> None:
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    assert a.mode == b.mode, msg or f"got mode {repr(a.mode)}, expected {repr(b.mode)}"
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    assert a.size == b.size, msg or f"got size {repr(a.size)}, expected {repr(b.size)}"
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    if a.tobytes() != b.tobytes():
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        try:
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            url = upload(a, b)
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            if url:
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                logger.error("URL for test images: %s", url)
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        except Exception:
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            pass
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        pytest.fail(msg or "got different content")
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def assert_image_equal_tofile(
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    a: Image.Image, filename: str, msg: str | None = None, mode: str | None = None
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) -> None:
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    with Image.open(filename) as img:
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        if mode:
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            img = img.convert(mode)
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        assert_image_equal(a, img, msg)
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def assert_image_similar(
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    a: Image.Image, b: Image.Image, epsilon: float, msg: str | None = None
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) -> None:
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    assert a.mode == b.mode, msg or f"got mode {repr(a.mode)}, expected {repr(b.mode)}"
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    assert a.size == b.size, msg or f"got size {repr(a.size)}, expected {repr(b.size)}"
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    a, b = convert_to_comparable(a, b)
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    diff = 0
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    for ach, bch in zip(a.split(), b.split()):
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        chdiff = ImageMath.lambda_eval(
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            lambda args: abs(args["a"] - args["b"]), a=ach, b=bch
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        ).convert("L")
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        diff += sum(i * num for i, num in enumerate(chdiff.histogram()))
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    ave_diff = diff / (a.size[0] * a.size[1])
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    try:
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        assert epsilon >= ave_diff, (
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            (msg or "")
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            + f" average pixel value difference {ave_diff:.4f} > epsilon {epsilon:.4f}"
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        )
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    except Exception as e:
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        try:
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            url = upload(a, b)
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            if url:
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                logger.exception("URL for test images: %s", url)
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        except Exception:
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            pass
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        raise e
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def assert_image_similar_tofile(
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    a: Image.Image,
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    filename: str,
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    epsilon: float,
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    msg: str | None = None,
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    mode: str | None = None,
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) -> None:
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    with Image.open(filename) as img:
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        if mode:
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            img = img.convert(mode)
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        assert_image_similar(a, img, epsilon, msg)
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def assert_all_same(items: Sequence[Any], msg: str | None = None) -> None:
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    assert items.count(items[0]) == len(items), msg
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def assert_not_all_same(items: Sequence[Any], msg: str | None = None) -> None:
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    assert items.count(items[0]) != len(items), msg
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def assert_tuple_approx_equal(
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    actuals: Sequence[int], targets: tuple[int, ...], threshold: int, msg: str
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) -> None:
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    """Tests if actuals has values within threshold from targets"""
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    for i, target in enumerate(targets):
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        if not (target - threshold <= actuals[i] <= target + threshold):
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            pytest.fail(msg + ": " + repr(actuals) + " != " + repr(targets))
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def skip_unless_feature(feature: str) -> pytest.MarkDecorator:
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    reason = f"{feature} not available"
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    return pytest.mark.skipif(not features.check(feature), reason=reason)
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def skip_unless_feature_version(
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    feature: str, required: str, reason: str | None = None
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) -> pytest.MarkDecorator:
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    version = features.version(feature)
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    if version is None:
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        return pytest.mark.skip(f"{feature} not available")
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    if reason is None:
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        reason = f"{feature} is older than {required}"
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    version_required = parse_version(required)
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    version_available = parse_version(version)
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    return pytest.mark.skipif(version_available < version_required, reason=reason)
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def mark_if_feature_version(
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    mark: pytest.MarkDecorator,
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    feature: str,
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    version_blacklist: str,
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    reason: str | None = None,
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) -> pytest.MarkDecorator:
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    version = features.version(feature)
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    if version is None:
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        return pytest.mark.pil_noop_mark()
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    if reason is None:
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        reason = f"{feature} is {version_blacklist}"
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    version_required = parse_version(version_blacklist)
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    version_available = parse_version(version)
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    if (
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        version_available.major == version_required.major
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        and version_available.minor == version_required.minor
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    ):
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        return mark(reason=reason)
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    return pytest.mark.pil_noop_mark()
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@pytest.mark.skipif(sys.platform.startswith("win32"), reason="Requires Unix or macOS")
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class PillowLeakTestCase:
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    # requires unix/macOS
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    iterations = 100  # count
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    mem_limit = 512  # k
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    def _get_mem_usage(self) -> float:
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        """
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        Gets the RUSAGE memory usage, returns in K. Encapsulates the difference
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        between macOS and Linux rss reporting
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        :returns: memory usage in kilobytes
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        """
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        from resource import RUSAGE_SELF, getrusage
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        mem = getrusage(RUSAGE_SELF).ru_maxrss
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        # man 2 getrusage:
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        #     ru_maxrss
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        # This is the maximum resident set size utilized
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        # in bytes on macOS, in kilobytes on Linux
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        return mem / 1024 if sys.platform == "darwin" else mem
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    def _test_leak(self, core: Callable[[], None]) -> None:
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        start_mem = self._get_mem_usage()
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        for cycle in range(self.iterations):
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            core()
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            mem = self._get_mem_usage() - start_mem
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            msg = f"memory usage limit exceeded in iteration {cycle}"
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            assert mem < self.mem_limit, msg
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# helpers
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def fromstring(data: bytes) -> ImageFile.ImageFile:
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    return Image.open(BytesIO(data))
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def tostring(im: Image.Image, string_format: str, **options: Any) -> bytes:
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    out = BytesIO()
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    im.save(out, string_format, **options)
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    return out.getvalue()
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def hopper(mode: str | None = None) -> Image.Image:
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    # Use caching to reduce reading from disk, but return a copy
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    # so that the cached image isn't modified by the tests
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    # (for fast, isolated, repeatable tests).
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    if mode is None:
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        # Always return fresh not-yet-loaded version of image.
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        # Operations on not-yet-loaded images are a separate class of errors
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        # that we should catch.
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        return Image.open("Tests/images/hopper.ppm")
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    return _cached_hopper(mode).copy()
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@lru_cache
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def _cached_hopper(mode: str) -> Image.Image:
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    if mode == "F":
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        im = hopper("L")
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    else:
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        im = hopper()
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    if mode.startswith("BGR;"):
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        with pytest.warns(DeprecationWarning):
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            im = im.convert(mode)
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    else:
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        try:
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            im = im.convert(mode)
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        except ImportError:
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            if mode == "LAB":
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                im = Image.open("Tests/images/hopper.Lab.tif")
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            else:
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                raise
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    return im
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def djpeg_available() -> bool:
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    if shutil.which("djpeg"):
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        try:
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            subprocess.check_call(["djpeg", "-version"])
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            return True
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        except subprocess.CalledProcessError:  # pragma: no cover
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            return False
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    return False
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def cjpeg_available() -> bool:
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    if shutil.which("cjpeg"):
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        try:
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            subprocess.check_call(["cjpeg", "-version"])
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            return True
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        except subprocess.CalledProcessError:  # pragma: no cover
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            return False
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    return False
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def netpbm_available() -> bool:
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    return bool(shutil.which("ppmquant") and shutil.which("ppmtogif"))
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def magick_command() -> list[str] | None:
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    if sys.platform == "win32":
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        magickhome = os.environ.get("MAGICK_HOME")
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        if magickhome:
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            imagemagick = [os.path.join(magickhome, "convert.exe")]
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            graphicsmagick = [os.path.join(magickhome, "gm.exe"), "convert"]
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        else:
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            imagemagick = None
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            graphicsmagick = None
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    else:
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        imagemagick = ["convert"]
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        graphicsmagick = ["gm", "convert"]
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    if imagemagick and shutil.which(imagemagick[0]):
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        return imagemagick
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    if graphicsmagick and shutil.which(graphicsmagick[0]):
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        return graphicsmagick
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    return None
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def on_appveyor() -> bool:
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    return "APPVEYOR" in os.environ
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def on_github_actions() -> bool:
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    return "GITHUB_ACTIONS" in os.environ
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def on_ci() -> bool:
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    # GitHub Actions and AppVeyor have "CI"
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    return "CI" in os.environ
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def is_big_endian() -> bool:
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    return sys.byteorder == "big"
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def is_ppc64le() -> bool:
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    import platform
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    return platform.machine() == "ppc64le"
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def is_win32() -> bool:
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    return sys.platform.startswith("win32")
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def is_pypy() -> bool:
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    return hasattr(sys, "pypy_translation_info")
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def is_mingw() -> bool:
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    return sysconfig.get_platform() == "mingw"
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class CachedProperty:
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    def __init__(self, func: Callable[[Any], Any]) -> None:
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        self.func = func
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    def __get__(self, instance: Any, cls: type[Any] | None = None) -> Any:
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        result = instance.__dict__[self.func.__name__] = self.func(instance)
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        return result
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