Pillow/Tests/helper.py
Hugo van Kemenade 51bd7d2ea8
Drop support for Python 3.8 (#8183)
Co-authored-by: Andrew Murray <radarhere@users.noreply.github.com>
Co-authored-by: Andrew Murray <3112309+radarhere@users.noreply.github.com>
2024-07-03 00:44:45 -06:00

374 lines
10 KiB
Python

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