Pillow/Tests/helper.py
2024-02-12 09:28:53 +11:00

360 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 io import BytesIO
from typing import Any, Callable, Sequence
import pytest
from packaging.version import parse as parse_version
from PIL import Image, 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.eval("abs(a - 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:
if not features.check(feature):
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(features.version(feature))
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:
if not features.check(feature):
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(features.version(feature))
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
if sys.platform == "darwin":
# man 2 getrusage:
# ru_maxrss
# This is the maximum resident set size utilized (in bytes).
return mem / 1024 # Kb
# linux
# man 2 getrusage
# ru_maxrss (since Linux 2.6.32)
# This is the maximum resident set size used (in kilobytes).
return mem # Kb
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) -> Image.Image:
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, cache: dict[str, Image.Image] = {}) -> Image.Image:
if mode is None:
# Always return fresh not-yet-loaded version of image.
# Operations on not-yet-loaded images is separate class of errors
# what we should catch.
return Image.open("Tests/images/hopper.ppm")
# Use caching to reduce reading from disk but so an original copy is
# returned each time and the cached image isn't modified by tests
# (for fast, isolated, repeatable tests).
im = cache.get(mode)
if im is None:
if mode == "F":
im = hopper("L").convert(mode)
elif mode[:4] == "I;16":
im = hopper("I").convert(mode)
else:
im = hopper().convert(mode)
cache[mode] = im
return im.copy()
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], None]) -> 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