merge(thumbs): thumbnails sized for the tile's width at 2x, and a cache that cannot be planted

Operator-approved 2026-09-23 ("fix it, one bigger thumbnail"), after his
report that sindra-nude-final looked "blurry until selected". c2b1454 sizes
thumbnails at 768 wide (the widest desktop tile, doubled for a 2x screen) and
caps them at 4096 tall. A browser test holds the number against the rendered
grid. c19d8c9 folds the heid bug-hunt (4/4 arms, five seat-executed probes):
cache hits must be regular files carrying the source's exact mtime, the cache
dirs never follow a link, the temp file is mkstemp, palette alpha and EXIF
orientation survive, and there is a 64 MP decode budget. 828 passed on the
branch; thumbs.toml 14/14.
This commit is contained in:
vh
2026-09-23 23:07:07 -07:00
5 changed files with 546 additions and 51 deletions
+134 -44
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@@ -8,12 +8,16 @@ counted IMAGES and never weighed BYTES. The live set on 2026-09-23:
sindra-sfw-pool 59 images 71.7 MB
sindra 30 images 61.6 MB 2.1 MB average
A tile renders around 250px wide, so the gallery shipped roughly 16x the pixels
A tile renders a few hundred px wide, so the gallery shipped roughly 16x the pixels
that reach the screen and 77 MB on one page load. 66 is a fine count sitting on
a terrible payload; the operator found it in about a minute of using the Desk.
The cache lives at `<booth>/.thumbs/<rel>.webp` — inside the booth on purpose,
so it is swept with the booth and never outlives what it describes. Both
The cache lives at `<booth>/.thumbs/<rel>.<rule>.webp` (see `thumb_path`),
inside the booth on purpose, so it is swept with the booth and never outlives
what it describes. And because it is inside the booth, where any fleet session
can write, every entry on the way to it may be planted: the cache directories,
the cache file and the temp file are each checked or created so that a link,
a directory or a planted file cannot redirect a write or pose as a thumbnail. Both
`booth_items` and `zip_booth` skip every dot-prefixed path COMPONENT, which they
did not do until this module needed them to.
"""
@@ -21,16 +25,45 @@ did not do until this module needed them to.
from __future__ import annotations
import os
import stat
import tempfile
from pathlib import Path
try: # optional: absence degrades to full-size images, never to a broken page
from PIL import Image as _Image
from PIL import ImageOps as _ImageOps
except ImportError: # pragma: no cover
_Image = None
_ImageOps = None
THUMB_DIR = ".thumbs"
THUMB_MAX = 512 # longest side, px — comfortably above any tile size
# SIZED FOR THE TILE'S WIDTH, AT 2x DENSITY. A gallery tile is sized by its
# width (the image is `width:100%; height:auto`), and on the desktop grid (3
# columns, 1440px viewports and up) it measures 321-361 CSS px, so 768 covers
# the widest one on a 2x screen. This used to be 512 on the LONGEST side, which
# the comment called "comfortably above any tile size", and it was, for a square.
# A 704x1408 portrait got 256px of width for a 361px tile: 1.4x stretched at 1x,
# 2.8x on a 2x screen, and the operator saw it as "blurry until selected".
# Narrower windows reflow to 2 columns (up to 472px) or 1 (up to 650px) and are
# softer than this covers at 2x. tests/test_thumbs_browser.py holds this number
# against the rendered grid, so a wider tile turns it red instead of soft.
THUMB_WIDTH = 768
# Width alone would let a long screenshot through at full height.
THUMB_HEIGHT_MAX = 4096
# An original that already fits the bounds is served as-is only when it is also
# LIGHT: fitting a tile in pixels is not being cheap in bytes, and a 704x1408
# PNG is about a megabyte. Measured on the 381 live images, 2026-09-23: 768-wide
# thumbnails average 39 KB, so anything at or under 64 KB has nothing to save.
THUMB_LIGHT_BYTES = 64 * 1024
THUMB_QUALITY = 78
# A header is free to read and claims any size it likes; `thumbnail()` then
# decodes it, on every request, because a failure is not cached. Past this the
# original is served and nothing is decoded. 64 MP is 8K x 8K, far past any
# image a booth has held.
THUMB_MAX_PIXELS = 64_000_000
# Bump when the ENCODING changes in a way the numbers above do not show (a mode
# conversion, an orientation rule), so every cached thumbnail is rebuilt.
THUMB_VERSION = 2
# What Pillow can open from a plain install. SVG is vector (Pillow cannot read
# it, and it is already small); AVIF needs a plugin we do not require.
@@ -39,8 +72,15 @@ THUMBABLE = {".png", ".jpg", ".jpeg", ".webp", ".gif", ".bmp"}
def thumb_path(booth: Path, rel: str) -> Path:
"""Where `rel`'s thumbnail lives. Mirrors the tree so two files with the
same basename in different folders cannot collide."""
return booth / THUMB_DIR / (rel + ".webp")
same basename in different folders cannot collide.
THE WHOLE RULE IS IN THE NAME: width, height cap, quality and an encoding
version. The freshness check below only notices a changed source, so a
thumbnail cut to an older rule would otherwise be served forever. A change
to any of them is a cache miss, and the old files are orphans swept with
their booth."""
rule = f"{THUMB_WIDTH}x{THUMB_HEIGHT_MAX}q{THUMB_QUALITY}v{THUMB_VERSION}"
return booth / THUMB_DIR / f"{rel}.{rule}.webp"
def wants_thumb(rel: str) -> bool:
@@ -51,17 +91,66 @@ def wants_thumb(rel: str) -> bool:
return Path(rel).suffix.lower() in THUMBABLE
def _fresh(out: Path, s_stat: os.stat_result) -> bool:
"""A cache hit: a REGULAR file (lstat, so a link or a directory planted at
the name never counts) carrying its source's EXACT mtime. Exact, not
"at least as new": a source replaced by `cp -p` or an archive extract keeps
an OLDER stamp, and `>=` served the old thumbnail forever."""
try:
o = os.lstat(out)
except OSError:
return False
return stat.S_ISREG(o.st_mode) and o.st_mtime_ns == s_stat.st_mtime_ns
def _cache_dir(booth: Path, parent: Path) -> bool:
"""Make `parent` (a directory under `booth`) exist as REAL directories,
component by component, never following a link. False when something that
is not a directory is in the way: a `.thumbs` planted as a link would
otherwise put the cache outside the booth, beyond the sweep.
⚠ CREATING `.thumbs` TOUCHES THE BOOTH DIRECTORY'S OWN MTIME, and
`_newest_mtime` seeds from exactly that — so merely LOOKING at a booth aged
it, and once the Desk pulls a thumbnail per booth, one index load would push
every expiry out and the TTL would never fire again. Excluding the cache's
CONTENTS is not enough; the directory entry is the leak. So the booth's
mtime is put back after `.thumbs` is made. That cannot hide real activity:
any file an agent adds is counted by its OWN mtime in the same walk, and the
directory stamp is only the seed."""
cur = booth
for part in parent.relative_to(booth).parts:
cur = cur / part
try:
if not stat.S_ISDIR(os.lstat(cur).st_mode):
return False
continue
except FileNotFoundError:
pass
restore = booth.stat() if cur.parent == booth else None
try:
os.mkdir(cur)
except FileExistsError:
pass
if restore is not None:
try:
os.utime(booth, ns=(restore.st_atime_ns, restore.st_mtime_ns))
except OSError:
pass
if not stat.S_ISDIR(os.lstat(cur).st_mode):
return False
return True
def ensure_thumb(booth: Path, rel: str) -> Path | None:
"""The cached thumbnail for `rel`, generating it if needed. None when there
should not be one — Pillow absent, unsupported type, source already small
enough, or anything at all went wrong.
should not be one — Pillow absent, unsupported type, source already
tile-sized and light, an animation that already fits (a thumbnail is one
frame; an animation too big to fit IS flattened), over the pixel budget,
something planted in the cache's way, or anything at all went wrong.
NEVER RAISES. A thumbnail is an optimisation; a booth page that will not
load is worse than a page that loads slowly, which is the posture every
other read on this path already takes.
Regenerates when the source is newer than the cache, so editing a file in
place does not leave the old thumbnail behind forever.
"""
if _Image is None or not wants_thumb(rel):
return None
@@ -69,48 +158,49 @@ def ensure_thumb(booth: Path, rel: str) -> Path | None:
out = thumb_path(booth, rel)
try:
s_stat = src.stat()
try:
if out.stat().st_mtime >= s_stat.st_mtime:
return out
except OSError:
pass # no cache yet, or unreadable — fall through and build one
if _fresh(out, s_stat):
return out
with _Image.open(src) as im:
# `open` reads the header only, so this is cheap enough to decide on.
if max(im.size) <= THUMB_MAX:
return None # already tile-sized; serving the original is right
im.thumbnail((THUMB_MAX, THUMB_MAX))
w, h = im.size
if w * h > THUMB_MAX_PIXELS:
return None
# The size the picture is SEEN at: a camera stores a portrait
# sideways and says so in EXIF, and the browser honours it on the
# original. Pillow does not, so sizing the raw pixels tiled a
# portrait as a landscape (groa, seat-verified).
orientation = im.getexif().get(0x0112, 1)
if orientation in (5, 6, 7, 8):
w, h = h, w
fits = w <= THUMB_WIDTH and h <= THUMB_HEIGHT_MAX
if fits and (s_stat.st_size <= THUMB_LIGHT_BYTES or getattr(im, "is_animated", False)):
return None # already tile-sized and cheap (or moving): serve the original
if orientation != 1:
im = _ImageOps.exif_transpose(im)
im.thumbnail((THUMB_WIDTH, THUMB_HEIGHT_MAX))
if im.mode not in ("RGB", "RGBA"):
im = im.convert("RGBA" if "A" in im.getbands() else "RGB")
# ⚠ CREATING THE CACHE DIR TOUCHES THE BOOTH DIRECTORY'S OWN
# MTIME, and `_newest_mtime` seeds from exactly that — so merely
# LOOKING at a booth aged it, and once the Desk pulls a thumbnail
# per booth, one index load would push every expiry out and the TTL
# would never fire again. Excluding the cache's CONTENTS is not
# enough; the directory entry is the leak.
#
# Restoring the booth's mtime cannot hide real activity: any file an
# agent adds is counted by its OWN mtime in the same walk, and the
# directory stamp is only the seed.
made = not out.parent.exists()
booth_stat = booth.stat() if made else None
out.parent.mkdir(parents=True, exist_ok=True)
if booth_stat is not None:
try:
os.utime(booth, ns=(booth_stat.st_atime_ns, booth_stat.st_mtime_ns))
except OSError:
pass
# Atomic, like every other sidecar this service writes: a reader
# polling the cache never sees a half-encoded image.
tmp = out.with_name(out.name + f".{os.getpid()}.tmp")
# A palette PNG carries transparency in `info`, not as a band:
# `getbands()` alone baked it opaque (3/4 arms, seat-executed).
alpha = "A" in im.getbands() or "transparency" in im.info
im = im.convert("RGBA" if alpha else "RGB")
if not _cache_dir(booth, out.parent):
return None
# Atomic, like every other sidecar this service writes, through a
# temp file created O_EXCL under an unpredictable name: the old
# `<out>.<pid>.tmp` could be planted as a link, and the encoder
# wrote THROUGH it (seat P5: 600 B -> 316,400 B).
fd, tmp = tempfile.mkstemp(prefix=".", suffix=".tmp", dir=out.parent)
try:
im.save(tmp, "WEBP", quality=THUMB_QUALITY, method=4)
with os.fdopen(fd, "wb") as fh:
im.save(fh, "WEBP", quality=THUMB_QUALITY, method=4)
os.utime(tmp, ns=(s_stat.st_atime_ns, s_stat.st_mtime_ns))
os.replace(tmp, out)
finally:
try:
tmp.unlink()
os.unlink(tmp)
except OSError:
pass
return out
return out if _fresh(out, s_stat) else None
except Exception: # noqa: BLE001 — a bad image costs its own tile, never the page
return None
+19 -3
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@@ -66,9 +66,25 @@ _As of 2026-09-23:_
/b/<name>/blurbooth`, and **`booth blur <name>` with NO files fogs the whole
booth**. COMPOSES with `.blurred`, never overrides. All 17 handles can
self-blur at post time.
- ✅ **THUMBNAILS ARE LIVE.** 77.5 MB → 0.78 MB on the biggest gallery; the Desk
~100 MB → 1.12 MB. Four surfaces (tile, Desk strip, flag tray, filmstrip); the
review stage keeps the original.
- ✅ **THUMBNAILS ARE LIVE, AND SIZED FOR THE TILE'S WIDTH** (operator,
2026-09-23: "blurry until selected"). The first cut capped the LONGEST side at
512, so a 704x1408 portrait got 256px of width for a 361px tile, stretched
1.4x at 1x and 2.8x on a 2x screen. Now they are 768 wide (2x the widest
desktop tile) and capped at 4096 tall, and an original that fits but weighs
over 64 KB is still re-encoded. Measured on the 381 live images: all
thumbnails 4.8 → 14.2 MB, still ~27x under the originals. ⚠ **768 is a LAYOUT
number:** `tests/test_thumbs_browser.py` holds it against the rendered grid,
so if a redesign widens the tiles, that test goes red. The 2-column (≤472px)
and 1-column (≤650px) reflows are softer than 768 covers at 2x; 1024 would
cover 2 columns for 18.5 MB total. Four surfaces (tile, Desk strip, flag tray,
filmstrip); the review stage keeps the original. The heid bug-hunt (4/4
arms) folded: a cache hit must be a regular file carrying its source's EXACT
mtime (a planted directory, or a `cp -p` older source, no longer pins a
thumbnail); the cache dirs are made without following links; the temp file is
mkstemp (the old `<out>.<pid>.tmp` could be planted as a link and was written
through); palette transparency survives; EXIF orientation is honoured; and
there's a 64 MP decode budget. The cache name carries the whole rule
(`.768x4096q78v2.webp`).
→ `persistent-memory.d/2026-09-23-the-cache-that-aged-the-thing-it-cached.md`
- ✅ **CREATION + UPDATE DATES ARE ON THE RECORD** for all 30 booths
(`created_at` via `statx`, `landed_at` already existed). design-dev renders
+142
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@@ -0,0 +1,142 @@
# Thumbnails sized for the tile's WIDTH at 2x density, not 512 on the longest
# side. The operator on sindra-nude-final, 2026-09-23: "the images look blurry
# until they're selected and blown up". Every row is a change
# tests/test_thumbs.py or tests/test_thumbs_browser.py claims to forbid.
unit = "thumbnails sized for the tile"
[[mutation]]
label = "the old rule: bound the longest side at 512 (portraits get 256px of width)"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_a_portrait_keeps_its_full_width"
old = '''
im.thumbnail((THUMB_WIDTH, THUMB_HEIGHT_MAX))'''
new = '''
im.thumbnail((512, 512))'''
[[mutation]]
label = "the width bound is below what the desktop tile needs at 2x"
file = "booth/thumbs.py"
test = "tests/test_thumbs_browser.py::test_a_thumbnail_covers_its_tile_at_2x_density"
old = '''
THUMB_WIDTH = 768'''
new = '''
THUMB_WIDTH = 640'''
[[mutation]]
label = "no height bound: a long screenshot goes through at full height"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_an_extremely_tall_image_is_bounded_by_height_too"
old = '''
im.thumbnail((THUMB_WIDTH, THUMB_HEIGHT_MAX))'''
new = '''
im.thumbnail((THUMB_WIDTH, 10 ** 6))'''
[[mutation]]
label = "fitting in pixels is taken as light in bytes (the megabyte portrait is served whole)"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_a_tile_width_image_that_is_heavy_still_gets_a_thumbnail"
old = '''
if fits and (s_stat.st_size <= THUMB_LIGHT_BYTES or getattr(im, "is_animated", False)):'''
new = '''
if fits:'''
[[mutation]]
label = "an already small, light image gets a cache entry that saves nothing"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_an_already_small_image_gets_no_thumbnail"
old = '''
if fits and (s_stat.st_size <= THUMB_LIGHT_BYTES or getattr(im, "is_animated", False)):'''
new = '''
if fits and getattr(im, "is_animated", False):'''
[[mutation]]
label = "a heavy animated GIF that fits is flattened to one frame"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_an_animated_gif_that_fits_is_served_as_itself"
old = '''
if fits and (s_stat.st_size <= THUMB_LIGHT_BYTES or getattr(im, "is_animated", False)):'''
new = '''
if fits and s_stat.st_size <= THUMB_LIGHT_BYTES:'''
[[mutation]]
label = "an unversioned cache name: a thumbnail cut to the old rule is served forever"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_a_thumbnail_cut_to_the_old_rule_is_not_served"
old = '''
return booth / THUMB_DIR / f"{rel}.{rule}.webp"'''
new = '''
return booth / THUMB_DIR / (rel + ".webp")'''
# ---- the heid bug-hunt on this change (4/4 arms), folded ------------------------
[[mutation]]
label = "a cache hit trusts the name and the mtime (a planted directory is served)"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_a_planted_directory_at_the_cache_path_is_not_served"
old = '''
return stat.S_ISREG(o.st_mode) and o.st_mtime_ns == s_stat.st_mtime_ns'''
new = '''
return o.st_mtime_ns >= s_stat.st_mtime_ns'''
[[mutation]]
label = "freshness is 'at least as new' (a cp -p'd older source pins the old thumbnail)"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_a_source_replaced_with_an_older_mtime_is_rebuilt"
old = '''
return stat.S_ISREG(o.st_mode) and o.st_mtime_ns == s_stat.st_mtime_ns'''
new = '''
return stat.S_ISREG(o.st_mode) and o.st_mtime_ns >= s_stat.st_mtime_ns'''
[[mutation]]
label = "the cache dirs are made by following links (a planted .thumbs link escapes the booth)"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_a_symlinked_cache_dir_is_never_written_through"
old = '''
if not _cache_dir(booth, out.parent):
return None'''
new = '''
out.parent.mkdir(parents=True, exist_ok=True)'''
[[mutation]]
label = "a predictable temp name the encoder writes through"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_a_planted_link_at_the_old_temp_name_cannot_redirect_the_write"
old = '''
fd, tmp = tempfile.mkstemp(prefix=".", suffix=".tmp", dir=out.parent)
try:
with os.fdopen(fd, "wb") as fh:
im.save(fh, "WEBP", quality=THUMB_QUALITY, method=4)'''
new = '''
tmp = str(out) + f".{os.getpid()}.tmp"
try:
im.save(tmp, "WEBP", quality=THUMB_QUALITY, method=4)'''
[[mutation]]
label = "RGBA chosen by getbands() alone (palette transparency baked opaque)"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_palette_transparency_survives_the_thumbnail"
old = '''
alpha = "A" in im.getbands() or "transparency" in im.info'''
new = '''
alpha = "A" in im.getbands()'''
[[mutation]]
label = "EXIF orientation ignored (a camera portrait tiled sideways)"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_a_camera_portrait_is_sized_and_saved_upright"
old = '''
orientation = im.getexif().get(0x0112, 1)'''
new = '''
orientation = 1'''
[[mutation]]
label = "no pixel budget: whatever the header claims is decoded"
file = "booth/thumbs.py"
test = "tests/test_thumbs.py::test_an_image_past_the_pixel_budget_is_never_decoded"
old = '''
if w * h > THUMB_MAX_PIXELS:
return None'''
new = '''
if False:
return None'''
+201 -4
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@@ -18,7 +18,15 @@ sys.path.insert(0, str(pathlib.Path(__file__).parent.parent))
from booth.app import create_app # noqa: E402
from booth.items import booth_items # noqa: E402
from booth.thumbs import THUMB_DIR, THUMB_MAX, ensure_thumb, wants_thumb # noqa: E402
from booth.thumbs import ( # noqa: E402
THUMB_DIR,
THUMB_HEIGHT_MAX,
THUMB_LIGHT_BYTES,
THUMB_WIDTH,
ensure_thumb,
thumb_path,
wants_thumb,
)
PIL = pytest.importorskip("PIL.Image", reason="Pillow is not installed")
@@ -36,15 +44,16 @@ def test_a_big_image_gets_a_much_smaller_thumbnail(tmp_path):
src = _img(b / "big.png", 1024, 1024)
out = ensure_thumb(b, "big.png")
assert out is not None and out.is_file()
assert max(PIL.open(out).size) <= THUMB_MAX
w, h = PIL.open(out).size
assert w <= THUMB_WIDTH and h <= THUMB_HEIGHT_MAX
assert out.stat().st_size * 4 < src.stat().st_size, (
f"thumb {out.stat().st_size}B vs source {src.stat().st_size}B — not worth the cache"
)
def test_an_already_small_image_gets_no_thumbnail(tmp_path):
"""Serving the original is correct when it is already tile-sized. A cache
entry that saves nothing is pure cost.
"""Serving the original is correct when it is already tile-sized AND already
light. A cache entry that saves nothing is pure cost.
Defeating change: generating unconditionally."""
b = tmp_path / "g"
@@ -177,3 +186,191 @@ def test_the_desk_preview_strip_uses_thumbnails(tmp_path):
html = c.get("/").text
assert 'src="/b/one/a.png?thumb=1"' in html, "the Desk strip still pulls full images"
assert 'src="/b/one/a.png"' not in html
# ---- sized for the tile's WIDTH, at 2x density ---------------------------------
#
# The operator, on sindra-nude-final: "the images look blurry until they're
# selected and blown up". The cap was 512 on the LONGEST side, but a tile is sized
# by its WIDTH, so a 704x1408 portrait got a 256px-wide thumbnail stretched into
# a 361px tile: 1.4x at 1x density, 2.8x on a 2x screen.
def _noise(path: pathlib.Path, w: int, h: int):
"""A photographic-weight image: incompressible, so its bytes are realistic.
A flat colour compresses to almost nothing and would take the light path."""
import os
path.parent.mkdir(parents=True, exist_ok=True)
PIL.frombytes("RGB", (w, h), os.urandom(w * h * 3)).save(path, "PNG")
return path
def test_a_portrait_keeps_its_full_width(tmp_path):
"""Defeating change: bounding the longest side, which gave this image 256px
of width for a tile that shows 361."""
b = tmp_path / "g"
_noise(b / "p.png", 704, 1408)
out = ensure_thumb(b, "p.png")
assert out is not None
assert PIL.open(out).size == (704, 1408)
def test_a_wide_image_is_bounded_by_width(tmp_path):
b = tmp_path / "g"
_noise(b / "w.png", 2048, 1024)
out = ensure_thumb(b, "w.png")
assert PIL.open(out).size == (THUMB_WIDTH, THUMB_WIDTH // 2)
def test_a_tile_width_image_that_is_heavy_still_gets_a_thumbnail(tmp_path):
"""Fitting the tile in PIXELS is not being light in BYTES: a 704x1408 PNG is
about a megabyte, and serving it as its own thumbnail would undo the cache.
Defeating change: skipping every image that fits the bounds."""
b = tmp_path / "g"
src = _noise(b / "p.png", 704, 1408)
assert src.stat().st_size > THUMB_LIGHT_BYTES
out = ensure_thumb(b, "p.png")
assert out is not None and out.stat().st_size < src.stat().st_size
def test_an_extremely_tall_image_is_bounded_by_height_too(tmp_path):
"""Width alone would let a long screenshot through at full height."""
b = tmp_path / "g"
_noise(b / "t.png", 300, THUMB_HEIGHT_MAX * 2)
w, h = PIL.open(ensure_thumb(b, "t.png")).size
assert h <= THUMB_HEIGHT_MAX and w <= 150
def test_an_animated_gif_that_fits_is_served_as_itself(tmp_path):
"""A thumbnail is one frame. A heavy GIF that already fits the tile used to
be served whole (it was under the old cap) and must stay animated.
Defeating change: dropping the animation guard on the fits-but-heavy path."""
import os
b = tmp_path / "g"
b.mkdir()
frames = [PIL.frombytes("RGB", (300, 300), os.urandom(300 * 300 * 3)) for _ in range(3)]
frames[0].save(b / "a.gif", save_all=True, append_images=frames[1:])
assert (b / "a.gif").stat().st_size > THUMB_LIGHT_BYTES
assert ensure_thumb(b, "a.gif") is None
def test_a_thumbnail_cut_to_the_old_rule_is_not_served(tmp_path):
"""The live booths hold 512-cap thumbnails that are NEWER than their
sources, so the mtime check alone would serve them forever. The size rule
is in the cache name, so a thumbnail cut to another rule is simply not
found. Defeating change: an unversioned cache name."""
import os
b = tmp_path / "g"
_noise(b / "p.png", 704, 1408)
legacy = b / THUMB_DIR / "p.png.webp"
legacy.parent.mkdir(parents=True)
PIL.new("RGB", (256, 512)).save(legacy, "WEBP")
os.utime(legacy, None)
out = ensure_thumb(b, "p.png")
assert out == thumb_path(b, "p.png") and out != legacy
assert PIL.open(out).size == (704, 1408)
# ---- the heid bug-hunt on this change (4/4 arms), folded ------------------------
#
# The cache sits in a directory any fleet session can write into, so every entry
# on the way to it may be planted. The new size rules only governed cache MISSES;
# the hit path trusted a name and an mtime.
def test_a_planted_directory_at_the_cache_path_is_not_served(tmp_path):
"""4/4, seat-executed: a directory at the cache path, with a future mtime,
was returned AS the thumbnail. Defeating change: a cache hit that checks
only the mtime."""
import os
b = tmp_path / "g"
_noise(b / "p.png", 704, 1408)
out = thumb_path(b, "p.png")
out.mkdir(parents=True)
os.utime(out, (2e9, 2e9))
got = ensure_thumb(b, "p.png")
assert got is None or got.is_file()
def test_a_source_replaced_with_an_older_mtime_is_rebuilt(tmp_path):
"""kimi: `cp -p` or an archive extract keeps an OLDER mtime, and a cache
newer than its source was served forever. The cache now carries its
source's exact mtime, so any change is a miss. Defeating change: `>=`."""
import os
b = tmp_path / "g"
_noise(b / "p.png", 704, 1408)
first = ensure_thumb(b, "p.png")
assert PIL.open(first).size == (704, 1408)
_noise(b / "p.png", 1536, 768)
os.utime(b / "p.png", (1e9, 1e9)) # an older stamp than the cache
assert PIL.open(ensure_thumb(b, "p.png")).size == (THUMB_WIDTH, THUMB_WIDTH // 2)
def test_a_symlinked_cache_dir_is_never_written_through(tmp_path):
"""seat P4: `.thumbs` planted as a link to another directory put the cache
outside the booth, beyond the sweep. Defeating change: `mkdir(parents=True)`,
which follows an existing link."""
b = tmp_path / "g"
_noise(b / "p.png", 704, 1408)
elsewhere = tmp_path / "elsewhere"
elsewhere.mkdir()
(b / THUMB_DIR).symlink_to(elsewhere)
assert ensure_thumb(b, "p.png") is None
assert list(elsewhere.iterdir()) == []
def test_a_planted_link_at_the_old_temp_name_cannot_redirect_the_write(tmp_path):
"""groa, seat P5: the temp name was `<out>.<pid>.tmp`, predictable, so a
link planted there made the encoder truncate and overwrite its target
(600 B -> 316,400 B). Defeating change: any predictable temp name."""
import os
b = tmp_path / "g"
_noise(b / "p.png", 704, 1408)
victim = tmp_path / "victim.txt"
victim.write_text("untouched")
out = thumb_path(b, "p.png")
out.parent.mkdir(parents=True)
(out.parent / (out.name + f".{os.getpid()}.tmp")).symlink_to(victim)
ensure_thumb(b, "p.png")
assert victim.read_text() == "untouched"
def test_palette_transparency_survives_the_thumbnail(tmp_path):
"""3/4, seat-executed, and INTRODUCED by this change: the fits-but-heavy
branch newly re-encodes palette PNGs, and `getbands()` of mode P has no A
even with a tRNS chunk, so transparency became opaque. Defeating change:
choosing RGBA by `getbands()` alone."""
import os
b = tmp_path / "g"
b.mkdir()
im = PIL.frombytes("P", (400, 400), os.urandom(400 * 400))
im.putpalette(os.urandom(768))
im.save(b / "p.png", "PNG", transparency=0)
assert (b / "p.png").stat().st_size > THUMB_LIGHT_BYTES
t = PIL.open(ensure_thumb(b, "p.png"))
assert t.mode == "RGBA" and t.getchannel("A").getextrema()[0] == 0
def test_a_camera_portrait_is_sized_and_saved_upright(tmp_path):
"""groa, seat-verified: EXIF orientation was ignored, so a portrait shot
stored sideways was sized as a landscape and tiled sideways. Defeating
change: sizing the raw pixels without `exif_transpose`."""
import os
b = tmp_path / "g"
b.mkdir()
exif = PIL.Exif()
exif[0x0112] = 6 # rotate 90 CW to display
PIL.frombytes("RGB", (1200, 800), os.urandom(1200 * 800 * 3)).save(
b / "cam.jpg", "JPEG", exif=exif, quality=95)
assert PIL.open(ensure_thumb(b, "cam.jpg")).size == (THUMB_WIDTH, 1152)
def test_an_image_past_the_pixel_budget_is_never_decoded(tmp_path, monkeypatch):
"""2/4: the header is free to read and `thumbnail()` then decodes whatever it
claims, on every request, since a failure is not cached. Over the budget,
the original is served instead. Defeating change: no budget check."""
import booth.thumbs as thumbs
b = tmp_path / "g"
_noise(b / "p.png", 704, 1408)
monkeypatch.setattr(thumbs, "THUMB_MAX_PIXELS", 704 * 1408 - 1)
assert ensure_thumb(b, "p.png") is None
+50
View File
@@ -0,0 +1,50 @@
"""Thumbnails against the tile they are drawn into, in a real browser.
`THUMB_WIDTH` is derived from a LAYOUT number: the widest gallery tile on the
desktop grid, doubled for a 2x screen. A Python test cannot see a CSS width, so
without this file the constant and the grid could drift apart silently, which
is how the tiles went soft in the first place. If the grid widens its tiles,
this goes red and the constant is revisited, rather than the operator finding
it by eye.
Scoped to the desktop layout (3 columns, 1440px and up), which is where tiles
are measured at 321-361 CSS px. Narrower windows reflow to 2 columns (up to
472 px) or 1 (up to 650 px): at 2x density those are softer than this bound
covers, and that is a known limit, not a defect this file asserts against.
"""
from __future__ import annotations
import os
import pytest
from test_embed_browser import browser, live # noqa: F401 (fixtures)
from booth.thumbs import THUMB_WIDTH
PIL = pytest.importorskip("PIL.Image", reason="Pillow is not installed")
@pytest.mark.parametrize("viewport", [(1440, 900), (1920, 1080), (2560, 1440)])
def test_a_thumbnail_covers_its_tile_at_2x_density(browser, live, viewport): # noqa: F811
base, root = live
b = root / "g"
b.mkdir()
for n in ("a.png", "b.png", "c.png"):
PIL.frombytes("RGB", (1024, 1024), os.urandom(1024 * 1024 * 3)).save(b / n, "PNG")
pg = browser.new_page(viewport={"width": viewport[0], "height": viewport[1]})
try:
pg.goto(f"{base}/b/g/", wait_until="load")
pg.wait_for_function(
"Array.from(document.querySelectorAll('.gallery .item img'))"
".every(i => i.complete && i.naturalWidth)", timeout=15000)
tiles = pg.evaluate(
"Array.from(document.querySelectorAll('.gallery .item img'))"
".map(i => [i.currentSrc, i.clientWidth, i.naturalWidth])")
finally:
pg.close()
assert tiles, "no gallery tiles rendered"
for src, shown, natural in tiles:
assert "thumb=1" in src, f"{src} is not the thumbnail"
assert natural >= 2 * shown, (
f"{src}: a {shown}px tile needs {2 * shown}px at 2x, the thumbnail has {natural}px"
f" (THUMB_WIDTH={THUMB_WIDTH})")