Problem:
- `static` variables consume memory and sometimes are less
optimizable.
- `static const` variables can be `constexpr`, usually.
- `static` function-local variables require an initialization check
every time the function is run.
Solution:
- If a global `static` variable is only used in a single function then
move it into the function and make it non-`static` and `constexpr`.
- Make all global `static` variables `constexpr` instead of `const`.
- Change function-local `static const[expr]` variables to be just
`constexpr`.
This wasn't much of a problem before because copying the ByteBuffer
merely copied the RefPtr but now that ByteBuffer behaves like Vector
this causes unnecessary allocations.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
As per the PNG specification: "Filter method is a single-byte
integer that indicates the preprocessing method applied to the
image data before compression. At present, only filter method 0
(adaptive filtering with five basic filter types) is defined."
As per the PNG specification: "For all x < 0, assume Raw(x) = 0 and
Prior(x) = 0. On the first scanline of an image (or of a pass of an
interlaced image), assume Prior(x) = 0 for all x."
PNGs use deflate with zlib, however we were just skipping the zlib
bytes and then piping it into deflate decompressor. Since we have a
zlib decompressor, lets use that instead.
This has the added benefit of extra error checking.
The previous names (RGBA32 and RGB32) were misleading since that's not
the actual byte order in memory. The new names reflect exactly how the
color values get laid out in bitmap data.
This commit removes the only 3rd party library (and its usages)
in serenity: puff, which is used for deflate decompression. and
replaces it with the existing original serenity implementation
in LibCompress. :^)
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
This was done with the help of several scripts, I dump them here to
easily find them later:
awk '/#ifdef/ { print "#cmakedefine01 "$2 }' AK/Debug.h.in
for debug_macro in $(awk '/#ifdef/ { print $2 }' AK/Debug.h.in)
do
find . \( -name '*.cpp' -o -name '*.h' -o -name '*.in' \) -not -path './Toolchain/*' -not -path './Build/*' -exec sed -i -E 's/#ifdef '$debug_macro'/#if '$debug_macro'/' {} \;
done
# Remember to remove WRAPPER_GERNERATOR_DEBUG from the list.
awk '/#cmake/ { print "set("$2" ON)" }' AK/Debug.h.in
decode_png_chunks() is not handling "critical" chunks, unlike
decode_png_size() for example. When we encounter a chunk decoding
failure, e.g. because not enough bytes were left to read, just continue
with decoding the bitmap - which will fail on its own, if we're missing
some required chunk(s).
Fixes#4984.
