Problem:
- Output of decode and encode grow as the decode and encode
happen. This is inefficient because a large size will require many
reallocations.
- `const` qualifiers are missing on variables which are not intended
to change.
Solution:
- Since the size of the decoded or encoded message is known prior to
starting, calculate the size and set the output to that size
immediately. All appends will not incur the reallocation overhead.
- Add `const` qualifiers to show intent.
When we're initializing objects, we're just adding a bunch of new
properties, without transition, and without overlap (we never add
the same property twice.)
Take advantage of this by skipping lookups entirely (no need to see
if we're overwriting an existing property) during initialization.
Another nice test-js speedup :^)
Roughly 7% of test-js runtime was spent creating FlyStrings from string
literals. This patch frontloads that work and caches all the commonly
used names in LibJS on a CommonPropertyNames struct that hangs off VM.
This patch causes cp to investigate whether a directory is being copied
into a subdirectory of itself. It uses realpath(3) to ensure that links
do not confound detection.
* AK: Add formatter for JsonValue.
* Inspector: Use new format functions.
* Profiler: Use new format functions.
* UserspaceEmulator: Use new format functions.
Problem:
- The Base64 alphabet and lookup table are initialized at
run-time. This results in an initial start-up cost as well as a
boolean evaluation and branch every time the function is called.
Solution:
- Provide `constexpr` functions which initialize the alphabet and
lookup table at compile-time. These can be called and assigned to a
`constexpr` variable so that there is no run-time cost associated
with the initialization or lookup.
By allowing to specify a separate source bitmap when calling Filter::apply
the same filter can be applied to multiple areas, and also doesn't need
to use a temporary bitmap. This also enables us to apply the filter to
multiple regions properly, even if they are (almost) adjacent.
If no separate source bitmap is supplied then a temporary bitmap is still
necessary.
By moving the Bitmap and Rect out of Filter::Parameters we can re-use
the parameters more efficiently, allowing the filter to be applied
to many bitmaps without having to re-create the filter every time.
Add an overload of GenericConvolutionFilter::apply that can be used
with a GenericConvolutionFilter::ApplyCache instance to avoid having
to allocate a temporary bitmap every time the filter is being applied.
Notice that we ensured that the size is a multiple of the page size and
that there is at least one page there, otherwise, this change would be
invalid.
We create an empty region and then expand it:
// First iteration.
m_user_physical_regions.append(PhysicalRegion::create(addr, addr));
// Following iterations.
region->expand(region->lower(), addr);
So if the memory region only has one page, we would end up with an empty
region. Thus we need to do one more iteration.
In addition to being reference-counted, all nodes that are part of a
document must also keep the document alive.
This is achieved by adding a second ref-count to the Document object
and incrementing/decrementing it whenever a node is created/destroyed
in that document.
This brings us much closer to a proper DOM lifetime model, although
the JS bindings still need more work.
If something goes wrong when trying to write out a perfcore file during
process finalization, there's nowhere to report an error to, other than
the debug log. So write it to the debug log.
This allows layout nodes to do some setup before their children paint,
and cleanup after their children paint. This will be used for SVG
components, where their attributes (like stroke width, fill color, etc)
need to be correctly propogated to layout nodes down the line.
This is a hack to stop chewing CPU on sites that use a font we don't
have and have a lot of text or changes text often.
Examples are the Serenity 2nd birthday page and the JS specification.
When changing the attributes of an existing property of an object with
unique shape we must not change the PropertyMetadata offset.
Doing so without resizing the underlying storage vector caused an OOB
write crash.
Fixes#3735.
We are adding the process name as prefix and a newline as suffix to any
message written to debug. Thus, the following doesn't make any sense:
for (u8 byte : bytes)
dbg("{:02x} ", byte);
dbgln();
Which function call would put the prefix? This doesn't make any sense,
thus these functions must go.
The example above could be converted to:
StringBuilder builder;
for (u8 byte : bytes)
builder.appendff("{:02x} ", byte);
dbgln("{}", builder.build());
Problem:
- Constructors and conversion operators are not `constexpr`,
but they can be.
- `constexpr` is needed here so that other classes can add `constexpr`
evaluation.
Solution:
- Add the `constexpr` keyword to the constructors and
conversion operators.
- Add `static_assert` tests which ensure the capability works.
