SmolStr has an Arc internally for large strings. This allows
cheap copies of large strings, but we lose that ability
when we convert the SmolStr to a &str and then reconstruct a
SmolStr from that slice.
I was hoping for some larger gains here, considering the impact
of this code change, but it only removes ~50k allocations,
while the impact on the runtime is not noticeable at all.
Still, I believe this is the right thing to do.
Before:
```
allocations: 2338981
Time (mean ± σ): 988.3 ms ± 17.9 ms [User: 690.2 ms, System: 206.4 ms]
Range (min … max): 956.4 ms … 1016.3 ms 10 runs
```
After:
```
allocations: 2287723
Time (mean ± σ): 989.8 ms ± 23.2 ms [User: 699.2 ms, System: 197.6 ms]
Range (min … max): 945.3 ms … 1021.4 ms 10 runs
```
Popups are stored in a HashMap and are assigned an ID so popup.close(); closes the correct popup and so a single PopupWindow cannot be opened multiple times
This currently doesn't have public API to enable it yet.
TODO:
- Error handling in the compiler
- Public API in the compiler configuration
- Documentation
This is just for completeness, we "only" save ~13k allocations
with no measurable speed impact:
Before:
```
Time (mean ± σ): 1.019 s ± 0.033 s [User: 0.716 s, System: 0.203 s]
Range (min … max): 0.957 s … 1.061 s 10 runs
allocations: 2679001
```
After:
```
Time (mean ± σ): 1.015 s ± 0.015 s [User: 0.715 s, System: 0.201 s]
Range (min … max): 0.997 s … 1.038 s 10 runs
allocations: 2666889
```
This is rarely used, but using Rc here like elsewhere allows us to
elide a few unneccessary memory allocations when copying such types.
The speed impact is not measurable though. With heaptrack I see that
we get rid of the last ~7600 allocations in my benchmark when cloning
Type.
This makes copying such types much cheaper and will allow us to
intern common struct types in the future too. This further
drops the sample cost for langtype.rs from ~6.6% down to 4.0%.
We are now also able to share/intern common struct types.
Before:
```
Time (mean ± σ): 1.073 s ± 0.021 s [User: 0.759 s, System: 0.215 s]
Range (min … max): 1.034 s … 1.105 s 10 runs
allocations: 3074261
```
After:
```
Time (mean ± σ): 1.034 s ± 0.026 s [User: 0.733 s, System: 0.201 s]
Range (min … max): 1.000 s … 1.078 s 10 runs
allocations: 2917476
```
This allows us to cheaply copy the langtype::Type values which
contain such a type. The runtime impact is small and barely noticable
but a sampling profiler shows a clear reduction in samples pointing
at langtype.rs, roughly reducing that from ~8.6% inclusive cost
down to 6.6% inclusive cost.
Furthermore, this allows us to share/intern common types.
Before:
```
Benchmark 1: ./target/release/slint-viewer ../slint-perf/app.slint
Time (mean ± σ): 1.089 s ± 0.026 s [User: 0.771 s, System: 0.216 s]
Range (min … max): 1.046 s … 1.130 s 10 runs
allocations: 3152149
```
After:
```
Time (mean ± σ): 1.073 s ± 0.021 s [User: 0.759 s, System: 0.215 s]
Range (min … max): 1.034 s … 1.105 s 10 runs
allocations: 3074261
```
This removes a lot of allocations and speeds up the compiler step
a bit. Sadly, this patch is very invasive as it touches a lot of
files. That said, each individual hunk is pretty trivial.
For a non-trivial real-world example, the impact is significant,
we get rid of ~29% of all allocations and improve the runtime by
about 4.8% (measured until the viewer loop would start).
Before:
```
Benchmark 1: ./target/release/slint-viewer ../slint-perf/app.slint
Time (mean ± σ): 664.2 ms ± 6.7 ms [User: 589.2 ms, System: 74.0 ms]
Range (min … max): 659.0 ms … 682.4 ms 10 runs
allocations: 4886888
temporary allocations: 857508
```
After:
```
Benchmark 1: ./target/release/slint-viewer ../slint-perf/app.slint
Time (mean ± σ): 639.5 ms ± 17.8 ms [User: 556.9 ms, System: 76.2 ms]
Range (min … max): 621.4 ms … 666.5 ms 10 runs
allocations: 3544318
temporary allocations: 495685
```
The struct held provides access to the design metrics of the font scaled
to the font pixel size used by the element.
ChangeLog: Slint Language: Added font-metrics property to `Text` and `TextInput`.
Closes#6047
We need to skip the generation of the local property so it directly
forward to the alias in the public property
Fixes#5855
ChangeLog: Fixed generated getter and setter of alias properties in globals
If a property is only used once, we can inline it with a bigger
threshold.
But this require to first compute the use, and then do the inlining
while adjusting the usages
A `Rectangle { clip: true; }` will generate an intermediate `Clip` rectangle, which
certainly has no debug info.
The check whether debug info is present or not should not be done on a per-element
level but it can be done on the level of the compilation unit.
Preparation for multi-components
Note that this had to rename one instance of TextStyle because it
conflicts with the struct of the same name used in the FontSettings
in the style. This wasn't a problem before because it shares some
property in common, and the the order of processing of component has
changed leading to the other one being generated.
(But that is a wider bug in the compiler outside of the scope of this
refactoring)
There currently still can only be one because the passes expect that,
but now the LLR and generator should be ready to accept multiple public
component later
Keep merging elements, but remember the boundaries in the debug info, separated by a slash.
Also fixed tests that rely on accessible-label being set only once. For example
```
Button { text: "foo"; }
```
will certainly have "foo" as accessible-label on `Button`, but its internal `Text` element has
an implicit "accessible-label" set to the same
value.
So don't rely on that for now but search by id instead.
The `SLINT_EMIT_DEBUG_INFO` environment variable needs to be set for Rust and C++ builds. For the interpreter it's always enabled, since ... we have it.
