This reduces the resident memory by another ~10% because it avoids
keeping as many runs of whitespace.
Runtime for `time cat enwiki8.wiki` is still ~11-12s, resident: 530K
refs: https://github.com/wez/wezterm/issues/1626
The previous commit added the option to convert the storage to
the cluster format. That saves memory as rows are moved to scrollback,
but makes scrolling back more expensive due to that conversion.
This commit adds a fast(ish) path for the common case of simply
appending text to a new line before it gets scrolled: the default
format for lines in the screen is now the cluster format and,
provided that the cursor moves from left to right as text is
emitted, can simply append to the cluster storage in-place
and avoids a conversion when the line is moved to scrollback.
This improves the throughput of `time cat enwiki8.wiki` so
that the runtime is typically around 11-12s (compared to 9-10s
before introducing cluster storage). However, this is often
a deal of variance in the measured time and I believe that
that is due to the renderer triggering conversions back to
the vec storage and introducing slowdowns from the render side.
That's what I'll investigate next.
This commit causes lines to be "compressed" (really, just translated
to the new clustered line storage variant) as they move into scrollback.
The memory savings are significant for large scrollback:
`wezterm -n --config scrollback_lines=1000000`
`time cat enwiki8.wiki`
before: ~9s, Resident: 2.1G
after: ~15s, Resident: 620K (!)
The performance impact is non-trivial, and I will dig into that
next.
refs: https://github.com/wez/wezterm/issues/1626
Previously this would create a new String because it had to, but
with the clustered storage we may be able to simply reference the
existing string as a str reference, so allow for that.
Adds the option to use an alternative clusted line storage for
the cells component of the line.
This structure is not optimal for mutation, but is better structured
for:
* matching/extracting textual content
* using less memory than the prior simple vector
For some contrast: the line "hello" occupies 5 Cells in the cell based
storage; that 5 discrete Cells each with their own tiny string
and a copy of their attributes.
The clustered version of the line stores one copy of the cell
attributes, the string "hello" and some small (almost constant size)
overhead for some metadata. For simple lines of ascii text, the
clustered version is smaller as there are fewer copies of the cell
attributes. Over the span of a large scrollback and typical terminal
display composition, this saving is anticipated to be significant.
The clustered version is also cheaper to search as it doesn't require
building a copy of the search text for each line (provided the line is
already in clustered form).
This commit introduces the capability: none of the internals request the
new form yet, and there are likely a few call sites that need to be
tweaked to avoid coersion from clustered to vector form.
We didn't actually update the global config, just the per-window
configs, which led to weird stale throwbacks to earlier versions
of the config when spawning windows or new panes.
Fix that up by explicitly reloading the global config when the
window appearance is changed. That isn't ideal as we will reload
once per window, but it's "OK".
While poking at this, I noticed that the get/set config methods
on the termwiztermtab overlay weren't hooked up, and also made
a point of calling those for any overlays during a window config
reload event, so that per-window overrides are more likely to get
picked up and respected.
refs: https://github.com/wez/wezterm/issues/2295
While profiling `time cat bigfile` I noted that a big chunk of the
time is spent computing widths, so I wanted to dig into a bit.
After playing around with a few options, I settled on the approach
in this commit.
The key observations:
* WcWidth::from_char performs a series of binary searches.
The fast path was for ASCII, but anything outside that range
suffered in terms of latency.
* Binary search does a lot more work than a simple table lookup,
so it is desirable to use a lookup, and moreso to combine the
different tables into a single table so that classification
is an O(1) super fast lookup in the most common cases.
Here's some benchmarking results comparing the prior implementation
(grapheme_column_width) against this new pre-computed table
implementation (grapheme_column_width_tbl).
The ASCII case is more than 5x faster than before at a reasonably snappy
~3.5ns, with the more complex cases being closer to a constant ~20ns
down from 120ns in some cases.
There are changes here to widechar_width.rs that should get
upstreamed.
```
column_width ASCII/grapheme_column_width
time: [23.413 ns 23.432 ns 23.451 ns]
column_width ASCII/grapheme_column_width_tbl
time: [3.4066 ns 3.4092 ns 3.4121 ns]
column_width variation selector/grapheme_column_width
time: [119.99 ns 120.13 ns 120.28 ns]
column_width variation selector/grapheme_column_width_tbl
time: [21.185 ns 21.253 ns 21.346 ns]
column_width variation selector unicode 14/grapheme_column_width
time: [119.44 ns 119.56 ns 119.69 ns]
column_width variation selector unicode 14/grapheme_column_width_tbl
time: [21.214 ns 21.236 ns 21.264 ns]
column_width WidenedIn9/grapheme_column_width
time: [99.652 ns 99.905 ns 100.18 ns]
column_width WidenedIn9/grapheme_column_width_tbl
time: [21.394 ns 21.419 ns 21.446 ns]
column_width Unassigned/grapheme_column_width
time: [82.767 ns 82.843 ns 82.926 ns]
column_width Unassigned/grapheme_column_width_tbl
time: [24.230 ns 24.319 ns 24.428 ns]
```
Here's the benchmark summary after cleaning this diff up ready
to commit; it shows ~70-80% improvement in these cases:
```
; cargo criterion -- column_width
column_width ASCII/grapheme_column_width
time: [3.4237 ns 3.4347 ns 3.4463 ns]
change: [-85.401% -85.353% -85.302%] (p = 0.00 < 0.05)
Performance has improved.
column_width variation selector/grapheme_column_width
time: [20.918 ns 20.935 ns 20.957 ns]
change: [-82.562% -82.384% -82.152%] (p = 0.00 < 0.05)
Performance has improved.
column_width variation selector unicode 14/grapheme_column_width
time: [21.190 ns 21.210 ns 21.233 ns]
change: [-82.294% -82.261% -82.224%] (p = 0.00 < 0.05)
Performance has improved.
column_width WidenedIn9/grapheme_column_width
time: [21.603 ns 21.630 ns 21.662 ns]
change: [-78.429% -78.375% -78.322%] (p = 0.00 < 0.05)
Performance has improved.
column_width Unassigned/grapheme_column_width
time: [23.283 ns 23.355 ns 23.435 ns]
change: [-71.826% -71.734% -71.641%] (p = 0.00 < 0.05)
Performance has improved.
```
The .deb package registers that script as the alternative for
a terminal emulator in the hope that various "open terminal here..."
functions in other tools will use that to detect wezterm and run
thing in the cwd.
refs: https://github.com/wez/wezterm/issues/2103
so have the arg parser raise an error if used without it:
```
; wezterm cli spawn --workspace foo
error: The following required arguments were not provided:
--new-window
USAGE:
wezterm cli spawn --new-window --workspace <WORKSPACE>
For more information try --help
```
refs: https://github.com/wez/wezterm/issues/2248#issuecomment-1192119746
Need to explicitly pop it in front of the tab text layer so that
the button is physically rendered on top of the tab title.
refs: https://github.com/wez/wezterm/issues/2269
Various color schemes have been duplicated as they have been added to
different scheme collections. They don't always have identical names
(eg: some remove spaces) and sometimes they have very different names
(eg: _bash vs. nightfox, or Miu vs. Blazer).
We already detected duplicates from different collections but previously
we would omit those dupes.
This commit allows us to track those duplicates by recording their
aliases.
When we write out our data, we only include "interesting" alias names;
those where the name isn't trivially identical.
Some scheme collections (eg: iterm2 color schemes) have duplicates
(eg: zenbones and zenbones_light are identical) and we have previously
shipped with both of those names, so we special case to emit dupes
for which we have prior version information in order to avoid
breaking backwards compatibility for our users.
In the doc generation we can generate links to the aliases if we
included them, but also note about the other names and how we don't
include them. That is so that someone searching the docs for say
"_bash" can discover that it is actually a duplicate of "nightfox" and
use nightfox instead.
This allows the hook to choose how to handle eg: `wezterm start -- top`.
Previously, if you had implemented this event you would essentially lose
the ability to specify a command that you wanted to launch.
refs: https://github.com/wez/wezterm/issues/284
I needed this while swinging through to the new color scheme data stuff,
but I don't need it any more, and it causes problems with external toml
files.
