Continuing from the previous commit, this shifts:
* In-memory data -> temporary file
* Image decoding -> background thread
The background thread asynchronously decodes frames and
sends them to the render thread via a bounded channel.
While decoding frames, it writes them, uncompressed, to
a scratch file so that when the animation loops, it is
a very cheap operation to rewind and pull that data
from the file, without having to burn CPU to re-decode
the data from the start.
Memory usage is bounded to 4 uncompressed frames while
decoding, then 3 uncompressed frames (triple buffered)
while looping over the rest.
However, disk usage is N uncompressed frames.
refs: https://github.com/wez/wezterm/issues/3263
Need to use a newer version of libssh-rs that can report this state,
as the underlying libssh doesn't fold it into the process exit
status.
refs: https://github.com/wez/wezterm/issues/3095
This breaking API change allows us to explicitly generate EOF when the
taken writer is dropped.
The examples have been updated to show how to manage read, write
and waiting without deadlock for both linux and windows.
Need to confirm that this is still good on macOS, but my
confidence is high.
I've also removed ssh2 support from this crate as part of this
change. We haven't used it directly in wezterm in a long while
and removing it from here means that there is slightly less code
to keep compiling over and over.
refs: https://github.com/wez/wezterm/discussions/2392
refs: https://github.com/wez/wezterm/issues/1396
Go directly to the underlying env_logger crate, as pretty_env_logger
hasn't been updated in some time, and I'd like to be able to redirect
the log output to a file more directly, and that feature is in a newer
version of the env logger than pretty_env_logger was pulling in.
It looks like the debian 9 test failures with libssh are the
same underlying issue as https://github.com/wez/wezterm/issues/1262
Poking around in the debug output, and then spelunking through the code,
we can use the `pubkeyacceptedtypes` ssh config option to add the key
type to the list of keys. This doesn't appear to be a documented
option in the current versions of openssh.
I'm not 100% sure that this is right, but it's worth a shot.
A recent cargo update caused openssl-sys to do a minor semver update
from 0.9.71 -> 0.9.72, but that release downgraded from openssl 3
to openssl 1 to resolve a performance regression:
<https://github.com/sfackler/rust-openssl/pull/1578>
That in turn caused libssh to fail to build because the ENGINE
feature required by libssh isn't compiled in in openssl-src 1
crate when vendoring on windows.
For now, my libssh git repo is constrained to openssl-sys 0.9.71,
and we're pointing to that from the wezterm repo.
In the mux layer, we have some code that takes a `Child` and then
does a bit of naughty reaching through the abstraction to get at
the pid/handle of the child so that we can send it signals even
if the child is itself mutably (and thus exclusively) borrowed
for the purposes of waiting.
That worked fine for local processes spawned in the mux, but we also
use LocalPane to wrap around arbitrary `Child`ren, such as Ssh,
that are not local and that don't have a local process id, which
meant that this hack wouldn't work for them.
To make things a bit worse, those ssh ptys were used to ssh2 days
where we didn't have a way to signal the remote process and just
did nothing, leading to confusing situations such as
https://github.com/wez/wezterm/issues/1197
This commit graduates the hack mentioned in the first paragraph
to its own ChildKiller trait. This makes the concept of waiting
for the Child distinct from signalling it and explicitly allows
getting a separate object that can be used for signalling.
With that in place, we're forced to implement something appropriate
for the ssh pty implementations; one in the pty crate itself,
one in wezterm-ssh and the wrapper that we use in the mux crate.
The upshot of this is that the `CloseCurrentPane` action now operates
correctly on panes that were the result of split operations.
This is a fairly far-reaching commit. The idea is:
* Introduce a unicode_version config that specifies the default level
of unicode conformance for each newly created Terminal (each Pane)
* The unicode_version is passed down to the `grapheme_column_width`
function which interprets the width based on the version
* `Cell` records the width so that later calculations don't need to
know the unicode version
In a subsequent diff, I will introduce an escape sequence that allows
setting/pushing/popping the unicode version so that it can be overridden
via eg: a shell alias prior to launching an application that uses a
different version of unicode from the default.
This approach allows output from multiple applications with differing
understanding of unicode to coexist on the same screen a little more
sanely.
Note that the default `unicode_version` is set to 9, which means that
emoji presentation selectors are now by-default ignored. This was
selected to better match the level of support in widely deployed
applications.
I expect to raise that default version in the future.
Also worth noting: there are a number of callers of
`unicode_column_width` in things like overlays and lua helper functions
that pass `None` for the unicode version: these will assume the latest
known-to-wezterm/termwiz version of unicode to be desired. If those
overlays do things with emoji presentation selectors, then there may be
some alignment artifacts. That can be tackled in a follow up commit.
refs: #1231
refs: #997
This works, but on macOS, there is a segfault in openssl when the
session is closed... I'm going to try this on Linux to see if it
is consistent behavior and ponder next steps.
