On Windows, the console mode flag `ENABLE_VIRTUAL_TERMINAL_PROCESSING` determines whether or not ANSI escape codes are parsed/acted on. On the newer Windows Terminal, this flag is set by default, but on the older Windows Console, it is not set by default, but *can* be enabled (since Windows 10 RS1 from June 2016).
The new `File.getOrEnableAnsiEscapeSupport` function will get the current status of ANSI escape code support, but will also attempt to enable `ENABLE_VIRTUAL_TERMINAL_PROCESSING` on Windows if necessary which will provide better/more consistent results for things like `std.Progress` and `std.io.tty`.
This type of change was not done previously due to a mistaken assumption (on my part) that the console mode would persist after the run of a program. However, it turns out that the console mode is always reset to the default for each program run in a console session.
The \r\n is necessary to get the progress tree to work properly in the old console when ENABLE_VIRTUAL_TERMINAL_PROCESSING and DISABLE_NEWLINE_AUTO_RETURN are set.
The line_upper_bound_len fix addresses part of #20161
This changes the terminal display to keep the cursor at the top left of
the progress display, so that unlocked stderr writes, perhaps by child
processes, don't get eaten by the clear.
Reduce node_storage_buffer_len from 200 to 83. This makes messages over
the pipe fit in a single packet (4096 bytes). There is now a comptime
assert to ensure this. In practice this is plenty of storage because
typical terminal heights are significantly less than 83 rows.
Handling of split reads is fixed; instead of using a global
`remaining_read_trash_bytes`, the value is stored in the "saved
metadata" for the IPC node.
Saved metadata is split into two arrays so that the "find" operation can
quickly scan over fds for a match, looking at 332 bytes maximum, and
only reading the memory for the other data upon match. More typical
number of bytes read for this operation would be 0 (no child processes),
4 (1 child process), or 64 (16 child processes reporting progress).
Removed an align(4) that was leftover from an older design.
This also includes part of Jacob Young's not-yet-landed patch that
implements `writevNonblock`.
3a3d2187f986066859cfb793fb7ee1cae4dfea08 unintentionally broke some of the Windows console API implementation.
- The 'marker' character was no longer being written at all
- The ANSI escape codes for syncing were being written unconditionally
* Merge a bunch of related state together into TerminalMode. Windows
sometimes follows the same path as posix via ansi_escape_codes,
sometimes not.
* Use a different thread entry point for Windows API but share the same
entry point on Windows when the terminal is in ansi_escape_codes mode.
* Only clear the terminal when the stderr lock is held.
* Don't try to clear the terminal when nothing has been written yet.
* Don't try to clear the terminal in IPC mode.
* Fix size detection logic bug under error conditions.
The update thread was sometimes reading the special state and then
incorrectly getting 0 for the file descriptor, making it hang since it
tried to read from stdin.
Slightly slower refresh rate. It's still updating very quickly.
Lower the initial delay so that CLI applications feel more responsive.
Even though the application is doing work for the full 500ms until
something is displayed on the screen, it feels nicer to get the progress
earlier.
when the root progress node has a zero length name, the sub-tree is
flattened one layer, reducing visual noise, as well as bytes written to
the terminal.
Split newline_count into written_newline_count and
accumulated_newline_count. This handle the case when the tryLock() fails
to obtain the lock, because in such case there would not be any newlines
written to the terminal but the system would incorrectly think there
were. Now, written_newline_count is only adjusted when the write() call
succeeds.
Furthermore, write() call failure is handled by exiting the update
thread.
Don't truncate trailing newline. This better handles stray writes to
stderr that are not std.Progress-aware, such as from non-zig child
processes.
This commit also makes `Node.start` and `Node.end` bail out early with a
comptime branch when it is known the target will not be spawning an
update thread.
Switch Node.Parent, Node.Index, and Node.OptionalIndex to be backed by
u8 rather than u16. This works fine since we use 200 as the preallocated
node buffer. This has the nice property that scanning the entire parents
array for allocated nodes fits in 4 cache lines, even if we bumped the
200 up to 254 (leaving room for the two special states).
The thread that reads progress updates from the pipe now handles short
reads by ignoring messages that are sent in multiple reads.
When checking the terminal size, if there is a failure, fall back to a
conservative guess of 80x25 rather than panicking. A debug message is
also emitted which would be displayed only in a debug build.
This accomplishes 2 things simultaneously:
1. Don't trust child process data; if the data is outside the expected
range, ignore the data.
2. If there is too much data to fit in the preallocated buffers, drop
the data.
Instead of making static buffers configurable, let's pick strong
defaults and then use the update thread's stack memory to store the
preallocations. The thread uses a fairly shallow stack so this memory is
otherwise unused. This also makes the data section of the executable
smaller since it runtime allocates the memory when a `std.Progress`
instance is allocated, and in the case that the process is not connected
to a terminal, it never allocates the memory.
It stored some metadata into the canonical node storage data but that is
a race condition because another thread recycles those nodes.
Also, keep the parent name for empty child root node names.
* bump default statically allocated resources
* debug help when multiple instances of std.Progress are initialized
* only handle sigwinch on supported operating systems
* handle when reading from the pipe returns 0 bytes
* avoid printing more lines than rows
This time, we preallocate a fixed set of nodes and have the user-visible
Node only be an index into them. This allows for lock-free management of
the node storage.
Only the parent indexes are stored, and the update thread makes a
serialized copy of the state before trying to compute children lists.
The update thread then walks the tree and outputs an entire tree of
progress rather than only one line.
There is a problem with clearing from the cursor to the end of the
screen when the cursor is at the bottom of the terminal.
New design ideas:
* One global instance, don't try to play nicely with other instances
except via IPC.
* One process owns the terminal and the other processes communicate via
IPC.
* Clear the whole terminal and use multiple lines.
What's implemented so far:
* Query the terminal for size.
* Register a SIGWINCH handler.
* Use a thread for redraws.
To be done:
* IPC
* Handling single threaded targets
* Porting to Windows
* More intelligent display of the progress tree rather than only using
one line.
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:
* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
API users can take advantage of these to freely write to the terminal
which has an ongoing progress display, similar to what Ninja does when
compiling C/C++ objects and a warning or error message is printed.
