zig/lib/std/Progress.zig
mlugg 0fe3fd01dd
std: update std.builtin.Type fields to follow naming conventions
The compiler actually doesn't need any functional changes for this: Sema
does reification based on the tag indices of `std.builtin.Type` already!
So, no zig1.wasm update is necessary.

This change is necessary to disallow name clashes between fields and
decls on a type, which is a prerequisite of #9938.
2024-08-28 08:39:59 +01:00

1424 lines
52 KiB
Zig

//! This API is non-allocating, non-fallible, thread-safe, and lock-free.
const std = @import("std");
const builtin = @import("builtin");
const windows = std.os.windows;
const testing = std.testing;
const assert = std.debug.assert;
const Progress = @This();
const posix = std.posix;
const is_big_endian = builtin.cpu.arch.endian() == .big;
const is_windows = builtin.os.tag == .windows;
/// `null` if the current node (and its children) should
/// not print on update()
terminal: std.fs.File,
terminal_mode: TerminalMode,
update_thread: ?std.Thread,
/// Atomically set by SIGWINCH as well as the root done() function.
redraw_event: std.Thread.ResetEvent,
/// Indicates a request to shut down and reset global state.
/// Accessed atomically.
done: bool,
need_clear: bool,
refresh_rate_ns: u64,
initial_delay_ns: u64,
rows: u16,
cols: u16,
/// Accessed only by the update thread.
draw_buffer: []u8,
/// This is in a separate array from `node_storage` but with the same length so
/// that it can be iterated over efficiently without trashing too much of the
/// CPU cache.
node_parents: []Node.Parent,
node_storage: []Node.Storage,
node_freelist: []Node.OptionalIndex,
node_freelist_first: Node.OptionalIndex,
node_end_index: u32,
pub const TerminalMode = union(enum) {
off,
ansi_escape_codes,
/// This is not the same as being run on windows because other terminals
/// exist like MSYS/git-bash.
windows_api: if (is_windows) WindowsApi else void,
pub const WindowsApi = struct {
/// The output code page of the console.
code_page: windows.UINT,
};
};
pub const Options = struct {
/// User-provided buffer with static lifetime.
///
/// Used to store the entire write buffer sent to the terminal. Progress output will be truncated if it
/// cannot fit into this buffer which will look bad but not cause any malfunctions.
///
/// Must be at least 200 bytes.
draw_buffer: []u8 = &default_draw_buffer,
/// How many nanoseconds between writing updates to the terminal.
refresh_rate_ns: u64 = 80 * std.time.ns_per_ms,
/// How many nanoseconds to keep the output hidden
initial_delay_ns: u64 = 200 * std.time.ns_per_ms,
/// If provided, causes the progress item to have a denominator.
/// 0 means unknown.
estimated_total_items: usize = 0,
root_name: []const u8 = "",
disable_printing: bool = false,
};
/// Represents one unit of progress. Each node can have children nodes, or
/// one can use integers with `update`.
pub const Node = struct {
index: OptionalIndex,
pub const none: Node = .{ .index = .none };
pub const max_name_len = 40;
const Storage = extern struct {
/// Little endian.
completed_count: u32,
/// 0 means unknown.
/// Little endian.
estimated_total_count: u32,
name: [max_name_len]u8 align(@alignOf(usize)),
/// Not thread-safe.
fn getIpcFd(s: Storage) ?posix.fd_t {
return if (s.estimated_total_count == std.math.maxInt(u32)) switch (@typeInfo(posix.fd_t)) {
.int => @bitCast(s.completed_count),
.pointer => @ptrFromInt(s.completed_count),
else => @compileError("unsupported fd_t of " ++ @typeName(posix.fd_t)),
} else null;
}
/// Thread-safe.
fn setIpcFd(s: *Storage, fd: posix.fd_t) void {
const integer: u32 = switch (@typeInfo(posix.fd_t)) {
.int => @bitCast(fd),
.pointer => @intFromPtr(fd),
else => @compileError("unsupported fd_t of " ++ @typeName(posix.fd_t)),
};
// `estimated_total_count` max int indicates the special state that
// causes `completed_count` to be treated as a file descriptor, so
// the order here matters.
@atomicStore(u32, &s.completed_count, integer, .monotonic);
@atomicStore(u32, &s.estimated_total_count, std.math.maxInt(u32), .release);
}
/// Not thread-safe.
fn byteSwap(s: *Storage) void {
s.completed_count = @byteSwap(s.completed_count);
s.estimated_total_count = @byteSwap(s.estimated_total_count);
}
comptime {
assert((@sizeOf(Storage) % 4) == 0);
}
};
const Parent = enum(u8) {
/// Unallocated storage.
unused = std.math.maxInt(u8) - 1,
/// Indicates root node.
none = std.math.maxInt(u8),
/// Index into `node_storage`.
_,
fn unwrap(i: @This()) ?Index {
return switch (i) {
.unused, .none => return null,
else => @enumFromInt(@intFromEnum(i)),
};
}
};
pub const OptionalIndex = enum(u8) {
none = std.math.maxInt(u8),
/// Index into `node_storage`.
_,
pub fn unwrap(i: @This()) ?Index {
if (i == .none) return null;
return @enumFromInt(@intFromEnum(i));
}
fn toParent(i: @This()) Parent {
assert(@intFromEnum(i) != @intFromEnum(Parent.unused));
return @enumFromInt(@intFromEnum(i));
}
};
/// Index into `node_storage`.
pub const Index = enum(u8) {
_,
fn toParent(i: @This()) Parent {
assert(@intFromEnum(i) != @intFromEnum(Parent.unused));
assert(@intFromEnum(i) != @intFromEnum(Parent.none));
return @enumFromInt(@intFromEnum(i));
}
pub fn toOptional(i: @This()) OptionalIndex {
return @enumFromInt(@intFromEnum(i));
}
};
/// Create a new child progress node. Thread-safe.
///
/// Passing 0 for `estimated_total_items` means unknown.
pub fn start(node: Node, name: []const u8, estimated_total_items: usize) Node {
if (noop_impl) {
assert(node.index == .none);
return Node.none;
}
const node_index = node.index.unwrap() orelse return Node.none;
const parent = node_index.toParent();
const freelist_head = &global_progress.node_freelist_first;
var opt_free_index = @atomicLoad(Node.OptionalIndex, freelist_head, .seq_cst);
while (opt_free_index.unwrap()) |free_index| {
const freelist_ptr = freelistByIndex(free_index);
opt_free_index = @cmpxchgWeak(Node.OptionalIndex, freelist_head, opt_free_index, freelist_ptr.*, .seq_cst, .seq_cst) orelse {
// We won the allocation race.
return init(free_index, parent, name, estimated_total_items);
};
}
const free_index = @atomicRmw(u32, &global_progress.node_end_index, .Add, 1, .monotonic);
if (free_index >= global_progress.node_storage.len) {
// Ran out of node storage memory. Progress for this node will not be tracked.
_ = @atomicRmw(u32, &global_progress.node_end_index, .Sub, 1, .monotonic);
return Node.none;
}
return init(@enumFromInt(free_index), parent, name, estimated_total_items);
}
/// This is the same as calling `start` and then `end` on the returned `Node`. Thread-safe.
pub fn completeOne(n: Node) void {
const index = n.index.unwrap() orelse return;
const storage = storageByIndex(index);
_ = @atomicRmw(u32, &storage.completed_count, .Add, 1, .monotonic);
}
/// Thread-safe.
pub fn setCompletedItems(n: Node, completed_items: usize) void {
const index = n.index.unwrap() orelse return;
const storage = storageByIndex(index);
@atomicStore(u32, &storage.completed_count, std.math.lossyCast(u32, completed_items), .monotonic);
}
/// Thread-safe. 0 means unknown.
pub fn setEstimatedTotalItems(n: Node, count: usize) void {
const index = n.index.unwrap() orelse return;
const storage = storageByIndex(index);
// Avoid u32 max int which is used to indicate a special state.
const saturated = @min(std.math.maxInt(u32) - 1, count);
@atomicStore(u32, &storage.estimated_total_count, saturated, .monotonic);
}
/// Thread-safe.
pub fn increaseEstimatedTotalItems(n: Node, count: usize) void {
const index = n.index.unwrap() orelse return;
const storage = storageByIndex(index);
_ = @atomicRmw(u32, &storage.estimated_total_count, .Add, std.math.lossyCast(u32, count), .monotonic);
}
/// Finish a started `Node`. Thread-safe.
pub fn end(n: Node) void {
if (noop_impl) {
assert(n.index == .none);
return;
}
const index = n.index.unwrap() orelse return;
const parent_ptr = parentByIndex(index);
if (parent_ptr.unwrap()) |parent_index| {
_ = @atomicRmw(u32, &storageByIndex(parent_index).completed_count, .Add, 1, .monotonic);
@atomicStore(Node.Parent, parent_ptr, .unused, .seq_cst);
const freelist_head = &global_progress.node_freelist_first;
var first = @atomicLoad(Node.OptionalIndex, freelist_head, .seq_cst);
while (true) {
freelistByIndex(index).* = first;
first = @cmpxchgWeak(Node.OptionalIndex, freelist_head, first, index.toOptional(), .seq_cst, .seq_cst) orelse break;
}
} else {
@atomicStore(bool, &global_progress.done, true, .seq_cst);
global_progress.redraw_event.set();
if (global_progress.update_thread) |thread| thread.join();
}
}
/// Posix-only. Used by `std.process.Child`. Thread-safe.
pub fn setIpcFd(node: Node, fd: posix.fd_t) void {
const index = node.index.unwrap() orelse return;
assert(fd >= 0);
assert(fd != posix.STDOUT_FILENO);
assert(fd != posix.STDIN_FILENO);
assert(fd != posix.STDERR_FILENO);
storageByIndex(index).setIpcFd(fd);
}
/// Posix-only. Thread-safe. Assumes the node is storing an IPC file
/// descriptor.
pub fn getIpcFd(node: Node) ?posix.fd_t {
const index = node.index.unwrap() orelse return null;
const storage = storageByIndex(index);
const int = @atomicLoad(u32, &storage.completed_count, .monotonic);
return switch (@typeInfo(posix.fd_t)) {
.int => @bitCast(int),
.pointer => @ptrFromInt(int),
else => @compileError("unsupported fd_t of " ++ @typeName(posix.fd_t)),
};
}
fn storageByIndex(index: Node.Index) *Node.Storage {
return &global_progress.node_storage[@intFromEnum(index)];
}
fn parentByIndex(index: Node.Index) *Node.Parent {
return &global_progress.node_parents[@intFromEnum(index)];
}
fn freelistByIndex(index: Node.Index) *Node.OptionalIndex {
return &global_progress.node_freelist[@intFromEnum(index)];
}
fn init(free_index: Index, parent: Parent, name: []const u8, estimated_total_items: usize) Node {
assert(parent == .none or @intFromEnum(parent) < node_storage_buffer_len);
const storage = storageByIndex(free_index);
@atomicStore(u32, &storage.completed_count, 0, .monotonic);
@atomicStore(u32, &storage.estimated_total_count, std.math.lossyCast(u32, estimated_total_items), .monotonic);
const name_len = @min(max_name_len, name.len);
copyAtomicStore(storage.name[0..name_len], name[0..name_len]);
if (name_len < storage.name.len)
@atomicStore(u8, &storage.name[name_len], 0, .monotonic);
const parent_ptr = parentByIndex(free_index);
assert(parent_ptr.* == .unused);
@atomicStore(Node.Parent, parent_ptr, parent, .release);
return .{ .index = free_index.toOptional() };
}
};
var global_progress: Progress = .{
.terminal = undefined,
.terminal_mode = .off,
.update_thread = null,
.redraw_event = .{},
.refresh_rate_ns = undefined,
.initial_delay_ns = undefined,
.rows = 0,
.cols = 0,
.draw_buffer = undefined,
.done = false,
.need_clear = false,
.node_parents = &node_parents_buffer,
.node_storage = &node_storage_buffer,
.node_freelist = &node_freelist_buffer,
.node_freelist_first = .none,
.node_end_index = 0,
};
const node_storage_buffer_len = 83;
var node_parents_buffer: [node_storage_buffer_len]Node.Parent = undefined;
var node_storage_buffer: [node_storage_buffer_len]Node.Storage = undefined;
var node_freelist_buffer: [node_storage_buffer_len]Node.OptionalIndex = undefined;
var default_draw_buffer: [4096]u8 = undefined;
var debug_start_trace = std.debug.Trace.init;
pub const have_ipc = switch (builtin.os.tag) {
.wasi, .freestanding, .windows => false,
else => true,
};
const noop_impl = builtin.single_threaded or switch (builtin.os.tag) {
.wasi, .freestanding => true,
else => false,
};
/// Initializes a global Progress instance.
///
/// Asserts there is only one global Progress instance.
///
/// Call `Node.end` when done.
pub fn start(options: Options) Node {
// Ensure there is only 1 global Progress object.
if (global_progress.node_end_index != 0) {
debug_start_trace.dump();
unreachable;
}
debug_start_trace.add("first initialized here");
@memset(global_progress.node_parents, .unused);
const root_node = Node.init(@enumFromInt(0), .none, options.root_name, options.estimated_total_items);
global_progress.done = false;
global_progress.node_end_index = 1;
assert(options.draw_buffer.len >= 200);
global_progress.draw_buffer = options.draw_buffer;
global_progress.refresh_rate_ns = options.refresh_rate_ns;
global_progress.initial_delay_ns = options.initial_delay_ns;
if (noop_impl)
return Node.none;
if (std.process.parseEnvVarInt("ZIG_PROGRESS", u31, 10)) |ipc_fd| {
global_progress.update_thread = std.Thread.spawn(.{}, ipcThreadRun, .{
@as(posix.fd_t, switch (@typeInfo(posix.fd_t)) {
.int => ipc_fd,
.pointer => @ptrFromInt(ipc_fd),
else => @compileError("unsupported fd_t of " ++ @typeName(posix.fd_t)),
}),
}) catch |err| {
std.log.warn("failed to spawn IPC thread for communicating progress to parent: {s}", .{@errorName(err)});
return Node.none;
};
} else |env_err| switch (env_err) {
error.EnvironmentVariableNotFound => {
if (options.disable_printing) {
return Node.none;
}
const stderr = std.io.getStdErr();
global_progress.terminal = stderr;
if (stderr.getOrEnableAnsiEscapeSupport()) {
global_progress.terminal_mode = .ansi_escape_codes;
} else if (is_windows and stderr.isTty()) {
global_progress.terminal_mode = TerminalMode{ .windows_api = .{
.code_page = windows.kernel32.GetConsoleOutputCP(),
} };
}
if (global_progress.terminal_mode == .off) {
return Node.none;
}
if (have_sigwinch) {
var act: posix.Sigaction = .{
.handler = .{ .sigaction = handleSigWinch },
.mask = posix.empty_sigset,
.flags = (posix.SA.SIGINFO | posix.SA.RESTART),
};
posix.sigaction(posix.SIG.WINCH, &act, null);
}
if (switch (global_progress.terminal_mode) {
.off => unreachable, // handled a few lines above
.ansi_escape_codes => std.Thread.spawn(.{}, updateThreadRun, .{}),
.windows_api => if (is_windows) std.Thread.spawn(.{}, windowsApiUpdateThreadRun, .{}) else unreachable,
}) |thread| {
global_progress.update_thread = thread;
} else |err| {
std.log.warn("unable to spawn thread for printing progress to terminal: {s}", .{@errorName(err)});
return Node.none;
}
},
else => |e| {
std.log.warn("invalid ZIG_PROGRESS file descriptor integer: {s}", .{@errorName(e)});
return Node.none;
},
}
return root_node;
}
/// Returns whether a resize is needed to learn the terminal size.
fn wait(timeout_ns: u64) bool {
const resize_flag = if (global_progress.redraw_event.timedWait(timeout_ns)) |_|
true
else |err| switch (err) {
error.Timeout => false,
};
global_progress.redraw_event.reset();
return resize_flag or (global_progress.cols == 0);
}
fn updateThreadRun() void {
// Store this data in the thread so that it does not need to be part of the
// linker data of the main executable.
var serialized_buffer: Serialized.Buffer = undefined;
{
const resize_flag = wait(global_progress.initial_delay_ns);
if (@atomicLoad(bool, &global_progress.done, .seq_cst)) return;
maybeUpdateSize(resize_flag);
const buffer, _ = computeRedraw(&serialized_buffer);
if (stderr_mutex.tryLock()) {
defer stderr_mutex.unlock();
write(buffer) catch return;
global_progress.need_clear = true;
}
}
while (true) {
const resize_flag = wait(global_progress.refresh_rate_ns);
if (@atomicLoad(bool, &global_progress.done, .seq_cst)) {
stderr_mutex.lock();
defer stderr_mutex.unlock();
return clearWrittenWithEscapeCodes() catch {};
}
maybeUpdateSize(resize_flag);
const buffer, _ = computeRedraw(&serialized_buffer);
if (stderr_mutex.tryLock()) {
defer stderr_mutex.unlock();
write(buffer) catch return;
global_progress.need_clear = true;
}
}
}
fn windowsApiWriteMarker() void {
// Write the marker that we will use to find the beginning of the progress when clearing.
// Note: This doesn't have to use WriteConsoleW, but doing so avoids dealing with the code page.
var num_chars_written: windows.DWORD = undefined;
const handle = global_progress.terminal.handle;
_ = windows.kernel32.WriteConsoleW(handle, &[_]u16{windows_api_start_marker}, 1, &num_chars_written, null);
}
fn windowsApiUpdateThreadRun() void {
var serialized_buffer: Serialized.Buffer = undefined;
{
const resize_flag = wait(global_progress.initial_delay_ns);
if (@atomicLoad(bool, &global_progress.done, .seq_cst)) return;
maybeUpdateSize(resize_flag);
const buffer, const nl_n = computeRedraw(&serialized_buffer);
if (stderr_mutex.tryLock()) {
defer stderr_mutex.unlock();
windowsApiWriteMarker();
write(buffer) catch return;
global_progress.need_clear = true;
windowsApiMoveToMarker(nl_n) catch return;
}
}
while (true) {
const resize_flag = wait(global_progress.refresh_rate_ns);
if (@atomicLoad(bool, &global_progress.done, .seq_cst)) {
stderr_mutex.lock();
defer stderr_mutex.unlock();
return clearWrittenWindowsApi() catch {};
}
maybeUpdateSize(resize_flag);
const buffer, const nl_n = computeRedraw(&serialized_buffer);
if (stderr_mutex.tryLock()) {
defer stderr_mutex.unlock();
clearWrittenWindowsApi() catch return;
windowsApiWriteMarker();
write(buffer) catch return;
global_progress.need_clear = true;
windowsApiMoveToMarker(nl_n) catch return;
}
}
}
/// Allows the caller to freely write to stderr until `unlockStdErr` is called.
///
/// During the lock, any `std.Progress` information is cleared from the terminal.
///
/// The lock is recursive; the same thread may hold the lock multiple times.
pub fn lockStdErr() void {
stderr_mutex.lock();
clearWrittenWithEscapeCodes() catch {};
}
pub fn unlockStdErr() void {
stderr_mutex.unlock();
}
fn ipcThreadRun(fd: posix.fd_t) anyerror!void {
// Store this data in the thread so that it does not need to be part of the
// linker data of the main executable.
var serialized_buffer: Serialized.Buffer = undefined;
{
_ = wait(global_progress.initial_delay_ns);
if (@atomicLoad(bool, &global_progress.done, .seq_cst))
return;
const serialized = serialize(&serialized_buffer);
writeIpc(fd, serialized) catch |err| switch (err) {
error.BrokenPipe => return,
};
}
while (true) {
_ = wait(global_progress.refresh_rate_ns);
if (@atomicLoad(bool, &global_progress.done, .seq_cst))
return;
const serialized = serialize(&serialized_buffer);
writeIpc(fd, serialized) catch |err| switch (err) {
error.BrokenPipe => return,
};
}
}
const start_sync = "\x1b[?2026h";
const up_one_line = "\x1bM";
const clear = "\x1b[J";
const save = "\x1b7";
const restore = "\x1b8";
const finish_sync = "\x1b[?2026l";
const TreeSymbol = enum {
/// ├─
tee,
/// │
line,
/// └─
langle,
const Encoding = enum {
ansi_escapes,
code_page_437,
utf8,
ascii,
};
/// The escape sequence representation as a string literal
fn escapeSeq(symbol: TreeSymbol) *const [9:0]u8 {
return switch (symbol) {
.tee => "\x1B\x28\x30\x74\x71\x1B\x28\x42 ",
.line => "\x1B\x28\x30\x78\x1B\x28\x42 ",
.langle => "\x1B\x28\x30\x6d\x71\x1B\x28\x42 ",
};
}
fn bytes(symbol: TreeSymbol, encoding: Encoding) []const u8 {
return switch (encoding) {
.ansi_escapes => escapeSeq(symbol),
.code_page_437 => switch (symbol) {
.tee => "\xC3\xC4 ",
.line => "\xB3 ",
.langle => "\xC0\xC4 ",
},
.utf8 => switch (symbol) {
.tee => "├─ ",
.line => "",
.langle => "└─ ",
},
.ascii => switch (symbol) {
.tee => "|- ",
.line => "| ",
.langle => "+- ",
},
};
}
fn maxByteLen(symbol: TreeSymbol) usize {
var max: usize = 0;
inline for (@typeInfo(Encoding).@"enum".fields) |field| {
const len = symbol.bytes(@field(Encoding, field.name)).len;
max = @max(max, len);
}
return max;
}
};
fn appendTreeSymbol(symbol: TreeSymbol, buf: []u8, start_i: usize) usize {
switch (global_progress.terminal_mode) {
.off => unreachable,
.ansi_escape_codes => {
const bytes = symbol.escapeSeq();
buf[start_i..][0..bytes.len].* = bytes.*;
return start_i + bytes.len;
},
.windows_api => |windows_api| {
const bytes = if (!is_windows) unreachable else switch (windows_api.code_page) {
// Code page 437 is the default code page and contains the box drawing symbols
437 => symbol.bytes(.code_page_437),
// UTF-8
65001 => symbol.bytes(.utf8),
// Fall back to ASCII approximation
else => symbol.bytes(.ascii),
};
@memcpy(buf[start_i..][0..bytes.len], bytes);
return start_i + bytes.len;
},
}
}
fn clearWrittenWithEscapeCodes() anyerror!void {
if (!global_progress.need_clear) return;
global_progress.need_clear = false;
try write(clear);
}
/// U+25BA or ►
const windows_api_start_marker = 0x25BA;
fn clearWrittenWindowsApi() error{Unexpected}!void {
// This uses a 'marker' strategy. The idea is:
// - Always write a marker (in this case U+25BA or ►) at the beginning of the progress
// - Get the current cursor position (at the end of the progress)
// - Subtract the number of lines written to get the expected start of the progress
// - Check to see if the first character at the start of the progress is the marker
// - If it's not the marker, keep checking the line before until we find it
// - Clear the screen from that position down, and set the cursor position to the start
//
// This strategy works even if there is line wrapping, and can handle the window
// being resized/scrolled arbitrarily.
//
// Notes:
// - Ideally, the marker would be a zero-width character, but the Windows console
// doesn't seem to support rendering zero-width characters (they show up as a space)
// - This same marker idea could technically be done with an attribute instead
// (https://learn.microsoft.com/en-us/windows/console/console-screen-buffers#character-attributes)
// but it must be a valid attribute and it actually needs to apply to the first
// character in order to be readable via ReadConsoleOutputAttribute. It doesn't seem
// like any of the available attributes are invisible/benign.
if (!global_progress.need_clear) return;
const handle = global_progress.terminal.handle;
const screen_area = @as(windows.DWORD, global_progress.cols) * global_progress.rows;
var console_info: windows.CONSOLE_SCREEN_BUFFER_INFO = undefined;
if (windows.kernel32.GetConsoleScreenBufferInfo(handle, &console_info) == 0) {
return error.Unexpected;
}
var num_chars_written: windows.DWORD = undefined;
if (windows.kernel32.FillConsoleOutputCharacterW(handle, ' ', screen_area, console_info.dwCursorPosition, &num_chars_written) == 0) {
return error.Unexpected;
}
}
fn windowsApiMoveToMarker(nl_n: usize) error{Unexpected}!void {
const handle = global_progress.terminal.handle;
var console_info: windows.CONSOLE_SCREEN_BUFFER_INFO = undefined;
if (windows.kernel32.GetConsoleScreenBufferInfo(handle, &console_info) == 0) {
return error.Unexpected;
}
const cursor_pos = console_info.dwCursorPosition;
const expected_y = cursor_pos.Y - @as(i16, @intCast(nl_n));
var start_pos: windows.COORD = .{ .X = 0, .Y = expected_y };
while (start_pos.Y >= 0) {
var wchar: [1]u16 = undefined;
var num_console_chars_read: windows.DWORD = undefined;
if (windows.kernel32.ReadConsoleOutputCharacterW(handle, &wchar, wchar.len, start_pos, &num_console_chars_read) == 0) {
return error.Unexpected;
}
if (wchar[0] == windows_api_start_marker) break;
start_pos.Y -= 1;
} else {
// If we couldn't find the marker, then just assume that no lines wrapped
start_pos = .{ .X = 0, .Y = expected_y };
}
if (windows.kernel32.SetConsoleCursorPosition(handle, start_pos) == 0) {
return error.Unexpected;
}
}
const Children = struct {
child: Node.OptionalIndex,
sibling: Node.OptionalIndex,
};
const Serialized = struct {
parents: []Node.Parent,
storage: []Node.Storage,
const Buffer = struct {
parents: [node_storage_buffer_len]Node.Parent,
storage: [node_storage_buffer_len]Node.Storage,
map: [node_storage_buffer_len]Node.OptionalIndex,
parents_copy: [node_storage_buffer_len]Node.Parent,
storage_copy: [node_storage_buffer_len]Node.Storage,
ipc_metadata_fds_copy: [node_storage_buffer_len]Fd,
ipc_metadata_copy: [node_storage_buffer_len]SavedMetadata,
ipc_metadata_fds: [node_storage_buffer_len]Fd,
ipc_metadata: [node_storage_buffer_len]SavedMetadata,
};
};
fn serialize(serialized_buffer: *Serialized.Buffer) Serialized {
var serialized_len: usize = 0;
var any_ipc = false;
// Iterate all of the nodes and construct a serializable copy of the state that can be examined
// without atomics.
const end_index = @atomicLoad(u32, &global_progress.node_end_index, .monotonic);
for (
global_progress.node_parents[0..end_index],
global_progress.node_storage[0..end_index],
serialized_buffer.map[0..end_index],
) |*parent_ptr, *storage_ptr, *map| {
var begin_parent = @atomicLoad(Node.Parent, parent_ptr, .acquire);
while (begin_parent != .unused) {
const dest_storage = &serialized_buffer.storage[serialized_len];
copyAtomicLoad(&dest_storage.name, &storage_ptr.name);
dest_storage.estimated_total_count = @atomicLoad(u32, &storage_ptr.estimated_total_count, .acquire);
dest_storage.completed_count = @atomicLoad(u32, &storage_ptr.completed_count, .monotonic);
const end_parent = @atomicLoad(Node.Parent, parent_ptr, .acquire);
if (begin_parent == end_parent) {
any_ipc = any_ipc or (dest_storage.getIpcFd() != null);
serialized_buffer.parents[serialized_len] = begin_parent;
map.* = @enumFromInt(serialized_len);
serialized_len += 1;
break;
}
begin_parent = end_parent;
} else {
// A node may be freed during the execution of this loop, causing
// there to be a parent reference to a nonexistent node. Without
// this assignment, this would lead to the map entry containing
// stale data. By assigning none, the child node with the bad
// parent pointer will be harmlessly omitted from the tree.
map.* = .none;
}
}
// Remap parents to point inside serialized arrays.
for (serialized_buffer.parents[0..serialized_len]) |*parent| {
parent.* = switch (parent.*) {
.unused => unreachable,
.none => .none,
_ => |p| serialized_buffer.map[@intFromEnum(p)].toParent(),
};
}
// Find nodes which correspond to child processes.
if (any_ipc)
serialized_len = serializeIpc(serialized_len, serialized_buffer);
return .{
.parents = serialized_buffer.parents[0..serialized_len],
.storage = serialized_buffer.storage[0..serialized_len],
};
}
const SavedMetadata = struct {
remaining_read_trash_bytes: u16,
main_index: u8,
start_index: u8,
nodes_len: u8,
};
const Fd = enum(i32) {
_,
fn init(fd: posix.fd_t) Fd {
return @enumFromInt(if (is_windows) @as(isize, @bitCast(@intFromPtr(fd))) else fd);
}
fn get(fd: Fd) posix.fd_t {
return if (is_windows)
@ptrFromInt(@as(usize, @bitCast(@as(isize, @intFromEnum(fd)))))
else
@intFromEnum(fd);
}
};
var ipc_metadata_len: u8 = 0;
fn serializeIpc(start_serialized_len: usize, serialized_buffer: *Serialized.Buffer) usize {
const ipc_metadata_fds_copy = &serialized_buffer.ipc_metadata_fds_copy;
const ipc_metadata_copy = &serialized_buffer.ipc_metadata_copy;
const ipc_metadata_fds = &serialized_buffer.ipc_metadata_fds;
const ipc_metadata = &serialized_buffer.ipc_metadata;
var serialized_len = start_serialized_len;
var pipe_buf: [2 * 4096]u8 = undefined;
const old_ipc_metadata_fds = ipc_metadata_fds_copy[0..ipc_metadata_len];
const old_ipc_metadata = ipc_metadata_copy[0..ipc_metadata_len];
ipc_metadata_len = 0;
main_loop: for (
serialized_buffer.parents[0..serialized_len],
serialized_buffer.storage[0..serialized_len],
0..,
) |main_parent, *main_storage, main_index| {
if (main_parent == .unused) continue;
const fd = main_storage.getIpcFd() orelse continue;
const opt_saved_metadata = findOld(fd, old_ipc_metadata_fds, old_ipc_metadata);
var bytes_read: usize = 0;
while (true) {
const n = posix.read(fd, pipe_buf[bytes_read..]) catch |err| switch (err) {
error.WouldBlock => break,
else => |e| {
std.log.debug("failed to read child progress data: {s}", .{@errorName(e)});
main_storage.completed_count = 0;
main_storage.estimated_total_count = 0;
continue :main_loop;
},
};
if (n == 0) break;
if (opt_saved_metadata) |m| {
if (m.remaining_read_trash_bytes > 0) {
assert(bytes_read == 0);
if (m.remaining_read_trash_bytes >= n) {
m.remaining_read_trash_bytes = @intCast(m.remaining_read_trash_bytes - n);
continue;
}
const src = pipe_buf[m.remaining_read_trash_bytes..n];
std.mem.copyForwards(u8, &pipe_buf, src);
m.remaining_read_trash_bytes = 0;
bytes_read = src.len;
continue;
}
}
bytes_read += n;
}
// Ignore all but the last message on the pipe.
var input: []u8 = pipe_buf[0..bytes_read];
if (input.len == 0) {
serialized_len = useSavedIpcData(serialized_len, serialized_buffer, main_storage, main_index, opt_saved_metadata, 0, fd);
continue;
}
const storage, const parents = while (true) {
const subtree_len: usize = input[0];
const expected_bytes = 1 + subtree_len * (@sizeOf(Node.Storage) + @sizeOf(Node.Parent));
if (input.len < expected_bytes) {
// Ignore short reads. We'll handle the next full message when it comes instead.
const remaining_read_trash_bytes: u16 = @intCast(expected_bytes - input.len);
serialized_len = useSavedIpcData(serialized_len, serialized_buffer, main_storage, main_index, opt_saved_metadata, remaining_read_trash_bytes, fd);
continue :main_loop;
}
if (input.len > expected_bytes) {
input = input[expected_bytes..];
continue;
}
const storage_bytes = input[1..][0 .. subtree_len * @sizeOf(Node.Storage)];
const parents_bytes = input[1 + storage_bytes.len ..][0 .. subtree_len * @sizeOf(Node.Parent)];
break .{
std.mem.bytesAsSlice(Node.Storage, storage_bytes),
std.mem.bytesAsSlice(Node.Parent, parents_bytes),
};
};
const nodes_len: u8 = @intCast(@min(parents.len - 1, serialized_buffer.storage.len - serialized_len));
// Remember in case the pipe is empty on next update.
ipc_metadata_fds[ipc_metadata_len] = Fd.init(fd);
ipc_metadata[ipc_metadata_len] = .{
.remaining_read_trash_bytes = 0,
.start_index = @intCast(serialized_len),
.nodes_len = nodes_len,
.main_index = @intCast(main_index),
};
ipc_metadata_len += 1;
// Mount the root here.
copyRoot(main_storage, &storage[0]);
if (is_big_endian) main_storage.byteSwap();
// Copy the rest of the tree to the end.
const storage_dest = serialized_buffer.storage[serialized_len..][0..nodes_len];
@memcpy(storage_dest, storage[1..][0..nodes_len]);
// Always little-endian over the pipe.
if (is_big_endian) for (storage_dest) |*s| s.byteSwap();
// Patch up parent pointers taking into account how the subtree is mounted.
for (serialized_buffer.parents[serialized_len..][0..nodes_len], parents[1..][0..nodes_len]) |*dest, p| {
dest.* = switch (p) {
// Fix bad data so the rest of the code does not see `unused`.
.none, .unused => .none,
// Root node is being mounted here.
@as(Node.Parent, @enumFromInt(0)) => @enumFromInt(main_index),
// Other nodes mounted at the end.
// Don't trust child data; if the data is outside the expected range, ignore the data.
// This also handles the case when data was truncated.
_ => |off| if (@intFromEnum(off) > nodes_len)
.none
else
@enumFromInt(serialized_len + @intFromEnum(off) - 1),
};
}
serialized_len += nodes_len;
}
// Save a copy in case any pipes are empty on the next update.
@memcpy(serialized_buffer.parents_copy[0..serialized_len], serialized_buffer.parents[0..serialized_len]);
@memcpy(serialized_buffer.storage_copy[0..serialized_len], serialized_buffer.storage[0..serialized_len]);
@memcpy(ipc_metadata_fds_copy[0..ipc_metadata_len], ipc_metadata_fds[0..ipc_metadata_len]);
@memcpy(ipc_metadata_copy[0..ipc_metadata_len], ipc_metadata[0..ipc_metadata_len]);
return serialized_len;
}
fn copyRoot(dest: *Node.Storage, src: *align(1) Node.Storage) void {
dest.* = .{
.completed_count = src.completed_count,
.estimated_total_count = src.estimated_total_count,
.name = if (src.name[0] == 0) dest.name else src.name,
};
}
fn findOld(
ipc_fd: posix.fd_t,
old_metadata_fds: []Fd,
old_metadata: []SavedMetadata,
) ?*SavedMetadata {
for (old_metadata_fds, old_metadata) |fd, *m| {
if (fd.get() == ipc_fd)
return m;
}
return null;
}
fn useSavedIpcData(
start_serialized_len: usize,
serialized_buffer: *Serialized.Buffer,
main_storage: *Node.Storage,
main_index: usize,
opt_saved_metadata: ?*SavedMetadata,
remaining_read_trash_bytes: u16,
fd: posix.fd_t,
) usize {
const parents_copy = &serialized_buffer.parents_copy;
const storage_copy = &serialized_buffer.storage_copy;
const ipc_metadata_fds = &serialized_buffer.ipc_metadata_fds;
const ipc_metadata = &serialized_buffer.ipc_metadata;
const saved_metadata = opt_saved_metadata orelse {
main_storage.completed_count = 0;
main_storage.estimated_total_count = 0;
if (remaining_read_trash_bytes > 0) {
ipc_metadata_fds[ipc_metadata_len] = Fd.init(fd);
ipc_metadata[ipc_metadata_len] = .{
.remaining_read_trash_bytes = remaining_read_trash_bytes,
.start_index = @intCast(start_serialized_len),
.nodes_len = 0,
.main_index = @intCast(main_index),
};
ipc_metadata_len += 1;
}
return start_serialized_len;
};
const start_index = saved_metadata.start_index;
const nodes_len = @min(saved_metadata.nodes_len, serialized_buffer.storage.len - start_serialized_len);
const old_main_index = saved_metadata.main_index;
ipc_metadata_fds[ipc_metadata_len] = Fd.init(fd);
ipc_metadata[ipc_metadata_len] = .{
.remaining_read_trash_bytes = remaining_read_trash_bytes,
.start_index = @intCast(start_serialized_len),
.nodes_len = nodes_len,
.main_index = @intCast(main_index),
};
ipc_metadata_len += 1;
const parents = parents_copy[start_index..][0..nodes_len];
const storage = storage_copy[start_index..][0..nodes_len];
copyRoot(main_storage, &storage_copy[old_main_index]);
@memcpy(serialized_buffer.storage[start_serialized_len..][0..storage.len], storage);
for (serialized_buffer.parents[start_serialized_len..][0..parents.len], parents) |*dest, p| {
dest.* = switch (p) {
.none, .unused => .none,
_ => |prev| d: {
if (@intFromEnum(prev) == old_main_index) {
break :d @enumFromInt(main_index);
} else if (@intFromEnum(prev) > nodes_len) {
break :d .none;
} else {
break :d @enumFromInt(@intFromEnum(prev) - start_index + start_serialized_len);
}
},
};
}
return start_serialized_len + storage.len;
}
fn computeRedraw(serialized_buffer: *Serialized.Buffer) struct { []u8, usize } {
const serialized = serialize(serialized_buffer);
// Now we can analyze our copy of the graph without atomics, reconstructing
// children lists which do not exist in the canonical data. These are
// needed for tree traversal below.
var children_buffer: [node_storage_buffer_len]Children = undefined;
const children = children_buffer[0..serialized.parents.len];
@memset(children, .{ .child = .none, .sibling = .none });
for (serialized.parents, 0..) |parent, child_index_usize| {
const child_index: Node.Index = @enumFromInt(child_index_usize);
assert(parent != .unused);
const parent_index = parent.unwrap() orelse continue;
const children_node = &children[@intFromEnum(parent_index)];
if (children_node.child.unwrap()) |existing_child_index| {
const existing_child = &children[@intFromEnum(existing_child_index)];
children[@intFromEnum(child_index)].sibling = existing_child.sibling;
existing_child.sibling = child_index.toOptional();
} else {
children_node.child = child_index.toOptional();
}
}
// The strategy is, with every redraw:
// erase to end of screen, write, move cursor to beginning of line, move cursor up N lines
// This keeps the cursor at the beginning so that unlocked stderr writes
// don't get eaten by the clear.
var i: usize = 0;
const buf = global_progress.draw_buffer;
if (global_progress.terminal_mode == .ansi_escape_codes) {
buf[i..][0..start_sync.len].* = start_sync.*;
i += start_sync.len;
}
switch (global_progress.terminal_mode) {
.off => unreachable,
.ansi_escape_codes => {
buf[i..][0..clear.len].* = clear.*;
i += clear.len;
},
.windows_api => if (!is_windows) unreachable,
}
const root_node_index: Node.Index = @enumFromInt(0);
i, const nl_n = computeNode(buf, i, 0, serialized, children, root_node_index);
if (global_progress.terminal_mode == .ansi_escape_codes) {
if (nl_n > 0) {
buf[i] = '\r';
i += 1;
for (0..nl_n) |_| {
buf[i..][0..up_one_line.len].* = up_one_line.*;
i += up_one_line.len;
}
}
buf[i..][0..finish_sync.len].* = finish_sync.*;
i += finish_sync.len;
}
return .{ buf[0..i], nl_n };
}
fn computePrefix(
buf: []u8,
start_i: usize,
nl_n: usize,
serialized: Serialized,
children: []const Children,
node_index: Node.Index,
) usize {
var i = start_i;
const parent_index = serialized.parents[@intFromEnum(node_index)].unwrap() orelse return i;
if (serialized.parents[@intFromEnum(parent_index)] == .none) return i;
if (@intFromEnum(serialized.parents[@intFromEnum(parent_index)]) == 0 and
serialized.storage[0].name[0] == 0)
{
return i;
}
i = computePrefix(buf, i, nl_n, serialized, children, parent_index);
if (children[@intFromEnum(parent_index)].sibling == .none) {
const prefix = " ";
const upper_bound_len = prefix.len + lineUpperBoundLen(nl_n);
if (i + upper_bound_len > buf.len) return buf.len;
buf[i..][0..prefix.len].* = prefix.*;
i += prefix.len;
} else {
const upper_bound_len = TreeSymbol.line.maxByteLen() + lineUpperBoundLen(nl_n);
if (i + upper_bound_len > buf.len) return buf.len;
i = appendTreeSymbol(.line, buf, i);
}
return i;
}
fn lineUpperBoundLen(nl_n: usize) usize {
// \r\n on Windows, \n otherwise.
const nl_len = if (is_windows) 2 else 1;
return @max(TreeSymbol.tee.maxByteLen(), TreeSymbol.langle.maxByteLen()) +
"[4294967296/4294967296] ".len + Node.max_name_len + nl_len +
(1 + (nl_n + 1) * up_one_line.len) +
finish_sync.len;
}
fn computeNode(
buf: []u8,
start_i: usize,
start_nl_n: usize,
serialized: Serialized,
children: []const Children,
node_index: Node.Index,
) struct { usize, usize } {
var i = start_i;
var nl_n = start_nl_n;
i = computePrefix(buf, i, nl_n, serialized, children, node_index);
if (i + lineUpperBoundLen(nl_n) > buf.len)
return .{ start_i, start_nl_n };
const storage = &serialized.storage[@intFromEnum(node_index)];
const estimated_total = storage.estimated_total_count;
const completed_items = storage.completed_count;
const name = if (std.mem.indexOfScalar(u8, &storage.name, 0)) |end| storage.name[0..end] else &storage.name;
const parent = serialized.parents[@intFromEnum(node_index)];
if (parent != .none) p: {
if (@intFromEnum(parent) == 0 and serialized.storage[0].name[0] == 0) {
break :p;
}
if (children[@intFromEnum(node_index)].sibling == .none) {
i = appendTreeSymbol(.langle, buf, i);
} else {
i = appendTreeSymbol(.tee, buf, i);
}
}
const is_empty_root = @intFromEnum(node_index) == 0 and serialized.storage[0].name[0] == 0;
if (!is_empty_root) {
if (name.len != 0 or estimated_total > 0) {
if (estimated_total > 0) {
i += (std.fmt.bufPrint(buf[i..], "[{d}/{d}] ", .{ completed_items, estimated_total }) catch &.{}).len;
} else if (completed_items != 0) {
i += (std.fmt.bufPrint(buf[i..], "[{d}] ", .{completed_items}) catch &.{}).len;
}
if (name.len != 0) {
i += (std.fmt.bufPrint(buf[i..], "{s}", .{name}) catch &.{}).len;
}
}
i = @min(global_progress.cols + start_i, i);
if (is_windows) {
// \r\n on Windows is necessary for the old console with the
// ENABLE_VIRTUAL_TERMINAL_PROCESSING | DISABLE_NEWLINE_AUTO_RETURN
// console modes set to behave properly.
buf[i] = '\r';
i += 1;
}
buf[i] = '\n';
i += 1;
nl_n += 1;
}
if (global_progress.withinRowLimit(nl_n)) {
if (children[@intFromEnum(node_index)].child.unwrap()) |child| {
i, nl_n = computeNode(buf, i, nl_n, serialized, children, child);
}
}
if (global_progress.withinRowLimit(nl_n)) {
if (children[@intFromEnum(node_index)].sibling.unwrap()) |sibling| {
i, nl_n = computeNode(buf, i, nl_n, serialized, children, sibling);
}
}
return .{ i, nl_n };
}
fn withinRowLimit(p: *Progress, nl_n: usize) bool {
// The +2 here is so that the PS1 is not scrolled off the top of the terminal.
// one because we keep the cursor on the next line
// one more to account for the PS1
return nl_n + 2 < p.rows;
}
fn write(buf: []const u8) anyerror!void {
try global_progress.terminal.writeAll(buf);
}
var remaining_write_trash_bytes: usize = 0;
fn writeIpc(fd: posix.fd_t, serialized: Serialized) error{BrokenPipe}!void {
// Byteswap if necessary to ensure little endian over the pipe. This is
// needed because the parent or child process might be running in qemu.
if (is_big_endian) for (serialized.storage) |*s| s.byteSwap();
assert(serialized.parents.len == serialized.storage.len);
const serialized_len: u8 = @intCast(serialized.parents.len);
const header = std.mem.asBytes(&serialized_len);
const storage = std.mem.sliceAsBytes(serialized.storage);
const parents = std.mem.sliceAsBytes(serialized.parents);
var vecs: [3]posix.iovec_const = .{
.{ .base = header.ptr, .len = header.len },
.{ .base = storage.ptr, .len = storage.len },
.{ .base = parents.ptr, .len = parents.len },
};
// Ensures the packet can fit in the pipe buffer.
const upper_bound_msg_len = 1 + node_storage_buffer_len * @sizeOf(Node.Storage) +
node_storage_buffer_len * @sizeOf(Node.OptionalIndex);
comptime assert(upper_bound_msg_len <= 4096);
while (remaining_write_trash_bytes > 0) {
// We do this in a separate write call to give a better chance for the
// writev below to be in a single packet.
const n = @min(parents.len, remaining_write_trash_bytes);
if (posix.write(fd, parents[0..n])) |written| {
remaining_write_trash_bytes -= written;
continue;
} else |err| switch (err) {
error.WouldBlock => return,
error.BrokenPipe => return error.BrokenPipe,
else => |e| {
std.log.debug("failed to send progress to parent process: {s}", .{@errorName(e)});
return error.BrokenPipe;
},
}
}
// If this write would block we do not want to keep trying, but we need to
// know if a partial message was written.
if (writevNonblock(fd, &vecs)) |written| {
const total = header.len + storage.len + parents.len;
if (written < total) {
remaining_write_trash_bytes = total - written;
}
} else |err| switch (err) {
error.WouldBlock => {},
error.BrokenPipe => return error.BrokenPipe,
else => |e| {
std.log.debug("failed to send progress to parent process: {s}", .{@errorName(e)});
return error.BrokenPipe;
},
}
}
fn writevNonblock(fd: posix.fd_t, iov: []posix.iovec_const) posix.WriteError!usize {
var iov_index: usize = 0;
var written: usize = 0;
var total_written: usize = 0;
while (true) {
while (if (iov_index < iov.len)
written >= iov[iov_index].len
else
return total_written) : (iov_index += 1) written -= iov[iov_index].len;
iov[iov_index].base += written;
iov[iov_index].len -= written;
written = try posix.writev(fd, iov[iov_index..]);
if (written == 0) return total_written;
total_written += written;
}
}
fn maybeUpdateSize(resize_flag: bool) void {
if (!resize_flag) return;
const fd = global_progress.terminal.handle;
if (is_windows) {
var info: windows.CONSOLE_SCREEN_BUFFER_INFO = undefined;
if (windows.kernel32.GetConsoleScreenBufferInfo(fd, &info) != windows.FALSE) {
// In the old Windows console, dwSize.Y is the line count of the
// entire scrollback buffer, so we use this instead so that we
// always get the size of the screen.
const screen_height = info.srWindow.Bottom - info.srWindow.Top;
global_progress.rows = @intCast(screen_height);
global_progress.cols = @intCast(info.dwSize.X);
} else {
std.log.debug("failed to determine terminal size; using conservative guess 80x25", .{});
global_progress.rows = 25;
global_progress.cols = 80;
}
} else {
var winsize: posix.winsize = .{
.row = 0,
.col = 0,
.xpixel = 0,
.ypixel = 0,
};
const err = posix.system.ioctl(fd, posix.T.IOCGWINSZ, @intFromPtr(&winsize));
if (posix.errno(err) == .SUCCESS) {
global_progress.rows = winsize.row;
global_progress.cols = winsize.col;
} else {
std.log.debug("failed to determine terminal size; using conservative guess 80x25", .{});
global_progress.rows = 25;
global_progress.cols = 80;
}
}
}
fn handleSigWinch(sig: i32, info: *const posix.siginfo_t, ctx_ptr: ?*anyopaque) callconv(.C) void {
_ = info;
_ = ctx_ptr;
assert(sig == posix.SIG.WINCH);
global_progress.redraw_event.set();
}
const have_sigwinch = switch (builtin.os.tag) {
.linux,
.plan9,
.solaris,
.netbsd,
.openbsd,
.haiku,
.macos,
.ios,
.watchos,
.tvos,
.visionos,
.dragonfly,
.freebsd,
=> true,
else => false,
};
/// The primary motivation for recursive mutex here is so that a panic while
/// stderr mutex is held still dumps the stack trace and other debug
/// information.
var stderr_mutex = std.Thread.Mutex.Recursive.init;
fn copyAtomicStore(dest: []align(@alignOf(usize)) u8, src: []const u8) void {
assert(dest.len == src.len);
const chunked_len = dest.len / @sizeOf(usize);
const dest_chunked: []usize = @as([*]usize, @ptrCast(dest))[0..chunked_len];
const src_chunked: []align(1) const usize = @as([*]align(1) const usize, @ptrCast(src))[0..chunked_len];
for (dest_chunked, src_chunked) |*d, s| {
@atomicStore(usize, d, s, .monotonic);
}
const remainder_start = chunked_len * @sizeOf(usize);
for (dest[remainder_start..], src[remainder_start..]) |*d, s| {
@atomicStore(u8, d, s, .monotonic);
}
}
fn copyAtomicLoad(
dest: *align(@alignOf(usize)) [Node.max_name_len]u8,
src: *align(@alignOf(usize)) const [Node.max_name_len]u8,
) void {
const chunked_len = @divExact(dest.len, @sizeOf(usize));
const dest_chunked: *[chunked_len]usize = @ptrCast(dest);
const src_chunked: *const [chunked_len]usize = @ptrCast(src);
for (dest_chunked, src_chunked) |*d, *s| {
d.* = @atomicLoad(usize, s, .monotonic);
}
}