Add and use new Signals struct (#13314)

# Description
This PR introduces a new `Signals` struct to replace our adhoc passing
around of `ctrlc: Option<Arc<AtomicBool>>`. Doing so has a few benefits:
- We can better enforce when/where resetting or triggering an interrupt
is allowed.
- Consolidates `nu_utils::ctrl_c::was_pressed` and other ad-hoc
re-implementations into a single place: `Signals::check`.
- This allows us to add other types of signals later if we want. E.g.,
exiting or suspension.
- Similarly, we can more easily change the underlying implementation if
we need to in the future.
- Places that used to have a `ctrlc` of `None` now use
`Signals::empty()`, so we can double check these usages for correctness
in the future.

crates/nu-explore/src/commands/expand.rs

@@ -67,12 +67,11 @@ fn convert_value_to_string(
         let config = engine_state.get_config();
         Ok(vals[0][0].to_abbreviated_string(config))
     } else {
-        let ctrlc = engine_state.ctrlc.clone();
         let config = engine_state.get_config();
         let style_computer = StyleComputer::from_config(engine_state, stack);
 
         Ok(nu_common::try_build_table(
-            ctrlc,
+            engine_state.signals(),
             config,
             &style_computer,
             value,

crates/nu-explore/src/explore.rs

@@ -63,7 +63,6 @@ impl Command for Explore {
         let tail: bool = call.has_flag(engine_state, stack, "tail")?;
         let peek_value: bool = call.has_flag(engine_state, stack, "peek")?;
 
-        let ctrlc = engine_state.ctrlc.clone();
         let nu_config = engine_state.get_config();
         let style_computer = StyleComputer::from_config(engine_state, stack);
 
@@ -83,7 +82,7 @@ impl Command for Explore {
             tail,
         );
 
-        let result = run_pager(engine_state, &mut stack.clone(), ctrlc, input, config);
+        let result = run_pager(engine_state, &mut stack.clone(), input, config);
 
         match result {
             Ok(Some(value)) => Ok(PipelineData::Value(value, None)),

crates/nu-explore/src/lib.rs

@@ -11,7 +11,7 @@ use commands::{ExpandCmd, HelpCmd, NuCmd, QuitCmd, TableCmd, TryCmd};
 pub use default_context::add_explore_context;
 pub use explore::Explore;
 use explore::ExploreConfig;
-use nu_common::{collect_pipeline, has_simple_value, CtrlC};
+use nu_common::{collect_pipeline, has_simple_value};
 use nu_protocol::{
     engine::{EngineState, Stack},
     PipelineData, Value,
@@ -28,7 +28,6 @@ mod util {
 fn run_pager(
     engine_state: &EngineState,
     stack: &mut Stack,
-    ctrlc: CtrlC,
     input: PipelineData,
     config: PagerConfig,
 ) -> Result<Option<Value>> {
@@ -45,14 +44,14 @@ fn run_pager(
         p.show_message("For help type :help");
 
         let view = binary_view(input, config.explore_config)?;
-        return p.run(engine_state, stack, ctrlc, Some(view), commands);
+        return p.run(engine_state, stack, Some(view), commands);
     }
 
     let (columns, data) = collect_pipeline(input)?;
 
     let has_no_input = columns.is_empty() && data.is_empty();
     if has_no_input {
-        return p.run(engine_state, stack, ctrlc, help_view(), commands);
+        return p.run(engine_state, stack, help_view(), commands);
     }
 
     p.show_message("For help type :help");
@@ -60,11 +59,11 @@ fn run_pager(
     if let Some(value) = has_simple_value(&data) {
         let text = value.to_abbreviated_string(config.nu_config);
         let view = Some(Page::new(Preview::new(&text), false));
-        return p.run(engine_state, stack, ctrlc, view, commands);
+        return p.run(engine_state, stack, view, commands);
     }
 
     let view = create_record_view(columns, data, is_record, config);
-    p.run(engine_state, stack, ctrlc, view, commands)
+    p.run(engine_state, stack, view, commands)
 }
 
 fn create_record_view(

crates/nu-explore/src/nu_common/mod.rs

@@ -6,13 +6,11 @@ mod value;
 
 use nu_color_config::TextStyle;
 use nu_protocol::Value;
-use std::sync::{atomic::AtomicBool, Arc};
 
 pub use nu_ansi_term::{Color as NuColor, Style as NuStyle};
 pub use nu_protocol::{Config as NuConfig, Span as NuSpan};
 
 pub type NuText = (String, TextStyle);
-pub type CtrlC = Option<Arc<AtomicBool>>;
 
 pub use command::run_command_with_value;
 pub use lscolor::{create_lscolors, lscolorize};

crates/nu-explore/src/nu_common/table.rs

@@ -1,22 +1,21 @@
 use crate::nu_common::NuConfig;
 use nu_color_config::StyleComputer;
-use nu_protocol::{Record, Span, Value};
+use nu_protocol::{Record, Signals, Span, Value};
 use nu_table::{
     common::{nu_value_to_string, nu_value_to_string_clean},
     ExpandedTable, TableOpts,
 };
-use std::sync::{atomic::AtomicBool, Arc};
 
 pub fn try_build_table(
-    ctrlc: Option<Arc<AtomicBool>>,
+    signals: &Signals,
     config: &NuConfig,
     style_computer: &StyleComputer,
     value: Value,
 ) -> String {
     let span = value.span();
     match value {
-        Value::List { vals, .. } => try_build_list(vals, ctrlc, config, span, style_computer),
-        Value::Record { val, .. } => try_build_map(&val, span, style_computer, ctrlc, config),
+        Value::List { vals, .. } => try_build_list(vals, signals, config, span, style_computer),
+        Value::Record { val, .. } => try_build_map(&val, span, style_computer, signals, config),
         val if matches!(val, Value::String { .. }) => {
             nu_value_to_string_clean(&val, config, style_computer).0
         }
@@ -28,13 +27,13 @@ fn try_build_map(
     record: &Record,
     span: Span,
     style_computer: &StyleComputer,
-    ctrlc: Option<Arc<AtomicBool>>,
+    signals: &Signals,
     config: &NuConfig,
 ) -> String {
     let opts = TableOpts::new(
         config,
         style_computer,
-        ctrlc,
+        signals,
         Span::unknown(),
         usize::MAX,
         (config.table_indent.left, config.table_indent.right),
@@ -53,7 +52,7 @@ fn try_build_map(
 
 fn try_build_list(
     vals: Vec<Value>,
-    ctrlc: Option<Arc<AtomicBool>>,
+    signals: &Signals,
     config: &NuConfig,
     span: Span,
     style_computer: &StyleComputer,
@@ -61,7 +60,7 @@ fn try_build_list(
     let opts = TableOpts::new(
         config,
         style_computer,
-        ctrlc,
+        signals,
         Span::unknown(),
         usize::MAX,
         (config.table_indent.left, config.table_indent.right),

crates/nu-explore/src/pager/mod.rs

@@ -11,7 +11,7 @@ use self::{
 use super::views::{Layout, View};
 use crate::{
     explore::ExploreConfig,
-    nu_common::{CtrlC, NuColor, NuConfig, NuStyle},
+    nu_common::{NuColor, NuConfig, NuStyle},
     registry::{Command, CommandRegistry},
     views::{util::nu_style_to_tui, ViewConfig},
 };
@@ -36,7 +36,6 @@ use std::{
     cmp::min,
     io::{self, Stdout},
     result,
-    sync::atomic::Ordering,
 };
 
 pub type Frame<'a> = ratatui::Frame<'a>;
@@ -89,7 +88,6 @@ impl<'a> Pager<'a> {
         &mut self,
         engine_state: &EngineState,
         stack: &mut Stack,
-        ctrlc: CtrlC,
         view: Option<Page>,
         commands: CommandRegistry,
     ) -> Result<Option<Value>> {
@@ -114,7 +112,6 @@ impl<'a> Pager<'a> {
             &mut terminal,
             engine_state,
             stack,
-            ctrlc,
             self,
             &mut info,
             view,
@@ -173,7 +170,6 @@ fn render_ui(
     term: &mut Terminal,
     engine_state: &EngineState,
     stack: &mut Stack,
-    ctrlc: CtrlC,
     pager: &mut Pager<'_>,
     info: &mut ViewInfo,
     view: Option<Page>,
@@ -183,11 +179,8 @@ fn render_ui(
     let mut view_stack = ViewStack::new(view, Vec::new());
 
     loop {
-        // handle CTRLC event
-        if let Some(ctrlc) = ctrlc.clone() {
-            if ctrlc.load(Ordering::SeqCst) {
-                break Ok(None);
-            }
+        if engine_state.signals().interrupted() {
+            break Ok(None);
         }
 
         let mut layout = Layout::default();