|
| 1 | +use std::{ |
| 2 | + io::{self}, |
| 3 | + sync::{Arc, Mutex}, |
| 4 | +}; |
| 5 | + |
| 6 | +use ansi_to_tui::IntoText; |
| 7 | +use crossterm::event; |
| 8 | +use ratatui::{ |
| 9 | + buffer::Buffer, |
| 10 | + layout::{Constraint, Layout, Rect}, |
| 11 | + style::Stylize, |
| 12 | + widgets::{Block, Widget}, |
| 13 | + DefaultTerminal, Frame, |
| 14 | +}; |
| 15 | +use tracing_subscriber::{filter::ParseError, fmt::MakeWriter, EnvFilter}; |
| 16 | +use tui_textarea::{Input, Key, TextArea}; |
| 17 | + |
| 18 | +/// A list of preset filters to make it easier to explore the filter syntax. |
| 19 | +/// |
| 20 | +/// The UI allows you to select a preset filter with the up/down arrow keys. |
| 21 | +const PRESET_FILTERS: &[&str] = &[ |
| 22 | + "trace", |
| 23 | + "debug", |
| 24 | + "info", |
| 25 | + "warn", |
| 26 | + "error", |
| 27 | + "[with_fields]", |
| 28 | + "[with_fields{foo}]", |
| 29 | + "[with_fields{bar}]", |
| 30 | + "[with_fields{foo=42}]", |
| 31 | + "[with_fields{bar=bar}]", |
| 32 | + "[with_fields{foo=99}]", |
| 33 | + "[with_fields{bar=nope}]", |
| 34 | + "[with_fields{nonexistent}]", |
| 35 | + "other_crate=info", |
| 36 | + "other_crate=debug", |
| 37 | + "trace,other_crate=warn", |
| 38 | + "warn,other_crate=info", |
| 39 | +]; |
| 40 | + |
| 41 | +fn main() -> io::Result<()> { |
| 42 | + let terminal = ratatui::init(); |
| 43 | + let result = App::new().run(terminal); |
| 44 | + ratatui::restore(); |
| 45 | + result |
| 46 | +} |
| 47 | + |
| 48 | +struct App { |
| 49 | + filter: TextArea<'static>, |
| 50 | + preset_index: usize, |
| 51 | + exit: bool, |
| 52 | + log_widget: Result<LogWidget, ParseError>, |
| 53 | +} |
| 54 | + |
| 55 | +impl App { |
| 56 | + /// Creates a new instance of the application, ready to run |
| 57 | + fn new() -> Self { |
| 58 | + let mut filter = TextArea::new(vec![PRESET_FILTERS[0].to_string()]); |
| 59 | + let title = "Env Filter Explorer. <Esc> to quit, <Up>/<Down> to select preset"; |
| 60 | + filter.set_block(Block::bordered().title(title)); |
| 61 | + Self { |
| 62 | + filter, |
| 63 | + preset_index: 0, |
| 64 | + exit: false, |
| 65 | + log_widget: Ok(LogWidget::default()), |
| 66 | + } |
| 67 | + } |
| 68 | + |
| 69 | + /// The application's main loop until the user exits. |
| 70 | + fn run(mut self, mut terminal: DefaultTerminal) -> io::Result<()> { |
| 71 | + while !self.exit { |
| 72 | + self.log_widget = self.evaluate_filter(); |
| 73 | + terminal.draw(|frame| self.render(frame))?; |
| 74 | + self.handle_event()?; |
| 75 | + } |
| 76 | + Ok(()) |
| 77 | + } |
| 78 | + |
| 79 | + /// Render the application with a filter input area and a log output area. |
| 80 | + fn render(&self, frame: &mut Frame) { |
| 81 | + let layout = Layout::vertical([Constraint::Length(3), Constraint::Fill(1)]); |
| 82 | + let [filter_area, main_area] = layout.areas(frame.area()); |
| 83 | + frame.render_widget(&self.filter, filter_area); |
| 84 | + match &self.log_widget { |
| 85 | + Ok(log_widget) => frame.render_widget(log_widget, main_area), |
| 86 | + Err(error) => frame.render_widget(error.to_string().red(), main_area), |
| 87 | + } |
| 88 | + } |
| 89 | + |
| 90 | + /// Handles a single terminal event (e.g. mouse, keyboard, resize). |
| 91 | + fn handle_event(&mut self) -> io::Result<()> { |
| 92 | + let event = event::read()?; |
| 93 | + let input = Input::from(event); |
| 94 | + match input.key { |
| 95 | + Key::Enter => return Ok(()), // ignore new lines |
| 96 | + Key::Esc => self.exit = true, |
| 97 | + Key::Up => self.select_previous_preset(), |
| 98 | + Key::Down => self.select_next_preset(), |
| 99 | + _ => self.add_input(input), |
| 100 | + } |
| 101 | + Ok(()) |
| 102 | + } |
| 103 | + |
| 104 | + /// Selects the previous preset filter in the list. |
| 105 | + fn select_previous_preset(&mut self) { |
| 106 | + self.select_preset(self.preset_index.saturating_sub(1)); |
| 107 | + } |
| 108 | + |
| 109 | + /// Selects the next preset filter in the list. |
| 110 | + fn select_next_preset(&mut self) { |
| 111 | + self.select_preset((self.preset_index + 1).min(PRESET_FILTERS.len() - 1)); |
| 112 | + } |
| 113 | + |
| 114 | + /// Selects a preset filter by index and updates the filter text area. |
| 115 | + fn select_preset(&mut self, index: usize) { |
| 116 | + self.preset_index = index; |
| 117 | + self.filter.select_all(); |
| 118 | + self.filter.delete_line_by_head(); |
| 119 | + self.filter.insert_str(PRESET_FILTERS[self.preset_index]); |
| 120 | + } |
| 121 | + |
| 122 | + /// Handles normal keyboard input by adding it to the filter text area. |
| 123 | + fn add_input(&mut self, input: Input) { |
| 124 | + self.filter.input(input); |
| 125 | + } |
| 126 | + |
| 127 | + /// Evaluates the current filter and returns a log widget with the filtered logs or an error. |
| 128 | + fn evaluate_filter(&mut self) -> Result<LogWidget, ParseError> { |
| 129 | + let filter = self.filter.lines()[0].to_string(); |
| 130 | + let env_filter = EnvFilter::builder().parse(filter)?; |
| 131 | + let log_widget = LogWidget::default(); |
| 132 | + let collector = tracing_subscriber::fmt() |
| 133 | + .with_env_filter(env_filter) |
| 134 | + .with_writer(log_widget.clone()) |
| 135 | + .finish(); |
| 136 | + tracing::collect::with_default(collector, || { |
| 137 | + simulate_logging(); |
| 138 | + other_crate_span(); |
| 139 | + }); |
| 140 | + Ok(log_widget) |
| 141 | + } |
| 142 | +} |
| 143 | + |
| 144 | +/// A writer that collects logs into a buffer and can be displayed as a widget. |
| 145 | +#[derive(Clone, Default, Debug)] |
| 146 | +struct LogWidget { |
| 147 | + buffer: Arc<Mutex<Vec<u8>>>, |
| 148 | +} |
| 149 | + |
| 150 | +impl io::Write for LogWidget { |
| 151 | + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { |
| 152 | + self.buffer.lock().unwrap().write(buf) |
| 153 | + } |
| 154 | + |
| 155 | + fn flush(&mut self) -> io::Result<()> { |
| 156 | + self.buffer.lock().unwrap().flush() |
| 157 | + } |
| 158 | +} |
| 159 | + |
| 160 | +impl<'a> MakeWriter<'a> for LogWidget { |
| 161 | + type Writer = Self; |
| 162 | + |
| 163 | + fn make_writer(&'a self) -> Self::Writer { |
| 164 | + self.clone() |
| 165 | + } |
| 166 | +} |
| 167 | + |
| 168 | +impl Widget for &LogWidget { |
| 169 | + /// Displays the logs that have been collected in the buffer. |
| 170 | + /// |
| 171 | + /// If the buffer is empty, it displays "No matching logs". |
| 172 | + fn render(self, area: Rect, buf: &mut Buffer) { |
| 173 | + let buffer = self.buffer.lock().unwrap(); |
| 174 | + let string = String::from_utf8_lossy(&buffer).to_string(); |
| 175 | + if string.is_empty() { |
| 176 | + "No matching logs".render(area, buf); |
| 177 | + return; |
| 178 | + } |
| 179 | + string |
| 180 | + .into_text() // convert a string with ANSI escape codes into ratatui Text |
| 181 | + .unwrap_or_else(|err| format!("Error parsing output: {err}").into()) |
| 182 | + .render(area, buf); |
| 183 | + } |
| 184 | +} |
| 185 | + |
| 186 | +#[tracing::instrument] |
| 187 | +fn simulate_logging() { |
| 188 | + tracing::info!("This is an info message"); |
| 189 | + tracing::error!("This is an error message"); |
| 190 | + tracing::warn!("This is a warning message"); |
| 191 | + tracing::debug!("This is a debug message"); |
| 192 | + tracing::trace!("This is a trace message"); |
| 193 | + |
| 194 | + with_fields(42, "bar"); |
| 195 | + with_fields(99, "nope"); |
| 196 | + |
| 197 | + trace_span(); |
| 198 | + debug_span(); |
| 199 | + info_span(); |
| 200 | + warn_span(); |
| 201 | + error_span(); |
| 202 | +} |
| 203 | + |
| 204 | +#[tracing::instrument] |
| 205 | +fn with_fields(foo: u32, bar: &'static str) { |
| 206 | + tracing::info!(foo, bar, "This is an info message with fields"); |
| 207 | +} |
| 208 | + |
| 209 | +#[tracing::instrument(level = "trace")] |
| 210 | +fn trace_span() { |
| 211 | + tracing::error!("Error message inside a span with trace level"); |
| 212 | + tracing::info!("Info message inside a span with trace level"); |
| 213 | + tracing::trace!("Trace message inside a span with trace level"); |
| 214 | +} |
| 215 | + |
| 216 | +#[tracing::instrument] |
| 217 | +fn debug_span() { |
| 218 | + tracing::error!("Error message inside a span with debug level"); |
| 219 | + tracing::info!("Info message inside a span with debug level"); |
| 220 | + tracing::debug!("Debug message inside a span with debug level"); |
| 221 | +} |
| 222 | + |
| 223 | +#[tracing::instrument] |
| 224 | +fn info_span() { |
| 225 | + tracing::error!("Error message inside a span with info level"); |
| 226 | + tracing::info!("Info message inside a span with info level"); |
| 227 | + tracing::debug!("Debug message inside a span with info level"); |
| 228 | +} |
| 229 | + |
| 230 | +#[tracing::instrument] |
| 231 | +fn warn_span() { |
| 232 | + tracing::error!("Error message inside a span with warn level"); |
| 233 | + tracing::info!("Info message inside a span with warn level"); |
| 234 | + tracing::debug!("Debug message inside a span with warn level"); |
| 235 | +} |
| 236 | + |
| 237 | +#[tracing::instrument] |
| 238 | +fn error_span() { |
| 239 | + tracing::error!("Error message inside a span with error level"); |
| 240 | + tracing::info!("Info message inside a span with error level"); |
| 241 | + tracing::debug!("Debug message inside a span with error level"); |
| 242 | +} |
| 243 | + |
| 244 | +#[tracing::instrument(target = "other_crate")] |
| 245 | +fn other_crate_span() { |
| 246 | + tracing::error!(target: "other_crate", "An error message from another crate"); |
| 247 | + tracing::warn!(target: "other_crate", "A warning message from another crate"); |
| 248 | + tracing::info!(target: "other_crate", "An info message from another crate"); |
| 249 | + tracing::debug!(target: "other_crate", "A debug message from another crate"); |
| 250 | + tracing::trace!(target: "other_crate", "A trace message from another crate"); |
| 251 | +} |
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