yazi/yazi-plugin/src/external/highlighter.rs

268 lines
8.3 KiB
Rust

use std::{borrow::Cow, io::Cursor, mem, path::{Path, PathBuf}, sync::OnceLock};
use anyhow::{Result, anyhow};
use ratatui::{layout::Size, text::{Line, Span, Text}};
use syntect::{LoadingError, dumps, easy::HighlightLines, highlighting::{self, Theme, ThemeSet}, parsing::{SyntaxReference, SyntaxSet}};
use tokio::{fs::File, io::{AsyncBufReadExt, BufReader}};
use yazi_config::{PREVIEW, THEME, preview::PreviewWrap};
use yazi_shared::{Ids, errors::PeekError, replace_to_printable};
static INCR: Ids = Ids::new();
static SYNTECT: OnceLock<(Theme, SyntaxSet)> = OnceLock::new();
pub struct Highlighter {
path: PathBuf,
}
impl Highlighter {
#[inline]
pub fn new(path: &Path) -> Self { Self { path: path.to_owned() } }
pub fn init() -> (&'static Theme, &'static SyntaxSet) {
let f = || {
let theme = std::fs::File::open(&THEME.mgr.syntect_theme)
.map_err(LoadingError::Io)
.and_then(|f| ThemeSet::load_from_reader(&mut std::io::BufReader::new(f)))
.or_else(|_| ThemeSet::load_from_reader(&mut Cursor::new(yazi_prebuild::ansi_theme())));
let syntaxes = dumps::from_uncompressed_data(yazi_prebuild::syntaxes());
(theme.unwrap(), syntaxes.unwrap())
};
let (theme, syntaxes) = SYNTECT.get_or_init(f);
(theme, syntaxes)
}
#[inline]
pub fn abort() { INCR.next(); }
pub async fn highlight(&self, skip: usize, size: Size) -> Result<Text<'static>, PeekError> {
let mut reader = BufReader::new(File::open(&self.path).await?);
let syntax = Self::find_syntax(&self.path).await;
let mut plain = syntax.is_err();
let mut before = Vec::with_capacity(if plain { 0 } else { skip });
let mut after = Vec::with_capacity(size.height as _);
let mut i = 0;
let mut buf = vec![];
let mut inspected = 0u16;
while reader.read_until(b'\n', &mut buf).await.is_ok_and(|n| n > 0) {
if Self::is_binary(&buf, &mut inspected) {
return Err("Binary file".into());
}
if !plain && (buf.len() > 5000 || Self::contains_control_chars(&buf)) {
plain = true;
drop(mem::take(&mut before));
}
if buf.ends_with(b"\r\n") {
buf.pop();
buf.pop();
buf.push(b'\n');
}
i += if i >= skip {
buf.iter_mut().for_each(Self::carriage_return_to_line_feed);
after.push(String::from_utf8_lossy(&buf).into_owned());
Self::line_height(&after[after.len() - 1], size.width)
} else if !plain {
before.push(String::from_utf8_lossy(&buf).into_owned());
Self::line_height(&before[before.len() - 1], size.width)
} else if PREVIEW.wrap == PreviewWrap::Yes {
Self::line_height(&String::from_utf8_lossy(&buf), size.width)
} else {
1
};
buf.clear();
if i > skip + size.height as usize {
break;
}
}
if skip > 0 && i < skip + size.height as usize {
return Err(PeekError::Exceed(i.saturating_sub(size.height as _)));
}
Ok(if plain {
Text::from(replace_to_printable(&after, PREVIEW.tab_size))
} else {
Self::highlight_with(before, after, syntax.unwrap()).await?
})
}
async fn highlight_with(
before: Vec<String>,
after: Vec<String>,
syntax: &'static SyntaxReference,
) -> Result<Text<'static>, PeekError> {
let ticket = INCR.current();
tokio::task::spawn_blocking(move || {
let (theme, syntaxes) = Self::init();
let mut h = HighlightLines::new(syntax, theme);
for line in before {
if ticket != INCR.current() {
return Err("Highlighting cancelled".into());
}
h.highlight_line(&line, syntaxes).map_err(|e| anyhow!(e))?;
}
let indent = PREVIEW.indent();
let mut lines = Vec::with_capacity(after.len());
for line in after {
if ticket != INCR.current() {
return Err("Highlighting cancelled".into());
}
let regions = h.highlight_line(&line, syntaxes).map_err(|e| anyhow!(e))?;
lines.push(Self::to_line_widget(regions, &indent));
}
Ok(Text::from(lines))
})
.await?
}
async fn find_syntax(path: &Path) -> Result<&'static SyntaxReference> {
let (_, syntaxes) = Self::init();
let name = path.file_name().map(|n| n.to_string_lossy()).unwrap_or_default();
if let Some(s) = syntaxes.find_syntax_by_extension(&name) {
return Ok(s);
}
let ext = path.extension().map(|e| e.to_string_lossy()).unwrap_or_default();
if let Some(s) = syntaxes.find_syntax_by_extension(&ext) {
return Ok(s);
}
let mut line = String::new();
let mut reader = BufReader::new(File::open(&path).await?);
reader.read_line(&mut line).await?;
syntaxes.find_syntax_by_first_line(&line).ok_or_else(|| anyhow!("No syntax found"))
}
#[inline(always)]
fn is_binary(buf: &[u8], inspected: &mut u16) -> bool {
if let Some(n) = 1024u16.checked_sub(*inspected) {
*inspected += n.min(buf.len() as u16);
buf.iter().take(n as usize).any(|&b| b == 0)
} else {
false
}
}
fn line_height(s: &str, width: u16) -> usize {
if PREVIEW.wrap != PreviewWrap::Yes {
return 1;
}
let pad = PREVIEW
.tab_size
.checked_sub(1)
.map(|n| s.bytes().filter(|&b| b == b'\t').count() * n as usize)
.map(|n| yazi_config::preview::Preview::indent_with(n))
.unwrap_or_default();
let line = Line {
spans: vec![Span { content: pad, style: Default::default() }, Span {
content: Cow::Borrowed(s),
..Default::default()
}],
..Default::default()
};
ratatui::widgets::Paragraph::new(line)
.wrap(ratatui::widgets::Wrap { trim: false })
.line_count(width)
}
#[inline(always)]
fn contains_control_chars(buf: &[u8]) -> bool {
buf.iter().any(|&b| b.is_ascii_control() && !matches!(b, b'\t' | b'\n' | b'\r'))
}
#[inline(always)]
fn carriage_return_to_line_feed(b: &mut u8) {
if *b == b'\r' {
*b = b'\n';
}
}
}
impl Highlighter {
pub fn to_line_widget(regions: Vec<(highlighting::Style, &str)>, indent: &str) -> Line<'static> {
let spans: Vec<_> = regions
.into_iter()
.map(|(style, s)| {
let mut modifier = ratatui::style::Modifier::empty();
if style.font_style.contains(highlighting::FontStyle::BOLD) {
modifier |= ratatui::style::Modifier::BOLD;
}
if style.font_style.contains(highlighting::FontStyle::ITALIC) {
modifier |= ratatui::style::Modifier::ITALIC;
}
if style.font_style.contains(highlighting::FontStyle::UNDERLINE) {
modifier |= ratatui::style::Modifier::UNDERLINED;
}
Span {
content: s.replace('\t', indent).into(),
style: ratatui::style::Style {
fg: Self::to_ansi_color(style.foreground),
// bg: Self::to_ansi_color(style.background),
add_modifier: modifier,
..Default::default()
},
}
})
.collect();
Line::from(spans)
}
// Copy from https://github.com/sharkdp/bat/blob/master/src/terminal.rs
fn to_ansi_color(color: highlighting::Color) -> Option<ratatui::style::Color> {
if color.a == 0 {
// Themes can specify one of the user-configurable terminal colors by
// encoding them as #RRGGBBAA with AA set to 00 (transparent) and RR set
// to the 8-bit color palette number. The built-in themes ansi, base16,
// and base16-256 use this.
Some(match color.r {
// For the first 8 colors, use the Color enum to produce ANSI escape
// sequences using codes 30-37 (foreground) and 40-47 (background).
// For example, red foreground is \x1b[31m. This works on terminals
// without 256-color support.
0x00 => ratatui::style::Color::Black,
0x01 => ratatui::style::Color::Red,
0x02 => ratatui::style::Color::Green,
0x03 => ratatui::style::Color::Yellow,
0x04 => ratatui::style::Color::Blue,
0x05 => ratatui::style::Color::Magenta,
0x06 => ratatui::style::Color::Cyan,
0x07 => ratatui::style::Color::White,
// For all other colors, use Fixed to produce escape sequences using
// codes 38;5 (foreground) and 48;5 (background). For example,
// bright red foreground is \x1b[38;5;9m. This only works on
// terminals with 256-color support.
//
// TODO: When ansi_term adds support for bright variants using codes
// 90-97 (foreground) and 100-107 (background), we should use those
// for values 0x08 to 0x0f and only use Fixed for 0x10 to 0xff.
n => ratatui::style::Color::Indexed(n),
})
} else if color.a == 1 {
// Themes can specify the terminal's default foreground/background color
// (i.e. no escape sequence) using the encoding #RRGGBBAA with AA set to
// 01. The built-in theme ansi uses this.
None
} else {
Some(ratatui::style::Color::Rgb(color.r, color.g, color.b))
}
}
}