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

262 lines
8.1 KiB
Rust

use std::{io::Cursor, 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::io::{AsyncBufReadExt, AsyncSeekExt, BufReader};
use yazi_config::{THEME, YAZI, preview::PreviewWrap};
use yazi_fs::provider::{Provider, local::Local};
use yazi_shared::{Ids, errors::PeekError, push_printable_char};
use yazi_shim::ratatui::line_count;
static INCR: Ids = Ids::new();
static SYNTECT: OnceLock<(Theme, SyntaxSet)> = OnceLock::new();
pub struct Highlighter {
path: PathBuf,
}
impl Highlighter {
pub fn new<P>(path: P) -> Self
where
P: Into<PathBuf>,
{
Self { path: path.into() }
}
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_prebuilt::ansi_theme())));
let syntaxes = dumps::from_uncompressed_data(yazi_prebuilt::syntaxes());
(theme.unwrap(), syntaxes.unwrap())
};
let (theme, syntaxes) = SYNTECT.get_or_init(f);
(theme, syntaxes)
}
pub fn abort() { INCR.next(); }
pub async fn highlight(&self, skip: usize, size: Size) -> Result<Text<'static>, PeekError> {
let indent = YAZI.preview.indent();
let mut reader = BufReader::new(Local::regular(&self.path).open().await?);
let syntax = Self::find_syntax(&self.path, &mut reader).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());
}
let remaining = Self::normalize_control_chars(&mut buf);
if !plain && (remaining || buf.len() > 5000) {
plain = true;
before.clear();
}
i += if i >= skip {
after.push(String::from_utf8_lossy(&buf).into_owned());
line_count(&**after.last().unwrap(), size.width, &indent, YAZI.preview.wrap)
} else if !plain {
before.push(String::from_utf8_lossy(&buf).into_owned());
line_count(&**before.last().unwrap(), size.width, &indent, YAZI.preview.wrap)
} else if YAZI.preview.wrap != PreviewWrap::No {
line_count(String::from_utf8_lossy(&buf), size.width, &indent, YAZI.preview.wrap)
} 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(Self::merge_highlight_lines(&after, YAZI.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 = YAZI.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,
reader: &mut BufReader<tokio::fs::File>,
) -> 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();
reader.read_line(&mut line).await?;
reader.rewind().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 normalize_control_chars(buf: &mut Vec<u8>) -> bool {
if buf.ends_with(b"\r\n") {
buf.pop();
buf.pop();
buf.push(b'\n');
}
let mut remaining = false;
for b in buf.iter_mut() {
if *b == b'\r' {
*b = b'\n';
} else {
remaining |= matches!(b, 0..=0x08 | 0x0B..=0x1F | 0x7F);
}
}
remaining
}
fn merge_highlight_lines(s: &[String], tab_size: u8) -> String {
let mut buf = Vec::new();
buf.reserve_exact(s.iter().map(|s| s.len()).sum::<usize>() | 15);
for &b in s.iter().flat_map(|s| s.as_bytes()) {
push_printable_char(&mut buf, b, true, tab_size, false);
}
unsafe { String::from_utf8_unchecked(buf) }
}
}
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))
}
}
}