Mercurial > hg
view rust/rhg/src/ui.rs @ 49513:467d9df98c68
rhg: centralize PlainInfo
author | Arseniy Alekseyev <aalekseyev@janestreet.com> |
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date | Thu, 22 Sep 2022 17:16:54 -0400 |
parents | 6939d5ed20e0 |
children | 364e78389653 |
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use crate::color::ColorConfig; use crate::color::Effect; use format_bytes::format_bytes; use format_bytes::write_bytes; use hg::config::Config; use hg::config::PlainInfo; use hg::errors::HgError; use std::borrow::Cow; use std::io; use std::io::{ErrorKind, Write}; pub struct Ui { stdout: std::io::Stdout, stderr: std::io::Stderr, colors: Option<ColorConfig>, } /// The kind of user interface error pub enum UiError { /// The standard output stream cannot be written to StdoutError(io::Error), /// The standard error stream cannot be written to StderrError(io::Error), } /// The commandline user interface impl Ui { pub fn new(config: &Config) -> Result<Self, HgError> { Ok(Ui { // If using something else, also adapt `isatty()` below. stdout: std::io::stdout(), stderr: std::io::stderr(), colors: ColorConfig::new(config)?, }) } /// Default to no color if color configuration errors. /// /// Useful when we’re already handling another error. pub fn new_infallible(config: &Config) -> Self { Ui { // If using something else, also adapt `isatty()` below. stdout: std::io::stdout(), stderr: std::io::stderr(), colors: ColorConfig::new(config).unwrap_or(None), } } /// Returns a buffered handle on stdout for faster batch printing /// operations. pub fn stdout_buffer(&self) -> StdoutBuffer<std::io::StdoutLock> { StdoutBuffer::new(self.stdout.lock()) } /// Write bytes to stdout pub fn write_stdout(&self, bytes: &[u8]) -> Result<(), UiError> { let mut stdout = self.stdout.lock(); stdout.write_all(bytes).or_else(handle_stdout_error)?; stdout.flush().or_else(handle_stdout_error) } /// Write bytes to stderr pub fn write_stderr(&self, bytes: &[u8]) -> Result<(), UiError> { let mut stderr = self.stderr.lock(); stderr.write_all(bytes).or_else(handle_stderr_error)?; stderr.flush().or_else(handle_stderr_error) } /// Write bytes to stdout with the given label /// /// Like the optional `label` parameter in `mercurial/ui.py`, /// this label influences the color used for this output. pub fn write_stdout_labelled( &self, bytes: &[u8], label: &str, ) -> Result<(), UiError> { if let Some(colors) = &self.colors { if let Some(effects) = colors.styles.get(label.as_bytes()) { if !effects.is_empty() { return self .write_stdout_with_effects(bytes, effects) .or_else(handle_stdout_error); } } } self.write_stdout(bytes) } fn write_stdout_with_effects( &self, bytes: &[u8], effects: &[Effect], ) -> io::Result<()> { let stdout = &mut self.stdout.lock(); let mut write_line = |line: &[u8], first: bool| { // `line` does not include the newline delimiter if !first { stdout.write_all(b"\n")?; } if line.is_empty() { return Ok(()); } /// 0x1B == 27 == 0o33 const ASCII_ESCAPE: &[u8] = b"\x1b"; write_bytes!(stdout, b"{}[0", ASCII_ESCAPE)?; for effect in effects { write_bytes!(stdout, b";{}", effect)?; } write_bytes!(stdout, b"m")?; stdout.write_all(line)?; write_bytes!(stdout, b"{}[0m", ASCII_ESCAPE) }; let mut lines = bytes.split(|&byte| byte == b'\n'); if let Some(first) = lines.next() { write_line(first, true)?; for line in lines { write_line(line, false)? } } stdout.flush() } } // TODO: pass the PlainInfo to call sites directly and // delete this function pub fn plain(opt_feature: Option<&str>) -> bool { let plain_info = PlainInfo::from_env(); match opt_feature { None => plain_info.is_plain(), Some(feature) => plain_info.is_feature_plain(feature), } } /// A buffered stdout writer for faster batch printing operations. pub struct StdoutBuffer<W: Write> { buf: io::BufWriter<W>, } impl<W: Write> StdoutBuffer<W> { pub fn new(writer: W) -> Self { let buf = io::BufWriter::new(writer); Self { buf } } /// Write bytes to stdout buffer pub fn write_all(&mut self, bytes: &[u8]) -> Result<(), UiError> { self.buf.write_all(bytes).or_else(handle_stdout_error) } /// Flush bytes to stdout pub fn flush(&mut self) -> Result<(), UiError> { self.buf.flush().or_else(handle_stdout_error) } } /// Sometimes writing to stdout is not possible, try writing to stderr to /// signal that failure, otherwise just bail. fn handle_stdout_error(error: io::Error) -> Result<(), UiError> { if let ErrorKind::BrokenPipe = error.kind() { // This makes `| head` work for example return Ok(()); } let mut stderr = io::stderr(); stderr .write_all(&format_bytes!( b"abort: {}\n", error.to_string().as_bytes() )) .map_err(UiError::StderrError)?; stderr.flush().map_err(UiError::StderrError)?; Err(UiError::StdoutError(error)) } /// Sometimes writing to stderr is not possible. fn handle_stderr_error(error: io::Error) -> Result<(), UiError> { // A broken pipe should not result in a error // like with `| head` for example if let ErrorKind::BrokenPipe = error.kind() { return Ok(()); } Err(UiError::StdoutError(error)) } /// Encode rust strings according to the user system. pub fn utf8_to_local(s: &str) -> Cow<[u8]> { // TODO encode for the user's system // let bytes = s.as_bytes(); Cow::Borrowed(bytes) } /// Decode user system bytes to Rust string. pub fn local_to_utf8(s: &[u8]) -> Cow<str> { // TODO decode from the user's system String::from_utf8_lossy(s) } /// Should formatted output be used? /// /// Note: rhg does not have the formatter mechanism yet, /// but this is also used when deciding whether to use color. pub fn formatted(config: &Config) -> Result<bool, HgError> { if let Some(formatted) = config.get_option(b"ui", b"formatted")? { Ok(formatted) } else { isatty(config) } } fn isatty(config: &Config) -> Result<bool, HgError> { Ok(if config.get_bool(b"ui", b"nontty")? { false } else { atty::is(atty::Stream::Stdout) }) }