rhg: add limited support for the `config` sub-command
Only with one argument and no flag. This is mostly for testing.
Differential Revision: https://phab.mercurial-scm.org/D9972
// layer.rs
//
// Copyright 2020
// Valentin Gatien-Baron,
// Raphaël Gomès <rgomes@octobus.net>
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.
use crate::errors::{HgError, IoResultExt};
use crate::utils::files::{get_bytes_from_path, get_path_from_bytes};
use format_bytes::{write_bytes, DisplayBytes};
use lazy_static::lazy_static;
use regex::bytes::Regex;
use std::collections::HashMap;
use std::path::{Path, PathBuf};
lazy_static! {
static ref SECTION_RE: Regex = make_regex(r"^\[([^\[]+)\]");
static ref ITEM_RE: Regex = make_regex(r"^([^=\s][^=]*?)\s*=\s*((.*\S)?)");
/// Continuation whitespace
static ref CONT_RE: Regex = make_regex(r"^\s+(\S|\S.*\S)\s*$");
static ref EMPTY_RE: Regex = make_regex(r"^(;|#|\s*$)");
static ref COMMENT_RE: Regex = make_regex(r"^(;|#)");
/// A directive that allows for removing previous entries
static ref UNSET_RE: Regex = make_regex(r"^%unset\s+(\S+)");
/// A directive that allows for including other config files
static ref INCLUDE_RE: Regex = make_regex(r"^%include\s+(\S|\S.*\S)\s*$");
}
/// All config values separated by layers of precedence.
/// Each config source may be split in multiple layers if `%include` directives
/// are used.
/// TODO detail the general precedence
#[derive(Clone)]
pub struct ConfigLayer {
/// Mapping of the sections to their items
sections: HashMap<Vec<u8>, ConfigItem>,
/// All sections (and their items/values) in a layer share the same origin
pub origin: ConfigOrigin,
/// Whether this layer comes from a trusted user or group
pub trusted: bool,
}
impl ConfigLayer {
pub fn new(origin: ConfigOrigin) -> Self {
ConfigLayer {
sections: HashMap::new(),
trusted: true, // TODO check
origin,
}
}
/// Parse `--config` CLI arguments and return a layer if there’s any
pub(crate) fn parse_cli_args(
cli_config_args: impl IntoIterator<Item = impl AsRef<[u8]>>,
) -> Result<Option<Self>, ConfigError> {
fn parse_one(arg: &[u8]) -> Option<(Vec<u8>, Vec<u8>, Vec<u8>)> {
use crate::utils::SliceExt;
let (section_and_item, value) = arg.split_2(b'=')?;
let (section, item) = section_and_item.trim().split_2(b'.')?;
Some((
section.to_owned(),
item.to_owned(),
value.trim().to_owned(),
))
}
let mut layer = Self::new(ConfigOrigin::CommandLine);
for arg in cli_config_args {
let arg = arg.as_ref();
if let Some((section, item, value)) = parse_one(arg) {
layer.add(section, item, value, None);
} else {
Err(HgError::abort(format!(
"malformed --config option: \"{}\" \
(use --config section.name=value)",
String::from_utf8_lossy(arg),
)))?
}
}
if layer.sections.is_empty() {
Ok(None)
} else {
Ok(Some(layer))
}
}
/// Returns whether this layer comes from `--config` CLI arguments
pub(crate) fn is_from_command_line(&self) -> bool {
if let ConfigOrigin::CommandLine = self.origin {
true
} else {
false
}
}
/// Add an entry to the config, overwriting the old one if already present.
pub fn add(
&mut self,
section: Vec<u8>,
item: Vec<u8>,
value: Vec<u8>,
line: Option<usize>,
) {
self.sections
.entry(section)
.or_insert_with(|| HashMap::new())
.insert(item, ConfigValue { bytes: value, line });
}
/// Returns the config value in `<section>.<item>` if it exists
pub fn get(&self, section: &[u8], item: &[u8]) -> Option<&ConfigValue> {
Some(self.sections.get(section)?.get(item)?)
}
pub fn is_empty(&self) -> bool {
self.sections.is_empty()
}
/// Returns a `Vec` of layers in order of precedence (so, in read order),
/// recursively parsing the `%include` directives if any.
pub fn parse(src: &Path, data: &[u8]) -> Result<Vec<Self>, ConfigError> {
let mut layers = vec![];
// Discard byte order mark if any
let data = if data.starts_with(b"\xef\xbb\xbf") {
&data[3..]
} else {
data
};
// TODO check if it's trusted
let mut current_layer = Self::new(ConfigOrigin::File(src.to_owned()));
let mut lines_iter =
data.split(|b| *b == b'\n').enumerate().peekable();
let mut section = b"".to_vec();
while let Some((index, bytes)) = lines_iter.next() {
if let Some(m) = INCLUDE_RE.captures(&bytes) {
let filename_bytes = &m[1];
// `Path::parent` only fails for the root directory,
// which `src` can’t be since we’ve managed to open it as a
// file.
let dir = src
.parent()
.expect("Path::parent fail on a file we’ve read");
// `Path::join` with an absolute argument correctly ignores the
// base path
let filename = dir.join(&get_path_from_bytes(&filename_bytes));
let data = std::fs::read(&filename).for_file(&filename)?;
layers.push(current_layer);
layers.extend(Self::parse(&filename, &data)?);
current_layer = Self::new(ConfigOrigin::File(src.to_owned()));
} else if let Some(_) = EMPTY_RE.captures(&bytes) {
} else if let Some(m) = SECTION_RE.captures(&bytes) {
section = m[1].to_vec();
} else if let Some(m) = ITEM_RE.captures(&bytes) {
let item = m[1].to_vec();
let mut value = m[2].to_vec();
loop {
match lines_iter.peek() {
None => break,
Some((_, v)) => {
if let Some(_) = COMMENT_RE.captures(&v) {
} else if let Some(_) = CONT_RE.captures(&v) {
value.extend(b"\n");
value.extend(&m[1]);
} else {
break;
}
}
};
lines_iter.next();
}
current_layer.add(
section.clone(),
item,
value,
Some(index + 1),
);
} else if let Some(m) = UNSET_RE.captures(&bytes) {
if let Some(map) = current_layer.sections.get_mut(§ion) {
map.remove(&m[1]);
}
} else {
return Err(ConfigParseError {
origin: ConfigOrigin::File(src.to_owned()),
line: Some(index + 1),
bytes: bytes.to_owned(),
}
.into());
}
}
if !current_layer.is_empty() {
layers.push(current_layer);
}
Ok(layers)
}
}
impl DisplayBytes for ConfigLayer {
fn display_bytes(
&self,
out: &mut dyn std::io::Write,
) -> std::io::Result<()> {
let mut sections: Vec<_> = self.sections.iter().collect();
sections.sort_by(|e0, e1| e0.0.cmp(e1.0));
for (section, items) in sections.into_iter() {
let mut items: Vec<_> = items.into_iter().collect();
items.sort_by(|e0, e1| e0.0.cmp(e1.0));
for (item, config_entry) in items {
write_bytes!(
out,
b"{}.{}={} # {}\n",
section,
item,
&config_entry.bytes,
&self.origin,
)?
}
}
Ok(())
}
}
/// Mapping of section item to value.
/// In the following:
/// ```text
/// [ui]
/// paginate=no
/// ```
/// "paginate" is the section item and "no" the value.
pub type ConfigItem = HashMap<Vec<u8>, ConfigValue>;
#[derive(Clone, Debug, PartialEq)]
pub struct ConfigValue {
/// The raw bytes of the value (be it from the CLI, env or from a file)
pub bytes: Vec<u8>,
/// Only present if the value comes from a file, 1-indexed.
pub line: Option<usize>,
}
#[derive(Clone, Debug)]
pub enum ConfigOrigin {
/// From a configuration file
File(PathBuf),
/// From a `--config` CLI argument
CommandLine,
/// From environment variables like `$PAGER` or `$EDITOR`
Environment(Vec<u8>),
/* TODO cli
* TODO defaults (configitems.py)
* TODO extensions
* TODO Python resources?
* Others? */
}
impl DisplayBytes for ConfigOrigin {
fn display_bytes(
&self,
out: &mut dyn std::io::Write,
) -> std::io::Result<()> {
match self {
ConfigOrigin::File(p) => out.write_all(&get_bytes_from_path(p)),
ConfigOrigin::CommandLine => out.write_all(b"--config"),
ConfigOrigin::Environment(e) => write_bytes!(out, b"${}", e),
}
}
}
#[derive(Debug)]
pub struct ConfigParseError {
pub origin: ConfigOrigin,
pub line: Option<usize>,
pub bytes: Vec<u8>,
}
#[derive(Debug, derive_more::From)]
pub enum ConfigError {
Parse(ConfigParseError),
Other(HgError),
}
fn make_regex(pattern: &'static str) -> Regex {
Regex::new(pattern).expect("expected a valid regex")
}