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revlog: update data file record before index rename...
revlog: update data file record before index rename When migrating from inline to non-inline data storage, the data file is recorded initially as zero sized so that it is removed on failure. But the record has to be updated before the index is renamed, otherwise data is lost on rollback. Differential Revision: https://phab.mercurial-scm.org/D10725

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layer.rs
319 lines | 10.8 KiB | application/rls-services+xml | RustLexer
// 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;
use crate::utils::files::{get_bytes_from_path, get_path_from_bytes};
use format_bytes::{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!(
"abort: 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)?)
}
/// Returns the keys defined in the given section
pub fn iter_keys(&self, section: &[u8]) -> impl Iterator<Item = &[u8]> {
self.sections
.get(section)
.into_iter()
.flat_map(|section| section.keys().map(|vec| &**vec))
}
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() {
let line = Some(index + 1);
if let Some(m) = INCLUDE_RE.captures(&bytes) {
let filename_bytes = &m[1];
let filename_bytes = crate::utils::expand_vars(filename_bytes);
// `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));
match std::fs::read(&filename) {
Ok(data) => {
layers.push(current_layer);
layers.extend(Self::parse(&filename, &data)?);
current_layer =
Self::new(ConfigOrigin::File(src.to_owned()));
}
Err(error) => {
if error.kind() != std::io::ErrorKind::NotFound {
return Err(ConfigParseError {
origin: ConfigOrigin::File(src.to_owned()),
line,
message: format_bytes!(
b"cannot include {} ({})",
filename_bytes,
format_bytes::Utf8(error)
),
}
.into());
}
}
}
} 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, line);
} else if let Some(m) = UNSET_RE.captures(&bytes) {
if let Some(map) = current_layer.sections.get_mut(&section) {
map.remove(&m[1]);
}
} else {
let message = if bytes.starts_with(b" ") {
format_bytes!(b"unexpected leading whitespace: {}", bytes)
} else {
bytes.to_owned()
};
return Err(ConfigParseError {
origin: ConfigOrigin::File(src.to_owned()),
line,
message,
}
.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 message: 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")
}