##// END OF EJS Templates
exchange: ensure all outgoing subrepo references are present before pushing...
exchange: ensure all outgoing subrepo references are present before pushing We've run into occasional problems with people committing a repo, and then amending or rebasing in the subrepo. That makes it so that the revision in the parent can't be checked out, and the problem gets propagated on push. Mercurial already tries to defend against this sort of dangling reference by pushing *all* subrepo revisions first. This reuses the checks that trigger warnings in `hg verify` to bail on the push unless using `--force`. I thought about putting this on the server side, but at that point, all of the data has been transferred, only to bail out. Additionally, SCM Manager hosts subrepos in a location that isn't nested in the parent, so normal subrepo code would complain that the subrepo is missing when run on the server. Because the push command pushes subrepos before calling this exchange code, a subrepo will be pushed before the parent is verified. Not great, but no dangling references are exchanged, so it solves the problem. This code isn't in the loop that pushes the subrepos because: 1) the list of outgoing revisions is needed to limit the scope of the check 2) the loop only accesses the current revision, and therefore can miss subrepos that were dropped in previous commits 3) this code is called when pushing a subrepo, so the protection is recursive I'm not sure if there's a cheap check for the list of files in the outgoing bundle. If there is, that would provide a fast path to bypass this check for people not using subrepos (or if no subrepo changes were made). There's probably also room for verifying other references like tags. But since that doesn't break checkouts, it's much less of a problem. Differential Revision: https://phab.mercurial-scm.org/D7616

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hg_path.rs
476 lines | 14.6 KiB | application/rls-services+xml | RustLexer
// hg_path.rs
//
// Copyright 2019 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 std::borrow::Borrow;
use std::ffi::{OsStr, OsString};
use std::fmt;
use std::ops::Deref;
use std::path::{Path, PathBuf};
#[derive(Debug, Eq, PartialEq)]
pub enum HgPathError {
/// Bytes from the invalid `HgPath`
LeadingSlash(Vec<u8>),
/// Bytes and index of the second slash
ConsecutiveSlashes(Vec<u8>, usize),
/// Bytes and index of the null byte
ContainsNullByte(Vec<u8>, usize),
/// Bytes
DecodeError(Vec<u8>),
}
impl ToString for HgPathError {
fn to_string(&self) -> String {
match self {
HgPathError::LeadingSlash(bytes) => {
format!("Invalid HgPath '{:?}': has a leading slash.", bytes)
}
HgPathError::ConsecutiveSlashes(bytes, pos) => format!(
"Invalid HgPath '{:?}': consecutive slahes at pos {}.",
bytes, pos
),
HgPathError::ContainsNullByte(bytes, pos) => format!(
"Invalid HgPath '{:?}': contains null byte at pos {}.",
bytes, pos
),
HgPathError::DecodeError(bytes) => {
format!("Invalid HgPath '{:?}': could not be decoded.", bytes)
}
}
}
}
impl From<HgPathError> for std::io::Error {
fn from(e: HgPathError) -> Self {
std::io::Error::new(std::io::ErrorKind::InvalidData, e.to_string())
}
}
/// This is a repository-relative path (or canonical path):
/// - no null characters
/// - `/` separates directories
/// - no consecutive slashes
/// - no leading slash,
/// - no `.` nor `..` of special meaning
/// - stored in repository and shared across platforms
///
/// Note: there is no guarantee of any `HgPath` being well-formed at any point
/// in its lifetime for performance reasons and to ease ergonomics. It is
/// however checked using the `check_state` method before any file-system
/// operation.
///
/// This allows us to be encoding-transparent as much as possible, until really
/// needed; `HgPath` can be transformed into a platform-specific path (`OsStr`
/// or `Path`) whenever more complex operations are needed:
/// On Unix, it's just byte-to-byte conversion. On Windows, it has to be
/// decoded from MBCS to WTF-8. If WindowsUTF8Plan is implemented, the source
/// character encoding will be determined on a per-repository basis.
//
// FIXME: (adapted from a comment in the stdlib)
// `HgPath::new()` current implementation relies on `Slice` being
// layout-compatible with `[u8]`.
// When attribute privacy is implemented, `Slice` should be annotated as
// `#[repr(transparent)]`.
// Anyway, `Slice` representation and layout are considered implementation
// detail, are not documented and must not be relied upon.
#[derive(Eq, Ord, PartialEq, PartialOrd, Hash)]
pub struct HgPath {
inner: [u8],
}
impl HgPath {
pub fn new<S: AsRef<[u8]> + ?Sized>(s: &S) -> &Self {
unsafe { &*(s.as_ref() as *const [u8] as *const Self) }
}
pub fn is_empty(&self) -> bool {
self.inner.is_empty()
}
pub fn len(&self) -> usize {
self.inner.len()
}
fn to_hg_path_buf(&self) -> HgPathBuf {
HgPathBuf {
inner: self.inner.to_owned(),
}
}
pub fn bytes(&self) -> std::slice::Iter<u8> {
self.inner.iter()
}
pub fn to_ascii_uppercase(&self) -> HgPathBuf {
HgPathBuf::from(self.inner.to_ascii_uppercase())
}
pub fn to_ascii_lowercase(&self) -> HgPathBuf {
HgPathBuf::from(self.inner.to_ascii_lowercase())
}
pub fn as_bytes(&self) -> &[u8] {
&self.inner
}
pub fn contains(&self, other: u8) -> bool {
self.inner.contains(&other)
}
pub fn starts_with(&self, needle: impl AsRef<HgPath>) -> bool {
self.inner.starts_with(needle.as_ref().as_bytes())
}
pub fn join<T: ?Sized + AsRef<HgPath>>(&self, other: &T) -> HgPathBuf {
let mut inner = self.inner.to_owned();
if inner.len() != 0 && inner.last() != Some(&b'/') {
inner.push(b'/');
}
inner.extend(other.as_ref().bytes());
HgPathBuf::from_bytes(&inner)
}
/// Given a base directory, returns the slice of `self` relative to the
/// base directory. If `base` is not a directory (does not end with a
/// `b'/'`), returns `None`.
pub fn relative_to(&self, base: impl AsRef<HgPath>) -> Option<&HgPath> {
let base = base.as_ref();
if base.is_empty() {
return Some(self);
}
let is_dir = base.as_bytes().ends_with(b"/");
if is_dir && self.starts_with(base) {
Some(HgPath::new(&self.inner[base.len()..]))
} else {
None
}
}
/// Checks for errors in the path, short-circuiting at the first one.
/// This generates fine-grained errors useful for debugging.
/// To simply check if the path is valid during tests, use `is_valid`.
pub fn check_state(&self) -> Result<(), HgPathError> {
if self.len() == 0 {
return Ok(());
}
let bytes = self.as_bytes();
let mut previous_byte = None;
if bytes[0] == b'/' {
return Err(HgPathError::LeadingSlash(bytes.to_vec()));
}
for (index, byte) in bytes.iter().enumerate() {
match byte {
0 => {
return Err(HgPathError::ContainsNullByte(
bytes.to_vec(),
index,
))
}
b'/' => {
if previous_byte.is_some() && previous_byte == Some(b'/') {
return Err(HgPathError::ConsecutiveSlashes(
bytes.to_vec(),
index,
));
}
}
_ => (),
};
previous_byte = Some(*byte);
}
Ok(())
}
#[cfg(test)]
/// Only usable during tests to force developers to handle invalid states
fn is_valid(&self) -> bool {
self.check_state().is_ok()
}
}
impl fmt::Debug for HgPath {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "HgPath({:?})", String::from_utf8_lossy(&self.inner))
}
}
impl fmt::Display for HgPath {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", String::from_utf8_lossy(&self.inner))
}
}
#[derive(Eq, Ord, Clone, PartialEq, PartialOrd, Hash)]
pub struct HgPathBuf {
inner: Vec<u8>,
}
impl HgPathBuf {
pub fn new() -> Self {
Self { inner: Vec::new() }
}
pub fn push(&mut self, byte: u8) {
self.inner.push(byte);
}
pub fn from_bytes(s: &[u8]) -> HgPathBuf {
HgPath::new(s).to_owned()
}
pub fn into_vec(self) -> Vec<u8> {
self.inner
}
pub fn as_ref(&self) -> &[u8] {
self.inner.as_ref()
}
}
impl fmt::Debug for HgPathBuf {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "HgPathBuf({:?})", String::from_utf8_lossy(&self.inner))
}
}
impl fmt::Display for HgPathBuf {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", String::from_utf8_lossy(&self.inner))
}
}
impl Deref for HgPathBuf {
type Target = HgPath;
#[inline]
fn deref(&self) -> &HgPath {
&HgPath::new(&self.inner)
}
}
impl From<Vec<u8>> for HgPathBuf {
fn from(vec: Vec<u8>) -> Self {
Self { inner: vec }
}
}
impl<T: ?Sized + AsRef<HgPath>> From<&T> for HgPathBuf {
fn from(s: &T) -> HgPathBuf {
s.as_ref().to_owned()
}
}
impl Into<Vec<u8>> for HgPathBuf {
fn into(self) -> Vec<u8> {
self.inner
}
}
impl Borrow<HgPath> for HgPathBuf {
fn borrow(&self) -> &HgPath {
&HgPath::new(self.as_bytes())
}
}
impl ToOwned for HgPath {
type Owned = HgPathBuf;
fn to_owned(&self) -> HgPathBuf {
self.to_hg_path_buf()
}
}
impl AsRef<HgPath> for HgPath {
fn as_ref(&self) -> &HgPath {
self
}
}
impl AsRef<HgPath> for HgPathBuf {
fn as_ref(&self) -> &HgPath {
self
}
}
impl Extend<u8> for HgPathBuf {
fn extend<T: IntoIterator<Item = u8>>(&mut self, iter: T) {
self.inner.extend(iter);
}
}
/// TODO: Once https://www.mercurial-scm.org/wiki/WindowsUTF8Plan is
/// implemented, these conversion utils will have to work differently depending
/// on the repository encoding: either `UTF-8` or `MBCS`.
pub fn hg_path_to_os_string<P: AsRef<HgPath>>(
hg_path: P,
) -> Result<OsString, HgPathError> {
hg_path.as_ref().check_state()?;
let os_str;
#[cfg(unix)]
{
use std::os::unix::ffi::OsStrExt;
os_str = std::ffi::OsStr::from_bytes(&hg_path.as_ref().as_bytes());
}
// TODO Handle other platforms
// TODO: convert from WTF8 to Windows MBCS (ANSI encoding).
Ok(os_str.to_os_string())
}
pub fn hg_path_to_path_buf<P: AsRef<HgPath>>(
hg_path: P,
) -> Result<PathBuf, HgPathError> {
Ok(Path::new(&hg_path_to_os_string(hg_path)?).to_path_buf())
}
pub fn os_string_to_hg_path_buf<S: AsRef<OsStr>>(
os_string: S,
) -> Result<HgPathBuf, HgPathError> {
let buf;
#[cfg(unix)]
{
use std::os::unix::ffi::OsStrExt;
buf = HgPathBuf::from_bytes(&os_string.as_ref().as_bytes());
}
// TODO Handle other platforms
// TODO: convert from WTF8 to Windows MBCS (ANSI encoding).
buf.check_state()?;
Ok(buf)
}
pub fn path_to_hg_path_buf<P: AsRef<Path>>(
path: P,
) -> Result<HgPathBuf, HgPathError> {
let buf;
let os_str = path.as_ref().as_os_str();
#[cfg(unix)]
{
use std::os::unix::ffi::OsStrExt;
buf = HgPathBuf::from_bytes(&os_str.as_bytes());
}
// TODO Handle other platforms
// TODO: convert from WTF8 to Windows MBCS (ANSI encoding).
buf.check_state()?;
Ok(buf)
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_path_states() {
assert_eq!(
Err(HgPathError::LeadingSlash(b"/".to_vec())),
HgPath::new(b"/").check_state()
);
assert_eq!(
Err(HgPathError::ConsecutiveSlashes(b"a/b//c".to_vec(), 4)),
HgPath::new(b"a/b//c").check_state()
);
assert_eq!(
Err(HgPathError::ContainsNullByte(b"a/b/\0c".to_vec(), 4)),
HgPath::new(b"a/b/\0c").check_state()
);
// TODO test HgPathError::DecodeError for the Windows implementation.
assert_eq!(true, HgPath::new(b"").is_valid());
assert_eq!(true, HgPath::new(b"a/b/c").is_valid());
// Backslashes in paths are not significant, but allowed
assert_eq!(true, HgPath::new(br"a\b/c").is_valid());
// Dots in paths are not significant, but allowed
assert_eq!(true, HgPath::new(b"a/b/../c/").is_valid());
assert_eq!(true, HgPath::new(b"./a/b/../c/").is_valid());
}
#[test]
fn test_iter() {
let path = HgPath::new(b"a");
let mut iter = path.bytes();
assert_eq!(Some(&b'a'), iter.next());
assert_eq!(None, iter.next_back());
assert_eq!(None, iter.next());
let path = HgPath::new(b"a");
let mut iter = path.bytes();
assert_eq!(Some(&b'a'), iter.next_back());
assert_eq!(None, iter.next_back());
assert_eq!(None, iter.next());
let path = HgPath::new(b"abc");
let mut iter = path.bytes();
assert_eq!(Some(&b'a'), iter.next());
assert_eq!(Some(&b'c'), iter.next_back());
assert_eq!(Some(&b'b'), iter.next_back());
assert_eq!(None, iter.next_back());
assert_eq!(None, iter.next());
let path = HgPath::new(b"abc");
let mut iter = path.bytes();
assert_eq!(Some(&b'a'), iter.next());
assert_eq!(Some(&b'b'), iter.next());
assert_eq!(Some(&b'c'), iter.next());
assert_eq!(None, iter.next_back());
assert_eq!(None, iter.next());
let path = HgPath::new(b"abc");
let iter = path.bytes();
let mut vec = Vec::new();
vec.extend(iter);
assert_eq!(vec![b'a', b'b', b'c'], vec);
let path = HgPath::new(b"abc");
let mut iter = path.bytes();
assert_eq!(Some(2), iter.rposition(|c| *c == b'c'));
let path = HgPath::new(b"abc");
let mut iter = path.bytes();
assert_eq!(None, iter.rposition(|c| *c == b'd'));
}
#[test]
fn test_join() {
let path = HgPathBuf::from_bytes(b"a").join(HgPath::new(b"b"));
assert_eq!(b"a/b", path.as_bytes());
let path = HgPathBuf::from_bytes(b"a/").join(HgPath::new(b"b/c"));
assert_eq!(b"a/b/c", path.as_bytes());
// No leading slash if empty before join
let path = HgPathBuf::new().join(HgPath::new(b"b/c"));
assert_eq!(b"b/c", path.as_bytes());
// The leading slash is an invalid representation of an `HgPath`, but
// it can happen. This creates another invalid representation of
// consecutive bytes.
// TODO What should be done in this case? Should we silently remove
// the extra slash? Should we change the signature to a problematic
// `Result<HgPathBuf, HgPathError>`, or should we just keep it so and
// let the error happen upon filesystem interaction?
let path = HgPathBuf::from_bytes(b"a/").join(HgPath::new(b"/b"));
assert_eq!(b"a//b", path.as_bytes());
let path = HgPathBuf::from_bytes(b"a").join(HgPath::new(b"/b"));
assert_eq!(b"a//b", path.as_bytes());
}
#[test]
fn test_relative_to() {
let path = HgPath::new(b"");
let base = HgPath::new(b"");
assert_eq!(Some(path), path.relative_to(base));
let path = HgPath::new(b"path");
let base = HgPath::new(b"");
assert_eq!(Some(path), path.relative_to(base));
let path = HgPath::new(b"a");
let base = HgPath::new(b"b");
assert_eq!(None, path.relative_to(base));
let path = HgPath::new(b"a/b");
let base = HgPath::new(b"a");
assert_eq!(None, path.relative_to(base));
let path = HgPath::new(b"a/b");
let base = HgPath::new(b"a/");
assert_eq!(Some(HgPath::new(b"b")), path.relative_to(base));
let path = HgPath::new(b"nested/path/to/b");
let base = HgPath::new(b"nested/path/");
assert_eq!(Some(HgPath::new(b"to/b")), path.relative_to(base));
let path = HgPath::new(b"ends/with/dir/");
let base = HgPath::new(b"ends/");
assert_eq!(Some(HgPath::new(b"with/dir/")), path.relative_to(base));
}
}