use super::ArtifactCommitOutcome;
use crate::{
model::artifacts::ArtifactChecksumRecord,
ops::{
artifacts::{checksum_reader, checksum_relative_files},
persistence::PersistenceError,
},
};
use std::{
ffi::OsStr,
fs::{self, File},
io::{self, Seek, SeekFrom},
os::unix::ffi::OsStrExt,
path::{Path, PathBuf},
};
use rustix::{
fd::{AsFd, OwnedFd},
fs::{self as unix_fs, AtFlags, Dir, FileType, Mode, OFlags, RenameFlags},
};
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub(super) enum ArtifactCommitStep {
RegularFileSync,
NestedDirectorySync,
RootDirectorySync,
Publication,
ParentDirectorySync,
PublicationDurable,
}
pub(super) fn commit_with_hook(
temporary: &Path,
canonical: &Path,
expected_checksum: &str,
mut at_step: impl FnMut(ArtifactCommitStep, &Path) -> io::Result<()>,
) -> Result<ArtifactCommitOutcome, PersistenceError> {
let (parent, temporary_name, canonical_name) = sibling_paths(temporary, canonical)?;
let temporary_exists = path_exists_without_following(temporary)?;
let canonical_exists = path_exists_without_following(canonical)?;
let parent_fd = open_parent_directory(parent)?;
match (temporary_exists, canonical_exists) {
(true, false) => {
let checksum = sync_tree(&parent_fd, temporary_name, temporary, &mut at_step)?;
checksum.verify(expected_checksum)?;
at_step(ArtifactCommitStep::Publication, canonical)?;
unix_fs::renameat_with(
&parent_fd,
temporary_name,
&parent_fd,
canonical_name,
RenameFlags::NOREPLACE,
)
.map_err(errno_to_io)?;
at_step(ArtifactCommitStep::ParentDirectorySync, parent)?;
unix_fs::fsync(&parent_fd).map_err(errno_to_io)?;
at_step(ArtifactCommitStep::PublicationDurable, canonical)?;
Ok(ArtifactCommitOutcome::Published)
}
(false, true) => {
let checksum = sync_tree(&parent_fd, canonical_name, canonical, &mut at_step)?;
checksum.verify(expected_checksum)?;
at_step(ArtifactCommitStep::ParentDirectorySync, parent)?;
unix_fs::fsync(&parent_fd).map_err(errno_to_io)?;
at_step(ArtifactCommitStep::PublicationDurable, canonical)?;
Ok(ArtifactCommitOutcome::Recovered)
}
(true, true) => Err(PersistenceError::ArtifactCommitPathConflict {
temporary: temporary.display().to_string(),
canonical: canonical.display().to_string(),
}),
(false, false) => Err(PersistenceError::ArtifactCommitPathMissing {
temporary: temporary.display().to_string(),
canonical: canonical.display().to_string(),
}),
}
}
fn sibling_paths<'a>(
temporary: &'a Path,
canonical: &'a Path,
) -> Result<(&'a Path, &'a OsStr, &'a OsStr), PersistenceError> {
let invalid_paths = || PersistenceError::ArtifactCommitPathMismatch {
temporary: temporary.display().to_string(),
canonical: canonical.display().to_string(),
};
let temporary_parent = temporary.parent().ok_or_else(invalid_paths)?;
let canonical_parent = canonical.parent().ok_or_else(invalid_paths)?;
let temporary_name = temporary.file_name().ok_or_else(invalid_paths)?;
let canonical_name = canonical.file_name().ok_or_else(invalid_paths)?;
if temporary == canonical || temporary_parent != canonical_parent {
return Err(invalid_paths());
}
Ok((temporary_parent, temporary_name, canonical_name))
}
fn path_exists_without_following(path: &Path) -> io::Result<bool> {
match fs::symlink_metadata(path) {
Ok(_) => Ok(true),
Err(error) if error.kind() == io::ErrorKind::NotFound => Ok(false),
Err(error) => Err(error),
}
}
fn open_parent_directory(path: &Path) -> io::Result<OwnedFd> {
unix_fs::open(
path,
OFlags::RDONLY | OFlags::DIRECTORY | OFlags::CLOEXEC,
Mode::empty(),
)
.map_err(errno_to_io)
}
fn sync_tree(
parent_fd: &impl AsFd,
directory_name: &OsStr,
display_root: &Path,
at_step: &mut impl FnMut(ArtifactCommitStep, &Path) -> io::Result<()>,
) -> Result<ArtifactChecksumRecord, PersistenceError> {
let directory_fd = unix_fs::openat(
parent_fd,
directory_name,
OFlags::RDONLY | OFlags::DIRECTORY | OFlags::NOFOLLOW | OFlags::CLOEXEC,
Mode::empty(),
)
.map_err(errno_to_io)?;
let mut checksums = Vec::new();
sync_directory(
&directory_fd,
Path::new(""),
display_root,
&mut checksums,
at_step,
)?;
Ok(checksum_relative_files(checksums))
}
fn sync_directory(
directory_fd: &OwnedFd,
relative_directory: &Path,
display_root: &Path,
checksums: &mut Vec<(PathBuf, ArtifactChecksumRecord)>,
at_step: &mut impl FnMut(ArtifactCommitStep, &Path) -> io::Result<()>,
) -> Result<(), PersistenceError> {
let mut directory = Dir::read_from(directory_fd).map_err(errno_to_io)?;
while let Some(entry) = directory.read() {
let entry = entry.map_err(errno_to_io)?;
let name_bytes = entry.file_name().to_bytes();
if matches!(name_bytes, b"." | b"..") {
continue;
}
let name = OsStr::from_bytes(name_bytes);
if name.to_str().is_none() {
return Err(crate::ops::artifacts::ArtifactError::NonUtf8Path {
path: display_root.join(name),
}
.into());
}
let relative_path = relative_directory.join(name);
let display_path = display_root.join(&relative_path);
let observed = unix_fs::statat(directory_fd, entry.file_name(), AtFlags::SYMLINK_NOFOLLOW)
.map_err(errno_to_io)?;
let observed_type = FileType::from_raw_mode(observed.st_mode);
match observed_type {
FileType::RegularFile => {
let child_fd = open_child(directory_fd, entry.file_name())?;
ensure_opened_type(&child_fd, FileType::RegularFile, &display_path)?;
let mut file = File::from(child_fd);
at_step(ArtifactCommitStep::RegularFileSync, &display_path)?;
file.sync_all()?;
file.seek(SeekFrom::Start(0))?;
checksums.push((relative_path, checksum_reader(&mut file)?));
}
FileType::Directory => {
let child_fd = open_child(directory_fd, entry.file_name())?;
ensure_opened_type(&child_fd, FileType::Directory, &display_path)?;
sync_directory(&child_fd, &relative_path, display_root, checksums, at_step)?;
}
kind => return Err(unsupported_entry(&display_path, kind)),
}
}
let (step, display_path) = if relative_directory.as_os_str().is_empty() {
(
ArtifactCommitStep::RootDirectorySync,
display_root.to_path_buf(),
)
} else {
(
ArtifactCommitStep::NestedDirectorySync,
display_root.join(relative_directory),
)
};
at_step(step, &display_path)?;
unix_fs::fsync(directory_fd).map_err(errno_to_io)?;
Ok(())
}
fn open_child(parent: &impl AsFd, name: &std::ffi::CStr) -> io::Result<OwnedFd> {
unix_fs::openat(
parent,
name,
OFlags::RDONLY | OFlags::NOFOLLOW | OFlags::NONBLOCK | OFlags::CLOEXEC,
Mode::empty(),
)
.map_err(errno_to_io)
}
fn ensure_opened_type(
fd: &impl AsFd,
expected: FileType,
path: &Path,
) -> Result<(), PersistenceError> {
let opened = unix_fs::fstat(fd).map_err(errno_to_io)?;
let actual = FileType::from_raw_mode(opened.st_mode);
if actual == expected {
Ok(())
} else {
Err(unsupported_entry(path, actual))
}
}
fn unsupported_entry(path: &Path, kind: FileType) -> PersistenceError {
PersistenceError::UnsupportedArtifactEntry {
path: path.display().to_string(),
kind: format!("{kind:?}"),
}
}
fn errno_to_io(error: rustix::io::Errno) -> io::Error {
io::Error::from_raw_os_error(error.raw_os_error())
}