| 1 | //! Workspace-confined file operations shared by Fleet artifacts and its ledger. |
| 2 | |
| 3 | use std::fs::File; |
| 4 | use std::io::{self, Write}; |
| 5 | use std::path::{Component, Path}; |
| 6 | |
| 7 | pub(crate) fn path_is_confined(path: &Path) -> bool { |
| 8 | !path.as_os_str().is_empty() |
| 9 | && path.components().all(|component| match component { |
| 10 | Component::Normal(name) => !cfg!(windows) || !name.as_encoded_bytes().contains(&b':'), |
| 11 | _ => false, |
| 12 | }) |
| 13 | } |
| 14 | |
| 15 | fn invalid_path() -> io::Error { |
| 16 | io::Error::new( |
| 17 | io::ErrorKind::InvalidInput, |
| 18 | "Fleet artifact path must stay within the workspace", |
| 19 | ) |
| 20 | } |
| 21 | |
| 22 | #[cfg(unix)] |
| 23 | #[derive(Debug)] |
| 24 | pub(crate) struct WorkspaceFile { |
| 25 | directory: File, |
| 26 | filename: std::ffi::CString, |
| 27 | } |
| 28 | |
| 29 | #[cfg(unix)] |
| 30 | impl WorkspaceFile { |
| 31 | pub(crate) fn open(workspace: &Path, relative: &Path, create: bool) -> io::Result<Self> { |
| 32 | use std::os::fd::{AsRawFd, FromRawFd}; |
| 33 | use std::os::unix::ffi::OsStrExt; |
| 34 | if !path_is_confined(relative) { |
| 35 | return Err(invalid_path()); |
| 36 | } |
| 37 | let workspace = workspace.canonicalize()?; |
| 38 | // Use the established credential/artifact openat pattern, without |
| 39 | // touching credentials or creating a second filesystem store. |
| 40 | // SAFETY: static path and immediate ownership of a successful fd. |
| 41 | let fd = unsafe { |
| 42 | libc::open( |
| 43 | c"/".as_ptr(), |
| 44 | libc::O_RDONLY | libc::O_DIRECTORY | libc::O_NOFOLLOW | libc::O_CLOEXEC, |
| 45 | ) |
| 46 | }; |
| 47 | if fd < 0 { |
| 48 | return Err(io::Error::last_os_error()); |
| 49 | } |
| 50 | // SAFETY: this fd was just created and has no other owner. |
| 51 | let mut directory = unsafe { File::from_raw_fd(fd) }; |
| 52 | let parents = relative.parent().ok_or_else(invalid_path)?; |
| 53 | for (path, may_create) in [(workspace.as_path(), false), (parents, create)] { |
| 54 | for component in path.components() { |
| 55 | let Component::Normal(name) = component else { |
| 56 | if component == Component::RootDir { |
| 57 | continue; |
| 58 | } |
| 59 | return Err(invalid_path()); |
| 60 | }; |
| 61 | let name = std::ffi::CString::new(name.as_bytes())?; |
| 62 | let flags = libc::O_RDONLY | libc::O_DIRECTORY | libc::O_NOFOLLOW | libc::O_CLOEXEC; |
| 63 | // SAFETY: directory pins the parent; name is one component. |
| 64 | let mut fd = unsafe { libc::openat(directory.as_raw_fd(), name.as_ptr(), flags) }; |
| 65 | if fd < 0 |
| 66 | && may_create |
| 67 | && io::Error::last_os_error().kind() == io::ErrorKind::NotFound |
| 68 | { |
| 69 | // SAFETY: directory and relative basename remain valid. |
| 70 | if unsafe { libc::mkdirat(directory.as_raw_fd(), name.as_ptr(), 0o700) } != 0 |
| 71 | && io::Error::last_os_error().kind() != io::ErrorKind::AlreadyExists |
| 72 | { |
| 73 | return Err(io::Error::last_os_error()); |
| 74 | } |
| 75 | // SAFETY: reject a symlink inserted after mkdirat. |
| 76 | fd = unsafe { libc::openat(directory.as_raw_fd(), name.as_ptr(), flags) }; |
| 77 | } |
| 78 | if fd < 0 { |
| 79 | return Err(io::Error::last_os_error()); |
| 80 | } |
| 81 | // SAFETY: fd is freshly owned. |
| 82 | directory = unsafe { File::from_raw_fd(fd) }; |
| 83 | } |
| 84 | } |
| 85 | Ok(Self { |
| 86 | directory, |
| 87 | filename: std::ffi::CString::new( |
| 88 | relative.file_name().ok_or_else(invalid_path)?.as_bytes(), |
| 89 | )?, |
| 90 | }) |
| 91 | } |
| 92 | |
| 93 | pub(crate) fn sibling(&self, name: &str) -> io::Result<Self> { |
| 94 | if !path_is_confined(Path::new(name)) || Path::new(name).components().count() != 1 { |
| 95 | return Err(invalid_path()); |
| 96 | } |
| 97 | Ok(Self { |
| 98 | directory: self.directory.try_clone()?, |
| 99 | filename: std::ffi::CString::new(name)?, |
| 100 | }) |
| 101 | } |
| 102 | |
| 103 | pub(crate) fn open_update(&self, create: bool, append: bool) -> io::Result<File> { |
| 104 | self.open_with_flags( |
| 105 | libc::O_RDWR |
| 106 | | if create { libc::O_CREAT } else { 0 } |
| 107 | | if append { libc::O_APPEND } else { 0 }, |
| 108 | ) |
| 109 | } |
| 110 | |
| 111 | pub(crate) fn open_file(&self) -> io::Result<File> { |
| 112 | self.open_with_flags(libc::O_RDONLY) |
| 113 | } |
| 114 | |
| 115 | fn open_with_flags(&self, flags: libc::c_int) -> io::Result<File> { |
| 116 | use std::os::fd::{AsRawFd, FromRawFd}; |
| 117 | use std::os::unix::fs::MetadataExt; |
| 118 | // SAFETY: a pinned parent and validated basename; never follows links. |
| 119 | let fd = unsafe { |
| 120 | libc::openat( |
| 121 | self.directory.as_raw_fd(), |
| 122 | self.filename.as_ptr(), |
| 123 | flags | libc::O_NOFOLLOW | libc::O_CLOEXEC | libc::O_NONBLOCK, |
| 124 | 0o600, |
| 125 | ) |
| 126 | }; |
| 127 | if fd < 0 { |
| 128 | return Err(io::Error::last_os_error()); |
| 129 | } |
| 130 | // SAFETY: fd is freshly owned. |
| 131 | let file = unsafe { File::from_raw_fd(fd) }; |
| 132 | let metadata = file.metadata()?; |
| 133 | if !metadata.is_file() || metadata.nlink() != 1 { |
| 134 | return Err(io::Error::new( |
| 135 | io::ErrorKind::InvalidData, |
| 136 | "Fleet file must be a regular, non-hard-linked file", |
| 137 | )); |
| 138 | } |
| 139 | Ok(file) |
| 140 | } |
| 141 | |
| 142 | pub(crate) fn publish(&self, bytes: &[u8]) -> io::Result<()> { |
| 143 | self.atomic_write(bytes, false) |
| 144 | } |
| 145 | |
| 146 | pub(crate) fn replace(&self, bytes: &[u8]) -> io::Result<()> { |
| 147 | self.atomic_write(bytes, true) |
| 148 | } |
| 149 | |
| 150 | fn atomic_write(&self, bytes: &[u8], replace: bool) -> io::Result<()> { |
| 151 | use std::os::fd::{AsRawFd, FromRawFd}; |
| 152 | let temporary = |
| 153 | std::ffi::CString::new(format!(".fleet-write-{}.tmp", uuid::Uuid::new_v4())) |
| 154 | .expect("generated basename"); |
| 155 | // SAFETY: parent is pinned; exclusive creation cannot follow a link. |
| 156 | let fd = unsafe { |
| 157 | libc::openat( |
| 158 | self.directory.as_raw_fd(), |
| 159 | temporary.as_ptr(), |
| 160 | libc::O_WRONLY | libc::O_CREAT | libc::O_EXCL | libc::O_NOFOLLOW | libc::O_CLOEXEC, |
| 161 | 0o600, |
| 162 | ) |
| 163 | }; |
| 164 | if fd < 0 { |
| 165 | return Err(io::Error::last_os_error()); |
| 166 | } |
| 167 | // SAFETY: fd is freshly owned. |
| 168 | let mut file = unsafe { File::from_raw_fd(fd) }; |
| 169 | let result = (|| { |
| 170 | file.write_all(bytes)?; |
| 171 | file.sync_all()?; |
| 172 | // SAFETY: both basenames are anchored to the same open parent. |
| 173 | // Replacement changes the directory entry, never a symlink target. |
| 174 | let published = unsafe { |
| 175 | if replace { |
| 176 | libc::renameat( |
| 177 | self.directory.as_raw_fd(), |
| 178 | temporary.as_ptr(), |
| 179 | self.directory.as_raw_fd(), |
| 180 | self.filename.as_ptr(), |
| 181 | ) |
| 182 | } else { |
| 183 | libc::linkat( |
| 184 | self.directory.as_raw_fd(), |
| 185 | temporary.as_ptr(), |
| 186 | self.directory.as_raw_fd(), |
| 187 | self.filename.as_ptr(), |
| 188 | 0, |
| 189 | ) |
| 190 | } |
| 191 | }; |
| 192 | if published != 0 { |
| 193 | return Err(io::Error::last_os_error()); |
| 194 | } |
| 195 | Ok(()) |
| 196 | })(); |
| 197 | // Successful rename already consumed this temporary entry. Never |
| 198 | // unlink the vacant old name, which another writer could now reuse. |
| 199 | if !replace || result.is_err() { |
| 200 | // SAFETY: unlink this call's exclusive temporary basename. |
| 201 | if unsafe { libc::unlinkat(self.directory.as_raw_fd(), temporary.as_ptr(), 0) } != 0 { |
| 202 | return Err(io::Error::last_os_error()); |
| 203 | } |
| 204 | } |
| 205 | result?; |
| 206 | self.directory.sync_all() |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | #[cfg(windows)] |
| 211 | #[derive(Debug)] |
| 212 | pub(crate) struct WorkspaceFile { |
| 213 | // Retaining every ancestor without delete/write sharing prevents a path |
| 214 | // swap or junction replacement while path-based Windows calls are running. |
| 215 | _ancestors: Vec<File>, |
| 216 | directory: std::path::PathBuf, |
| 217 | filename: std::ffi::OsString, |
| 218 | } |
| 219 | |
| 220 | #[cfg(windows)] |
| 221 | impl WorkspaceFile { |
| 222 | pub(crate) fn open(workspace: &Path, relative: &Path, create: bool) -> io::Result<Self> { |
| 223 | use std::os::windows::fs::OpenOptionsExt; |
| 224 | if !path_is_confined(relative) { |
| 225 | return Err(invalid_path()); |
| 226 | } |
| 227 | let workspace = workspace.canonicalize()?; |
| 228 | let mut ancestors = Vec::new(); |
| 229 | let mut directory = std::path::PathBuf::new(); |
| 230 | for (path, may_create) in [ |
| 231 | (workspace.as_path(), false), |
| 232 | (relative.parent().ok_or_else(invalid_path)?, create), |
| 233 | ] { |
| 234 | for component in path.components() { |
| 235 | directory.push(component.as_os_str()); |
| 236 | if matches!(component, Component::Prefix(_)) { |
| 237 | continue; |
| 238 | } |
| 239 | let open = || { |
| 240 | std::fs::OpenOptions::new() |
| 241 | .read(true) |
| 242 | .share_mode(0x0000_0001) |
| 243 | .custom_flags(0x0220_0000) |
| 244 | .open(&directory) |
| 245 | }; // BACKUP_SEMANTICS | OPEN_REPARSE_POINT |
| 246 | let file = match open() { |
| 247 | Err(error) if may_create && error.kind() == io::ErrorKind::NotFound => { |
| 248 | match std::fs::create_dir(&directory) { |
| 249 | Ok(()) => {} |
| 250 | Err(error) if error.kind() == io::ErrorKind::AlreadyExists => {} |
| 251 | Err(error) => return Err(error), |
| 252 | } |
| 253 | open()? |
| 254 | } |
| 255 | result => result?, |
| 256 | }; |
| 257 | let metadata = file.metadata()?; |
| 258 | if !metadata.is_dir() || crate::plugins::metadata_is_link_or_reparse(&metadata) { |
| 259 | return Err(invalid_path()); |
| 260 | } |
| 261 | ancestors.push(file); |
| 262 | } |
| 263 | } |
| 264 | Ok(Self { |
| 265 | _ancestors: ancestors, |
| 266 | directory, |
| 267 | filename: relative.file_name().ok_or_else(invalid_path)?.to_owned(), |
| 268 | }) |
| 269 | } |
| 270 | |
| 271 | pub(crate) fn sibling(&self, name: &str) -> io::Result<Self> { |
| 272 | if !path_is_confined(Path::new(name)) || Path::new(name).components().count() != 1 { |
| 273 | return Err(invalid_path()); |
| 274 | } |
| 275 | Ok(Self { |
| 276 | _ancestors: self |
| 277 | ._ancestors |
| 278 | .iter() |
| 279 | .map(File::try_clone) |
| 280 | .collect::<io::Result<_>>()?, |
| 281 | directory: self.directory.clone(), |
| 282 | filename: name.into(), |
| 283 | }) |
| 284 | } |
| 285 | |
| 286 | pub(crate) fn open_update(&self, create: bool, append: bool) -> io::Result<File> { |
| 287 | use std::os::windows::fs::OpenOptionsExt; |
| 288 | let file = std::fs::OpenOptions::new() |
| 289 | .read(true) |
| 290 | .write(true) |
| 291 | .append(append) |
| 292 | .create(create) |
| 293 | .truncate(false) |
| 294 | .share_mode(0x0000_0007) |
| 295 | .custom_flags(0x0020_0000) |
| 296 | .open(self.directory.join(&self.filename))?; |
| 297 | let metadata = file.metadata()?; |
| 298 | if !metadata.is_file() |
| 299 | || crate::plugins::metadata_is_link_or_reparse(&metadata) |
| 300 | || crate::plugins::windows_file_identity(&file)?.links != 1 |
| 301 | { |
| 302 | return Err(io::Error::new( |
| 303 | io::ErrorKind::InvalidData, |
| 304 | "Fleet file must be regular and not linked", |
| 305 | )); |
| 306 | } |
| 307 | Ok(file) |
| 308 | } |
| 309 | |
| 310 | pub(crate) fn open_file(&self) -> io::Result<File> { |
| 311 | // Existing protected reader rejects reparse points, hard links and |
| 312 | // non-regular files, and denies concurrent writes/replacement. |
| 313 | crate::plugins::manifest::open_bundle_file(&self.directory.join(&self.filename)) |
| 314 | } |
| 315 | |
| 316 | pub(crate) fn publish(&self, bytes: &[u8]) -> io::Result<()> { |
| 317 | self.atomic_write(bytes, false) |
| 318 | } |
| 319 | |
| 320 | pub(crate) fn replace(&self, bytes: &[u8]) -> io::Result<()> { |
| 321 | self.atomic_write(bytes, true) |
| 322 | } |
| 323 | |
| 324 | fn atomic_write(&self, bytes: &[u8], replace: bool) -> io::Result<()> { |
| 325 | use std::mem::{offset_of, size_of}; |
| 326 | use std::os::windows::ffi::OsStrExt; |
| 327 | use std::os::windows::fs::OpenOptionsExt; |
| 328 | use std::os::windows::io::AsRawHandle; |
| 329 | use windows_sys::Wdk::Storage::FileSystem::{ |
| 330 | FILE_RENAME_INFORMATION, FileRenameInformation, NtSetInformationFile, |
| 331 | }; |
| 332 | use windows_sys::Win32::Foundation::RtlNtStatusToDosError; |
| 333 | use windows_sys::Win32::Storage::FileSystem::{ |
| 334 | DELETE, FILE_GENERIC_READ, FILE_GENERIC_WRITE, FILE_SHARE_READ, |
| 335 | }; |
| 336 | use windows_sys::Win32::System::IO::IO_STATUS_BLOCK; |
| 337 | |
| 338 | let mut temporary = |
| 339 | tempfile::Builder::new() |
| 340 | .prefix(".fleet-write-") |
| 341 | .make_in(&self.directory, |path| { |
| 342 | std::fs::OpenOptions::new() |
| 343 | .write(true) |
| 344 | .create_new(true) |
| 345 | .access_mode(FILE_GENERIC_READ | FILE_GENERIC_WRITE | DELETE) |
| 346 | .share_mode(FILE_SHARE_READ) |
| 347 | .open(path) |
| 348 | })?; |
| 349 | let result = (|| { |
| 350 | temporary.write_all(bytes)?; |
| 351 | temporary.as_file().sync_all()?; |
| 352 | |
| 353 | // MoveFileExW (including tempfile::persist) reopens the destination |
| 354 | // directory with FILE_ADD_FILE, conflicting with our ancestor pins. |
| 355 | // A native rename with no root handle and a single basename uses |
| 356 | // the source file's existing parent instead. Keep all ancestor and |
| 357 | // source handles pinned; never relax their write/delete guards. |
| 358 | // https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/ntifs/ns-ntifs-_file_rename_information |
| 359 | let name = self.filename.encode_wide().collect::<Vec<_>>(); |
| 360 | let name_bytes = name.len() * size_of::<u16>(); |
| 361 | let buffer_size = (offset_of!(FILE_RENAME_INFORMATION, FileName) + name_bytes) |
| 362 | .max(size_of::<FILE_RENAME_INFORMATION>()); |
| 363 | let mut buffer = vec![0_usize; buffer_size.div_ceil(size_of::<usize>())]; |
| 364 | let rename = buffer.as_mut_ptr().cast::<FILE_RENAME_INFORMATION>(); |
| 365 | // SAFETY: the zeroed buffer is aligned and covers the struct plus |
| 366 | // the complete UTF-16 basename; no root means the source's parent. |
| 367 | unsafe { |
| 368 | (*rename).Anonymous.ReplaceIfExists = replace; |
| 369 | (*rename).FileNameLength = name_bytes as u32; |
| 370 | std::ptr::copy_nonoverlapping( |
| 371 | name.as_ptr(), |
| 372 | (*rename).FileName.as_mut_ptr(), |
| 373 | name.len(), |
| 374 | ); |
| 375 | } |
| 376 | let mut attempt = 0; |
| 377 | loop { |
| 378 | let mut status = IO_STATUS_BLOCK::default(); |
| 379 | // SAFETY: this synchronously opened file has DELETE access; |
| 380 | // every handle and buffer remains live throughout the call. |
| 381 | let result = unsafe { |
| 382 | NtSetInformationFile( |
| 383 | temporary.as_file().as_raw_handle(), |
| 384 | &mut status, |
| 385 | rename.cast(), |
| 386 | buffer_size as u32, |
| 387 | FileRenameInformation, |
| 388 | ) |
| 389 | }; |
| 390 | if result >= 0 { |
| 391 | return Ok(()); |
| 392 | } |
| 393 | // SAFETY: converts the returned NTSTATUS without dereferencing. |
| 394 | let error = |
| 395 | io::Error::from_raw_os_error(unsafe { RtlNtStatusToDosError(result) as i32 }); |
| 396 | let Some(backoff) = crate::utils::windows_publish_retry_delay(&error, attempt) |
| 397 | else { |
| 398 | return Err(error); |
| 399 | }; |
| 400 | std::thread::sleep(backoff); |
| 401 | attempt += 1; |
| 402 | } |
| 403 | })(); |
| 404 | match result { |
| 405 | Ok(()) => { |
| 406 | // The old name is vacant after the rename; do not unlink an |
| 407 | // entry another process might create there afterwards. |
| 408 | temporary.disable_cleanup(true); |
| 409 | Ok(()) |
| 410 | } |
| 411 | Err(error) => { |
| 412 | // Close the source's delete-denying handle before cleanup. |
| 413 | temporary.into_temp_path().close()?; |
| 414 | Err(error) |
| 415 | } |
| 416 | } |
| 417 | } |
| 418 | } |
| 419 | |
| 420 | #[cfg(all(test, windows))] |
| 421 | mod windows_publication_tests { |
| 422 | use super::*; |
| 423 | use std::os::windows::fs::OpenOptionsExt; |
| 424 | |
| 425 | #[test] |
| 426 | fn publication_and_replacement_keep_ancestor_write_and_delete_guards() { |
| 427 | let workspace = tempfile::tempdir().unwrap(); |
| 428 | let parent = workspace.path().join("private"); |
| 429 | let ledger = |
| 430 | WorkspaceFile::open(workspace.path(), Path::new("private/fleet.jsonl"), true).unwrap(); |
| 431 | let forbidden = std::fs::OpenOptions::new() |
| 432 | .write(true) |
| 433 | .custom_flags(0x0220_0000) |
| 434 | .open(&parent) |
| 435 | .unwrap_err(); |
| 436 | assert_eq!(forbidden.raw_os_error(), Some(32)); |
| 437 | assert!(std::fs::rename(&parent, workspace.path().join("swapped")).is_err()); |
| 438 | |
| 439 | // Both fail with MoveFileExW while the destination parent is pinned. |
| 440 | ledger.publish(b"first").unwrap(); |
| 441 | ledger.replace(b"compacted").unwrap(); |
| 442 | assert_eq!( |
| 443 | std::fs::read(parent.join("fleet.jsonl")).unwrap(), |
| 444 | b"compacted" |
| 445 | ); |
| 446 | assert_eq!(std::fs::read_dir(&parent).unwrap().count(), 1); |
| 447 | } |
| 448 | |
| 449 | #[test] |
| 450 | fn replacement_survives_a_short_lived_reader_without_delete_sharing() { |
| 451 | let workspace = tempfile::tempdir().unwrap(); |
| 452 | let relative = Path::new("fleet.jsonl"); |
| 453 | let ledger = WorkspaceFile::open(workspace.path(), relative, true).unwrap(); |
| 454 | ledger.publish(b"first").unwrap(); |
| 455 | let held = std::fs::OpenOptions::new() |
| 456 | .read(true) |
| 457 | .share_mode(0x1 | 0x2) |
| 458 | .open(workspace.path().join(relative)) |
| 459 | .unwrap(); |
| 460 | let release = std::thread::spawn(move || { |
| 461 | std::thread::sleep(std::time::Duration::from_millis(50)); |
| 462 | drop(held); |
| 463 | }); |
| 464 | ledger.replace(b"compacted").unwrap(); |
| 465 | release.join().unwrap(); |
| 466 | assert_eq!( |
| 467 | std::fs::read(workspace.path().join(relative)).unwrap(), |
| 468 | b"compacted" |
| 469 | ); |
| 470 | } |
| 471 | |
| 472 | #[test] |
| 473 | fn immutable_publication_preserves_existing_bytes_and_removes_its_temporary() { |
| 474 | let workspace = tempfile::tempdir().unwrap(); |
| 475 | let artifact = |
| 476 | WorkspaceFile::open(workspace.path(), Path::new("receipt.json"), true).unwrap(); |
| 477 | artifact.publish(b"receipt").unwrap(); |
| 478 | assert_eq!( |
| 479 | artifact.publish(b"replacement").unwrap_err().kind(), |
| 480 | io::ErrorKind::AlreadyExists |
| 481 | ); |
| 482 | assert_eq!( |
| 483 | std::fs::read(workspace.path().join("receipt.json")).unwrap(), |
| 484 | b"receipt" |
| 485 | ); |
| 486 | assert_eq!(std::fs::read_dir(workspace.path()).unwrap().count(), 1); |
| 487 | } |
| 488 | |
| 489 | #[test] |
| 490 | fn artifact_paths_cannot_name_windows_alternate_data_streams() { |
| 491 | for path in ["receipt.json:private", "dir/receipt:private", ":stream"] { |
| 492 | assert!( |
| 493 | !path_is_confined(Path::new(path)), |
| 494 | "accepted stream path {path}" |
| 495 | ); |
| 496 | } |
| 497 | } |
| 498 | } |
| 499 | |
| 500 | #[cfg(all(not(unix), not(windows)))] |
| 501 | #[derive(Debug)] |
| 502 | pub(crate) struct WorkspaceFile; |
| 503 | #[cfg(all(not(unix), not(windows)))] |
| 504 | impl WorkspaceFile { |
| 505 | pub(crate) fn open(_: &Path, _: &Path, _: bool) -> io::Result<Self> { |
| 506 | Err(io::Error::new( |
| 507 | io::ErrorKind::Unsupported, |
| 508 | "Confined Fleet artifact I/O is unavailable on this platform", |
| 509 | )) |
| 510 | } |
| 511 | pub(crate) fn sibling(&self, _: &str) -> io::Result<Self> { |
| 512 | unreachable!() |
| 513 | } |
| 514 | pub(crate) fn open_update(&self, _: bool, _: bool) -> io::Result<File> { |
| 515 | unreachable!() |
| 516 | } |
| 517 | pub(crate) fn replace(&self, _: &[u8]) -> io::Result<()> { |
| 518 | unreachable!() |
| 519 | } |
| 520 | pub(crate) fn open_file(&self) -> io::Result<File> { |
| 521 | unreachable!() |
| 522 | } |
| 523 | pub(crate) fn publish(&self, _: &[u8]) -> io::Result<()> { |
| 524 | unreachable!() |
| 525 | } |
| 526 | } |
| 527 | |
| 528 | /// Compare already opened lock handles; a replaced lock must never create two |
| 529 | /// independent critical sections for the same live ledger. |
| 530 | pub(crate) fn same_file(left: &File, right: &File) -> io::Result<bool> { |
| 531 | #[cfg(unix)] |
| 532 | { |
| 533 | use std::os::unix::fs::MetadataExt; |
| 534 | let a = left.metadata()?; |
| 535 | let b = right.metadata()?; |
| 536 | Ok(a.dev() == b.dev() && a.ino() == b.ino()) |
| 537 | } |
| 538 | #[cfg(windows)] |
| 539 | { |
| 540 | let a = crate::plugins::windows_file_identity(left)?; |
| 541 | let b = crate::plugins::windows_file_identity(right)?; |
| 542 | Ok(a.volume == b.volume && a.index == b.index) |
| 543 | } |
| 544 | #[cfg(all(not(unix), not(windows)))] |
| 545 | { |
| 546 | let _ = (left, right); |
| 547 | unreachable!() |
| 548 | } |
| 549 | } |
| 550 |