diff options
Diffstat (limited to 'crates/fparkan-vfs')
| -rw-r--r-- | crates/fparkan-vfs/src/lib.rs | 123 |
1 files changed, 104 insertions, 19 deletions
diff --git a/crates/fparkan-vfs/src/lib.rs b/crates/fparkan-vfs/src/lib.rs index a0cafa1..9ca57da 100644 --- a/crates/fparkan-vfs/src/lib.rs +++ b/crates/fparkan-vfs/src/lib.rs @@ -8,6 +8,10 @@ use std::fs; use std::path::{Path, PathBuf}; use std::sync::{Arc, Mutex}; use std::time::SystemTime; +#[cfg(unix)] +use std::os::unix::fs::MetadataExt; +#[cfg(windows)] +use std::os::windows::fs::MetadataExt; /// VFS metadata. #[derive(Clone, Debug, Eq, PartialEq)] @@ -110,6 +114,7 @@ impl DirectoryVfs { struct CachedHostFingerprint { len: u64, modified: Option<SystemTime>, + identity: Option<u64>, fingerprint: Sha256Digest, } @@ -120,14 +125,23 @@ impl Vfs for DirectoryVfs { fn read(&self, path: &NormalizedPath) -> Result<Arc<[u8]>, VfsError> { let host = self.host_path(path)?; - if fs::symlink_metadata(&host) - .map_err(VfsError::Io)? - .file_type() - .is_symlink() + let pre_metadata = fs::symlink_metadata(&host).map_err(VfsError::Io)?; + if pre_metadata.file_type().is_symlink() || !pre_metadata.is_file() { + return Err(VfsError::Path); + } + let pre_identity = file_identity(&pre_metadata); + let pre_len = pre_metadata.len(); + let pre_modified = pre_metadata.modified().ok(); + let bytes = fs::read(&host).map_err(VfsError::Io)?; + let post_metadata = fs::symlink_metadata(&host).map_err(VfsError::Io)?; + if post_metadata.file_type().is_symlink() + || !post_metadata.is_file() + || post_metadata.len() != pre_len + || post_metadata.modified().ok() != pre_modified + || file_identity(&post_metadata) != pre_identity { return Err(VfsError::Path); } - let bytes = fs::read(host).map_err(VfsError::Io)?; Ok(Arc::from(bytes.into_boxed_slice())) } @@ -248,7 +262,11 @@ fn metadata_from_host_file_with_cache( .map_err(|_| VfsError::Path)? .get(path) .cloned() - .filter(|cached| cached.len == len && cached.modified == modified) + .filter(|cached| { + cached.len == len + && cached.modified == modified + && cached.identity == file_identity(metadata) + }) { return Ok(VfsMetadata { len, @@ -266,6 +284,7 @@ fn metadata_from_host_file_with_cache( CachedHostFingerprint { len, modified, + identity: file_identity(metadata), fingerprint, }, ); @@ -275,15 +294,15 @@ fn metadata_from_host_file_with_cache( /// In-memory VFS. #[derive(Clone, Debug, Default)] pub struct MemoryVfs { - files: BTreeMap<String, Arc<[u8]>>, - lookup: BTreeMap<Vec<u8>, Vec<String>>, + files: BTreeMap<Vec<u8>, Arc<[u8]>>, + lookup: BTreeMap<Vec<u8>, Vec<Vec<u8>>>, } impl MemoryVfs { /// Inserts a file. #[allow(clippy::needless_pass_by_value)] pub fn insert(&mut self, path: NormalizedPath, bytes: Arc<[u8]>) { - let path = path.as_str().to_string(); + let path = path.as_bytes().to_vec(); self.files.insert(path, bytes); self.rebuild_lookup(); } @@ -292,7 +311,7 @@ impl MemoryVfs { self.lookup.clear(); for path in self.files.keys() { self.lookup - .entry(ascii_lookup_key(path.as_bytes()).0) + .entry(ascii_lookup_key(path).0) .or_default() .push(path.clone()); } @@ -301,20 +320,39 @@ impl MemoryVfs { } } - fn resolve_path(&self, path: &NormalizedPath) -> Result<&str, VfsError> { - let key = ascii_lookup_key(path.as_str().as_bytes()).0; + fn resolve_path(&self, path: &NormalizedPath) -> Result<&[u8], VfsError> { + let key = ascii_lookup_key(path.as_bytes()).0; let matches = self .lookup .get(&key) .ok_or_else(|| VfsError::NotFound(path.as_str().to_string()))?; match matches.as_slice() { - [single] => Ok(single.as_str()), + [single] => Ok(single.as_slice()), [] => Err(VfsError::NotFound(path.as_str().to_string())), _ => Err(VfsError::Ambiguous(path.as_str().to_string())), } } } +#[cfg(unix)] +fn file_identity(metadata: &fs::Metadata) -> Option<u64> { + Some((metadata.dev() as u64).rotate_left(32) ^ metadata.ino()) +} + +#[cfg(windows)] +fn file_identity(metadata: &fs::Metadata) -> Option<u64> { + Some( + (metadata.volume_serial_number() as u64).rotate_left(40) + ^ ((metadata.file_index_high() as u64) << 32) + ^ metadata.file_index_low() as u64, + ) +} + +#[cfg(not(any(unix, windows)))] +fn file_identity(_metadata: &fs::Metadata) -> Option<u64> { + None +} + impl Vfs for MemoryVfs { fn metadata(&self, path: &NormalizedPath) -> Result<VfsMetadata, VfsError> { let resolved = self.resolve_path(path)?; @@ -339,13 +377,9 @@ impl Vfs for MemoryVfs { fn list(&self, prefix: &NormalizedPath) -> Result<Vec<VfsEntry>, VfsError> { let mut out = Vec::new(); for (path, bytes) in &self.files { - if path - .as_bytes() - .get(..prefix.as_str().len()) - .is_some_and(|head| head.eq_ignore_ascii_case(prefix.as_str().as_bytes())) - { + if has_segment_boundary_prefix_bytes(path, prefix.as_bytes()) { let normalized = fparkan_path::normalize_relative( - path.as_bytes(), + path, fparkan_path::PathPolicy::StrictLegacy, ) .map_err(|_| VfsError::Path)?; @@ -362,6 +396,25 @@ impl Vfs for MemoryVfs { } } +fn has_segment_boundary_prefix_bytes(haystack: &[u8], needle: &[u8]) -> bool { + if haystack.len() < needle.len() { + return false; + } + if haystack.len() == needle.len() { + return haystack + .iter() + .zip(needle.iter()) + .all(|(left, right)| left.eq_ignore_ascii_case(right)); + } + if haystack[needle.len()] != b'/' { + return false; + } + haystack[..needle.len()] + .iter() + .zip(needle.iter()) + .all(|(left, right)| left.eq_ignore_ascii_case(right)) +} + /// Layered VFS with deterministic first-layer precedence. #[derive(Clone, Default)] pub struct OverlayVfs { @@ -508,6 +561,21 @@ mod tests { } #[test] + fn memory_vfs_list_prefix_is_boundary_safe() { + let mut vfs = MemoryVfs::default(); + let exact = normalize_relative(b"DATA/Land.map", PathPolicy::StrictLegacy).expect("path"); + let sibling = normalize_relative(b"DATA2/Land.map", PathPolicy::StrictLegacy).expect("path"); + vfs.insert(exact.clone(), Arc::from(b"exact".as_slice())); + vfs.insert(sibling, Arc::from(b"sibling".as_slice())); + + let prefix = normalize_relative(b"DATA", PathPolicy::StrictLegacy).expect("prefix"); + let entries = vfs.list(&prefix).expect("list"); + + assert_eq!(entries.len(), 1); + assert_eq!(entries[0].path.as_str(), exact.as_str()); + } + + #[test] fn directory_vfs_fingerprint_changes_for_same_length_content() { let root = unique_test_dir("content-fingerprint"); std::fs::create_dir_all(root.join("DATA")).expect("mkdir"); @@ -590,6 +658,23 @@ mod tests { } #[test] + fn memory_vfs_distinguishes_non_utf8_path_bytes() { + let mut vfs = MemoryVfs::default(); + let ascii = normalize_relative(b"DATA/normal.bin", PathPolicy::HostCompatible) + .expect("ascii path"); + let binary = normalize_relative(b"DATA/\xFF.bin", PathPolicy::HostCompatible) + .expect("binary path"); + vfs.insert(ascii.clone(), Arc::from(b"ascii".as_slice())); + vfs.insert(binary.clone(), Arc::from(b"binary".as_slice())); + + let binary_query = normalize_relative(b"DATA/\xFF.bin", PathPolicy::HostCompatible) + .expect("binary query"); + + assert_eq!(vfs.read(&binary_query).expect("read binary").as_ref(), b"binary"); + assert_eq!(vfs.read(&ascii).expect("read ascii").as_ref(), b"ascii"); + } + + #[test] fn overlay_vfs_uses_first_matching_layer() { let path = normalize_relative(b"DATA/File.bin", PathPolicy::StrictLegacy).expect("path"); let prefix = normalize_relative(b"DATA", PathPolicy::StrictLegacy).expect("prefix"); |