feat(api): newtype for inode numbers

Author: KSXGitHub

src/hook/record_hardlink.rs

@@ -4,6 +4,7 @@ pub use storage::RecordHardLinkStorage;
 
 use super::{Hook, HookArgument};
 use crate::{
+    inode::InodeNumber,
     reporter::{event::EncounterHardlink, Event, Reporter},
     size,
 };
@@ -52,6 +53,7 @@ where
             links,
         }));
 
-        self.storage.add(stats.ino(), size, path).unwrap(); // TODO: propagate the error
+        let ino = InodeNumber::get(stats);
+        self.storage.add(ino, size, path).unwrap(); // TODO: propagate the error
     }
 }

src/hook/record_hardlink/storage.rs

@@ -1,4 +1,4 @@
-use crate::{hardlink::LinkPathList, size};
+use crate::{hardlink::LinkPathList, inode::InodeNumber, size};
 use dashmap::{iter::Iter as DashIter, mapref::multiple::RefMulti, DashMap};
 use derive_more::{Display, Error};
 use pipe_trait::Pipe;
@@ -8,7 +8,7 @@ use std::{fmt::Debug, path::Path};
 #[derive(Debug, Clone)]
 pub struct RecordHardLinkStorage<Size>(
     /// Map an inode number to its size and detected paths.
-    DashMap<u64, (Size, LinkPathList)>, // TODO: benchmark against Mutex<HashMap<u64, (Size, LinkPathList)>>
+    DashMap<InodeNumber, (Size, LinkPathList)>, // TODO: benchmark against Mutex<HashMap<InodeNumber, (Size, LinkPathList)>>
 );
 
 impl<Size> RecordHardLinkStorage<Size> {
@@ -34,7 +34,7 @@ impl<Size> Default for RecordHardLinkStorage<Size> {
 #[display(bound(Size: Debug))]
 #[display("Size for inode {ino} changed from {recorded:?} to {detected:?}")]
 pub struct SizeConflictError<Size> {
-    pub ino: u64, // TODO: define a newtype of ino.
+    pub ino: InodeNumber,
     pub recorded: Size,
     pub detected: Size,
 }
@@ -52,7 +52,12 @@ where
     Size: size::Size,
 {
     /// Add an entry to the record.
-    pub(crate) fn add(&self, ino: u64, size: Size, path: &Path) -> Result<(), AddError<Size>> {
+    pub(crate) fn add(
+        &self,
+        ino: InodeNumber,
+        size: Size,
+        path: &Path,
+    ) -> Result<(), AddError<Size>> {
         let mut size_assertion = Ok(());
         self.0
             .entry(ino)
@@ -77,13 +82,13 @@ where
 #[derive(derive_more::Debug)]
 #[debug(bound())]
 #[debug("Iter(..)")]
-pub struct Iter<'a, Size>(DashIter<'a, u64, (Size, LinkPathList)>);
+pub struct Iter<'a, Size>(DashIter<'a, InodeNumber, (Size, LinkPathList)>);
 
 /// [Item](Iterator::Item) of [`Iter`].
 #[derive(derive_more::Debug)]
 #[debug(bound())]
 #[debug("IterItem(..)")]
-pub struct IterItem<'a, Size>(RefMulti<'a, u64, (Size, LinkPathList)>);
+pub struct IterItem<'a, Size>(RefMulti<'a, InodeNumber, (Size, LinkPathList)>);
 
 impl<'a, Size> Iterator for Iter<'a, Size> {
     type Item = IterItem<'a, Size>;
@@ -94,7 +99,7 @@ impl<'a, Size> Iterator for Iter<'a, Size> {
 
 impl<'a, Size> IterItem<'a, Size> {
     /// Number of the inode.
-    pub fn ino(&self) -> u64 {
+    pub fn ino(&self) -> InodeNumber {
         *self.0.key()
     }
 

src/inode.rs

@@ -0,0 +1,18 @@
+use derive_more::{Display, From, Into, LowerHex, Octal, UpperHex};
+
+/// The inode number of a file or directory.
+#[derive(
+    Debug, Display, LowerHex, UpperHex, Octal, Clone, Copy, PartialEq, Eq, Hash, From, Into,
+)]
+pub struct InodeNumber(u64);
+
+/// POSIX-exclusive functions.
+#[cfg(unix)]
+impl InodeNumber {
+    /// Get inode number of a [`std::fs::Metadata`].
+    pub fn get(stats: &std::fs::Metadata) -> Self {
+        use pipe_trait::Pipe;
+        use std::os::unix::fs::MetadataExt;
+        stats.ino().pipe(InodeNumber)
+    }
+}

src/lib.rs

@@ -35,6 +35,7 @@ pub mod fs_tree_builder;
 pub mod get_size;
 pub mod hardlink;
 pub mod hook;
+pub mod inode;
 pub mod json_data;
 pub mod os_string_display;
 pub mod reporter;