Use custom traits instead of libstd's MetadataExt and PermissionsExt.

Define our own copy of `MetadataExt` and `PermissionsExt` and change the
code to use them instead of `std::os::*::fs::MetadataExt` and
`std::os::*::fs::PermissionsExt'.

In general, we should be moving away from using std's `Ext` traits like
this, as they weren't meant to be used in this way.

Fixes #342.

Author: sunfishcode

cap-fs-ext/src/metadata_ext.rs

@@ -75,17 +75,17 @@ impl MetadataExt for std::fs::Metadata {
 impl MetadataExt for cap_primitives::fs::Metadata {
     #[inline]
     fn dev(&self) -> u64 {
-        std::os::unix::fs::MetadataExt::dev(self)
+        cap_primitives::fs::MetadataExt::dev(self)
     }
 
     #[inline]
     fn ino(&self) -> u64 {
-        std::os::unix::fs::MetadataExt::ino(self)
+        cap_primitives::fs::MetadataExt::ino(self)
     }
 
     #[inline]
     fn nlink(&self) -> u64 {
-        std::os::unix::fs::MetadataExt::nlink(self)
+        cap_primitives::fs::MetadataExt::nlink(self)
     }
 }
 

cap-primitives/src/fs/metadata.rs

@@ -1,4 +1,4 @@
-use crate::fs::{FileType, ImplFileTypeExt, MetadataExt, Permissions};
+use crate::fs::{FileType, ImplFileTypeExt, ImplMetadataExt, Permissions};
 use crate::time::SystemTime;
 use std::{fs, io};
 
@@ -18,7 +18,7 @@ pub struct Metadata {
     pub(crate) modified: Option<SystemTime>,
     pub(crate) accessed: Option<SystemTime>,
     pub(crate) created: Option<SystemTime>,
-    pub(crate) ext: MetadataExt,
+    pub(crate) ext: ImplMetadataExt,
 }
 
 #[allow(clippy::len_without_is_empty)]
@@ -27,7 +27,7 @@ impl Metadata {
     #[inline]
     pub fn from_file(file: &fs::File) -> io::Result<Self> {
         let std = file.metadata()?;
-        let ext = MetadataExt::from(file, &std)?;
+        let ext = ImplMetadataExt::from(file, &std)?;
         let file_type = ImplFileTypeExt::from(file, &std)?;
         Ok(Self::from_parts(std, ext, file_type))
     }
@@ -41,13 +41,13 @@ impl Metadata {
     /// [`std::fs::Metadata::volume_serial_number`]: https://doc.rust-lang.org/std/os/windows/fs/trait.MetadataExt.html#tymethod.volume_serial_number
     #[inline]
     pub fn from_just_metadata(std: fs::Metadata) -> Self {
-        let ext = MetadataExt::from_just_metadata(&std);
+        let ext = ImplMetadataExt::from_just_metadata(&std);
         let file_type = ImplFileTypeExt::from_just_metadata(&std);
         Self::from_parts(std, ext, file_type)
     }
 
     #[inline]
-    fn from_parts(std: fs::Metadata, ext: MetadataExt, file_type: FileType) -> Self {
+    fn from_parts(std: fs::Metadata, ext: ImplMetadataExt, file_type: FileType) -> Self {
         Self {
             file_type,
             len: std.len(),
@@ -198,129 +198,191 @@ impl Metadata {
     }
 }
 
+/// Unix-specific extensions for [`MetadataExt`].
+///
+/// This corresponds to [`std::os::unix::fs::MetadataExt`].
+#[cfg(any(unix, target_os = "vxworks"))]
+pub trait MetadataExt {
+    /// Returns the ID of the device containing the file.
+    fn dev(&self) -> u64;
+    /// Returns the inode number.
+    fn ino(&self) -> u64;
+    /// Returns the rights applied to this file.
+    fn mode(&self) -> u32;
+    /// Returns the number of hard links pointing to this file.
+    fn nlink(&self) -> u64;
+    /// Returns the user ID of the owner of this file.
+    fn uid(&self) -> u32;
+    /// Returns the group ID of the owner of this file.
+    fn gid(&self) -> u32;
+    /// Returns the device ID of this file (if it is a special one).
+    fn rdev(&self) -> u64;
+    /// Returns the total size of this file in bytes.
+    fn size(&self) -> u64;
+    /// Returns the last access time of the file, in seconds since Unix Epoch.
+    fn atime(&self) -> i64;
+    /// Returns the last access time of the file, in nanoseconds since [`atime`].
+    fn atime_nsec(&self) -> i64;
+    /// Returns the last modification time of the file, in seconds since Unix Epoch.
+    fn mtime(&self) -> i64;
+    /// Returns the last modification time of the file, in nanoseconds since [`mtime`].
+    fn mtime_nsec(&self) -> i64;
+    /// Returns the last status change time of the file, in seconds since Unix Epoch.
+    fn ctime(&self) -> i64;
+    /// Returns the last status change time of the file, in nanoseconds since [`ctime`].
+    fn ctime_nsec(&self) -> i64;
+    /// Returns the block size for filesystem I/O.
+    fn blksize(&self) -> u64;
+    /// Returns the number of blocks allocated to the file, in 512-byte units.
+    fn blocks(&self) -> u64;
+    #[cfg(target_os = "vxworks")]
+    fn attrib(&self) -> u8;
+}
+
+/// WASI-specific extensions for [`MetadataExt`].
+///
+/// This corresponds to [`std::os::wasi::fs::MetadataExt`].
+#[cfg(target_os = "wasi")]
+pub trait MetadataExt {
+    /// Returns the ID of the device containing the file.
+    fn dev(&self) -> u64;
+    /// Returns the inode number.
+    fn ino(&self) -> u64;
+    /// Returns the number of hard links pointing to this file.
+    fn nlink(&self) -> u64;
+    /// Returns the total size of this file in bytes.
+    fn size(&self) -> u64;
+    /// Returns the last access time of the file, in seconds since Unix Epoch.
+    fn atim(&self) -> u64;
+    /// Returns the last modification time of the file, in seconds since Unix Epoch.
+    fn mtim(&self) -> u64;
+    /// Returns the last status change time of the file, in seconds since Unix Epoch.
+    fn ctim(&self) -> u64;
+}
+
 #[cfg(unix)]
-impl std::os::unix::fs::MetadataExt for Metadata {
+impl MetadataExt for Metadata {
     #[inline]
     fn dev(&self) -> u64 {
-        self.ext.dev()
+        rustix::fs::MetadataExt::dev(&self.ext)
     }
 
     #[inline]
     fn ino(&self) -> u64 {
-        self.ext.ino()
+        rustix::fs::MetadataExt::ino(&self.ext)
     }
 
     #[inline]
     fn mode(&self) -> u32 {
-        self.ext.mode()
+        rustix::fs::MetadataExt::mode(&self.ext)
     }
 
     #[inline]
     fn nlink(&self) -> u64 {
-        self.ext.nlink()
+        rustix::fs::MetadataExt::nlink(&self.ext)
     }
 
     #[inline]
     fn uid(&self) -> u32 {
-        self.ext.uid()
+        rustix::fs::MetadataExt::uid(&self.ext)
     }
 
     #[inline]
     fn gid(&self) -> u32 {
-        self.ext.gid()
+        rustix::fs::MetadataExt::gid(&self.ext)
     }
 
     #[inline]
     fn rdev(&self) -> u64 {
-        self.ext.rdev()
+        rustix::fs::MetadataExt::rdev(&self.ext)
     }
 
     #[inline]
     fn size(&self) -> u64 {
-        self.ext.size()
+        rustix::fs::MetadataExt::size(&self.ext)
     }
 
     #[inline]
     fn atime(&self) -> i64 {
-        self.ext.atime()
+        rustix::fs::MetadataExt::atime(&self.ext)
     }
 
     #[inline]
     fn atime_nsec(&self) -> i64 {
-        self.ext.atime_nsec()
+        rustix::fs::MetadataExt::atime_nsec(&self.ext)
     }
 
     #[inline]
     fn mtime(&self) -> i64 {
-        self.ext.mtime()
+        rustix::fs::MetadataExt::mtime(&self.ext)
     }
 
     #[inline]
     fn mtime_nsec(&self) -> i64 {
-        self.ext.mtime_nsec()
+        rustix::fs::MetadataExt::mtime_nsec(&self.ext)
     }
 
     #[inline]
     fn ctime(&self) -> i64 {
-        self.ext.ctime()
+        rustix::fs::MetadataExt::ctime(&self.ext)
     }
 
     #[inline]
     fn ctime_nsec(&self) -> i64 {
-        self.ext.ctime_nsec()
+        rustix::fs::MetadataExt::ctime_nsec(&self.ext)
     }
 
     #[inline]
     fn blksize(&self) -> u64 {
-        self.ext.blksize()
+        rustix::fs::MetadataExt::blksize(&self.ext)
     }
 
     #[inline]
     fn blocks(&self) -> u64 {
-        self.ext.blocks()
+        rustix::fs::MetadataExt::blocks(&self.ext)
     }
 }
 
 #[cfg(target_os = "wasi")]
-impl std::os::wasi::fs::MetadataExt for Metadata {
+impl MetadataExt for Metadata {
     #[inline]
     fn dev(&self) -> u64 {
-        self.ext.dev()
+        rustix::fs::MetadataExt::dev(&self.ext)
     }
 
     #[inline]
     fn ino(&self) -> u64 {
-        self.ext.ino()
+        rustix::fs::MetadataExt::ino(&self.ext)
     }
 
     #[inline]
     fn nlink(&self) -> u64 {
-        self.ext.nlink()
+        rustix::fs::MetadataExt::nlink(&self.ext)
     }
 
     #[inline]
     fn size(&self) -> u64 {
-        self.ext.size()
+        rustix::fs::MetadataExt::size(&self.ext)
     }
 
     #[inline]
     fn atim(&self) -> u64 {
-        self.ext.atim()
+        rustix::fs::MetadataExt::atim(&self.ext)
     }
 
     #[inline]
     fn mtim(&self) -> u64 {
-        self.ext.mtim()
+        rustix::fs::MetadataExt::mtim(&self.ext)
     }
 
     #[inline]
     fn ctim(&self) -> u64 {
-        self.ext.ctim()
+        rustix::fs::MetadataExt::ctim(&self.ext)
     }
 }
 
 #[cfg(target_os = "vxworks")]
-impl std::os::vxworks::fs::MetadataExt for Metadata {
+impl MetadataExt for Metadata {
     #[inline]
     fn dev(&self) -> u64 {
         self.ext.dev()
@@ -403,7 +465,7 @@ impl std::os::vxworks::fs::MetadataExt for Metadata {
 }
 
 #[cfg(all(windows, windows_by_handle))]
-impl std::os::windows::fs::MetadataExt for Metadata {
+impl MetadataExt for Metadata {
     #[inline]
     fn file_attributes(&self) -> u32 {
         self.ext.file_attributes()

cap-primitives/src/fs/mod.rs

@@ -75,14 +75,14 @@ pub use file_type::_WindowsFileTypeExt;
 pub use follow_symlinks::FollowSymlinks;
 pub use hard_link::hard_link;
 pub use is_file_read_write::is_file_read_write;
-pub use metadata::Metadata;
 #[cfg(windows)]
 pub use metadata::_WindowsByHandle;
+pub use metadata::{Metadata, MetadataExt};
 pub use open::open;
 pub use open_ambient::open_ambient;
 pub use open_dir::*;
 pub use open_options::OpenOptions;
-pub use permissions::Permissions;
+pub use permissions::{Permissions, PermissionsExt};
 pub use read_dir::{read_base_dir, read_dir, ReadDir};
 pub use read_link::{read_link, read_link_contents};
 pub use remove_dir::remove_dir;

cap-primitives/src/fs/permissions.rs

@@ -1,5 +1,5 @@
 #[cfg(not(windows))]
-use crate::fs::PermissionsExt;
+use crate::fs::ImplPermissionsExt;
 #[cfg(unix)]
 use rustix::fs::RawMode;
 use std::{fs, io};
@@ -17,7 +17,7 @@ pub struct Permissions {
     pub(crate) readonly: bool,
 
     #[cfg(any(unix, target_os = "vxworks"))]
-    pub(crate) ext: PermissionsExt,
+    pub(crate) ext: ImplPermissionsExt,
 }
 
 impl Permissions {
@@ -29,7 +29,7 @@ impl Permissions {
             readonly: std.readonly(),
 
             #[cfg(any(unix, target_os = "vxworks"))]
-            ext: PermissionsExt::from_std(std),
+            ext: ImplPermissionsExt::from_std(std),
         }
     }
 
@@ -90,29 +90,44 @@ impl Permissions {
     }
 }
 
+/// Unix-specific extensions to [`Permissions`].
 #[cfg(unix)]
-impl std::os::unix::fs::PermissionsExt for Permissions {
+pub trait PermissionsExt {
+    /// Returns the underlying raw `st_mode` bits that contain the standard
+    /// Unix permissions for this file.
+    fn mode(&self) -> u32;
+
+    /// Sets the underlying raw bits for this set of permissions.
+    fn set_mode(&mut self, mode: u32);
+
+    /// Creates a new instance of `Permissions` from the given set of Unix
+    /// permission bits.
+    fn from_mode(mode: u32) -> Self;
+}
+
+#[cfg(unix)]
+impl PermissionsExt for Permissions {
     #[inline]
     fn mode(&self) -> u32 {
-        self.ext.mode()
+        std::os::unix::fs::PermissionsExt::mode(&self.ext)
     }
 
     #[inline]
     fn set_mode(&mut self, mode: u32) {
-        self.ext.set_mode(mode)
+        std::os::unix::fs::PermissionsExt::set_mode(&mut self.ext, mode)
     }
 
     #[inline]
     fn from_mode(mode: u32) -> Self {
         Self {
-            readonly: PermissionsExt::readonly(mode as RawMode),
-            ext: PermissionsExt::from_mode(mode),
+            readonly: ImplPermissionsExt::readonly(mode as RawMode),
+            ext: std::os::unix::fs::PermissionsExt::from_mode(mode),
         }
     }
 }
 
 #[cfg(target_os = "vxworks")]
-impl std::os::unix::fs::PermissionsExt for Permissions {
+impl PermissionsExt for Permissions {
     #[inline]
     fn mode(&self) -> u32 {
         self.ext.mode()
@@ -126,8 +141,8 @@ impl std::os::unix::fs::PermissionsExt for Permissions {
     #[inline]
     fn from_mode(mode: u32) -> Self {
         Self {
-            readonly: PermissionsExt::readonly(mode),
-            ext: PermissionsExt::from(mode),
+            readonly: ImplPermissionsExt::readonly(mode),
+            ext: ImplPermissionsExt::from(mode),
         }
     }
 }