Better support for os::windows::fs::MetadataExt on uwp

library/std/src/os/windows/fs.rs

@@ -288,18 +288,22 @@ impl OpenOptionsExt for OpenOptions {
 
 /// Windows-specific extensions to [`fs::Metadata`].
 ///
-/// The data members that this trait exposes correspond to the members
-/// of the [`BY_HANDLE_FILE_INFORMATION`] structure.
+/// The members of this trait correspond to metadata exposed by calls to either
+/// [`GetFileInformationByHandle`] or [`GetFileInformationByHandleEx`].
 ///
-/// [`BY_HANDLE_FILE_INFORMATION`]:
-///     https://docs.microsoft.com/en-us/windows/win32/api/fileapi/ns-fileapi-by_handle_file_information
+/// [`GetFileInformationByHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfileinformationbyhandle
+/// [`GetFileInformationByHandleEx`]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyhandleex
 #[stable(feature = "metadata_ext", since = "1.1.0")]
 pub trait MetadataExt {
-    /// Returns the value of the `dwFileAttributes` field of this metadata.
+    /// Returns the file attributes of a file or directory;
+    /// corresponds to the `dwFileAttributes` field returned by [`GetFileInformationByHandle`],
+    /// or the `FileAttributes` field returned by [`GetFileInformationByHandleEx`].
     ///
-    /// This field contains the file system attribute information for a file
-    /// or directory. For possible values and their descriptions, see
-    /// [File Attribute Constants] in the Windows Dev Center.
+    /// For possible values and their descriptions, see [File Attribute Constants] in the Windows Dev Center.
+    ///
+    /// [`GetFileInformationByHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfileinformationbyhandle
+    /// [`GetFileInformationByHandleEx`]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyhandleex
+    /// [File Attribute Constants]: https://docs.microsoft.com/en-us/windows/win32/fileio/file-attribute-constants
     ///
     /// # Examples
     ///
@@ -314,13 +318,12 @@ pub trait MetadataExt {
     ///     Ok(())
     /// }
     /// ```
-    ///
-    /// [File Attribute Constants]:
-    ///     https://docs.microsoft.com/en-us/windows/win32/fileio/file-attribute-constants
     #[stable(feature = "metadata_ext", since = "1.1.0")]
     fn file_attributes(&self) -> u32;
 
-    /// Returns the value of the `ftCreationTime` field of this metadata.
+    /// Returns the creation time of a file or directory;
+    /// corresponds to the `ftCreationTime` field returned by [`GetFileInformationByHandle`],
+    /// or the `CreationTime` field returned by [`GetFileInformationByHandleEx`].
     ///
     /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
     /// which represents the number of 100-nanosecond intervals since
@@ -331,6 +334,10 @@ pub trait MetadataExt {
     /// If the underlying filesystem does not support creation time, the
     /// returned value is 0.
     ///
+    /// [`GetFileInformationByHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfileinformationbyhandle
+    /// [`GetFileInformationByHandleEx`]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyhandleex
+    /// [`FILETIME`]: https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-filetime
+    ///
     /// # Examples
     ///
     /// ```no_run
@@ -344,12 +351,12 @@ pub trait MetadataExt {
     ///     Ok(())
     /// }
     /// ```
-    ///
-    /// [`FILETIME`]: https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-filetime
     #[stable(feature = "metadata_ext", since = "1.1.0")]
     fn creation_time(&self) -> u64;
 
-    /// Returns the value of the `ftLastAccessTime` field of this metadata.
+    /// Returns the last access time of a file or directory;
+    /// corresponds to the `ftLastAccessTime` field returned by [`GetFileInformationByHandle`],
+    /// or the `LastAccessTime` field returned by [`GetFileInformationByHandleEx`].
     ///
     /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
     /// which represents the number of 100-nanosecond intervals since
@@ -366,6 +373,10 @@ pub trait MetadataExt {
     /// If the underlying filesystem does not support last access time, the
     /// returned value is 0.
     ///
+    /// [`GetFileInformationByHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfileinformationbyhandle
+    /// [`GetFileInformationByHandleEx`]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyhandleex
+    /// [`FILETIME`]: https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-filetime
+    ///
     /// # Examples
     ///
     /// ```no_run
@@ -379,12 +390,12 @@ pub trait MetadataExt {
     ///     Ok(())
     /// }
     /// ```
-    ///
-    /// [`FILETIME`]: https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-filetime
     #[stable(feature = "metadata_ext", since = "1.1.0")]
     fn last_access_time(&self) -> u64;
 
-    /// Returns the value of the `ftLastWriteTime` field of this metadata.
+    /// Returns the last write time of a file or directory;
+    /// corresponds to the `ftLastWriteTime` field returned by [`GetFileInformationByHandle`],
+    /// or the `LastWriteTime` field returned by [`GetFileInformationByHandleEx`].
     ///
     /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
     /// which represents the number of 100-nanosecond intervals since
@@ -399,6 +410,10 @@ pub trait MetadataExt {
     /// If the underlying filesystem does not support the last write time,
     /// the returned value is 0.
     ///
+    /// [`GetFileInformationByHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfileinformationbyhandle
+    /// [`GetFileInformationByHandleEx`]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyhandleex
+    /// [`FILETIME`]: https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-filetime
+    ///
     /// # Examples
     ///
     /// ```no_run
@@ -412,16 +427,18 @@ pub trait MetadataExt {
     ///     Ok(())
     /// }
     /// ```
-    ///
-    /// [`FILETIME`]: https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-filetime
     #[stable(feature = "metadata_ext", since = "1.1.0")]
     fn last_write_time(&self) -> u64;
 
-    /// Returns the value of the `nFileSize{High,Low}` fields of this
-    /// metadata.
+    /// Returns the size of a file;
+    /// corresponds to the `nFileSize{High,Low}` fields returned by [`GetFileInformationByHandle`],
+    /// or the `AllocationSize` field returned by [`GetFileInformationByHandleEx`].
     ///
     /// The returned value does not have meaning for directories.
     ///
+    /// [`GetFileInformationByHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfileinformationbyhandle
+    /// [`GetFileInformationByHandleEx`]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyhandleex
+    ///
     /// # Examples
     ///
     /// ```no_run
@@ -438,32 +455,47 @@ pub trait MetadataExt {
     #[stable(feature = "metadata_ext", since = "1.1.0")]
     fn file_size(&self) -> u64;
 
-    /// Returns the value of the `dwVolumeSerialNumber` field of this
-    /// metadata.
+    /// Returns the volume serial number of a file or directory;
+    /// corresponds to the `dwVolumeSerialNumber` field returned by [`GetFileInformationByHandle`],
+    /// or the `VolumeSerialNumber` field returned by [`GetFileInformationByHandleEx`].
     ///
     /// This will return `None` if the `Metadata` instance was created from a
     /// call to `DirEntry::metadata`. If this `Metadata` was created by using
     /// `fs::metadata` or `File::metadata`, then this will return `Some`.
+    ///
+    /// [`GetFileInformationByHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfileinformationbyhandle
+    /// [`GetFileInformationByHandleEx`]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyhandleex
     #[unstable(feature = "windows_by_handle", issue = "63010")]
     fn volume_serial_number(&self) -> Option<u32>;
 
-    /// Returns the value of the `nNumberOfLinks` field of this
-    /// metadata.
+    /// Returns the number of links to a file or directory;
+    /// corresponds to the `nNumberOfLinks` field returned by [`GetFileInformationByHandle`],
+    /// or the `NumberOfLinks` field returned by [`GetFileInformationByHandleEx`].
     ///
     /// This will return `None` if the `Metadata` instance was created from a
     /// call to `DirEntry::metadata`. If this `Metadata` was created by using
     /// `fs::metadata` or `File::metadata`, then this will return `Some`.
+    ///
+    /// [`GetFileInformationByHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfileinformationbyhandle
+    /// [`GetFileInformationByHandleEx`]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyhandleex
     #[unstable(feature = "windows_by_handle", issue = "63010")]
     fn number_of_links(&self) -> Option<u32>;
 
-    /// Returns the value of the `nFileIndex{Low,High}` fields of this
-    /// metadata.
+    /// Returns the file identifier of a file or directory;
+    /// corresponds to the `nFileIndex{Low,High}` fields returned by [`GetFileInformationByHandle`],
+    /// or the `FileId` field returned by [`GetFileInformationByHandleEx`].
+    ///
+    /// Note that this is a `u128`, since `GetFileInformationByHandle` returns a 64-bit value,
+    /// and `GetFileInformationByHandleEx` returns a 128-bit value.
     ///
     /// This will return `None` if the `Metadata` instance was created from a
     /// call to `DirEntry::metadata`. If this `Metadata` was created by using
     /// `fs::metadata` or `File::metadata`, then this will return `Some`.
+    ///
+    /// [`GetFileInformationByHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfileinformationbyhandle
+    /// [`GetFileInformationByHandleEx`]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getfileinformationbyhandleex
     #[unstable(feature = "windows_by_handle", issue = "63010")]
-    fn file_index(&self) -> Option<u64>;
+    fn file_identifier(&self) -> Option<u128>;
 }
 
 #[stable(feature = "metadata_ext", since = "1.1.0")]
@@ -489,8 +521,8 @@ impl MetadataExt for Metadata {
     fn number_of_links(&self) -> Option<u32> {
         self.as_inner().number_of_links()
     }
-    fn file_index(&self) -> Option<u64> {
-        self.as_inner().file_index()
+    fn file_identifier(&self) -> Option<u128> {
+        self.as_inner().file_identifier()
     }
 }
 

library/std/src/sys/windows/c.rs

@@ -758,6 +758,9 @@ if #[cfg(not(target_vendor = "uwp"))] {
 // UWP specific functions & types
 cfg_if::cfg_if! {
 if #[cfg(target_vendor = "uwp")] {
+    use use crate::os::raw::c_ulonglong;
+    pub type ULONGLONG = c_ulonglong;
+
     pub const BCRYPT_USE_SYSTEM_PREFERRED_RNG: DWORD = 0x00000002;
 
     #[repr(C)]
@@ -769,6 +772,12 @@ if #[cfg(target_vendor = "uwp")] {
         pub Directory: BOOLEAN,
     }
 
+    #[repr(C)]
+    pub struct FILE_ID_INFO {
+        pub VolumeSerialNumber: ULONGLONG,
+        pub FileId: u128
+    }
+
     #[link(name = "bcrypt")]
     extern "system" {
         pub fn BCryptGenRandom(

library/std/src/sys/windows/fs.rs

@@ -29,7 +29,7 @@ pub struct FileAttr {
     reparse_tag: c::DWORD,
     volume_serial_number: Option<u32>,
     number_of_links: Option<u32>,
-    file_index: Option<u64>,
+    file_identifier: Option<u128>,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
@@ -163,7 +163,7 @@ impl DirEntry {
             },
             volume_serial_number: None,
             number_of_links: None,
-            file_index: None,
+            file_identifier: None,
         })
     }
 }
@@ -343,8 +343,8 @@ impl File {
                 reparse_tag,
                 volume_serial_number: Some(info.dwVolumeSerialNumber),
                 number_of_links: Some(info.nNumberOfLinks),
-                file_index: Some(
-                    (info.nFileIndexLow as u64) | ((info.nFileIndexHigh as u64) << 32),
+                file_identifier: Some(
+                    ((info.nFileIndexLow as u64) | ((info.nFileIndexHigh as u64) << 32)) as u128,
                 ),
             })
         }
@@ -379,7 +379,7 @@ impl File {
                 reparse_tag: 0,
                 volume_serial_number: None,
                 number_of_links: None,
-                file_index: None,
+                file_identifier: None,
             };
             let mut info: c::FILE_STANDARD_INFO = mem::zeroed();
             let size = mem::size_of_val(&info);
@@ -397,6 +397,16 @@ impl File {
                     attr.reparse_tag = buf.ReparseTag;
                 }
             }
+            let mut info: c::FILE_ID_INFO = mem::zeroed();
+            let size = mem::size_of_val(&info);
+            cvt(c::GetFileInformationByHandleEx(
+                self.handle.raw(),
+                c::FileIdInfo,
+                &mut info as *mut _ as *mut libc::c_void,
+                size as c::DWORD,
+            ))?;
+            attr.volume_serial_number = Some(info.VolumeSerialNumber);
+            attr.file_identifier = Some(info.FileId);
             Ok(attr)
         }
     }
@@ -618,8 +628,8 @@ impl FileAttr {
         self.number_of_links
     }
 
-    pub fn file_index(&self) -> Option<u64> {
-        self.file_index
+    pub fn file_identifier(&self) -> Option<u128> {
+        self.file_identifier
     }
 }