1 files changed, 32 insertions, 0 deletions
diff --git a/src/unique_id.rs b/src/unique_id.rs
new file mode 100644
index 0000000..eb44e72
--- /dev/null
+++ b/src/unique_id.rs
@@ -0,0 +1,32 @@
+#[derive(Eq, PartialEq, Hash)]
+pub struct UniqueID {
+    device: u64,
+    inode: u64,
+}
+
+#[cfg(not(windows))]
+pub fn generate_unique_id(metadata: &std::fs::Metadata) -> Option<UniqueID> {
+    use std::os::unix::fs::MetadataExt;
+    // If the entry has more than one hard link, generate
+    // a unique ID consisting of device and inode in order
+    // not to count this entry twice.
+    if metadata.is_file() && metadata.nlink() > 1 {
+        Some(UniqueID {
+            device: metadata.dev(),
+            inode: metadata.ino(),
+        })
+    } else {
+        None
+    }
+}
+
+#[cfg(windows)]
+pub fn generate_unique_id(_metadata: &std::fs::Metadata) -> Option<UniqueID> {
+    // Windows-internal tools such as Powershell, Explorer or `dir` are not respecting hardlinks
+    // or junction points when determining the size of a directory. `diskus` does the same and
+    // counts such entries multiple times (on Unix systems, multiple hardlinks to a single file are
+    // counted just once).
+    //
+    // See: https://github.com/sharkdp/diskus/issues/32
+    None
+}