feat(api): move instead of mutate

Author: KSXGitHub

src/app/sub.rs

@@ -129,8 +129,12 @@ where
             if !no_sort {
                 data_tree.par_sort_by(|left, right| left.size().cmp(&right.size()).reverse());
             }
-            let deduplication_record = hardlinks_handler.deduplicate(&mut data_tree);
-            (data_tree, deduplication_record)
+
+            // errors caused by failing deduplication shouldn't prevent data_tree from being visualized
+            match hardlinks_handler.deduplicate(data_tree) {
+                Ok((data_tree, record)) => (data_tree, Ok(record)),
+                Err((data_tree, error)) => (data_tree, Err(error)),
+            }
         };
 
         GLOBAL_STATUS_BOARD.clear_line(0);

src/hardlink/aware.rs

@@ -1,5 +1,5 @@
 use super::{
-    hardlink_list, DeduplicateSharedSize, HardlinkList, LinkPathList, RecordHardlinks,
+    deduplicate, hardlink_list, DeduplicateSharedSize, HardlinkList, LinkPathList, RecordHardlinks,
     RecordHardlinksArgument,
 };
 use crate::{
@@ -97,8 +97,8 @@ where
     type Error = Infallible;
     fn deduplicate(
         self,
-        data_tree: &mut DataTree<OsStringDisplay, Size>,
-    ) -> Result<Self::Report, Self::Error> {
+        mut data_tree: DataTree<OsStringDisplay, Size>,
+    ) -> deduplicate::Result<Size, Self::Report, Self::Error> {
         let record: Self::Report = self.into();
         let hardlink_info: Box<[(Size, LinkPathList)]> = record
             .iter()
@@ -109,6 +109,6 @@ where
             .map(|(size, paths)| (*size, paths.iter().map(AsRef::as_ref).collect()))
             .collect();
         data_tree.par_deduplicate_hardlinks(&hardlink_info);
-        Ok(record)
+        Ok((data_tree, record))
     }
 }

src/hardlink/deduplicate.rs

@@ -1,12 +1,15 @@
 use crate::{data_tree::DataTree, os_string_display::OsStringDisplay, size};
 
-// TODO:
-// Consider changing `deduplicate` into taking owned `DataTree` and returning `Result<(DataTree, Self::Report), Self::Error>`.
-
 // TODO:
 // Consider changing `deduplicate` into one that transforms `HardlinkDuplicated<DataTree>` into `DataTree`.
 // `HardlinkDuplicated` (name is non-final) cannot be constructed manually and is the only type accepted by `deduplicate`.
 
+type DataTreeTuple<Size, Other> = (DataTree<OsStringDisplay, Size>, Other);
+
+/// Result type of [`DeduplicateSharedSize::deduplicate`].
+pub type Result<Size, Report, Error> =
+    std::result::Result<DataTreeTuple<Size, Report>, DataTreeTuple<Size, Error>>;
+
 /// Ability to correct the sizes in a [`DataTree`] by reducing the size of recorded shared links.
 ///
 /// The input tree is assumed to be not yet deduplicated.
@@ -18,8 +21,8 @@ pub trait DeduplicateSharedSize<Size: size::Size>: Sized {
     /// Correct the sizes in a [`DataTree`] by reducing the size of recorded shared links.
     fn deduplicate(
         self,
-        data_tree: &mut DataTree<OsStringDisplay, Size>,
-    ) -> Result<Self::Report, Self::Error>;
+        data_tree: DataTree<OsStringDisplay, Size>,
+    ) -> Result<Size, Self::Report, Self::Error>;
 }
 
 /// Do deduplicate the sizes of hardlinks.

src/hardlink/ignorant.rs

@@ -1,4 +1,4 @@
-use super::{DeduplicateSharedSize, RecordHardlinks, RecordHardlinksArgument};
+use super::{deduplicate, DeduplicateSharedSize, RecordHardlinks, RecordHardlinksArgument};
 use crate::{data_tree::DataTree, os_string_display::OsStringDisplay, size};
 use std::convert::Infallible;
 
@@ -37,8 +37,8 @@ where
     /// Do nothing.
     fn deduplicate(
         self,
-        _: &mut DataTree<OsStringDisplay, Size>,
-    ) -> Result<Self::Report, Self::Error> {
-        Ok(())
+        data_tree: DataTree<OsStringDisplay, Size>,
+    ) -> deduplicate::Result<Size, Self::Report, Self::Error> {
+        Ok((data_tree, ()))
     }
 }