Add --dev flag to stay on the same filesystem

USAGE.md

@@ -94,6 +94,11 @@ Minimal size proportion required to appear.
 
 Do not sort the branches in the tree.
 
+<a id="dev" name="dev"></a>
+### `--dev`
+
+Stay on the same filesystem, do not cross mount points (POSIX only).
+
 <a id="option-s" name="option-s"></a><a id="silent-errors" name="silent-errors"></a><a id="no-errors" name="no-errors"></a>
 ### `--silent-errors`
 

exports/completion.bash

@@ -23,7 +23,7 @@ _pdu() {
 
     case "${cmd}" in
         pdu)
-            opts="-b -H -q -d -w -m -s -p -h -V --json-input --json-output --bytes-format --detect-links --dedupe-links --deduplicate-hardlinks --top-down --align-right --quantity --depth --max-depth --width --total-width --column-width --min-ratio --no-sort --no-errors --silent-errors --progress --threads --omit-json-shared-details --omit-json-shared-summary --help --version [FILES]..."
+            opts="-b -H -q -d -w -m -s -p -h -V --json-input --json-output --bytes-format --detect-links --dedupe-links --deduplicate-hardlinks --top-down --align-right --quantity --depth --max-depth --width --total-width --column-width --min-ratio --no-sort --dev --no-errors --silent-errors --progress --threads --omit-json-shared-details --omit-json-shared-summary --help --version [FILES]..."
             if [[ ${cur} == -* || ${COMP_CWORD} -eq 1 ]] ; then
                 COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                 return 0

exports/completion.elv

@@ -41,6 +41,7 @@ set edit:completion:arg-completer[pdu] = {|@words|
             cand --top-down 'Print the tree top-down instead of bottom-up'
             cand --align-right 'Set the root of the bars to the right'
             cand --no-sort 'Do not sort the branches in the tree'
+            cand --dev 'Stay on the same filesystem, do not cross mount points (POSIX only)'
             cand -s 'Prevent filesystem error messages from appearing in stderr'
             cand --silent-errors 'Prevent filesystem error messages from appearing in stderr'
             cand --no-errors 'Prevent filesystem error messages from appearing in stderr'

exports/completion.fish

@@ -15,6 +15,7 @@ complete -c pdu -s H -l deduplicate-hardlinks -l detect-links -l dedupe-links -d
 complete -c pdu -l top-down -d 'Print the tree top-down instead of bottom-up'
 complete -c pdu -l align-right -d 'Set the root of the bars to the right'
 complete -c pdu -l no-sort -d 'Do not sort the branches in the tree'
+complete -c pdu -l dev -d 'Stay on the same filesystem, do not cross mount points (POSIX only)'
 complete -c pdu -s s -l silent-errors -l no-errors -d 'Prevent filesystem error messages from appearing in stderr'
 complete -c pdu -s p -l progress -d 'Report progress being made at the expense of performance'
 complete -c pdu -l omit-json-shared-details -d 'Do not output `.shared.details` in the JSON output'

exports/completion.ps1

@@ -44,6 +44,7 @@ Register-ArgumentCompleter -Native -CommandName 'pdu' -ScriptBlock {
             [CompletionResult]::new('--top-down', '--top-down', [CompletionResultType]::ParameterName, 'Print the tree top-down instead of bottom-up')
             [CompletionResult]::new('--align-right', '--align-right', [CompletionResultType]::ParameterName, 'Set the root of the bars to the right')
             [CompletionResult]::new('--no-sort', '--no-sort', [CompletionResultType]::ParameterName, 'Do not sort the branches in the tree')
+            [CompletionResult]::new('--dev', '--dev', [CompletionResultType]::ParameterName, 'Stay on the same filesystem, do not cross mount points (POSIX only)')
             [CompletionResult]::new('-s', '-s', [CompletionResultType]::ParameterName, 'Prevent filesystem error messages from appearing in stderr')
             [CompletionResult]::new('--silent-errors', '--silent-errors', [CompletionResultType]::ParameterName, 'Prevent filesystem error messages from appearing in stderr')
             [CompletionResult]::new('--no-errors', '--no-errors', [CompletionResultType]::ParameterName, 'Prevent filesystem error messages from appearing in stderr')

exports/completion.zsh

@@ -46,6 +46,7 @@ block-count\:"Count numbers of blocks"))' \
 '--top-down[Print the tree top-down instead of bottom-up]' \
 '--align-right[Set the root of the bars to the right]' \
 '--no-sort[Do not sort the branches in the tree]' \
+'--dev[Stay on the same filesystem, do not cross mount points (POSIX only)]' \
 '-s[Prevent filesystem error messages from appearing in stderr]' \
 '--silent-errors[Prevent filesystem error messages from appearing in stderr]' \
 '--no-errors[Prevent filesystem error messages from appearing in stderr]' \

exports/long.help

@@ -69,6 +69,9 @@ Options:
       --no-sort
           Do not sort the branches in the tree
 
+      --dev
+          Stay on the same filesystem, do not cross mount points (POSIX only)
+
   -s, --silent-errors
           Prevent filesystem error messages from appearing in stderr
 

exports/short.help

@@ -30,6 +30,8 @@ Options:
           Minimal size proportion required to appear [default: 0.01]
       --no-sort
           Do not sort the branches in the tree
+      --dev
+          Stay on the same filesystem, do not cross mount points (POSIX only)
   -s, --silent-errors
           Prevent filesystem error messages from appearing in stderr [aliases: --no-errors]
   -p, --progress

src/app.rs

@@ -16,7 +16,7 @@ use crate::{
 use clap::Parser;
 use hdd::any_path_is_in_hdd;
 use pipe_trait::Pipe;
-use std::{io::stdin, time::Duration};
+use std::{io::stdin, path::PathBuf, time::Duration};
 use sub::JsonOutputParam;
 use sysinfo::{Disk, Disks};
 
@@ -133,6 +133,17 @@ impl App {
                 .pipe(Err);
         }
 
+        #[cfg(not(unix))]
+        if self.args.dev {
+            return crate::runtime_error::UnsupportedFeature::Dev
+                .pipe(RuntimeError::UnsupportedFeature)
+                .pipe(Err);
+        }
+
+        if self.args.dev && self.args.files.len() > 1 {
+            return Err(RuntimeError::DevArgConflict);
+        }
+
         let threads = match self.args.threads {
             Threads::Auto => {
                 let disks = Disks::new_with_refreshed_list();
@@ -275,14 +286,16 @@ impl App {
         macro_rules! run {
             ($(
                 $(#[$variant_attrs:meta])*
-                $size_getter:ident, $progress:literal, $hardlinks:ident;
+                $size_getter:ident, $progress:literal, $hardlinks:ident, $dev:ident;
             )*) => { match self.args {$(
                 $(#[$variant_attrs])*
                 Args {
                     quantity: <$size_getter as GetSizeUtils>::QUANTITY,
                     progress: $progress,
                     #[cfg(unix)] deduplicate_hardlinks: $hardlinks,
                     #[cfg(not(unix))] deduplicate_hardlinks: _,
+                    #[cfg(unix)] dev: $dev,
+                    #[cfg(not(unix))] dev: _,
                     files,
                     json_output,
                     bytes_format,
@@ -294,41 +307,78 @@ impl App {
                     omit_json_shared_details,
                     omit_json_shared_summary,
                     ..
-                } => Sub {
-                    direction: Direction::from_top_down(top_down),
-                    bar_alignment: BarAlignment::from_align_right(align_right),
-                    size_getter: <$size_getter as GetSizeUtils>::INSTANCE,
-                    hardlinks_handler: <$size_getter as CreateHardlinksHandler<{ cfg!(unix) && $hardlinks }, $progress>>::create_hardlinks_handler(),
-                    reporter: <$size_getter as CreateReporter<$progress>>::create_reporter(report_error),
-                    bytes_format: <$size_getter as GetSizeUtils>::formatter(bytes_format),
-                    files,
-                    json_output: JsonOutputParam::from_cli_flags(json_output, omit_json_shared_details, omit_json_shared_summary),
-                    column_width_distribution,
-                    max_depth,
-                    min_ratio,
-                    no_sort,
-                }
-                .run(),
+                } => {
+                    let root_dev = if cfg!(unix) && $dev {
+                        get_root_dev(&files)
+                    } else {
+                        None
+                    };
+                    Sub {
+                        direction: Direction::from_top_down(top_down),
+                        bar_alignment: BarAlignment::from_align_right(align_right),
+                        size_getter: <$size_getter as GetSizeUtils>::INSTANCE,
+                        hardlinks_handler: <$size_getter as CreateHardlinksHandler<{ cfg!(unix) && $hardlinks }, $progress>>::create_hardlinks_handler(),
+                        reporter: <$size_getter as CreateReporter<$progress>>::create_reporter(report_error),
+                        bytes_format: <$size_getter as GetSizeUtils>::formatter(bytes_format),
+                        files,
+                        json_output: JsonOutputParam::from_cli_flags(json_output, omit_json_shared_details, omit_json_shared_summary),
+                        column_width_distribution,
+                        max_depth,
+                        min_ratio,
+                        no_sort,
+                        root_dev,
+                    }
+                    .run()
+                },
             )*} };
         }
 
         run! {
-            GetApparentSize, false, false;
-            GetApparentSize, true, false;
-            #[cfg(unix)] GetBlockSize, false, false;
-            #[cfg(unix)] GetBlockSize, true, false;
-            #[cfg(unix)] GetBlockCount, false, false;
-            #[cfg(unix)] GetBlockCount, true, false;
-            #[cfg(unix)] GetApparentSize, false, true;
-            #[cfg(unix)] GetApparentSize, true, true;
-            #[cfg(unix)] GetBlockSize, false, true;
-            #[cfg(unix)] GetBlockSize, true, true;
-            #[cfg(unix)] GetBlockCount, false, true;
-            #[cfg(unix)] GetBlockCount, true, true;
+            GetApparentSize, false, false, false;
+            GetApparentSize, true, false, false;
+            #[cfg(unix)] GetBlockSize, false, false, false;
+            #[cfg(unix)] GetBlockSize, true, false, false;
+            #[cfg(unix)] GetBlockCount, false, false, false;
+            #[cfg(unix)] GetBlockCount, true, false, false;
+            #[cfg(unix)] GetApparentSize, false, true, false;
+            #[cfg(unix)] GetApparentSize, true, true, false;
+            #[cfg(unix)] GetBlockSize, false, true, false;
+            #[cfg(unix)] GetBlockSize, true, true, false;
+            #[cfg(unix)] GetBlockCount, false, true, false;
+            #[cfg(unix)] GetBlockCount, true, true, false;
+            #[cfg(unix)] GetApparentSize, false, false, true;
+            #[cfg(unix)] GetApparentSize, true, false, true;
+            #[cfg(unix)] GetBlockSize, false, false, true;
+            #[cfg(unix)] GetBlockSize, true, false, true;
+            #[cfg(unix)] GetBlockCount, false, false, true;
+            #[cfg(unix)] GetBlockCount, true, false, true;
+            #[cfg(unix)] GetApparentSize, false, true, true;
+            #[cfg(unix)] GetApparentSize, true, true, true;
+            #[cfg(unix)] GetBlockSize, false, true, true;
+            #[cfg(unix)] GetBlockSize, true, true, true;
+            #[cfg(unix)] GetBlockCount, false, true, true;
+            #[cfg(unix)] GetBlockCount, true, true, true;
         }
     }
 }
 
+/// Get the device ID of the root path for `--dev` filtering.
+#[cfg(unix)]
+fn get_root_dev(files: &[PathBuf]) -> Option<u64> {
+    use std::os::unix::fs::MetadataExt;
+    let root_path = files
+        .first()
+        .map(|p| p.as_path())
+        .unwrap_or(std::path::Path::new("."));
+    std::fs::symlink_metadata(root_path).ok().map(|m| m.dev())
+}
+
+/// Get the device ID of the root path for `--dev` filtering.
+#[cfg(not(unix))]
+fn get_root_dev(_files: &[PathBuf]) -> Option<u64> {
+    None
+}
+
 mod hdd;
 mod mount_point;
 mod overlapping_arguments;

src/app/sub.rs

@@ -49,6 +49,8 @@ where
     pub min_ratio: Fraction,
     /// Preserve order of entries.
     pub no_sort: bool,
+    /// Device ID of the root directory. When `Some`, entries on different devices are skipped.
+    pub root_dev: Option<u64>,
 }
 
 impl<Size, SizeGetter, HardlinksHandler, Report> Sub<Size, SizeGetter, HardlinksHandler, Report>
@@ -74,6 +76,7 @@ where
             reporter,
             min_ratio,
             no_sort,
+            root_dev,
         } = self;
 
         let max_depth = max_depth.get();
@@ -87,6 +90,7 @@ where
                     size_getter,
                     hardlinks_recorder: &hardlinks_handler,
                     max_depth,
+                    root_dev,
                 }
                 .into()
             });

src/args.rs

@@ -151,6 +151,11 @@ pub struct Args {
     #[clap(long)]
     pub no_sort: bool,
 
+    /// Stay on the same filesystem, do not cross mount points (POSIX only).
+    #[clap(long)]
+    #[cfg_attr(not(unix), clap(hide = true))]
+    pub dev: bool,
+
     /// Prevent filesystem error messages from appearing in stderr.
     #[clap(long, short, visible_alias = "no-errors")]
     pub silent_errors: bool,

src/fs_tree_builder.rs

@@ -33,6 +33,7 @@ use std::{
 ///     size_getter: GetApparentSize,
 ///     reporter: &ErrorOnlyReporter::new(ErrorReport::SILENT),
 ///     max_depth: 10,
+///     root_dev: None,
 /// };
 /// let data_tree: DataTree<OsStringDisplay, Bytes> = builder.into();
 /// ```
@@ -54,6 +55,8 @@ where
     pub reporter: &'a Report,
     /// Deepest level of descendant display in the graph. The sizes beyond the max depth still count toward total.
     pub max_depth: u64,
+    /// Device ID of the root directory. When `Some`, entries on different devices are skipped.
+    pub root_dev: Option<u64>,
 }
 
 impl<'a, Size, SizeGetter, HardlinksRecorder, Report>
@@ -67,12 +70,14 @@ where
 {
     /// Create a [`DataTree`] from an [`FsTreeBuilder`].
     fn from(builder: FsTreeBuilder<Size, SizeGetter, HardlinksRecorder, Report>) -> Self {
+        #[allow(unused_variables)] // root_dev is only used in #[cfg(unix)] block below
         let FsTreeBuilder {
             root,
             size_getter,
             hardlinks_recorder,
             reporter,
             max_depth,
+            root_dev,
         } = builder;
 
         TreeBuilder::<PathBuf, OsStringDisplay, Size, _, _> {
@@ -94,6 +99,17 @@ where
                         };
                     }
                     Ok(stats) => {
+                        // When --dev is active, skip entries on different filesystems
+                        #[cfg(unix)]
+                        if let Some(root_dev) = root_dev {
+                            use std::os::unix::fs::MetadataExt;
+                            if stats.dev() != root_dev {
+                                return Info {
+                                    size: Size::default(),
+                                    children: Vec::new(),
+                                };
+                            }
+                        }
                         // `stats` should be dropped ASAP to avoid piling up kernel memory usage
                         let is_dir = stats.is_dir();
                         let size = size_getter.get_size(&stats);

src/runtime_error.rs

@@ -19,6 +19,9 @@ pub enum RuntimeError {
     /// When input JSON data is not a valid tree.
     #[display("InvalidInputReflection: {_0}")]
     InvalidInputReflection(#[error(not(source))] String),
+    /// When `--dev` is used with more than one argument.
+    #[display("DevArgConflict: --dev cannot be used with more than one path argument")]
+    DevArgConflict,
     /// When the user attempts to use unavailable platform-specific features.
     #[display("UnsupportedFeature: {_0}")]
     UnsupportedFeature(UnsupportedFeature),
@@ -32,6 +35,10 @@ pub enum UnsupportedFeature {
     #[cfg(not(unix))]
     #[display("Feature --deduplicate-hardlinks is not available on this platform")]
     DeduplicateHardlink,
+    /// Using `--dev` on non-POSIX.
+    #[cfg(not(unix))]
+    #[display("Feature --dev is not available on this platform")]
+    Dev,
 }
 
 impl From<Infallible> for RuntimeError {
@@ -48,7 +55,8 @@ impl RuntimeError {
             RuntimeError::DeserializationFailure(_) => 3,
             RuntimeError::JsonInputArgConflict => 4,
             RuntimeError::InvalidInputReflection(_) => 5,
-            RuntimeError::UnsupportedFeature(_) => 6,
+            RuntimeError::DevArgConflict => 6,
+            RuntimeError::UnsupportedFeature(_) => 7,
         })
     }
 }

tests/_utils.rs

@@ -374,6 +374,7 @@ where
             }),
             root: root.join(suffix),
             max_depth: 10,
+            root_dev: None,
         }
         .pipe(DataTree::<OsStringDisplay, Size>::from)
         .into_par_sorted(|left, right| left.name().cmp(right.name()))

tests/cli_errors.rs

@@ -136,6 +136,7 @@ fn fs_errors() {
         hardlinks_recorder: &HardlinkIgnorant,
         reporter: &ErrorOnlyReporter::new(ErrorReport::SILENT),
         max_depth: 10,
+        root_dev: None,
     };
     let mut data_tree: DataTree<OsStringDisplay, _> = builder.into();
     data_tree.par_sort_by(|left, right| left.size().cmp(&right.size()).reverse());

tests/json.rs

@@ -86,6 +86,7 @@ fn json_output() {
         hardlinks_recorder: &HardlinkIgnorant,
         reporter: &ErrorOnlyReporter::new(ErrorReport::SILENT),
         max_depth: 10,
+        root_dev: None,
     };
     let expected = builder
         .pipe(DataTree::<_, Bytes>::from)