From 5850f787ffb254cdd47629eaa11728593f75d6f1 Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Sun, 11 Apr 2021 18:32:03 +0530
Subject: [PATCH 01/11] ls: Remove allocations by eliminating collect/clones

---
 src/uu/ls/src/ls.rs | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/src/uu/ls/src/ls.rs b/src/uu/ls/src/ls.rs
index 51453980929..96db3bb2900 100644
--- a/src/uu/ls/src/ls.rs
+++ b/src/uu/ls/src/ls.rs
@@ -1144,24 +1144,30 @@ fn should_display(entry: &DirEntry, config: &Config) -> bool {
 }
 
 fn enter_directory(dir: &Path, config: &Config) {
-    let mut entries: Vec<_> = safe_unwrap!(fs::read_dir(dir).and_then(Iterator::collect));
+    let mut entries: Vec<_> = if config.files == Files::All {
+        vec![dir.join("."), dir.join("..")]
+    } else {
+        vec![]
+    };
 
-    entries.retain(|e| should_display(e, config));
+    let mut temp: Vec<_> = safe_unwrap!(fs::read_dir(dir))
+        .map(|res| safe_unwrap!(res))
+        .filter(|e| should_display(e, config))
+        .map(|e| DirEntry::path(&e))
+        .collect();
 
-    let mut entries: Vec<_> = entries.iter().map(DirEntry::path).collect();
-    sort_entries(&mut entries, config);
+    sort_entries(&mut temp, config);
 
-    if config.files == Files::All {
-        let mut display_entries = entries.clone();
-        display_entries.insert(0, dir.join(".."));
-        display_entries.insert(0, dir.join("."));
-        display_items(&display_entries, Some(dir), config, false);
-    } else {
-        display_items(&entries, Some(dir), config, false);
-    }
+    entries.append(&mut temp);
+
+    display_items(&entries, Some(dir), config, false);
 
     if config.recursive {
-        for e in entries.iter().filter(|p| p.is_dir()) {
+        for e in entries
+            .iter()
+            .skip(if config.files == Files::All { 2 } else { 0 })
+            .filter(|p| p.is_dir())
+        {
             println!("\n{}:", e.to_string_lossy());
             enter_directory(&e, config);
         }

From 76cc7fbd568d2e43d9d5c78fb7d60a6e22236b4a Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Sat, 17 Apr 2021 14:22:29 +0530
Subject: [PATCH 02/11] ls: Introduce PathData structure

- PathData will hold Path related metadata / strings that are required
frequently in subsequent functions
- All data is precomputed and cached and subsequent functions just
use cached data
---
 src/uu/ls/src/ls.rs | 135 ++++++++++++++++++++++++--------------------
 1 file changed, 74 insertions(+), 61 deletions(-)

diff --git a/src/uu/ls/src/ls.rs b/src/uu/ls/src/ls.rs
index 96db3bb2900..d37033a9a34 100644
--- a/src/uu/ls/src/ls.rs
+++ b/src/uu/ls/src/ls.rs
@@ -1038,12 +1038,32 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
     list(locs, Config::from(matches))
 }
 
+struct PathData {
+    md: std::io::Result<Metadata>,
+    lossy_string: String,
+    p_buf: PathBuf,
+}
+
+impl PathData {
+    fn new(p_buf: PathBuf, config: &Config, command_line: bool) -> Self {
+        let md = get_metadata(&p_buf, config, command_line);
+        let lossy_string = p_buf.to_string_lossy().into_owned();
+        // let path_name: String =
+        Self {
+            md,
+            lossy_string,
+            p_buf,
+        }
+    }
+}
+
 fn list(locs: Vec<String>, config: Config) -> i32 {
     let number_of_locs = locs.len();
 
-    let mut files = Vec::<PathBuf>::new();
-    let mut dirs = Vec::<PathBuf>::new();
+    let mut files = Vec::<PathData>::new();
+    let mut dirs = Vec::<PathData>::new();
     let mut has_failed = false;
+
     for loc in locs {
         let p = PathBuf::from(&loc);
         if !p.exists() {
@@ -1054,36 +1074,28 @@ fn list(locs: Vec<String>, config: Config) -> i32 {
             continue;
         }
 
-        let show_dir_contents = if !config.directory {
-            match config.dereference {
-                Dereference::None => {
-                    if let Ok(md) = p.symlink_metadata() {
-                        md.is_dir()
-                    } else {
-                        show_error!("'{}': {}", &loc, "No such file or directory");
-                        has_failed = true;
-                        continue;
-                    }
-                }
-                _ => p.is_dir(),
-            }
+        let path_data = PathData::new(p, &config, true);
+
+        let show_dir_contents = if let Ok(md) = path_data.md.as_ref() {
+            !config.directory && md.is_dir()
         } else {
+            has_failed = true;
             false
         };
 
         if show_dir_contents {
-            dirs.push(p);
+            dirs.push(path_data);
         } else {
-            files.push(p);
+            files.push(path_data);
         }
     }
     sort_entries(&mut files, &config);
-    display_items(&files, None, &config, true);
+    display_items(&files, None, &config);
 
     sort_entries(&mut dirs, &config);
     for dir in dirs {
         if number_of_locs > 1 {
-            println!("\n{}:", dir.to_string_lossy());
+            println!("\n{}:", dir.lossy_string);
         }
         enter_directory(&dir, &config);
     }
@@ -1094,22 +1106,22 @@ fn list(locs: Vec<String>, config: Config) -> i32 {
     }
 }
 
-fn sort_entries(entries: &mut Vec<PathBuf>, config: &Config) {
+fn sort_entries(entries: &mut Vec<PathData>, config: &Config) {
     match config.sort {
         Sort::Time => entries.sort_by_key(|k| {
             Reverse(
-                get_metadata(k, false)
+                k.md.as_ref()
                     .ok()
                     .and_then(|md| get_system_time(&md, config))
                     .unwrap_or(UNIX_EPOCH),
             )
         }),
         Sort::Size => {
-            entries.sort_by_key(|k| Reverse(get_metadata(k, false).map(|md| md.len()).unwrap_or(0)))
+            entries.sort_by_key(|k| Reverse(k.md.as_ref().map(|md| md.len()).unwrap_or(0)))
         }
         // The default sort in GNU ls is case insensitive
-        Sort::Name => entries.sort_by_key(|k| k.to_string_lossy().to_lowercase()),
-        Sort::Version => entries.sort_by(|a, b| version_cmp::version_cmp(a, b)),
+        Sort::Name => entries.sort_by_key(|k| k.lossy_string.to_lowercase()),
+        Sort::Version => entries.sort_by(|k, j| version_cmp::version_cmp(&k.p_buf, &j.p_buf)),
         Sort::None => {}
     }
 
@@ -1143,38 +1155,57 @@ fn should_display(entry: &DirEntry, config: &Config) -> bool {
     true
 }
 
-fn enter_directory(dir: &Path, config: &Config) {
+fn enter_directory(dir: &PathData, config: &Config) {
     let mut entries: Vec<_> = if config.files == Files::All {
-        vec![dir.join("."), dir.join("..")]
+        vec![
+            PathData::new(dir.p_buf.join("."), config, false),
+            PathData::new(dir.p_buf.join(".."), config, false),
+        ]
     } else {
         vec![]
     };
 
-    let mut temp: Vec<_> = safe_unwrap!(fs::read_dir(dir))
+    let mut temp: Vec<_> = safe_unwrap!(fs::read_dir(&dir.p_buf))
         .map(|res| safe_unwrap!(res))
         .filter(|e| should_display(e, config))
-        .map(|e| DirEntry::path(&e))
+        .map(|e| PathData::new(DirEntry::path(&e), config, false))
         .collect();
 
     sort_entries(&mut temp, config);
 
     entries.append(&mut temp);
 
-    display_items(&entries, Some(dir), config, false);
+    display_items(&entries, Some(&dir.p_buf), config);
 
     if config.recursive {
         for e in entries
             .iter()
             .skip(if config.files == Files::All { 2 } else { 0 })
-            .filter(|p| p.is_dir())
+            .filter(|p| p.md.as_ref().map_or(false, |md| md.is_dir()))
         {
-            println!("\n{}:", e.to_string_lossy());
+            println!("\n{}:", e.lossy_string);
             enter_directory(&e, config);
         }
     }
 }
 
-fn get_metadata(entry: &Path, dereference: bool) -> std::io::Result<Metadata> {
+fn get_metadata(entry: &Path, config: &Config, command_line: bool) -> std::io::Result<Metadata> {
+    let dereference = match &config.dereference {
+        Dereference::All => true,
+        Dereference::Args => command_line,
+        Dereference::DirArgs => {
+            if command_line {
+                if let Ok(md) = entry.metadata() {
+                    md.is_dir()
+                } else {
+                    false
+                }
+            } else {
+                false
+            }
+        }
+        Dereference::None => false,
+    };
     if dereference {
         entry.metadata().or_else(|_| entry.symlink_metadata())
     } else {
@@ -1182,8 +1213,8 @@ fn get_metadata(entry: &Path, dereference: bool) -> std::io::Result<Metadata> {
     }
 }
 
-fn display_dir_entry_size(entry: &Path, config: &Config) -> (usize, usize) {
-    if let Ok(md) = get_metadata(entry, false) {
+fn display_dir_entry_size(entry: &PathData, config: &Config) -> (usize, usize) {
+    if let Ok(md) = entry.md.as_ref() {
         (
             display_symlink_count(&md).len(),
             display_file_size(&md, config).len(),
@@ -1197,7 +1228,7 @@ fn pad_left(string: String, count: usize) -> String {
     format!("{:>width$}", string, width = count)
 }
 
-fn display_items(items: &[PathBuf], strip: Option<&Path>, config: &Config, command_line: bool) {
+fn display_items(items: &[PathData], strip: Option<&Path>, config: &Config) {
     if config.format == Format::Long {
         let (mut max_links, mut max_size) = (1, 1);
         for item in items {
@@ -1206,18 +1237,18 @@ fn display_items(items: &[PathBuf], strip: Option<&Path>, config: &Config, comma
             max_size = size.max(max_size);
         }
         for item in items {
-            display_item_long(item, strip, max_links, max_size, config, command_line);
+            display_item_long(item, strip, max_links, max_size, config);
         }
     } else {
         let names = items.iter().filter_map(|i| {
-            let md = get_metadata(i, false);
+            let md = i.md.as_ref();
             match md {
                 Err(e) => {
-                    let filename = get_file_name(i, strip);
+                    let filename = get_file_name(&i.p_buf, strip);
                     show_error!("'{}': {}", filename, e);
                     None
                 }
-                Ok(md) => Some(display_file_name(&i, strip, &md, config)),
+                Ok(md) => Some(display_file_name(&i.p_buf, strip, &md, config)),
             }
         });
 
@@ -1277,33 +1308,15 @@ fn display_grid(names: impl Iterator<Item = Cell>, width: u16, direction: Direct
 use uucore::fs::display_permissions;
 
 fn display_item_long(
-    item: &Path,
+    item: &PathData,
     strip: Option<&Path>,
     max_links: usize,
     max_size: usize,
     config: &Config,
-    command_line: bool,
 ) {
-    let dereference = match &config.dereference {
-        Dereference::All => true,
-        Dereference::Args => command_line,
-        Dereference::DirArgs => {
-            if command_line {
-                if let Ok(md) = item.metadata() {
-                    md.is_dir()
-                } else {
-                    false
-                }
-            } else {
-                false
-            }
-        }
-        Dereference::None => false,
-    };
-
-    let md = match get_metadata(item, dereference) {
+    let md = match &item.md {
         Err(e) => {
-            let filename = get_file_name(&item, strip);
+            let filename = get_file_name(&item.p_buf, strip);
             show_error!("{}: {}", filename, e);
             return;
         }
@@ -1342,7 +1355,7 @@ fn display_item_long(
         " {} {} {}",
         pad_left(display_file_size(&md, config), max_size),
         display_date(&md, config),
-        display_file_name(&item, strip, &md, config).contents,
+        display_file_name(&item.p_buf, strip, &md, config).contents,
     );
 }
 

From af68ec853efbd2ecc9021b42205225b583a89b6a Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Sat, 17 Apr 2021 18:09:04 +0530
Subject: [PATCH 03/11] ls: Cache more data related to paths

- Cache filename and sort by filename instead of full path
- Cache uid->usr and gid->grp mappings
---
 Cargo.lock           | 238 ++++++++++++++++++++++++++++++++++++++++++-
 src/uu/ls/Cargo.toml |   1 +
 src/uu/ls/src/ls.rs  |  25 ++++-
 3 files changed, 259 insertions(+), 5 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 461716b1bc7..9c8a058bdd0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -37,6 +37,26 @@ dependencies = [
  "nodrop",
 ]
 
+[[package]]
+name = "async-mutex"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "479db852db25d9dbf6204e6cb6253698f175c15726470f78af0d918e99d6156e"
+dependencies = [
+ "event-listener",
+]
+
+[[package]]
+name = "async-trait"
+version = "0.1.49"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "589652ce7ccb335d1e7ecb3be145425702b290dbcb7029bbeaae263fc1d87b48"
+dependencies = [
+ "proc-macro2",
+ "quote 1.0.9",
+ "syn",
+]
+
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -125,6 +145,40 @@ version = "1.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"
 
+[[package]]
+name = "cached"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e2afe73808fbaac302e39c9754bfc3c4b4d0f99c9c240b9f4e4efc841ad1b74"
+dependencies = [
+ "async-mutex",
+ "async-trait",
+ "cached_proc_macro",
+ "cached_proc_macro_types",
+ "futures",
+ "hashbrown",
+ "once_cell",
+]
+
+[[package]]
+name = "cached_proc_macro"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bf857ae42d910aede5c5186e62684b0d7a597ce2fe3bd14448ab8f7ef439848c"
+dependencies = [
+ "async-mutex",
+ "cached_proc_macro_types",
+ "darling",
+ "quote 1.0.9",
+ "syn",
+]
+
+[[package]]
+name = "cached_proc_macro_types"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a4f925191b4367301851c6d99b09890311d74b0d43f274c0b34c86d308a3663"
+
 [[package]]
 name = "cast"
 version = "0.2.3"
@@ -172,7 +226,7 @@ dependencies = [
  "ansi_term",
  "atty",
  "bitflags",
- "strsim",
+ "strsim 0.8.0",
  "textwrap",
  "unicode-width",
  "vec_map",
@@ -523,6 +577,41 @@ version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ef8ae57c4978a2acd8b869ce6b9ca1dfe817bff704c220209fdef2c0b75a01b9"
 
+[[package]]
+name = "darling"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d706e75d87e35569db781a9b5e2416cff1236a47ed380831f959382ccd5f858"
+dependencies = [
+ "darling_core",
+ "darling_macro",
+]
+
+[[package]]
+name = "darling_core"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0c960ae2da4de88a91b2d920c2a7233b400bc33cb28453a2987822d8392519b"
+dependencies = [
+ "fnv",
+ "ident_case",
+ "proc-macro2",
+ "quote 1.0.9",
+ "strsim 0.9.3",
+ "syn",
+]
+
+[[package]]
+name = "darling_macro"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b5a2f4ac4969822c62224815d069952656cadc7084fdca9751e6d959189b72"
+dependencies = [
+ "darling_core",
+ "quote 1.0.9",
+ "syn",
+]
+
 [[package]]
 name = "data-encoding"
 version = "2.1.2"
@@ -560,6 +649,12 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "event-listener"
+version = "2.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7531096570974c3a9dcf9e4b8e1cede1ec26cf5046219fb3b9d897503b9be59"
+
 [[package]]
 name = "fake-simd"
 version = "0.1.2"
@@ -602,6 +697,98 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
 
+[[package]]
+name = "futures"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a9d5813545e459ad3ca1bff9915e9ad7f1a47dc6a91b627ce321d5863b7dd253"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "futures-executor",
+ "futures-io",
+ "futures-sink",
+ "futures-task",
+ "futures-util",
+]
+
+[[package]]
+name = "futures-channel"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce79c6a52a299137a6013061e0cf0e688fce5d7f1bc60125f520912fdb29ec25"
+dependencies = [
+ "futures-core",
+ "futures-sink",
+]
+
+[[package]]
+name = "futures-core"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "098cd1c6dda6ca01650f1a37a794245eb73181d0d4d4e955e2f3c37db7af1815"
+
+[[package]]
+name = "futures-executor"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10f6cb7042eda00f0049b1d2080aa4b93442997ee507eb3828e8bd7577f94c9d"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "futures-util",
+]
+
+[[package]]
+name = "futures-io"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "365a1a1fb30ea1c03a830fdb2158f5236833ac81fa0ad12fe35b29cddc35cb04"
+
+[[package]]
+name = "futures-macro"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "668c6733a182cd7deb4f1de7ba3bf2120823835b3bcfbeacf7d2c4a773c1bb8b"
+dependencies = [
+ "proc-macro-hack",
+ "proc-macro2",
+ "quote 1.0.9",
+ "syn",
+]
+
+[[package]]
+name = "futures-sink"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c5629433c555de3d82861a7a4e3794a4c40040390907cfbfd7143a92a426c23"
+
+[[package]]
+name = "futures-task"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba7aa51095076f3ba6d9a1f702f74bd05ec65f555d70d2033d55ba8d69f581bc"
+
+[[package]]
+name = "futures-util"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3c144ad54d60f23927f0a6b6d816e4271278b64f005ad65e4e35291d2de9c025"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "futures-io",
+ "futures-macro",
+ "futures-sink",
+ "futures-task",
+ "memchr 2.3.4",
+ "pin-project-lite",
+ "pin-utils",
+ "proc-macro-hack",
+ "proc-macro-nested",
+ "slab",
+]
+
 [[package]]
 name = "generic-array"
 version = "0.8.4"
@@ -663,6 +850,12 @@ version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "62aca2aba2d62b4a7f5b33f3712cb1b0692779a56fb510499d5c0aa594daeaf3"
 
+[[package]]
+name = "hashbrown"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
+
 [[package]]
 name = "heck"
 version = "0.3.2"
@@ -698,6 +891,12 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
+[[package]]
+name = "ident_case"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
+
 [[package]]
 name = "if_rust_version"
 version = "1.0.0"
@@ -897,6 +1096,12 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8f8bdf33df195859076e54ab11ee78a1b208382d3a26ec40d142ffc1ecc49ef"
 
+[[package]]
+name = "once_cell"
+version = "1.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af8b08b04175473088b46763e51ee54da5f9a164bc162f615b91bc179dbf15a3"
+
 [[package]]
 name = "onig"
 version = "4.3.3"
@@ -944,6 +1149,18 @@ dependencies = [
  "proc-macro-hack",
 ]
 
+[[package]]
+name = "pin-project-lite"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc0e1f259c92177c30a4c9d177246edd0a3568b25756a977d0632cf8fa37e905"
+
+[[package]]
+name = "pin-utils"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
+
 [[package]]
 name = "pkg-config"
 version = "0.3.19"
@@ -1000,6 +1217,12 @@ version = "0.5.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 
+[[package]]
+name = "proc-macro-nested"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc881b2c22681370c6a780e47af9840ef841837bc98118431d4e1868bd0c1086"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.26"
@@ -1353,6 +1576,12 @@ dependencies = [
  "generic-array",
 ]
 
+[[package]]
+name = "slab"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
+
 [[package]]
 name = "smallvec"
 version = "0.6.14"
@@ -1374,6 +1603,12 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 
+[[package]]
+name = "strsim"
+version = "0.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6446ced80d6c486436db5c078dde11a9f73d42b57fb273121e160b84f63d894c"
+
 [[package]]
 name = "strum"
 version = "0.20.0"
@@ -1987,6 +2222,7 @@ name = "uu_ls"
 version = "0.0.6"
 dependencies = [
  "atty",
+ "cached",
  "clap",
  "globset",
  "lazy_static",
diff --git a/src/uu/ls/Cargo.toml b/src/uu/ls/Cargo.toml
index dacdc7cd9fa..5684652b1b6 100644
--- a/src/uu/ls/Cargo.toml
+++ b/src/uu/ls/Cargo.toml
@@ -15,6 +15,7 @@ edition = "2018"
 path = "src/ls.rs"
 
 [dependencies]
+cached = "0.23.0"
 clap = "2.33"
 lazy_static = "1.0.1"
 number_prefix = "0.4"
diff --git a/src/uu/ls/src/ls.rs b/src/uu/ls/src/ls.rs
index d37033a9a34..a5523951038 100644
--- a/src/uu/ls/src/ls.rs
+++ b/src/uu/ls/src/ls.rs
@@ -16,6 +16,7 @@ extern crate uucore;
 mod quoting_style;
 mod version_cmp;
 
+use cached::proc_macro::cached;
 use clap::{App, Arg};
 use globset::{self, Glob, GlobSet, GlobSetBuilder};
 use number_prefix::NumberPrefix;
@@ -1041,6 +1042,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
 struct PathData {
     md: std::io::Result<Metadata>,
     lossy_string: String,
+    name: String,
     p_buf: PathBuf,
 }
 
@@ -1048,10 +1050,13 @@ impl PathData {
     fn new(p_buf: PathBuf, config: &Config, command_line: bool) -> Self {
         let md = get_metadata(&p_buf, config, command_line);
         let lossy_string = p_buf.to_string_lossy().into_owned();
-        // let path_name: String =
+        let name = p_buf
+            .file_name()
+            .map_or(String::new(), |s| s.to_string_lossy().into_owned());
         Self {
             md,
             lossy_string,
+            name,
             p_buf,
         }
     }
@@ -1120,7 +1125,7 @@ fn sort_entries(entries: &mut Vec<PathData>, config: &Config) {
             entries.sort_by_key(|k| Reverse(k.md.as_ref().map(|md| md.len()).unwrap_or(0)))
         }
         // The default sort in GNU ls is case insensitive
-        Sort::Name => entries.sort_by_key(|k| k.lossy_string.to_lowercase()),
+        Sort::Name => entries.sort_by_key(|k| k.name.to_lowercase()),
         Sort::Version => entries.sort_by(|k, j| version_cmp::version_cmp(&k.p_buf, &j.p_buf)),
         Sort::None => {}
     }
@@ -1369,21 +1374,33 @@ fn get_inode(metadata: &Metadata) -> String {
 #[cfg(unix)]
 use uucore::entries;
 
+#[cfg(unix)]
+#[cached]
+fn cached_uid2usr(uid: u32) -> String {
+    entries::uid2usr(uid).unwrap_or_else(|_| uid.to_string())
+}
+
 #[cfg(unix)]
 fn display_uname(metadata: &Metadata, config: &Config) -> String {
     if config.long.numeric_uid_gid {
         metadata.uid().to_string()
     } else {
-        entries::uid2usr(metadata.uid()).unwrap_or_else(|_| metadata.uid().to_string())
+        cached_uid2usr(metadata.uid())
     }
 }
 
+#[cfg(unix)]
+#[cached]
+fn cached_gid2grp(gid: u32) -> String {
+    entries::gid2grp(gid).unwrap_or_else(|_| gid.to_string())
+}
+
 #[cfg(unix)]
 fn display_group(metadata: &Metadata, config: &Config) -> String {
     if config.long.numeric_uid_gid {
         metadata.gid().to_string()
     } else {
-        entries::gid2grp(metadata.gid()).unwrap_or_else(|_| metadata.gid().to_string())
+        cached_gid2grp(metadata.gid())
     }
 }
 

From a7bbef9a0fcdde10ea39a136705feb01b484f95d Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Sun, 18 Apr 2021 15:26:45 +0530
Subject: [PATCH 04/11] ls: Add BENCHMARKING.md

---
 src/uu/ls/BENCHMARKING.md | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 src/uu/ls/BENCHMARKING.md

diff --git a/src/uu/ls/BENCHMARKING.md b/src/uu/ls/BENCHMARKING.md
new file mode 100644
index 00000000000..c23202ed2b3
--- /dev/null
+++ b/src/uu/ls/BENCHMARKING.md
@@ -0,0 +1,29 @@
+# Benchmarking ls
+
+ls majorly involves fetching a lot of details (depending upon what details are requested, eg. time/date, inode details, etc) for each path using system calls. Ideally, any system call should be done only once for each of the paths - not adhering to this principle leads to a lot of system call overhead multiplying and bubbling up, especially for recursive ls, therefore it is important to always benchmark multiple scenarios.
+This is an overwiew over what was benchmarked, and if you make changes to `ls`, you are encouraged to check
+how performance was affected for the workloads listed below. Feel free to add other workloads to the
+list that we should improve / make sure not to regress.
+
+Run `cargo build --release` before benchmarking after you make a change!
+
+## Simple recursive ls
+
+-   Get a large tree, for example linux kernel source tree.
+-   Benchmark simple recursive ls with hyperfine: `hyperfine --warmup 2 "target/release/coreutils ls -R tree > /dev/null"`.
+
+## Recursive ls with all and long options
+
+-   Same tree as above
+-   Benchmark recursive ls with -al -R options with hyperfine: `hyperfine --warmup 2 "target/release/coreutils ls -al -R tree > /dev/null"`.
+
+## Comparing with GNU sort
+
+Hyperfine accepts multiple commands to run and will compare them. To compare performance with GNU sort
+duplicate the string you passed to hyperfine but remove the `target/release/coreutils` bit from it.
+
+Example: `hyperfine --warmup 2 "target/release/coreutils ls -al -R tree > /dev/null"` becomes
+`hyperfine --warmup 2 "target/release/coreutils ls -al -R tree > /dev/null" "ls -al -R tree > /dev/null"`
+(This assumes GNU sort is installed as `sort`)
+
+This can also be used to compare with version of ls built before your changes to ensure your change does not regress this
\ No newline at end of file

From f89cb6d6c82a6fdcefdb46e69620eac13bdf4d89 Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Sun, 18 Apr 2021 16:09:23 +0530
Subject: [PATCH 05/11] ls: Document PathData structure

---
 src/uu/ls/src/ls.rs | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/uu/ls/src/ls.rs b/src/uu/ls/src/ls.rs
index a5523951038..1f5087c75c9 100644
--- a/src/uu/ls/src/ls.rs
+++ b/src/uu/ls/src/ls.rs
@@ -1039,10 +1039,17 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
     list(locs, Config::from(matches))
 }
 
+/// Represents a Path along with it's associated data
+/// Any data that will be reused several times makes sense to be added to this structure
+/// Caching data here helps eliminate redundant syscalls to fetch same information
 struct PathData {
+    // Result<MetaData> got from symlink_metadata() or metadata() based on config
     md: std::io::Result<Metadata>,
+    // String formed from get_lossy_string() for the path
     lossy_string: String,
-    name: String,
+    // Name of the file - will be empty for . or ..
+    file_name: String,
+    // PathBuf that all above data corresponds to
     p_buf: PathBuf,
 }
 
@@ -1056,7 +1063,7 @@ impl PathData {
         Self {
             md,
             lossy_string,
-            name,
+            file_name: name,
             p_buf,
         }
     }
@@ -1125,7 +1132,7 @@ fn sort_entries(entries: &mut Vec<PathData>, config: &Config) {
             entries.sort_by_key(|k| Reverse(k.md.as_ref().map(|md| md.len()).unwrap_or(0)))
         }
         // The default sort in GNU ls is case insensitive
-        Sort::Name => entries.sort_by_key(|k| k.name.to_lowercase()),
+        Sort::Name => entries.sort_by_key(|k| k.file_name.to_lowercase()),
         Sort::Version => entries.sort_by(|k, j| version_cmp::version_cmp(&k.p_buf, &j.p_buf)),
         Sort::None => {}
     }

From b4af0d02d5192924ae5252013e7673942cf1799c Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Sun, 18 Apr 2021 16:59:23 +0530
Subject: [PATCH 06/11] tests/ls: Add testcase for error paths with width
 option

---
 tests/by-util/test_ls.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tests/by-util/test_ls.rs b/tests/by-util/test_ls.rs
index d810cdc294f..5583dbaca5f 100644
--- a/tests/by-util/test_ls.rs
+++ b/tests/by-util/test_ls.rs
@@ -103,6 +103,14 @@ fn test_ls_width() {
             .succeeds()
             .stdout_only("test-width-1\ntest-width-2\ntest-width-3\ntest-width-4\n");
     }
+
+    for option in &["-w 1a", "-w=1a", "--width=1a", "--width 1a"] {
+        scene
+            .ucmd()
+            .args(&option.split(" ").collect::<Vec<_>>())
+            .fails()
+            .stderr_only("ls: error: invalid line width: ‘1a’");
+    }
 }
 
 #[test]

From 5731dc47548c8845324206c4473288c4aacc4a23 Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Mon, 19 Apr 2021 19:25:38 +0530
Subject: [PATCH 07/11] ls: Fix unused import warning

cached will be only used for unix currently as current use of
caching gid/uid mappings is only relevant on unix
---
 src/uu/ls/src/ls.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/uu/ls/src/ls.rs b/src/uu/ls/src/ls.rs
index 1f5087c75c9..0cf448b586e 100644
--- a/src/uu/ls/src/ls.rs
+++ b/src/uu/ls/src/ls.rs
@@ -16,6 +16,7 @@ extern crate uucore;
 mod quoting_style;
 mod version_cmp;
 
+#[cfg(unix)]
 use cached::proc_macro::cached;
 use clap::{App, Arg};
 use globset::{self, Glob, GlobSet, GlobSetBuilder};

From fc66b3205678b7423175a2f6e286b835e4e1a0c4 Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Mon, 19 Apr 2021 20:16:52 +0530
Subject: [PATCH 08/11] ls: Suggest checking syscall count in BENCHMARKING.md

---
 src/uu/ls/BENCHMARKING.md | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/uu/ls/BENCHMARKING.md b/src/uu/ls/BENCHMARKING.md
index c23202ed2b3..a902ea26103 100644
--- a/src/uu/ls/BENCHMARKING.md
+++ b/src/uu/ls/BENCHMARKING.md
@@ -26,4 +26,9 @@ Example: `hyperfine --warmup 2 "target/release/coreutils ls -al -R tree > /dev/n
 `hyperfine --warmup 2 "target/release/coreutils ls -al -R tree > /dev/null" "ls -al -R tree > /dev/null"`
 (This assumes GNU sort is installed as `sort`)
 
-This can also be used to compare with version of ls built before your changes to ensure your change does not regress this
\ No newline at end of file
+This can also be used to compare with version of ls built before your changes to ensure your change does not regress this
+
+## Checking system call count
+
+- Another thing to look at would be system calls count using strace (on linux) or equivalent on other operating systems.
+- Example: `strace -c target/release/coreutils ls -al -R tree`

From 34b4ae08a7970eefb4560b457fd85becc80479fb Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Mon, 19 Apr 2021 20:16:52 +0530
Subject: [PATCH 09/11] ls: Remove mentions of sort in BENCHMARKING.md

---
 src/uu/ls/BENCHMARKING.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/uu/ls/BENCHMARKING.md b/src/uu/ls/BENCHMARKING.md
index a902ea26103..84a0c3d843a 100644
--- a/src/uu/ls/BENCHMARKING.md
+++ b/src/uu/ls/BENCHMARKING.md
@@ -17,14 +17,14 @@ Run `cargo build --release` before benchmarking after you make a change!
 -   Same tree as above
 -   Benchmark recursive ls with -al -R options with hyperfine: `hyperfine --warmup 2 "target/release/coreutils ls -al -R tree > /dev/null"`.
 
-## Comparing with GNU sort
+## Comparing with GNU ls
 
-Hyperfine accepts multiple commands to run and will compare them. To compare performance with GNU sort
+Hyperfine accepts multiple commands to run and will compare them. To compare performance with GNU ls
 duplicate the string you passed to hyperfine but remove the `target/release/coreutils` bit from it.
 
 Example: `hyperfine --warmup 2 "target/release/coreutils ls -al -R tree > /dev/null"` becomes
 `hyperfine --warmup 2 "target/release/coreutils ls -al -R tree > /dev/null" "ls -al -R tree > /dev/null"`
-(This assumes GNU sort is installed as `sort`)
+(This assumes GNU ls is installed as `ls`)
 
 This can also be used to compare with version of ls built before your changes to ensure your change does not regress this
 

From 9415f6c15b6f3c8d6999e74a6fb05f4bbb228575 Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Tue, 20 Apr 2021 21:23:11 +0530
Subject: [PATCH 10/11] ls: Remove dependency on cached

Implement caching using HashMap and lazy_static
---
 Cargo.lock           | 238 +------------------------------------------
 src/uu/ls/Cargo.toml |   1 -
 src/uu/ls/src/ls.rs  |  34 +++++--
 3 files changed, 29 insertions(+), 244 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 9c8a058bdd0..461716b1bc7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -37,26 +37,6 @@ dependencies = [
  "nodrop",
 ]
 
-[[package]]
-name = "async-mutex"
-version = "1.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "479db852db25d9dbf6204e6cb6253698f175c15726470f78af0d918e99d6156e"
-dependencies = [
- "event-listener",
-]
-
-[[package]]
-name = "async-trait"
-version = "0.1.49"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "589652ce7ccb335d1e7ecb3be145425702b290dbcb7029bbeaae263fc1d87b48"
-dependencies = [
- "proc-macro2",
- "quote 1.0.9",
- "syn",
-]
-
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -145,40 +125,6 @@ version = "1.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"
 
-[[package]]
-name = "cached"
-version = "0.23.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e2afe73808fbaac302e39c9754bfc3c4b4d0f99c9c240b9f4e4efc841ad1b74"
-dependencies = [
- "async-mutex",
- "async-trait",
- "cached_proc_macro",
- "cached_proc_macro_types",
- "futures",
- "hashbrown",
- "once_cell",
-]
-
-[[package]]
-name = "cached_proc_macro"
-version = "0.6.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf857ae42d910aede5c5186e62684b0d7a597ce2fe3bd14448ab8f7ef439848c"
-dependencies = [
- "async-mutex",
- "cached_proc_macro_types",
- "darling",
- "quote 1.0.9",
- "syn",
-]
-
-[[package]]
-name = "cached_proc_macro_types"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a4f925191b4367301851c6d99b09890311d74b0d43f274c0b34c86d308a3663"
-
 [[package]]
 name = "cast"
 version = "0.2.3"
@@ -226,7 +172,7 @@ dependencies = [
  "ansi_term",
  "atty",
  "bitflags",
- "strsim 0.8.0",
+ "strsim",
  "textwrap",
  "unicode-width",
  "vec_map",
@@ -577,41 +523,6 @@ version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ef8ae57c4978a2acd8b869ce6b9ca1dfe817bff704c220209fdef2c0b75a01b9"
 
-[[package]]
-name = "darling"
-version = "0.10.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d706e75d87e35569db781a9b5e2416cff1236a47ed380831f959382ccd5f858"
-dependencies = [
- "darling_core",
- "darling_macro",
-]
-
-[[package]]
-name = "darling_core"
-version = "0.10.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f0c960ae2da4de88a91b2d920c2a7233b400bc33cb28453a2987822d8392519b"
-dependencies = [
- "fnv",
- "ident_case",
- "proc-macro2",
- "quote 1.0.9",
- "strsim 0.9.3",
- "syn",
-]
-
-[[package]]
-name = "darling_macro"
-version = "0.10.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d9b5a2f4ac4969822c62224815d069952656cadc7084fdca9751e6d959189b72"
-dependencies = [
- "darling_core",
- "quote 1.0.9",
- "syn",
-]
-
 [[package]]
 name = "data-encoding"
 version = "2.1.2"
@@ -649,12 +560,6 @@ dependencies = [
  "regex",
 ]
 
-[[package]]
-name = "event-listener"
-version = "2.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7531096570974c3a9dcf9e4b8e1cede1ec26cf5046219fb3b9d897503b9be59"
-
 [[package]]
 name = "fake-simd"
 version = "0.1.2"
@@ -697,98 +602,6 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
 
-[[package]]
-name = "futures"
-version = "0.3.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a9d5813545e459ad3ca1bff9915e9ad7f1a47dc6a91b627ce321d5863b7dd253"
-dependencies = [
- "futures-channel",
- "futures-core",
- "futures-executor",
- "futures-io",
- "futures-sink",
- "futures-task",
- "futures-util",
-]
-
-[[package]]
-name = "futures-channel"
-version = "0.3.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce79c6a52a299137a6013061e0cf0e688fce5d7f1bc60125f520912fdb29ec25"
-dependencies = [
- "futures-core",
- "futures-sink",
-]
-
-[[package]]
-name = "futures-core"
-version = "0.3.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "098cd1c6dda6ca01650f1a37a794245eb73181d0d4d4e955e2f3c37db7af1815"
-
-[[package]]
-name = "futures-executor"
-version = "0.3.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "10f6cb7042eda00f0049b1d2080aa4b93442997ee507eb3828e8bd7577f94c9d"
-dependencies = [
- "futures-core",
- "futures-task",
- "futures-util",
-]
-
-[[package]]
-name = "futures-io"
-version = "0.3.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "365a1a1fb30ea1c03a830fdb2158f5236833ac81fa0ad12fe35b29cddc35cb04"
-
-[[package]]
-name = "futures-macro"
-version = "0.3.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "668c6733a182cd7deb4f1de7ba3bf2120823835b3bcfbeacf7d2c4a773c1bb8b"
-dependencies = [
- "proc-macro-hack",
- "proc-macro2",
- "quote 1.0.9",
- "syn",
-]
-
-[[package]]
-name = "futures-sink"
-version = "0.3.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c5629433c555de3d82861a7a4e3794a4c40040390907cfbfd7143a92a426c23"
-
-[[package]]
-name = "futures-task"
-version = "0.3.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ba7aa51095076f3ba6d9a1f702f74bd05ec65f555d70d2033d55ba8d69f581bc"
-
-[[package]]
-name = "futures-util"
-version = "0.3.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3c144ad54d60f23927f0a6b6d816e4271278b64f005ad65e4e35291d2de9c025"
-dependencies = [
- "futures-channel",
- "futures-core",
- "futures-io",
- "futures-macro",
- "futures-sink",
- "futures-task",
- "memchr 2.3.4",
- "pin-project-lite",
- "pin-utils",
- "proc-macro-hack",
- "proc-macro-nested",
- "slab",
-]
-
 [[package]]
 name = "generic-array"
 version = "0.8.4"
@@ -850,12 +663,6 @@ version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "62aca2aba2d62b4a7f5b33f3712cb1b0692779a56fb510499d5c0aa594daeaf3"
 
-[[package]]
-name = "hashbrown"
-version = "0.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
-
 [[package]]
 name = "heck"
 version = "0.3.2"
@@ -891,12 +698,6 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
-[[package]]
-name = "ident_case"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
-
 [[package]]
 name = "if_rust_version"
 version = "1.0.0"
@@ -1096,12 +897,6 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8f8bdf33df195859076e54ab11ee78a1b208382d3a26ec40d142ffc1ecc49ef"
 
-[[package]]
-name = "once_cell"
-version = "1.7.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af8b08b04175473088b46763e51ee54da5f9a164bc162f615b91bc179dbf15a3"
-
 [[package]]
 name = "onig"
 version = "4.3.3"
@@ -1149,18 +944,6 @@ dependencies = [
  "proc-macro-hack",
 ]
 
-[[package]]
-name = "pin-project-lite"
-version = "0.2.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc0e1f259c92177c30a4c9d177246edd0a3568b25756a977d0632cf8fa37e905"
-
-[[package]]
-name = "pin-utils"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
-
 [[package]]
 name = "pkg-config"
 version = "0.3.19"
@@ -1217,12 +1000,6 @@ version = "0.5.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 
-[[package]]
-name = "proc-macro-nested"
-version = "0.1.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc881b2c22681370c6a780e47af9840ef841837bc98118431d4e1868bd0c1086"
-
 [[package]]
 name = "proc-macro2"
 version = "1.0.26"
@@ -1576,12 +1353,6 @@ dependencies = [
  "generic-array",
 ]
 
-[[package]]
-name = "slab"
-version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
-
 [[package]]
 name = "smallvec"
 version = "0.6.14"
@@ -1603,12 +1374,6 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
 
-[[package]]
-name = "strsim"
-version = "0.9.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6446ced80d6c486436db5c078dde11a9f73d42b57fb273121e160b84f63d894c"
-
 [[package]]
 name = "strum"
 version = "0.20.0"
@@ -2222,7 +1987,6 @@ name = "uu_ls"
 version = "0.0.6"
 dependencies = [
  "atty",
- "cached",
  "clap",
  "globset",
  "lazy_static",
diff --git a/src/uu/ls/Cargo.toml b/src/uu/ls/Cargo.toml
index 5684652b1b6..dacdc7cd9fa 100644
--- a/src/uu/ls/Cargo.toml
+++ b/src/uu/ls/Cargo.toml
@@ -15,7 +15,6 @@ edition = "2018"
 path = "src/ls.rs"
 
 [dependencies]
-cached = "0.23.0"
 clap = "2.33"
 lazy_static = "1.0.1"
 number_prefix = "0.4"
diff --git a/src/uu/ls/src/ls.rs b/src/uu/ls/src/ls.rs
index 0cf448b586e..47d1b708a06 100644
--- a/src/uu/ls/src/ls.rs
+++ b/src/uu/ls/src/ls.rs
@@ -16,8 +16,6 @@ extern crate uucore;
 mod quoting_style;
 mod version_cmp;
 
-#[cfg(unix)]
-use cached::proc_macro::cached;
 use clap::{App, Arg};
 use globset::{self, Glob, GlobSet, GlobSetBuilder};
 use number_prefix::NumberPrefix;
@@ -1380,12 +1378,25 @@ fn get_inode(metadata: &Metadata) -> String {
 // Currently getpwuid is `linux` target only. If it's broken out into
 // a posix-compliant attribute this can be updated...
 #[cfg(unix)]
+use std::sync::Mutex;
+#[cfg(unix)]
 use uucore::entries;
 
 #[cfg(unix)]
-#[cached]
 fn cached_uid2usr(uid: u32) -> String {
-    entries::uid2usr(uid).unwrap_or_else(|_| uid.to_string())
+    lazy_static! {
+        static ref UID_CACHE: Mutex<HashMap<u32, String>> = Mutex::new(HashMap::new());
+    }
+
+    let mut uid_cache = UID_CACHE.lock().unwrap();
+    match uid_cache.get(&uid) {
+        Some(usr) => usr.clone(),
+        None => {
+            let usr = entries::uid2usr(uid).unwrap_or_else(|_| uid.to_string());
+            uid_cache.insert(uid, usr.clone());
+            usr
+        }
+    }
 }
 
 #[cfg(unix)]
@@ -1398,9 +1409,20 @@ fn display_uname(metadata: &Metadata, config: &Config) -> String {
 }
 
 #[cfg(unix)]
-#[cached]
 fn cached_gid2grp(gid: u32) -> String {
-    entries::gid2grp(gid).unwrap_or_else(|_| gid.to_string())
+    lazy_static! {
+        static ref GID_CACHE: Mutex<HashMap<u32, String>> = Mutex::new(HashMap::new());
+    }
+
+    let mut gid_cache = GID_CACHE.lock().unwrap();
+    match gid_cache.get(&gid) {
+        Some(grp) => grp.clone(),
+        None => {
+            let grp = entries::gid2grp(gid).unwrap_or_else(|_| gid.to_string());
+            gid_cache.insert(gid, grp.clone());
+            grp
+        }
+    }
 }
 
 #[cfg(unix)]

From 42ecac32ffc6e606d1d04ed906176ca5f757e382 Mon Sep 17 00:00:00 2001
From: Anup Mahindre <anup.mahindre.7@gmail.com>
Date: Tue, 20 Apr 2021 22:49:10 +0530
Subject: [PATCH 11/11] ls: Fix MSRV error related to map_or

Rust 1.40 did not support map_or for result types
---
 src/uu/ls/src/ls.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/uu/ls/src/ls.rs b/src/uu/ls/src/ls.rs
index 47d1b708a06..e0aa3ec4bc4 100644
--- a/src/uu/ls/src/ls.rs
+++ b/src/uu/ls/src/ls.rs
@@ -1192,7 +1192,7 @@ fn enter_directory(dir: &PathData, config: &Config) {
         for e in entries
             .iter()
             .skip(if config.files == Files::All { 2 } else { 0 })
-            .filter(|p| p.md.as_ref().map_or(false, |md| md.is_dir()))
+            .filter(|p| p.md.as_ref().map(|md| md.is_dir()).unwrap_or(false))
         {
             println!("\n{}:", e.lossy_string);
             enter_directory(&e, config);