ls: Reduce xattr calls

src/uu/ls/src/colors.rs

@@ -530,7 +530,7 @@ pub(crate) fn color_name(
         let has_capabilities = style_manager
             .colors
             .has_explicit_style_for(Indicator::Capabilities)
-            && uucore::fsxattr::has_security_cap_acl(path.p_buf.as_path());
+            && path.has_security_cap();
 
         // If the file has capabilities, use a specific style for `ca` (capabilities)
         if has_capabilities {

src/uu/ls/src/ls.rs

@@ -9,12 +9,13 @@
 #[cfg(unix)]
 use rustc_hash::FxHashMap;
 use rustc_hash::FxHashSet;
-use std::borrow::Cow;
-use std::cell::RefCell;
 #[cfg(unix)]
 use std::os::unix::fs::{FileTypeExt, MetadataExt};
 #[cfg(windows)]
 use std::os::windows::fs::MetadataExt;
+#[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
+use std::sync::Once;
+use std::{borrow::Cow, cell::RefCell};
 use std::{
     cell::{LazyCell, OnceCell},
     cmp::Reverse,
@@ -42,7 +43,7 @@ use thiserror::Error;
 #[cfg(unix)]
 use uucore::entries;
 #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
-use uucore::fsxattr::has_acl;
+use uucore::fsxattr::retrieve_xattr_list;
 #[cfg(unix)]
 use uucore::libc::{S_IXGRP, S_IXOTH, S_IXUSR};
 #[cfg(any(
@@ -63,14 +64,13 @@ use uucore::{
     error::{UError, UResult, set_exit_code},
     format::human::{SizeFormat, human_readable},
     format_usage,
-    fs::FileInformation,
-    fs::display_permissions,
+    fs::{FileInformation, display_permissions},
     fsext::{MetadataTimeField, metadata_get_time},
     line_ending::LineEnding,
     os_str_as_bytes_lossy,
-    parser::parse_glob,
-    parser::parse_size::parse_size_non_zero_u64,
-    parser::shortcut_value_parser::ShortcutValueParser,
+    parser::{
+        parse_glob, parse_size::parse_size_non_zero_u64, shortcut_value_parser::ShortcutValueParser,
+    },
     quoting_style::{QuotingStyle, locale_aware_escape_dir_name, locale_aware_escape_name},
     show, show_error, show_warning,
     time::{FormatSystemTimeFallback, format, format_system_time},
@@ -1939,6 +1939,10 @@ struct PathData {
     p_buf: PathBuf,
     must_dereference: bool,
     command_line: bool,
+    #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
+    has_acl: OnceCell<bool>,
+    #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
+    has_security_cap: OnceCell<bool>,
 }
 
 impl PathData {
@@ -2011,6 +2015,10 @@ impl PathData {
             p_buf,
             must_dereference,
             command_line,
+            #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
+            has_acl: OnceCell::new(),
+            #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
+            has_security_cap: OnceCell::new(),
         }
     }
 
@@ -2051,6 +2059,43 @@ impl PathData {
             .as_ref()
     }
 
+    #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
+    pub fn has_acl(&self) -> bool {
+        self.init_xattrs_once();
+
+        self.has_acl.get().is_some_and(|inner| *inner)
+    }
+
+    #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
+    pub fn has_security_cap(&self) -> bool {
+        self.init_xattrs_once();
+
+        self.has_security_cap.get().is_some_and(|inner| *inner)
+    }
+
+    #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
+    pub fn init_xattrs_once(&self) {
+        static START: Once = Once::new();
+
+        START.call_once(|| {
+            let _ = retrieve_xattr_list(self.path()).map(|inner| {
+                self.has_security_cap.get_or_init(|| {
+                    let cap_key = OsStr::new("security.capability");
+
+                    !self.file_type().is_some_and(FileType::is_symlink) && inner.contains(cap_key)
+                });
+
+                self.has_acl.get_or_init(|| {
+                    !self.file_type().is_some_and(FileType::is_symlink)
+                        && inner
+                            .iter()
+                            .filter_map(|key| key.to_str().map(str::to_lowercase))
+                            .any(|xattr| xattr.contains("acl"))
+                });
+            });
+        });
+    }
+
     fn file_type(&self) -> Option<&FileType> {
         self.ft
             .get_or_init(|| self.metadata().map(Metadata::file_type))
@@ -3018,7 +3063,7 @@ fn display_item_long(
         // TODO: See how Mac should work here
         let is_acl_set = false;
         #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
-        let is_acl_set = has_acl(item.path());
+        let is_acl_set = item.has_acl();
         output_display.extend(display_permissions(md, true).as_bytes());
         if item.security_context(config).len() > 1 {
             // GNU `ls` uses a "." character to indicate a file with a security context,
@@ -3737,7 +3782,7 @@ fn calculate_padding_collection(
                 // TODO: See how Mac should work here
                 let is_acl_set = false;
                 #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
-                let is_acl_set = has_acl(item.display_name());
+                let is_acl_set = item.has_acl();
                 if context_len > 1 || is_acl_set {
                     padding_collections.link_count += 1;
                 }

src/uucore/src/lib/features/fsxattr.rs

@@ -6,11 +6,9 @@
 // spell-checker:ignore getxattr posix_acl_default
 
 //! Set of functions to manage xattr on files and dirs
-use itertools::Itertools;
-use rustc_hash::FxHashMap;
-use std::ffi::{OsStr, OsString};
+use rustc_hash::{FxHashMap, FxHashSet};
+use std::ffi::OsString;
 #[cfg(unix)]
-use std::os::unix::ffi::OsStrExt;
 use std::path::Path;
 
 /// Copies extended attributes (xattrs) from one file or directory to another.
@@ -56,14 +54,27 @@ pub fn copy_xattrs_skip_selinux<P: AsRef<Path>>(source: P, dest: P) -> std::io::
 /// A result containing a HashMap of attributes names and values, or an error.
 pub fn retrieve_xattrs<P: AsRef<Path>>(source: P) -> std::io::Result<FxHashMap<OsString, Vec<u8>>> {
     let mut attrs = FxHashMap::default();
-    for attr_name in xattr::list(&source)? {
+    for attr_name in retrieve_xattr_list(&source)? {
         if let Some(value) = xattr::get(&source, &attr_name)? {
             attrs.insert(attr_name, value);
         }
     }
     Ok(attrs)
 }
 
+/// Retrieves the extended attributes keys only of a given file or directory.
+///
+/// # Arguments
+///
+/// * `source` - A reference to the path of the file or directory.
+///
+/// # Returns
+///
+/// A result containing a HashSet of attributes names
+pub fn retrieve_xattr_list<P: AsRef<Path>>(source: P) -> std::io::Result<FxHashSet<OsString>> {
+    Ok(xattr::list(&source)?.collect())
+}
+
 /// Applies extended attributes (xattrs) to a given file or directory.
 ///
 /// # Arguments
@@ -112,13 +123,10 @@ pub fn has_acl<P: AsRef<Path>>(file: P) -> bool {
 /// `true` if the file has an extended attribute named "security.capability", `false` otherwise.
 pub fn has_security_cap_acl<P: AsRef<Path>>(file: P) -> bool {
     // don't use exacl here, it is doing more getxattr call then needed
-    xattr::list_deref(file).is_ok_and(|mut acl| {
-        #[cfg(unix)]
-        return acl.contains(OsStr::from_bytes(b"security.capability"));
-
-        #[cfg(not(unix))]
-        return false;
-    })
+    xattr::get_deref(file, "security.capability")
+        .ok()
+        .flatten()
+        .is_some()
 }
 
 /// Returns the permissions bits of a file or directory which has Access Control List (ACL) entries based on its
@@ -137,38 +145,39 @@ pub fn get_acl_perm_bits_from_xattr<P: AsRef<Path>>(source: P) -> u32 {
 
     // Only default acl entries get inherited by objects under the path i.e. if child directories
     // will have their permissions modified.
-    if let Ok(entries) = retrieve_xattrs(source) {
-        let mut perm: u32 = 0;
-        if let Some(value) = entries.get(&OsString::from("system.posix_acl_default")) {
-            // value is xattr byte vector
-            // value follows a starts with a 4 byte header, and then has posix_acl_entries, each
-            // posix_acl_entry is separated by a u32 sequence i.e. 0xFFFFFFFF
-            //
-            // struct posix_acl_entries {
-            // e_tag: u16
-            //  e_perm: u16
-            //  e_id: u32
-            // }
-            //
-            // Reference: `https://github.com/torvalds/linux/blob/master/include/uapi/linux/posix_acl_xattr.h`
-            //
-            // The value of the header is 0x0002, so we skip the first four bytes of the value and
-            // process the rest
-
-            let acl_entries = value
-                .split_at(3)
-                .1
-                .iter()
-                .filter(|&x| *x != 255)
-                .copied()
-                .collect::<Vec<u8>>();
-
-            for entry in acl_entries.chunks_exact(4) {
-                // Third byte and fourth byte will be the perm bits
-                perm = (perm << 3) | u32::from(entry[2]) | u32::from(entry[3]);
-            }
-            return perm;
+    let mut perm: u32 = 0;
+    if let Some(value) = xattr::get(source, "system.posix_acl_default")
+        .ok()
+        .flatten()
+    {
+        // value is xattr byte vector
+        // value follows a starts with a 4 byte header, and then has posix_acl_entries, each
+        // posix_acl_entry is separated by a u32 sequence i.e. 0xFFFFFFFF
+        //
+        // struct posix_acl_entries {
+        // e_tag: u16
+        //  e_perm: u16
+        //  e_id: u32
+        // }
+        //
+        // Reference: `https://github.com/torvalds/linux/blob/master/include/uapi/linux/posix_acl_xattr.h`
+        //
+        // The value of the header is 0x0002, so we skip the first four bytes of the value and
+        // process the rest
+
+        let acl_entries = value
+            .split_at(3)
+            .1
+            .iter()
+            .filter(|&x| *x != 255)
+            .copied()
+            .collect::<Vec<u8>>();
+
+        for entry in acl_entries.chunks_exact(4) {
+            // Third byte and fourth byte will be the perm bits
+            perm = (perm << 3) | u32::from(entry[2]) | u32::from(entry[3]);
         }
+        return perm;
     }
     0
 }