Coalesce platform-specific xattr modules

Now we have one Ur-module that contains functionality common to both supported platforms.

The benefits of doing it this way are that:

1. It doesn't implement a dummy interface - rather, there will be less code generated when the feature is not present;
2. The code shared between them can be kept in sync. The other two modules were something like 80% the same.
This commit is contained in:
Ben S 2015-08-25 18:29:23 +01:00
parent e523520b56
commit a250f21282
8 changed files with 251 additions and 309 deletions

View File

@ -1,13 +1,5 @@
// Extended attribute support // Extended attribute support
pub mod xattr;
#[cfg(target_os = "macos")] mod xattr_darwin;
#[cfg(target_os = "macos")] pub use self::xattr_darwin::Attribute;
#[cfg(target_os = "linux")] mod xattr_linux;
#[cfg(target_os = "linux")] pub use self::xattr_linux::Attribute;
#[cfg(not(any(target_os = "macos", target_os = "linux")))] mod xattr_dummy;
#[cfg(not(any(target_os = "macos", target_os = "linux")))] pub use self::xattr_dummy::Attribute;
// Git support // Git support

237
src/feature/xattr.rs Normal file
View File

@ -0,0 +1,237 @@
//! Extended attribute support for Darwin and Linux systems.
extern crate libc;
use std::io;
use std::path::Path;
pub const ENABLED: bool = cfg!(feature="git") && cfg!(any(target_os="macos", target_os="linux"));
pub trait FileAttributes {
fn attributes(&self) -> io::Result<Vec<Attribute>>;
fn symlink_attributes(&self) -> io::Result<Vec<Attribute>>;
}
impl FileAttributes for Path {
fn attributes(&self) -> io::Result<Vec<Attribute>> {
list_attrs(lister::Lister::new(FollowSymlinks::Yes), &self)
}
fn symlink_attributes(&self) -> io::Result<Vec<Attribute>> {
list_attrs(lister::Lister::new(FollowSymlinks::No), &self)
}
}
/// Attributes which can be passed to `Attribute::list_with_flags`
#[derive(Copy, Clone)]
pub enum FollowSymlinks {
Yes,
No
}
/// Extended attribute
#[derive(Debug, Clone)]
pub struct Attribute {
pub name: String,
pub size: usize,
}
pub fn list_attrs(lister: lister::Lister, path: &Path) -> io::Result<Vec<Attribute>> {
let c_path = match path.as_os_str().to_cstring() {
Some(cstring) => cstring,
None => return Err(io::Error::new(io::ErrorKind::Other, "could not read extended attributes")),
};
let bufsize = lister.listxattr_first(&c_path);
if bufsize > 0 {
let mut buf = vec![0u8; bufsize as usize];
let err = lister.listxattr_second(&c_path, &mut buf, bufsize);
if err > 0 {
// End indicies of the attribute names
// the buffer contains 0-terminates c-strings
let idx = buf.iter().enumerate().filter_map(|(i, v)|
if *v == 0 { Some(i) } else { None }
);
let mut names = Vec::new();
let mut start = 0;
for end in idx {
let c_end = end + 1; // end of the c-string (including 0)
let size = lister.getxattr(&c_path, &buf[start..c_end]);
if size > 0 {
names.push(Attribute {
name: lister.translate_attribute_name(&buf[start..end]),
size: size as usize
});
}
start = c_end;
}
Ok(names)
}
else {
Err(io::Error::new(io::ErrorKind::Other, "could not read extended attributes"))
}
}
else {
Err(io::Error::new(io::ErrorKind::Other, "could not read extended attributes"))
}
}
#[cfg(target_os = "macos")]
mod lister {
use std::ffi::CString;
use libc::{c_int, size_t, ssize_t, c_char, c_void, uint32_t};
use super::FollowSymlinks;
use std::ptr;
extern "C" {
fn listxattr(
path: *const c_char, namebuf: *mut c_char,
size: size_t, options: c_int
) -> ssize_t;
fn getxattr(
path: *const c_char, name: *const c_char,
value: *mut c_void, size: size_t, position: uint32_t,
options: c_int
) -> ssize_t;
}
pub struct Lister {
c_flags: c_int,
}
impl Lister {
pub fn new(do_follow: FollowSymlinks) -> Lister {
let c_flags: c_int = match do_follow {
FollowSymlinks::Yes => 0x0001,
FollowSymlinks::No => 0x0000,
};
Lister { c_flags: c_flags }
}
pub fn translate_attribute_name(&self, input: &[u8]) -> String {
use std::str::from_utf8_unchecked;
unsafe {
from_utf8_unchecked(input).into()
}
}
pub fn listxattr_first(&self, c_path: &CString) -> ssize_t {
unsafe {
listxattr(c_path.as_ptr(), ptr::null_mut(), 0, self.c_flags)
}
}
pub fn listxattr_second(&self, c_path: &CString, buf: &mut Vec<u8>, bufsize: ssize_t) -> ssize_t {
unsafe {
listxattr(
c_path.as_ptr(),
buf.as_mut_ptr() as *mut c_char,
bufsize as size_t, self.c_flags
)
}
}
pub fn getxattr(&self, c_path: &CString, buf: &[u8]) -> ssize_t {
unsafe {
getxattr(
c_path.as_ptr(),
buf.as_ptr() as *const c_char,
ptr::null_mut(), 0, 0, self.c_flags
)
}
}
}
}
#[cfg(target_os = "linux")]
mod lister {
use std::ffi::CString;
use libc::{size_t, ssize_t, c_char, c_void};
use super::FollowSymlinks;
use std::ptr;
extern "C" {
fn listxattr(
path: *const c_char, list: *mut c_char, size: size_t
) -> ssize_t;
fn llistxattr(
path: *const c_char, list: *mut c_char, size: size_t
) -> ssize_t;
fn getxattr(
path: *const c_char, name: *const c_char,
value: *mut c_void, size: size_t
) -> ssize_t;
fn lgetxattr(
path: *const c_char, name: *const c_char,
value: *mut c_void, size: size_t
) -> ssize_t;
}
pub struct Lister {
follow_symlinks: FollowSymlinks,
}
impl Lister {
pub fn new(follow_symlinks: FollowSymlinks) -> Lister {
Lister { follow_symlinks: follow_symlinks }
}
pub fn translate_attribute_name(&self, input: &[u8]) -> String {
String::from_utf8_lossy(input).into_owned()
}
pub fn listxattr_first(&self, c_path: &CString) -> ssize_t {
let listxattr = match self.follow_symlinks {
FollowSymlinks::Yes => listxattr,
FollowSymlinks::No => llistxattr,
};
unsafe {
listxattr(c_path.as_ptr(), ptr::null_mut(), 0)
}
}
pub fn listxattr_second(&self, c_path: &CString, buf: &mut Vec<u8>, bufsize: ssize_t) -> ssize_t {
let listxattr = match self.follow_symlinks {
FollowSymlinks::Yes => listxattr,
FollowSymlinks::No => llistxattr,
};
unsafe {
listxattr(
c_path.as_ptr(),
buf.as_mut_ptr() as *mut c_char,
bufsize as size_t
)
}
}
pub fn getxattr(&self, c_path: &CString, buf: &[u8]) -> ssize_t {
let getxattr = match self.follow_symlinks {
FollowSymlinks::Yes => getxattr,
FollowSymlinks::No => lgetxattr,
};
unsafe {
getxattr(
c_path.as_ptr(),
buf.as_ptr() as *const c_char,
ptr::null_mut(), 0
)
}
}
}
}

View File

@ -1,133 +0,0 @@
//! Extended attribute support for darwin
extern crate libc;
use std::io;
use std::mem;
use std::path::Path;
use std::ptr;
use self::libc::{c_int, size_t, ssize_t, c_char, c_void, uint32_t};
/// Don't follow symbolic links
const XATTR_NOFOLLOW: c_int = 0x0001;
/// Expose HFS Compression extended attributes
const XATTR_SHOWCOMPRESSION: c_int = 0x0020;
extern "C" {
fn listxattr(path: *const c_char, namebuf: *mut c_char,
size: size_t, options: c_int) -> ssize_t;
fn getxattr(path: *const c_char, name: *const c_char,
value: *mut c_void, size: size_t, position: uint32_t,
options: c_int) -> ssize_t;
}
/// Attributes which can be passed to `Attribute::list_with_flags`
#[derive(Copy, Clone)]
pub enum ListFlags {
/// Don't follow symbolic links
NoFollow = XATTR_NOFOLLOW as isize,
/// Expose HFS Compression extended attributes
ShowCompression = XATTR_SHOWCOMPRESSION as isize
}
/// Extended attribute
#[derive(Debug, Clone)]
pub struct Attribute {
name: String,
size: usize,
}
impl Attribute {
/// Lists the extended attribute of `path`.
/// Does follow symlinks by default.
pub fn list_attrs(path: &Path, flags: &[ListFlags]) -> io::Result<Vec<Attribute>> {
let mut c_flags: c_int = 0;
for &flag in flags.iter() {
c_flags |= flag as c_int
}
let c_path = match path.as_os_str().to_cstring() {
Some(cstring) => cstring,
None => return Err(io::Error::new(io::ErrorKind::Other, "could not read extended attributes")),
};
let bufsize = unsafe {
listxattr(c_path.as_ptr(), ptr::null_mut(), 0, c_flags)
};
if bufsize > 0 {
let mut buf = vec![0u8; bufsize as usize];
let err = unsafe { listxattr(
c_path.as_ptr(),
buf.as_mut_ptr() as *mut c_char,
bufsize as size_t, c_flags
)};
if err > 0 {
// End indicies of the attribute names
// the buffer contains 0-terminates c-strings
let idx = buf.iter().enumerate().filter_map(|(i, v)|
if *v == 0 { Some(i) } else { None }
);
let mut names = Vec::new();
let mut start = 0;
for end in idx {
let c_end = end + 1; // end of the c-string (including 0)
let size = unsafe {
getxattr(
c_path.as_ptr(),
buf[start..c_end].as_ptr() as *const c_char,
ptr::null_mut(), 0, 0, c_flags
)
};
if size > 0 {
names.push(Attribute {
name: unsafe {
// buf is guaranteed to contain valid utf8 strings
// see man listxattr
mem::transmute::<&[u8], &str>(&buf[start..end]).to_string()
},
size: size as usize
});
}
start = c_end;
}
Ok(names)
} else {
Err(io::Error::new(io::ErrorKind::Other, "could not read extended attributes"))
}
} else {
Err(io::Error::new(io::ErrorKind::Other, "could not read extended attributes"))
}
}
/// Getter for name
pub fn name(&self) -> &str {
&self.name
}
/// Getter for size
pub fn size(&self) -> usize {
self.size
}
/// Lists the extended attributes.
/// Follows symlinks like `metadata`
pub fn list(path: &Path) -> io::Result<Vec<Attribute>> {
Attribute::list_attrs(path, &[])
}
/// Lists the extended attributes.
/// Does not follow symlinks like `symlink_metadata`
pub fn llist(path: &Path) -> io::Result<Vec<Attribute>> {
Attribute::list_attrs(path, &[ListFlags::NoFollow])
}
/// Returns true if the extended attribute feature is implemented on this platform.
#[inline(always)]
pub fn feature_implemented() -> bool { true }
}

View File

@ -1,32 +0,0 @@
use std::io;
use std::path::Path;
#[derive(Clone)]
pub struct Attribute;
impl Attribute {
/// Getter for name
pub fn name(&self) -> &str {
unimplemented!()
}
/// Getter for size
pub fn size(&self) -> usize {
unimplemented!()
}
/// Lists the extended attributes. Follows symlinks like `metadata`
pub fn list(_: &Path) -> io::Result<Vec<Attribute>> {
Ok(Vec::new())
}
/// Lists the extended attributes. Does not follow symlinks like `symlink_metadata`
pub fn llist(_: &Path) -> io::Result<Vec<Attribute>> {
Ok(Vec::new())
}
pub fn feature_implemented() -> bool { false }
}

View File

@ -1,122 +0,0 @@
//! Extended attribute support for darwin
extern crate libc;
use std::ffi::CString;
use std::io;
use std::path::Path;
use std::ptr;
use self::libc::{size_t, ssize_t, c_char, c_void};
extern "C" {
fn listxattr(path: *const c_char, list: *mut c_char, size: size_t) -> ssize_t;
fn llistxattr(path: *const c_char, list: *mut c_char, size: size_t) -> ssize_t;
fn getxattr(path: *const c_char, name: *const c_char,
value: *mut c_void, size: size_t
) -> ssize_t;
fn lgetxattr(path: *const c_char, name: *const c_char,
value: *mut c_void, size: size_t
) -> ssize_t;
}
/// Attributes which can be passed to `Attribute::list_with_flags`
#[derive(Copy, Clone)]
pub enum FollowSymlinks {
Yes,
No
}
/// Extended attribute
#[derive(Debug, Clone)]
pub struct Attribute {
name: String,
size: usize,
}
impl Attribute {
/// Lists the extended attribute of `path`.
/// Does follow symlinks by default.
pub fn list_attrs(path: &Path, do_follow: FollowSymlinks) -> io::Result<Vec<Attribute>> {
let (listxattr, getxattr) = match do_follow {
FollowSymlinks::Yes => (listxattr, getxattr),
FollowSymlinks::No => (llistxattr, lgetxattr),
};
let c_path = match path.as_os_str().to_cstring() {
Some(cstring) => cstring,
None => return Err(io::Error::new(io::ErrorKind::Other, "could not read extended attributes")),
};
let bufsize = unsafe {
listxattr(c_path.as_ptr(), ptr::null_mut(), 0)
};
if bufsize > 0 {
let mut buf = vec![0u8; bufsize as usize];
let err = unsafe { listxattr(
c_path.as_ptr(),
buf.as_mut_ptr() as *mut c_char,
bufsize as size_t
)};
if err > 0 {
// End indicies of the attribute names
// the buffer contains 0-terminates c-strings
let idx = buf.iter().enumerate().filter_map(|(i, v)|
if *v == 0 { Some(i) } else { None }
);
let mut names = Vec::new();
let mut start = 0;
for end in idx {
let c_end = end + 1; // end of the c-string (including 0)
let size = unsafe {
getxattr(
c_path.as_ptr(),
buf[start..c_end].as_ptr() as *const c_char,
ptr::null_mut(), 0
)
};
if size > 0 {
names.push(Attribute {
name: String::from_utf8_lossy(&buf[start..end]).into_owned(),
size: size as usize
});
}
start = c_end;
}
Ok(names)
} else {
Err(io::Error::new(io::ErrorKind::Other, "could not read extended attributes"))
}
} else {
Err(io::Error::new(io::ErrorKind::Other, "could not read extended attributes"))
}
}
/// Getter for name
pub fn name(&self) -> &str {
&self.name
}
/// Getter for size
pub fn size(&self) -> usize {
self.size
}
/// Lists the extended attributes.
/// Follows symlinks like `metadata`
pub fn list(path: &Path) -> io::Result<Vec<Attribute>> {
Attribute::list_attrs(path, FollowSymlinks::Yes)
}
/// Lists the extended attributes.
/// Does not follow symlinks like `symlink_metadata`
pub fn llist(path: &Path) -> io::Result<Vec<Attribute>> {
Attribute::list_attrs(path, FollowSymlinks::No)
}
/// Returns true if the extended attribute feature is implemented on this platform.
#[inline(always)]
pub fn feature_implemented() -> bool { true }
}

View File

@ -12,7 +12,7 @@ use unicode_width::UnicodeWidthStr;
use dir::Dir; use dir::Dir;
use options::TimeType; use options::TimeType;
use feature::Attribute; use feature::xattr::{Attribute, FileAttributes};
use self::fields as f; use self::fields as f;
@ -93,7 +93,7 @@ impl<'dir> File<'dir> {
dir: parent, dir: parent,
metadata: metadata, metadata: metadata,
ext: ext(&filename), ext: ext(&filename),
xattrs: Attribute::llist(path).unwrap_or(Vec::new()), xattrs: path.symlink_attributes().unwrap_or(Vec::new()),
name: filename.to_string(), name: filename.to_string(),
this: this, this: this,
} }
@ -199,7 +199,7 @@ impl<'dir> File<'dir> {
dir: self.dir, dir: self.dir,
metadata: metadata, metadata: metadata,
ext: ext(&filename), ext: ext(&filename),
xattrs: Attribute::list(&target_path).unwrap_or(Vec::new()), xattrs: target_path.attributes().unwrap_or(Vec::new()),
name: filename.to_string(), name: filename.to_string(),
this: None, this: None,
}) })

View File

@ -11,7 +11,7 @@ use colours::Colours;
use column::Column; use column::Column;
use column::Column::*; use column::Column::*;
use dir::Dir; use dir::Dir;
use feature::Attribute; use feature::xattr;
use file::File; use file::File;
use output::{Grid, Details, GridDetails, Lines}; use output::{Grid, Details, GridDetails, Lines};
use term::dimensions; use term::dimensions;
@ -62,7 +62,7 @@ impl Options {
opts.optflag("", "git", "show git status"); opts.optflag("", "git", "show git status");
} }
if Attribute::feature_implemented() { if xattr::ENABLED {
opts.optflag("@", "extended", "display extended attribute keys and sizes in long (-l) output"); opts.optflag("@", "extended", "display extended attribute keys and sizes in long (-l) output");
} }
@ -281,7 +281,7 @@ impl View {
columns: Some(try!(Columns::deduce(matches))), columns: Some(try!(Columns::deduce(matches))),
header: matches.opt_present("header"), header: matches.opt_present("header"),
recurse: dir_action.recurse_options().map(|o| (o, filter)), recurse: dir_action.recurse_options().map(|o| (o, filter)),
xattr: Attribute::feature_implemented() && matches.opt_present("extended"), xattr: xattr::ENABLED && matches.opt_present("extended"),
colours: if dimensions().is_some() { Colours::colourful() } else { Colours::plain() }, colours: if dimensions().is_some() { Colours::colourful() } else { Colours::plain() },
}; };
@ -302,7 +302,7 @@ impl View {
else if matches.opt_present("level") && !matches.opt_present("recurse") && !matches.opt_present("tree") { else if matches.opt_present("level") && !matches.opt_present("recurse") && !matches.opt_present("tree") {
Err(Useless2("level", "recurse", "tree")) Err(Useless2("level", "recurse", "tree"))
} }
else if Attribute::feature_implemented() && matches.opt_present("extended") { else if xattr::ENABLED && matches.opt_present("extended") {
Err(Useless("extended", false, "long")) Err(Useless("extended", false, "long"))
} }
else { else {
@ -640,7 +640,7 @@ impl Columns {
mod test { mod test {
use super::Options; use super::Options;
use super::Misfire; use super::Misfire;
use feature::Attribute; use feature::xattr;
fn is_helpful<T>(misfire: Result<T, Misfire>) -> bool { fn is_helpful<T>(misfire: Result<T, Misfire>) -> bool {
match misfire { match misfire {
@ -742,7 +742,7 @@ mod test {
#[test] #[test]
fn extended_without_long() { fn extended_without_long() {
if Attribute::feature_implemented() { if xattr::ENABLED {
let opts = Options::getopts(&[ "--extended".to_string() ]); let opts = Options::getopts(&[ "--extended".to_string() ]);
assert_eq!(opts.unwrap_err(), Misfire::Useless("extended", false, "long")) assert_eq!(opts.unwrap_err(), Misfire::Useless("extended", false, "long"))
} }

View File

@ -7,7 +7,7 @@ use std::string::ToString;
use colours::Colours; use colours::Colours;
use column::{Alignment, Column, Cell}; use column::{Alignment, Column, Cell};
use dir::Dir; use dir::Dir;
use feature::Attribute; use feature::xattr::Attribute;
use file::fields as f; use file::fields as f;
use file::File; use file::File;
use options::{Columns, FileFilter, RecurseOptions, SizeFormat}; use options::{Columns, FileFilter, RecurseOptions, SizeFormat};
@ -508,11 +508,11 @@ impl<U> Table<U> where U: Users {
filename_length += row.name.length; filename_length += row.name.length;
if xattr { if xattr {
let width = row.attrs.iter().map(|a| a.name().len()).max().unwrap_or(0); let width = row.attrs.iter().map(|a| a.name.len()).max().unwrap_or(0);
for attr in row.attrs.iter() { for attr in row.attrs.iter() {
let name = attr.name(); let name = &*attr.name;
let spaces: String = repeat(" ").take(width - name.len()).collect(); let spaces: String = repeat(" ").take(width - name.len()).collect();
filename.push_str(&*format!("\n{}{} {}", name, spaces, attr.size())) filename.push_str(&*format!("\n{}{} {}", name, spaces, attr.size))
} }
} }