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use env::SubEnvironment;
use path::NormalizedPath;
use std::borrow::Cow;
use std::env;
use std::io;
use std::path::{Path, PathBuf};
use std::rc::Rc;
use std::sync::Arc;
/// An interface for working with the shell's current working directory.
pub trait WorkingDirectoryEnvironment {
/// Converts the specified path to one relative to the environment's working directory.
fn path_relative_to_working_dir<'a>(&self, path: Cow<'a, Path>) -> Cow<'a, Path>;
/// Retrieves the current working directory of this environment.
fn current_working_dir(&self) -> &Path;
}
impl<'b, T: ?Sized + WorkingDirectoryEnvironment> WorkingDirectoryEnvironment for &'b T {
fn path_relative_to_working_dir<'a>(&self, path: Cow<'a, Path>) -> Cow<'a, Path> {
(**self).path_relative_to_working_dir(path)
}
fn current_working_dir(&self) -> &Path {
(**self).current_working_dir()
}
}
impl<'b, T: ?Sized + WorkingDirectoryEnvironment> WorkingDirectoryEnvironment for &'b mut T {
fn path_relative_to_working_dir<'a>(&self, path: Cow<'a, Path>) -> Cow<'a, Path> {
(**self).path_relative_to_working_dir(path)
}
fn current_working_dir(&self) -> &Path {
(**self).current_working_dir()
}
}
/// An interface for changing the shell's current working directory.
pub trait ChangeWorkingDirectoryEnvironment: WorkingDirectoryEnvironment {
/// Changes the environment's current working directory to the following path.
///
/// The provided `path` can either be an absolute path, or one which will be
/// treated as relative to the current working directory.
fn change_working_dir<'a>(&mut self, path: Cow<'a, Path>) -> io::Result<()>;
}
impl<'b, T: ?Sized> ChangeWorkingDirectoryEnvironment for &'b mut T
where T: ChangeWorkingDirectoryEnvironment
{
fn change_working_dir<'a>(&mut self, path: Cow<'a, Path>) -> io::Result<()> {
(**self).change_working_dir(path)
}
}
macro_rules! impl_env {
($(#[$attr:meta])* pub struct $Env:ident, $Rc:ident) => {
$(#[$attr])*
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct $Env {
cwd: $Rc<NormalizedPath>,
}
impl $Env {
/// Constructs a new environment with a provided working directory.
///
/// The specified `path` *must* be an absolute path or an error will result.
pub fn new<P: AsRef<Path>>(path: P) -> io::Result<Self> {
Self::with_path_buf(path.as_ref().to_path_buf())
}
/// Constructs a new environment with a provided `PathBuf` as a working directory.
///
/// The specified `path` *must* be an absolute path or an error will result.
pub fn with_path_buf(path: PathBuf) -> io::Result<Self> {
if path.is_absolute() {
let normalized = NormalizedPath::new_normalized_logical(path);
if normalized.is_dir() {
Ok($Env {
cwd: $Rc::new(normalized),
})
} else {
let msg = format!("not a directory: {}", normalized.display());
Err(io::Error::new(io::ErrorKind::NotFound, msg))
}
} else {
let msg = format!("specified path not absolute: {}", path.display());
Err(io::Error::new(io::ErrorKind::InvalidInput, msg))
}
}
/// Constructs a new environment and initializes it with the current
/// working directory of the current process.
pub fn with_process_working_dir() -> io::Result<Self> {
env::current_dir().and_then(Self::with_path_buf)
}
}
impl WorkingDirectoryEnvironment for $Env {
fn path_relative_to_working_dir<'a>(&self, path: Cow<'a, Path>) -> Cow<'a, Path> {
if path.is_absolute() {
path
} else {
let mut new_cwd = (*self.cwd).clone();
new_cwd.join_normalized_logial(&path);
Cow::Owned(new_cwd.into_inner())
}
}
fn current_working_dir(&self) -> &Path {
&*self.cwd
}
}
impl ChangeWorkingDirectoryEnvironment for $Env {
fn change_working_dir<'a>(&mut self, path: Cow<'a, Path>) -> io::Result<()> {
let mut new_cwd = (*self.cwd).clone();
// NB: use logical normalization here for maximum flexibility.
// If physical normalization is needed, it can always be done
// by the caller (logical normalization is a no-op if `path`
// has already been canonicalized/symlinks resolved)
new_cwd.join_normalized_logial(&path);
if new_cwd.is_dir() {
self.cwd = $Rc::new(new_cwd);
Ok(())
} else {
let msg = format!("not a directory: {}", new_cwd.display());
Err(io::Error::new(io::ErrorKind::NotFound, msg))
}
}
}
impl SubEnvironment for $Env {
fn sub_env(&self) -> Self {
self.clone()
}
}
};
}
impl_env!(
/// An environment module for keeping track of the current working directory.
///
/// This is a "virtual" implementation because changing the working directory
/// through this environment will not affect the working directory of the
/// entire process.
///
/// Uses `Rc` internally. For a possible `Send` and `Sync` implementation,
/// see `env::atomic::VirtualWorkingDirEnv`.
pub struct VirtualWorkingDirEnv,
Rc
);
impl_env!(
/// An environment module for keeping track of the current working directory.
///
/// This is a "virtual" implementation because changing the working directory
/// through this environment will not affect the working directory of the
/// entire process.
///
/// Uses `Arc` internally. If `Send` and `Sync` is not required of the implementation,
/// see `env::VirtualWorkingDirEnv` as a cheaper alternative.
pub struct AtomicVirtualWorkingDirEnv,
Arc
);