Add NamedTempFile<F>, Builder::{make,make_in}, and NamedTempFile::from_parts

Cargo.toml

@@ -5,7 +5,7 @@ authors = [
  "Steven Allen <steven@stebalien.com>",
  "The Rust Project Developers",
  "Ashley Mannix <ashleymannix@live.com.au>",
- "Jason White <jasonaw0@gmail.com>",
+ "Jason White <me@jasonwhite.io>",
 ]
 documentation = "https://docs.rs/tempfile"
 edition = "2018"

NEWS

@@ -1,3 +1,13 @@
+3.4.0 (WIP)
+=====
+
+Features:
+
+ * Add `Builder::make` and `Builder::make_in` for generalized temp file
+ creation.
+ * Add `NamedTempFile::from_parts` to complement `NamedTempFile::into_parts`.
+ * Add generic parameter to `NamedTempFile` to support wrapping non-File types.
+
 3.3.0
 =====
 

src/file/mod.rs

@@ -478,60 +478,65 @@ impl AsRef<OsStr> for TempPath {
 /// [`NamedTempFile::new_in()`]: #method.new_in
 /// [`std::env::temp_dir()`]: https://doc.rust-lang.org/std/env/fn.temp_dir.html
 /// [`std::process::exit()`]: http://doc.rust-lang.org/std/process/fn.exit.html
-pub struct NamedTempFile {
+pub struct NamedTempFile<F = File> {
  path: TempPath,
- file: File,
+ file: F,
 }
 
-impl fmt::Debug for NamedTempFile {
+impl<F> fmt::Debug for NamedTempFile<F> {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  write!(f, "NamedTempFile({:?})", self.path)
  }
 }
 
-impl AsRef<Path> for NamedTempFile {
+impl<F> AsRef<Path> for NamedTempFile<F> {
  #[inline]
  fn as_ref(&self) -> &Path {
  self.path()
  }
 }
 
 /// Error returned when persisting a temporary file fails.
-#[derive(Debug)]
-pub struct PersistError {
+pub struct PersistError<F = File> {
  /// The underlying IO error.
  pub error: io::Error,
  /// The temporary file that couldn't be persisted.
- pub file: NamedTempFile,
+ pub file: NamedTempFile<F>,
+}
+
+impl<F> fmt::Debug for PersistError<F> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ write!(f, "PersistError({:?})", self.error)
+ }
 }
 
-impl From<PersistError> for io::Error {
+impl<F> From<PersistError<F>> for io::Error {
  #[inline]
- fn from(error: PersistError) -> io::Error {
+ fn from(error: PersistError<F>) -> io::Error {
  error.error
  }
 }
 
-impl From<PersistError> for NamedTempFile {
+impl<F> From<PersistError<F>> for NamedTempFile<F> {
  #[inline]
- fn from(error: PersistError) -> NamedTempFile {
+ fn from(error: PersistError<F>) -> NamedTempFile<F> {
  error.file
  }
 }
 
-impl fmt::Display for PersistError {
+impl<F> fmt::Display for PersistError<F> {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  write!(f, "failed to persist temporary file: {}", self.error)
  }
 }
 
-impl error::Error for PersistError {
+impl<F> error::Error for PersistError<F> {
  fn source(&self) -> Option<&(dyn error::Error + 'static)> {
  Some(&self.error)
  }
 }
 
-impl NamedTempFile {
+impl NamedTempFile<File> {
  /// Create a new named temporary file.
  ///
  /// See [`Builder`] for more configuration.
@@ -601,7 +606,9 @@ impl NamedTempFile {
  pub fn new_in<P: AsRef<Path>>(dir: P) -> io::Result<NamedTempFile> {
  Builder::new().tempfile_in(dir)
  }
+}
 
+impl<F> NamedTempFile<F> {
  /// Get the temporary file's path.
  ///
  /// # Security
@@ -711,7 +718,7 @@ impl NamedTempFile {
  /// ```
  ///
  /// [`PersistError`]: struct.PersistError.html
- pub fn persist<P: AsRef<Path>>(self, new_path: P) -> Result<File, PersistError> {
+ pub fn persist<P: AsRef<Path>>(self, new_path: P) -> Result<F, PersistError<F>> {
  let NamedTempFile { path, file } = self;
  match path.persist(new_path) {
  Ok(_) => Ok(file),
@@ -764,7 +771,7 @@ impl NamedTempFile {
  /// # Ok(())
  /// # }
  /// ```
- pub fn persist_noclobber<P: AsRef<Path>>(self, new_path: P) -> Result<File, PersistError> {
+ pub fn persist_noclobber<P: AsRef<Path>>(self, new_path: P) -> Result<F, PersistError<F>> {
  let NamedTempFile { path, file } = self;
  match path.persist_noclobber(new_path) {
  Ok(_) => Ok(file),
@@ -808,7 +815,7 @@ impl NamedTempFile {
  /// ```
  ///
  /// [`PathPersistError`]: struct.PathPersistError.html
- pub fn keep(self) -> Result<(File, PathBuf), PersistError> {
+ pub fn keep(self) -> Result<(F, PathBuf), PersistError<F>> {
  let (file, path) = (self.file, self.path);
  match path.keep() {
  Ok(path) => Ok((file, path)),
@@ -819,6 +826,49 @@ impl NamedTempFile {
  }
  }
 
+ /// Get a reference to the underlying file.
+ pub fn as_file(&self) -> &F {
+ &self.file
+ }
+
+ /// Get a mutable reference to the underlying file.
+ pub fn as_file_mut(&mut self) -> &mut F {
+ &mut self.file
+ }
+
+ /// Convert the temporary file into a `std::fs::File`.
+ ///
+ /// The inner file will be deleted.
+ pub fn into_file(self) -> F {
+ self.file
+ }
+
+ /// Closes the file, leaving only the temporary file path.
+ ///
+ /// This is useful when another process must be able to open the temporary
+ /// file.
+ pub fn into_temp_path(self) -> TempPath {
+ self.path
+ }
+
+ /// Converts the named temporary file into its constituent parts.
+ ///
+ /// Note: When the path is dropped, the file is deleted but the file handle
+ /// is still usable.
+ pub fn into_parts(self) -> (F, TempPath) {
+ (self.file, self.path)
+ }
+
+ /// Creates a `NamedTempFile` from its constituent parts.
+ ///
+ /// This can be used with [`NamedTempFile::into_parts`] to reconstruct the
+ /// `NamedTempFile`.
+ pub fn from_parts(file: F, path: TempPath) -> Self {
+ Self { file, path }
+ }
+}
+
+impl NamedTempFile<File> {
  /// Securely reopen the temporary file.
  ///
  /// This function is useful when you need multiple independent handles to
@@ -858,54 +908,24 @@ impl NamedTempFile {
  imp::reopen(self.as_file(), NamedTempFile::path(self))
  .with_err_path(|| NamedTempFile::path(self))
  }
-
- /// Get a reference to the underlying file.
- pub fn as_file(&self) -> &File {
- &self.file
- }
-
- /// Get a mutable reference to the underlying file.
- pub fn as_file_mut(&mut self) -> &mut File {
- &mut self.file
- }
-
- /// Convert the temporary file into a `std::fs::File`.
- ///
- /// The inner file will be deleted.
- pub fn into_file(self) -> File {
- self.file
- }
-
- /// Closes the file, leaving only the temporary file path.
- ///
- /// This is useful when another process must be able to open the temporary
- /// file.
- pub fn into_temp_path(self) -> TempPath {
- self.path
- }
-
- /// Converts the named temporary file into its constituent parts.
- ///
- /// Note: When the path is dropped, the file is deleted but the file handle
- /// is still usable.
- pub fn into_parts(self) -> (File, TempPath) {
- (self.file, self.path)
- }
 }
 
-impl Read for NamedTempFile {
+impl<F: Read> Read for NamedTempFile<F> {
  fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
  self.as_file_mut().read(buf).with_err_path(|| self.path())
  }
 }
 
-impl<'a> Read for &'a NamedTempFile {
+impl<'a, F> Read for &'a NamedTempFile<F>
+where
+ &'a F: Read,
+{
  fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
  self.as_file().read(buf).with_err_path(|| self.path())
  }
 }
 
-impl Write for NamedTempFile {
+impl<F: Write> Write for NamedTempFile<F> {
  fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
  self.as_file_mut().write(buf).with_err_path(|| self.path())
  }
@@ -915,7 +935,10 @@ impl Write for NamedTempFile {
  }
 }
 
-impl<'a> Write for &'a NamedTempFile {
+impl<'a, F> Write for &'a NamedTempFile<F>
+where
+ &'a F: Write,
+{
  fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
  self.as_file().write(buf).with_err_path(|| self.path())
  }
@@ -925,28 +948,37 @@ impl<'a> Write for &'a NamedTempFile {
  }
 }
 
-impl Seek for NamedTempFile {
+impl<F: Seek> Seek for NamedTempFile<F> {
  fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
  self.as_file_mut().seek(pos).with_err_path(|| self.path())
  }
 }
 
-impl<'a> Seek for &'a NamedTempFile {
+impl<'a, F> Seek for &'a NamedTempFile<F>
+where
+ &'a F: Seek,
+{
  fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
  self.as_file().seek(pos).with_err_path(|| self.path())
  }
 }
 
 #[cfg(unix)]
-impl std::os::unix::io::AsRawFd for NamedTempFile {
+impl<F> std::os::unix::io::AsRawFd for NamedTempFile<F>
+where
+ F: std::os::unix::io::AsRawFd,
+{
  #[inline]
  fn as_raw_fd(&self) -> std::os::unix::io::RawFd {
  self.as_file().as_raw_fd()
  }
 }
 
 #[cfg(windows)]
-impl std::os::windows::io::AsRawHandle for NamedTempFile {
+impl<F> std::os::windows::io::AsRawHandle for NamedTempFile<F>
+where
+ F: std::os::windows::io::AsRawHandle,
+{
  #[inline]
  fn as_raw_handle(&self) -> std::os::windows::io::RawHandle {
  self.as_file().as_raw_handle()