Tempfile V4

.cargo/config.toml

@@ -0,0 +1,2 @@
+[resolver]
+incompatible-rust-versions = "allow"

.github/workflows/ci.yml

@@ -15,6 +15,11 @@ env:
   ANDROID_VERSION: "12.0.0"
   WASMTIME_BACKTRACE_DETAILS: 1
 
+# Because Windows on GitHub CI
+defaults:
+  run:
+    shell: bash
+
 permissions: {}
 
 name: CI
@@ -33,14 +38,32 @@ jobs:
       - uses: EmbarkStudios/cargo-deny-action@91bf2b620e09e18d6eb78b92e7861937469acedb # v2
     timeout-minutes: 10
 
+  determine_msrv:
+    name: Determining MSRV
+    runs-on: ubuntu-latest
+    outputs:
+      msrv: ${{ steps.msrv.outputs.MSRV }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
+      - name: Determine MSRV
+        id: msrv
+        run: |
+          cargo metadata --no-deps --format-version 1 \
+            | jq -r '.packages[] | select(.name == "tempfile") | "MSRV=\(.rust_version)"' \
+            >> "$GITHUB_OUTPUT"
+
   build_and_test:
+    needs: determine_msrv
     strategy:
       fail-fast: false
       matrix:
         rust-version:
           - nightly
           - stable
-          - "1.63"
+          - "${{ needs.determine_msrv.outputs.msrv }}"
         platform:
           - name: "Linux"
             os: ubuntu-latest
@@ -62,24 +85,6 @@ jobs:
             os: ubuntu-latest
             target: wasm32-wasip2
             test-flags: --tests
-        exclude:
-          - rust-version: "1.63"
-            platform:
-              name: "Android"
-              os: ubuntu-latest
-              target: x86_64-linux-android
-          - rust-version: "1.63"
-            platform:
-              name: "WASI P1"
-              os: ubuntu-latest
-              target: wasm32-wasip1
-              test-flags: --tests
-          - rust-version: "1.63"
-            platform:
-              name: "WASI P2"
-              os: ubuntu-latest
-              target: wasm32-wasip2
-              test-flags: --tests
     name: Platform Test (${{ matrix.platform.name }} / ${{ matrix.rust-version }})
     runs-on: ${{ matrix.platform.os }}
     steps:
@@ -92,20 +97,13 @@ jobs:
         with:
           toolchain: ${{ matrix.rust-version }}
           targets: ${{ matrix.platform.target }}
-      - name: Generating the Cargo.lock
-        run: cargo generate-lockfile
-      - name: Downgrading once_cell
-        if: matrix.rust-version == 1.63
-        run: cargo update -p once_cell --precise 1.20.3
-      - name: Downgrading windows-sys
-        if: matrix.rust-version == 1.63
-        run: cargo update -p windows-sys --precise 0.60.2
-      - name: Downgrading getrandom
-        if: matrix.rust-version == 1.63
-        run: cargo update -p getrandom --precise 0.3.4
-      - name: Downgrading libc
-        if: matrix.rust-version == 1.63
-        run: cargo update -p libc --precise 0.2.183
+      - name: Selecting dependency versions
+        env:
+          CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS: 'fallback'
+        run: |
+          RUSTC_VERSION="$(rustc --version | sed 's/^rustc \([^ -]*\).*/\1/')"
+          sed -i -e 's/^rust-version = .*/rust-version = "'"$RUSTC_VERSION"'"/' Cargo.toml
+          cargo generate-lockfile
       - name: Install Wasmtime
         if: ${{ startsWith(matrix.platform.target, 'wasm32-wasi') }}
         run: curl https://wasmtime.dev/install.sh -sSf | bash

Cargo.toml

@@ -8,8 +8,8 @@ authors = [
   "Jason White <me@jasonwhite.io>",
 ]
 documentation = "https://docs.rs/tempfile"
-edition = "2021"
-rust-version = "1.63"
+edition = "2024"
+rust-version = "1.85"
 homepage = "https://stebalien.com/projects/tempfile-rs/"
 keywords = ["tempfile", "tmpfile", "filesystem"]
 license = "MIT OR Apache-2.0"
@@ -20,8 +20,6 @@ include = ["CHANGELOG.md", "Cargo.toml", "LICENSE-*", "README.md", "src/**/*.rs"
 
 [dependencies]
 fastrand = "2.1.1"
-# Not available in stdlib until 1.70, but we support 1.63 to support Debian stable.
-once_cell = { version = "1.19.0", default-features = false, features = ["std"] }
 
 [target.'cfg(any(unix, windows, target_os = "wasi"))'.dependencies]
 getrandom = { version = ">=0.3.0, <0.5", default-features = false, optional = true }
@@ -41,7 +39,6 @@ doc-comment = "0.3"
 
 [features]
 default = ["getrandom"]
-nightly = [] # DEPRECATED
 
 [package.metadata.docs.rs]
 rustdoc-args = ["--generate-link-to-definition"]

README.md

@@ -12,7 +12,7 @@ patterns and surprisingly difficult to implement securely).
 
 ## Usage
 
-Minimum required Rust version: 1.63.0
+Minimum required Rust version: 1.85.0
 
 Add this to your `Cargo.toml`:
 

src/dir/imp/any.rs

@@ -1,5 +1,5 @@
-use crate::error::IoResultExt;
 use crate::TempDir;
+use crate::error::IoResultExt;
 use std::path::PathBuf;
 use std::{fs, io};
 

src/dir/imp/unix.rs

@@ -1,5 +1,5 @@
-use crate::error::IoResultExt;
 use crate::TempDir;
+use crate::error::IoResultExt;
 use std::io;
 use std::path::PathBuf;
 
@@ -12,9 +12,7 @@ pub fn create(
     #[cfg(not(target_os = "wasi"))]
     {
         use std::os::unix::fs::{DirBuilderExt, PermissionsExt};
-        if let Some(p) = permissions {
-            dir_options.mode(p.mode());
-        }
+        dir_options.mode(permissions.map(|p| p.mode()).unwrap_or(0o700));
     }
     dir_options
         .create(&path)

src/dir/mod.rs

@@ -12,8 +12,8 @@ use std::mem;
 use std::path::{self, Path, PathBuf};
 use std::{fmt, io};
 
-use crate::error::IoResultExt;
 use crate::Builder;
+use crate::error::IoResultExt;
 
 #[cfg(doc)]
 use crate::env;
@@ -380,13 +380,6 @@ impl TempDir {
         self.path.as_ref()
     }
 
-    /// Deprecated alias for [`TempDir::keep`].
-    #[must_use]
-    #[deprecated = "use TempDir::keep()"]
-    pub fn into_path(self) -> PathBuf {
-        self.keep()
-    }
-
     /// Persist the temporary directory to disk, returning the [`PathBuf`] where it is located.
     ///
     /// This consumes the [`TempDir`] without deleting directory on the filesystem, meaning that
@@ -481,7 +474,10 @@ impl TempDir {
     }
 }
 
-impl AsRef<Path> for TempDir {
+// NOTE: This is implemented on &TempDir, not TempDir, to prevent accidentally moving the TempDir
+// into a function that calls `as_ref()` before immediately dropping it (deleting the underlying
+// temporary directory).
+impl AsRef<Path> for &TempDir {
     fn as_ref(&self) -> &Path {
         self.path()
     }

src/env.rs

@@ -1,13 +1,20 @@
-use std::env;
+use std::ffi::{OsStr, OsString};
 use std::path::{Path, PathBuf};
+use std::sync::{LazyLock, OnceLock};
+use std::{env, io};
 
 #[cfg(doc)]
-use crate::{tempdir_in, tempfile_in, Builder};
-
-// Once rust 1.70 is wide-spread (Debian stable), we can use OnceLock from stdlib.
-use once_cell::sync::OnceCell as OnceLock;
+use crate::{Builder, tempdir_in, tempfile_in};
 
+static ENV_TEMPDIR: LazyLock<Option<PathBuf>> =
+    // Only call env::temp_dir() on platforms known to not panic.
+    LazyLock::new(if cfg!(any(unix, windows, target_os = "hermit")) {
+            || Some(env::temp_dir())
+        } else {
+            || None
+        });
 static DEFAULT_TEMPDIR: OnceLock<PathBuf> = OnceLock::new();
+static DEFAULT_PREFIX: OnceLock<OsString> = OnceLock::new();
 
 /// Override the default temporary directory (defaults to [`std::env::temp_dir`]). This function
 /// changes the _global_ default temporary directory for the entire program and should not be called
@@ -18,34 +25,63 @@ static DEFAULT_TEMPDIR: OnceLock<PathBuf> = OnceLock::new();
 /// should instead use the `_in` variants of the various temporary file/directory constructors
 /// ([`tempdir_in`], [`tempfile_in`], the so-named functions on [`Builder`], etc.).
 ///
-/// Only the first call to this function will succeed. All further calls will fail with `Err(path)`
-/// where `path` is previously set default temporary directory override.
+/// Only the **first** call to this function will succeed and return `Ok(path)` where `path` is a
+/// static reference to the temporary directory. All further calls will fail with `Err(path)` where
+/// `path` is the previously set default temporary directory override.
 ///
 /// **NOTE:** This function does not check if the specified directory exists and/or is writable.
-pub fn override_temp_dir(path: &Path) -> Result<(), PathBuf> {
-    let mut we_set = false;
-    let val = DEFAULT_TEMPDIR.get_or_init(|| {
-        we_set = true;
-        path.to_path_buf()
-    });
-    if we_set {
-        Ok(())
-    } else {
-        Err(val.to_owned())
+pub fn override_temp_dir(path: impl Into<PathBuf>) -> Result<&'static Path, &'static Path> {
+    let mut path = Some(path.into());
+    let val = DEFAULT_TEMPDIR.get_or_init(|| path.take().unwrap());
+    match path {
+        Some(_) => Err(val),
+        None => Ok(val),
     }
 }
 
 /// Returns the default temporary directory, used for both temporary directories and files if no
 /// directory is explicitly specified.
 ///
-/// This function simply delegates to [`std::env::temp_dir`] unless the default temporary directory
-/// has been overridden by a call to [`override_temp_dir`].
+/// Unless the default temporary directory has been overridden by a call to [`override_temp_dir`],
+/// this function delegates to [`std::env::temp_dir`] (when supported by the platform). It returns
+/// an error on platforms with no default temporary directory (e.g., WASI/WASM) unless
+/// [`override_temp_dir`] has already been called to set the temporary directory.
+///
+/// **NOTE:**
 ///
-/// **NOTE:** This function does not check if the returned directory exists and/or is writable.
-pub fn temp_dir() -> PathBuf {
+/// 1. This function does not check if the returned directory exists and/or is writable.
+/// 2. This function caches the result of [`std::env::temp_dir`]. Any future changes to, e.g., the
+///    `TMPDIR` environment variable won't have any effect.
+pub fn temp_dir() -> io::Result<&'static Path> {
     DEFAULT_TEMPDIR
         .get()
-        .map(|p| p.to_owned())
-        // Don't cache this in case the user uses std::env::set to change the temporary directory.
-        .unwrap_or_else(env::temp_dir)
+        .or_else(|| ENV_TEMPDIR.as_ref())
+        .map(|a| &**a)
+        .ok_or_else(|| io::Error::other("no temporary directory configured"))
+}
+
+/// Override the default prefix for new temporary files (defaults to "tmp"). This function changes
+/// the _global_ default prefix used by the entire program and should only be used by the top-level
+/// application. It's recommended that the top-level application call this function to specify an
+/// application-specific prefix to make it easier to identify temporary files belonging to the
+/// application.
+///
+/// Only the **first** call to this function will succeed and return `Ok(prefix)` where `prefix` is
+/// a static reference to the default temporary file prefix. All further calls will fail with
+/// `Err(prefix)` where `prefix` is the previously set default temporary file prefix.
+pub fn override_default_prefix(
+    prefix: impl Into<OsString>,
+) -> Result<&'static OsStr, &'static OsStr> {
+    let mut prefix = Some(prefix.into());
+    let val = DEFAULT_PREFIX.get_or_init(|| prefix.take().unwrap());
+    match prefix {
+        Some(_) => Err(val),
+        None => Ok(val),
+    }
+}
+
+/// Returns the default prefix used for new temporary files if no prefix is explicitly specified via
+/// [`Builder::prefix`].
+pub fn default_prefix() -> &'static OsStr {
+    DEFAULT_PREFIX.get().map(|p| &**p).unwrap_or("tmp".as_ref())
 }

src/file/imp/unix.rs

@@ -71,7 +71,7 @@ pub fn create(dir: &Path) -> io::Result<File> {
 fn create_unix(dir: &Path) -> io::Result<File> {
     util::create_helper(
         dir,
-        OsStr::new(".tmp"),
+        crate::env::default_prefix(),
         OsStr::new(""),
         crate::NUM_RAND_CHARS,
         |path| create_unlinked(&path),
@@ -108,7 +108,7 @@ pub fn persist(old_path: &Path, new_path: &Path, overwrite: bool) -> io::Result<
             target_os = "redox",
         ))]
         {
-            use rustix::fs::{renameat_with, RenameFlags, CWD};
+            use rustix::fs::{CWD, RenameFlags, renameat_with};
             use rustix::io::Errno;
             use std::sync::atomic::{AtomicBool, Ordering::Relaxed};
 

src/file/imp/windows.rs

@@ -8,9 +8,9 @@ use std::{io, iter};
 
 use windows_sys::Win32::Foundation::{HANDLE, INVALID_HANDLE_VALUE};
 use windows_sys::Win32::Storage::FileSystem::{
-    MoveFileExW, ReOpenFile, SetFileAttributesW, FILE_ATTRIBUTE_NORMAL, FILE_ATTRIBUTE_TEMPORARY,
-    FILE_FLAG_DELETE_ON_CLOSE, FILE_GENERIC_READ, FILE_GENERIC_WRITE, FILE_SHARE_DELETE,
-    FILE_SHARE_READ, FILE_SHARE_WRITE, MOVEFILE_REPLACE_EXISTING,
+    FILE_ATTRIBUTE_NORMAL, FILE_ATTRIBUTE_TEMPORARY, FILE_FLAG_DELETE_ON_CLOSE, FILE_GENERIC_READ,
+    FILE_GENERIC_WRITE, FILE_SHARE_DELETE, FILE_SHARE_READ, FILE_SHARE_WRITE,
+    MOVEFILE_REPLACE_EXISTING, MoveFileExW, ReOpenFile, SetFileAttributesW,
 };
 
 use crate::util;
@@ -42,7 +42,7 @@ pub fn create_named(
 pub fn create(dir: &Path) -> io::Result<File> {
     util::create_helper(
         dir,
-        OsStr::new(".tmp"),
+        crate::env::default_prefix(),
         OsStr::new(""),
         crate::NUM_RAND_CHARS,
         |path| {