.idea/runConfigurations/Run.xml

@@ -6,7 +6,6 @@
     <option name="requiredFeatures" value="true" />
     <option name="allFeatures" value="false" />
     <option name="emulateTerminal" value="false" />
-    <option name="withSudo" value="false" />
     <option name="backtrace" value="SHORT" />
     <envs>
       <env name="RUST_LOG" value="debug" />

.idea/vcs.xml

@@ -2,6 +2,5 @@
 <project version="4">
   <component name="VcsDirectoryMappings">
     <mapping directory="$PROJECT_DIR$" vcs="Git" />
-    <mapping directory="$PROJECT_DIR$/src/walkdir" vcs="Git" />
   </component>
 </project>

CHANGELOG.md

@@ -5,15 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## Unreleased
-
-## v0.3.7 - 2021-09-25
 ### Added
-- `-j`/`--jobs` flag for specifying the number of threads fif should use for scanning files
 - AIFF (Audio Interchange File Format, a PCM audio format like WAV) detection to [`infer`] backend
 - `--version` output now includes the (short) hash of the git commit fif was built from
-### Changed
-- fif will no longer use multithreading when scanning less than 32 files - the overhead of spawning threads isn't really
-  worth it
 ### Other
 - Refactoring - split fif into `main.rs` and `lib.rs`, moved file-related functionality (directory scanning, etc.) into
 files module, removed string module, etc.

Cargo.lock

@@ -1,7 +1,5 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
-
 [[package]]
 name = "arrayvec"
 version = "0.5.2"
@@ -175,7 +173,7 @@ checksum = "de853764b47027c2e862a995c34978ffa63c1501f2e15f987ba11bd4f9bba193"
 
 [[package]]
 name = "fif"
-version = "0.3.7"
+version = "0.3.6"
 dependencies = [
  "bitflags",
  "cfg-if",
@@ -188,7 +186,6 @@ dependencies = [
  "log",
  "mime",
  "new_mime_guess",
- "num_cpus",
  "once_cell",
  "rand",
  "rayon",

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "fif"
 description = "A command-line tool for detecting and optionally correcting files with incorrect extensions."
-version = "0.3.7"
+version = "0.3.6"
 authors = ["Lynnesbian <lynne@bune.city>"]
 edition = "2018"
 license = "GPL-3.0-or-later"
@@ -17,7 +17,7 @@ maintenance = { status = "experimental" }
 
 [features]
 default = ["multi-threaded", "json"]
-multi-threaded = ["rayon", "num_cpus"]
+multi-threaded = ["rayon"]
 infer-backend = ["infer"]
 xdg-mime-backend = ["xdg-mime"]
 json = ["serde", "serde_json"]
@@ -36,7 +36,6 @@ itertools = "0.10.0"
 serde = { version = "1.0", features = ["derive"], optional = true }
 serde_json = { version = "1.0", optional = true }
 bitflags = "~1.2.1" # 1.3+ requires Rust >= 1.46
-num_cpus = { version = "1.13.0", optional = true }
 
 [target.'cfg(not(unix))'.dependencies]
 xdg-mime = { version = "0.3.3", optional = true }

src/files.rs

@@ -136,42 +136,25 @@ pub fn scan_file(entry: &DirEntry, canonical_paths: bool) -> Result<Findings, Sc
 }
 
 /// Takes a slice of [`DirEntry`]s and calls [`scan_file`] on each one, returning the results in a vector.
-pub fn scan_from_walkdir(
+pub fn scan_from_walkdir(entries: &[DirEntry], canonical_paths: bool) -> Vec<Result<Findings, ScanError>> {
-	entries: &[DirEntry],
-	canonical_paths: bool,
-	use_threads: bool,
-) -> Vec<Result<Findings, ScanError>> {
 	cfg_if! {
 		if #[cfg(feature = "multi-threaded")] {
 			use rayon::prelude::*;
-			const CHUNKS: usize = 32;
 
-			if use_threads && entries.len() > CHUNKS {
+			// split the entries into chunks of 32, and iterate over each chunk of entries in a separate thread
-				// split the entries into chunks of 32, and iterate over each chunk of entries in a separate thread
+			entries
-				return entries
+				.par_chunks(32)
-					.par_chunks(CHUNKS)
+				.flat_map(|chunk| {
-					.flat_map_iter(|chunk| {
+					chunk
-						chunk
+						.iter() // iter over the chunk, which is a slice of DirEntry structs
-							.iter() // iter over the chunk, which is a slice of DirEntry structs
+						.map(|entry| scan_file(entry, canonical_paths))
-							.map(|entry| scan_file(entry, canonical_paths))
+						.collect::<Vec<_>>()
-							.collect::<Vec<_>>() // TODO: is there a way to avoid having to collect here?
+				})
-					})
+				.collect()
-					.collect()
-			}
 		} else {
-			// should always be false when multi-threading is disabled at compile time
+			entries.iter().map(|entry: &DirEntry| scan_file(entry, canonical_paths)).collect()
-			assert!(!use_threads)
 		}
 	}
-
-	// if we end up here, either
-	// - there were less than CHUNKS files to scan, or
-	// - the user specified that only one thread should be used, by specifying `-j 1`
-	// - fif was compiled without the `multi-threading` feature
-	entries
-		.iter()
-		.map(|entry: &DirEntry| scan_file(entry, canonical_paths))
-		.collect()
 }
 
 /// Scans a given directory with [`WalkDir`], filters with [`wanted_file`], checks for errors, and returns a vector of

src/formats.rs

@@ -7,7 +7,7 @@ use std::os::unix::ffi::OsStrExt;
 use std::path::Path;
 
 use cfg_if::cfg_if;
-use itertools::Itertools;
+use itertools::{Either, Itertools};
 use snailquote::escape;
 
 use crate::findings::ScanError;
@@ -338,8 +338,6 @@ pub struct Json;
 #[cfg(feature = "json")]
 impl Format for Json {
 	fn write_all<W: Write>(&self, f: &mut W, entries: &Entries) -> io::Result<()> {
-		use itertools::Either;
-
 		#[derive(serde::Serialize)]
 		struct SerdeEntries<'a> {
 			errors: &'a Vec<&'a ScanError<'a>>,

src/main.rs

@@ -20,7 +20,6 @@
 use std::io::{stdout, BufWriter, Write};
 use std::process::exit;
 
-use cfg_if::cfg_if;
 use clap::Clap;
 use fif::files::{scan_directory, scan_from_walkdir};
 use fif::formats::Format;
@@ -88,28 +87,7 @@ fn main() {
 
 	trace!("Found {} items to check", entries.len());
 
-	cfg_if! {
+	let results: Vec<_> = scan_from_walkdir(&entries, args.canonical_paths)
-		if #[cfg(feature = "multi-threaded")] {
-			let use_threads = args.jobs != 1;
-
-			if use_threads {
-				// 0 is a special case - it should be understood to mean "all available host CPUs"
-				let jobs = if args.jobs == 0 { num_cpus::get() } else { args.jobs };
-
-				// set up the global thread pool with the requested number of threads
-				rayon::ThreadPoolBuilder::new().num_threads(jobs).build_global().unwrap();
-				trace!("Multithreading enabled, using {} threads", jobs);
-			} else {
-				trace!("Multithreading disabled at runtime");
-			}
-
-		} else { // `multi-threading` feature disabled
-			let use_threads = false;
-			trace!("Multithreading disabled at compile time");
-		}
-	}
-
-	let results: Vec<_> = scan_from_walkdir(&entries, args.canonical_paths, use_threads)
 		.into_iter()
 		.filter(
 			|result| result.is_err() || !result.as_ref().unwrap().valid,
@@ -123,16 +101,12 @@ fn main() {
 	for result in &results {
 		match result {
 			Ok(r) => {
-				// check to see if debug logging is enabled before invoking debug! macro
+				debug!(
-				// https://github.com/rust-lang/log/pull/394#issuecomment-630490343
+					"{:?} is of type {}, should have extension \"{}\"",
-				if log::max_level() >= log::Level::Debug {
+					r.file,
-					debug!(
+					r.mime,
-						"{:?} is of type {}, should have extension \"{}\"",
+					r.recommended_extension().unwrap_or_else(|| "???".into())
-						r.file,
+				);
-						r.mime,
-						r.recommended_extension().unwrap_or_else(|| "???".into())
-					);
-				}
 			}
 			Err(f) => warn!("{}", f),
 		}

src/parameters.rs

@@ -133,14 +133,6 @@ pub struct Parameters {
 	/// For example, with this option, fif will not rename "image.unknown" to "image.jpg"
 	#[clap(short = 'I', long)]
 	pub ignore_unknown_exts: bool,
-
-	#[cfg(feature = "multi-threaded")]
-	/// Number of jobs (threads) to use when scanning results.
-	/// The default behaviour is to use one thread per CPU thread. This behaviour can be manually requested by setting
-	/// `-j 0`. Using `-j 1` will disable multi-threading behaviour, as if you had compiled fif with the multi-threading
-	/// feature disabled. Setting more jobs than you have CPU threads is not recommended.
-	#[clap(short = 'j', long, default_value = "0")]
-	pub jobs: usize,
 }
 
 fn lowercase_exts(exts: &str) -> Result<(), String> {

src/tests/mod.rs

@@ -114,10 +114,8 @@ fn simple_directory() {
 	// there should be one file missing: "ignore.fake_ext"
 	assert_eq!(entries.len(), files.len() - 1);
 
-	let use_threads = cfg!(feature = "multi-threaded");
+	let results = scan_from_walkdir(&entries, false);
-
+	let canonical_results = scan_from_walkdir(&entries, true);
-	let results = scan_from_walkdir(&entries, false, use_threads);
-	let canonical_results = scan_from_walkdir(&entries, true, use_threads);
 	assert_eq!(results.len(), canonical_results.len());
 
 	for (result, canonical_result) in results.iter().zip(canonical_results.iter()) {
@@ -293,8 +291,6 @@ fn rejects_bad_args() {
 		vec!["fif", "-X", "pebis"],
 		// `-e` with nothing but commas:
 		vec!["fif", "-e", ",,,,,"],
-		// `-j` with a negative value:
-		vec!["fif", "-j", "-1"],
 	];
 
 	for test in &tests {