use cfg_if to make the code more readable

Cargo.lock

@@ -176,7 +176,7 @@ checksum = "de853764b47027c2e862a995c34978ffa63c1501f2e15f987ba11bd4f9bba193"
 
 [[package]]
 name = "fif"
-version = "0.2.4"
+version = "0.2.5"
 dependencies = [
  "cached",
  "cfg-if",

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "fif"
 description = "A command-line tool for detecting and optionally correcting files with incorrect extensions."
-version = "0.2.4"
+version = "0.2.5"
 authors = ["Lynnesbian <lynne@bune.city>"]
 edition = "2018"
 license = "GPL-3.0-or-later"

src/main.rs

@@ -17,6 +17,7 @@
 use std::io::{stdout, BufWriter};
 use std::path::{Path, PathBuf};
 
+use cfg_if::cfg_if;
 use clap::Clap;
 use log::{debug, error, info, trace, warn};
 use once_cell::sync::OnceCell;
@@ -40,29 +41,33 @@ mod mimedb;
 mod parameters;
 mod scanerror;
 
-#[cfg(any(all(not(target_os = "linux"), not(feature = "xdg-mime-backend")), all(target_os = "linux", feature = "infer-backend")))]
-static MIMEDB: OnceCell<mimedb::InferDb> = OnceCell::new();
+cfg_if! {
+	if #[cfg(any(all(not(target_os = "linux"), not(feature = "xdg-mime-backend")), all(target_os = "linux", feature = "infer-backend")))] {
+		static MIMEDB: OnceCell<mimedb::InferDb> = OnceCell::new();
+	} else {
+		static MIMEDB: OnceCell<mimedb::XdgDb> = OnceCell::new();
+	}
+}
 
-#[cfg(any(all(target_os = "linux", not(feature = "infer-backend")), all(not(target_os = "linux"), not(feature = "xdg-mime-backend"))))]
-static MIMEDB: OnceCell<mimedb::XdgDb> = OnceCell::new();
-
-// TODO: test if this actually works on a windows machine
-#[cfg(windows)]
-fn is_hidden(entry: &DirEntry) -> bool {
+cfg_if! {
+	// TODO: test if this actually works on a windows machine
+	if #[cfg(windows)] {
+		fn is_hidden(entry: &DirEntry) -> bool {
 		use std::os::windows::prelude::*;
 		std::fs::metadata(entry.path()) // try to get metadata for file
 			.map_or(
 				false,                             // if getting metadata/attributes fails, assume it's not hidden
 				|f| f.file_attributes() & 0x2 > 0, // flag for hidden - https://docs.microsoft.com/windows/win32/fileio/file-attribute-constants
 			)
-}
-
-#[cfg(not(windows))]
-fn is_hidden(entry: &DirEntry) -> bool {
+		}
+	} else {
+		fn is_hidden(entry: &DirEntry) -> bool {
 		entry
 			.file_name()
 			.to_str()
 			.map_or(false, |f| f.starts_with('.') && f != ".")
+		}
+	}
 }
 
 fn wanted_file(args: &parameters::Parameters, exts: &[&str], entry: &DirEntry) -> bool {
@@ -129,8 +134,8 @@ fn scan_file(entry: &DirEntry) -> Result<Findings, (ScanError, PathBuf)> {
 }
 
 fn scan_from_walkdir(entries: &[DirEntry]) -> Vec<Result<Findings, (ScanError, PathBuf)>> {
-	#[cfg(feature = "multi-threaded")]
-	{
+	cfg_if! {
+		if #[cfg(feature = "multi-threaded")] {
 			// rather than using a standard par_iter, split the entries into chunks of 32 first.
 			// this allows each spawned thread to handle 32 files before before closing, rather than creating a new thread for
 			// each file. this leads to a pretty substantial speedup that i'm pretty substantially happy about 0u0
@@ -143,12 +148,10 @@ fn scan_from_walkdir(entries: &[DirEntry]) -> Vec<Result<Findings, (ScanError, P
 						.collect::<Vec<_>>()
 				})
 				.collect()
-	}
-
-	#[cfg(not(feature = "multi-threaded"))]
-	{
+		} else {
 			entries.iter().map(|entry: &DirEntry| scan_file(entry)).collect()
 		}
+	}
 }
 
 fn main() {
@@ -162,17 +165,19 @@ fn main() {
 		// .target(env_logger::Target::Stdout) // log to stdout rather than stderr
 		.init();
 
-	#[cfg(any(all(not(target_os = "linux"), not(feature = "xdg-mime-backend")), all(target_os = "linux", feature = "infer-backend")))]
+	cfg_if! {
+		if #[cfg(any(all(not(target_os = "linux"), not(feature = "xdg-mime-backend")), all(target_os = "linux", feature = "infer-backend")))] {
 			MIMEDB
 				.set(mimedb::InferDb::init())
 				.or(Err("Failed to initialise Infer backend!"))
 				.unwrap();
-
-	#[cfg(any(all(target_os = "linux", not(feature = "infer-backend")), all(not(target_os = "linux"), not(feature = "xdg-mime-backend"))))]
+		} else {
 			MIMEDB
 				.set(mimedb::XdgDb::init())
 				.or(Err("Failed to initialise XDG Mime backend!"))
 				.unwrap();
+		}
+	}
 
 	debug!("Iterating directory: {:?}", args.dirs);
 

src/mimedb.rs

@@ -1,6 +1,4 @@
-#[cfg(any(all(not(target_os = "linux"), not(feature = "xdg-mime-backend")), all(target_os = "linux", feature = "infer-backend")))]
-use std::str::FromStr;
-
+use cfg_if::cfg_if;
 use mime_guess::Mime;
 
 pub trait MimeDb {
@@ -8,21 +6,22 @@ pub trait MimeDb {
 	fn get_type(&self, data: &[u8]) -> Option<Mime>;
 }
 
-#[cfg(any(all(not(target_os = "linux"), not(feature = "xdg-mime-backend")), all(target_os = "linux", feature = "infer-backend")))]
-pub struct InferDb {
-	db: infer::Infer,
-}
+cfg_if! {
+	if #[cfg(any(all(not(target_os = "linux"), not(feature = "xdg-mime-backend")), all(target_os = "linux", feature = "infer-backend")))] {
+		use std::str::FromStr;
 
-#[cfg(any(all(not(target_os = "linux"), not(feature = "xdg-mime-backend")), all(target_os = "linux", feature = "infer-backend")))]
-fn open_document_check(buf: &[u8], kind: &str) -> bool {
+		pub struct InferDb {
+			db: infer::Infer,
+		}
+
+		fn open_document_check(buf: &[u8], kind: &str) -> bool {
 			let mime = format!("application/vnd.oasis.opendocument.{}", kind);
 			let mime = mime.as_bytes();
 
 			buf.len() > 38 + mime.len() && buf.starts_with(b"PK\x03\x04") && buf[38..mime.len() + 38] == mime[..]
-}
+		}
 
-#[cfg(any(all(not(target_os = "linux"), not(feature = "xdg-mime-backend")), all(target_os = "linux", feature = "infer-backend")))]
-impl MimeDb for InferDb {
+		impl MimeDb for InferDb {
 			fn init() -> Self {
 				let mut info = infer::Infer::new();
 
@@ -81,22 +80,20 @@ impl MimeDb for InferDb {
 			fn get_type(&self, data: &[u8]) -> Option<Mime> {
 				self.db.get(data).map(|f| Mime::from_str(f.mime_type()).unwrap())
 			}
-}
-
-#[cfg(any(all(target_os = "linux", not(feature = "infer-backend")), all(not(target_os = "linux"), not(feature = "xdg-mime-backend"))))]
-pub struct XdgDb {
-	db: xdg_mime::SharedMimeInfo,
-}
-
-#[cfg(any(all(target_os = "linux", not(feature = "infer-backend")), all(not(target_os = "linux"), not(feature = "xdg-mime-backend"))))]
-impl MimeDb for XdgDb {
-	fn init() -> Self {
-		Self {
-			db: xdg_mime::SharedMimeInfo::new(),
 		}
+	} else {
+		pub struct XdgDb {
+			db: xdg_mime::SharedMimeInfo,
+		}
+
+		impl MimeDb for XdgDb {
+			fn init() -> Self {
+				Self { db: xdg_mime::SharedMimeInfo::new() }
 			}
 
 			fn get_type(&self, data: &[u8]) -> Option<Mime> {
 				self.db.get_mime_type_for_data(&data).map(|m| m.0)
 			}
+		}
+	}
 }