Optimize filename parsing

Cargo.lock

@@ -1348,6 +1348,7 @@ dependencies = [
  "is-terminal",
  "libc",
  "num_cpus",
+ "once_cell",
  "owo-colors",
  "predicates",
  "rayon",

Cargo.toml

@@ -14,6 +14,7 @@ is-terminal = "0.4"
 libc = "0.2"
 num_cpus = "1.16"
 owo-colors = "4.1"
+once_cell = "1.19"
 rayon = "1.10"
 regex = "1.10"
 reqwest = { version = "0.11", features = ["blocking", "json", "rustls-tls"] }

src/parse.rs

@@ -1,5 +1,7 @@
+use std::collections::HashSet;
 use std::path::Path;
 
+use once_cell::sync::Lazy;
 use regex::Regex;
 
 use crate::utils::{collapse_whitespace, normalize_title};
@@ -12,6 +14,24 @@ pub struct FileHints {
     pub alt_titles: Vec<String>,
 }
 
+static YEAR_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"(19|20)\d{2}").expect("year regex"));
+static BRACKET_SQUARE_RE: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r"\[[^\]]*\]").expect("square bracket regex"));
+static BRACKET_ROUND_RE: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r"\([^\)]*\)").expect("round bracket regex"));
+static STOPWORDS: Lazy<HashSet<&'static str>> = Lazy::new(|| {
+    [
+        "1080p", "720p", "2160p", "480p", "360p", "4k", "uhd", "hdr", "dvdrip",
+        "bdrip", "brrip", "bluray", "blu", "webdl", "web-dl", "webrip", "hdrip",
+        "remux", "x264", "x265", "h264", "h265", "hevc", "aac", "dts", "ac3",
+        "proper", "repack", "limited", "extended", "uncut", "remastered", "subbed",
+        "subs", "multi", "dubbed", "dub", "yts", "yify", "rarbg", "web", "hd",
+        "hq", "cam", "ts", "dvdscr", "r5", "r6",
+    ]
+    .into_iter()
+    .collect()
+});
+
 pub fn parse_filename(path: &Path) -> FileHints {
     let stem = path
         .file_stem()
@@ -44,9 +64,8 @@ pub fn parse_filename(path: &Path) -> FileHints {
 }
 
 fn extract_year(raw: &str) -> Option<i32> {
-    let re = Regex::new(r"(19|20)\d{2}").ok()?;
     let mut year: Option<i32> = None;
-    for mat in re.find_iter(raw) {
+    for mat in YEAR_RE.find_iter(raw) {
         if let Ok(parsed) = mat.as_str().parse::<i32>() {
             year = Some(parsed);
         }
@@ -55,10 +74,8 @@ fn extract_year(raw: &str) -> Option<i32> {
 }
 
 fn strip_bracketed(raw: &str) -> String {
-    let re_square = Regex::new(r"\[[^\]]*\]").unwrap();
+    let without_square = BRACKET_SQUARE_RE.replace_all(raw, " ");
-    let re_round = Regex::new(r"\([^\)]*\)").unwrap();
+    let without_round = BRACKET_ROUND_RE.replace_all(&without_square, " ");
-    let without_square = re_square.replace_all(raw, " ");
-    let without_round = re_round.replace_all(&without_square, " ");
     without_round.to_string()
 }
 
@@ -83,7 +100,6 @@ fn clean_title_fragment(fragment: &str, year: Option<i32>) -> String {
 }
 
 fn tokenize(raw: &str, year: Option<i32>) -> Vec<String> {
-    let stopwords = stopwords();
     let mut tokens = Vec::new();
     for token in raw.split(|c: char| !c.is_alphanumeric()) {
         if token.is_empty() {
@@ -95,7 +111,7 @@ fn tokenize(raw: &str, year: Option<i32>) -> Vec<String> {
                 continue;
             }
         }
-        if stopwords.contains(lower.as_str()) {
+        if STOPWORDS.contains(lower.as_str()) {
             continue;
         }
         if token.chars().all(|c| c.is_ascii_uppercase()) && token.len() <= 8 {
@@ -106,19 +122,6 @@ fn tokenize(raw: &str, year: Option<i32>) -> Vec<String> {
     tokens
 }
 
-fn stopwords() -> std::collections::HashSet<&'static str> {
-    [
-        "1080p", "720p", "2160p", "480p", "360p", "4k", "uhd", "hdr", "dvdrip",
-        "bdrip", "brrip", "bluray", "blu", "webdl", "web-dl", "webrip", "hdrip",
-        "remux", "x264", "x265", "h264", "h265", "hevc", "aac", "dts", "ac3",
-        "proper", "repack", "limited", "extended", "uncut", "remastered", "subbed",
-        "subs", "multi", "dubbed", "dub", "yts", "yify", "rarbg", "web", "hd",
-        "hq", "cam", "ts", "dvdscr", "r5", "r6",
-    ]
-    .into_iter()
-    .collect()
-}
-
 #[cfg(test)]
 mod tests {
     use super::parse_filename;