From 6bdbd821e38cbe279615b602d8c8acee973e1293 Mon Sep 17 00:00:00 2001
From: Ed Page <epage@duosecurity.com>
Date: Tue, 10 Nov 2020 20:50:10 -0600
Subject: [PATCH] perf(dict): Avoid hashing unknwon words

Bypass hashing when we know (through str::len) that a word won't be in
the dict.

Master:
```
real    0m26.675s
user    0m33.683s
sys     0m4.535s
```

With this change
```
real    0m24.432s
user    0m32.492s
sys     0m4.190s
```
---
 crates/typos-vars/codegen/src/main.rs | 9 +++++++++
 crates/typos-vars/src/vars_codegen.rs | 3 +++
 src/dict.rs                           | 9 ++++++++-
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/crates/typos-vars/codegen/src/main.rs b/crates/typos-vars/codegen/src/main.rs
index c718ee8..981a85c 100644
--- a/crates/typos-vars/codegen/src/main.rs
+++ b/crates/typos-vars/codegen/src/main.rs
@@ -76,6 +76,9 @@ fn generate_variations<W: std::io::Write>(file: &mut W) {
     writeln!(file, "}}").unwrap();
     writeln!(file).unwrap();
 
+    let mut smallest = usize::MAX;
+    let mut largest = usize::MIN;
+
     writeln!(
         file,
         "pub static VARS_DICTIONARY: phf::Map<unicase::UniCase<&'static str>, &'static [(u8, &VariantsMap)]> = "
@@ -92,11 +95,17 @@ fn generate_variations<W: std::io::Write>(file: &mut W) {
         referenced_symbols.extend(data.iter().map(|(s, _)| s));
         let value = generate_link(&data);
         builder.entry(unicase::UniCase::new(word), &value);
+        smallest = std::cmp::min(smallest, word.len());
+        largest = std::cmp::max(largest, word.len());
     }
     let codegenned = builder.build();
     writeln!(file, "{}", codegenned).unwrap();
     writeln!(file, ";").unwrap();
 
+    writeln!(file).unwrap();
+    writeln!(file, "pub const WORD_MIN: usize = {};", smallest).unwrap();
+    writeln!(file, "pub const WORD_MAX: usize = {};", largest).unwrap();
+
     for (symbol, entry) in entries.iter() {
         if !referenced_symbols.contains(symbol.as_str()) {
             continue;
diff --git a/crates/typos-vars/src/vars_codegen.rs b/crates/typos-vars/src/vars_codegen.rs
index 03ac102..e511b01 100644
--- a/crates/typos-vars/src/vars_codegen.rs
+++ b/crates/typos-vars/src/vars_codegen.rs
@@ -113081,6 +113081,9 @@ pub static VARS_DICTIONARY: phf::Map<
         ),
     ]),
 };
+
+pub const WORD_MIN: usize = 2;
+pub const WORD_MAX: usize = 24;
 pub(crate) static ENTRY_ABETTORS_7043394254318611656: VariantsMap =
     [&["abettors"], &["abetters"], &["abettors"], &["abetters"]];
 
diff --git a/src/dict.rs b/src/dict.rs
index 504bec1..d0e0aa9 100644
--- a/src/dict.rs
+++ b/src/dict.rs
@@ -54,7 +54,14 @@ impl BuiltIn {
     }
 
     fn correct_with_vars(&self, word: &str) -> Option<Status<'static>> {
-        map_lookup(&typos_vars::VARS_DICTIONARY, word).map(|variants| self.select_variant(variants))
+        const WORD_RANGE: std::ops::RangeInclusive<usize> =
+            typos_vars::WORD_MIN..=typos_vars::WORD_MAX;
+        if WORD_RANGE.contains(&word.len()) {
+            map_lookup(&typos_vars::VARS_DICTIONARY, word)
+                .map(|variants| self.select_variant(variants))
+        } else {
+            None
+        }
     }
 
     fn select_variant(