globset: polishing

This brings the code in line with my current style. It also inlines the
dozen or so lines of code for FNV hashing instead of bringing in a
micro-crate for it. Finally, it drops the dependency on regex in favor
of using regex-syntax and regex-automata directly.

crates/globset/Cargo.toml

@@ -13,24 +13,32 @@ repository = "https://github.com/BurntSushi/ripgrep/tree/master/crates/globset"
 readme = "README.md"
 keywords = ["regex", "glob", "multiple", "set", "pattern"]
 license = "Unlicense OR MIT"
-edition = "2018"
+edition = "2021"
 
 [lib]
 name = "globset"
 bench = false
 
 [dependencies]
-aho-corasick = "1.0.2"
-bstr = { version = "1.6.0", default-features = false, features = ["std"] }
-fnv = "1.0.6"
-log = { version = "0.4.5", optional = true }
-regex = { version = "1.8.3", default-features = false, features = ["perf", "std"] }
-serde = { version = "1.0.104", optional = true }
+aho-corasick = "1.1.1"
+bstr = { version = "1.6.2", default-features = false, features = ["std"] }
+log = { version = "0.4.20", optional = true }
+serde = { version = "1.0.188", optional = true }
+
+[dependencies.regex-syntax]
+version = "0.7.5"
+default-features = false
+features = ["std"]
+
+[dependencies.regex-automata]
+version = "0.3.8"
+default-features = false
+features = ["std", "perf", "syntax", "meta", "nfa", "hybrid"]
 
 [dev-dependencies]
-glob = "0.3.0"
+glob = "0.3.1"
 lazy_static = "1"
-serde_json = "1.0.45"
+serde_json = "1.0.107"
 
 [features]
 default = ["log"]

crates/globset/src/fnv.rs

@@ -0,0 +1,30 @@
+/// A convenience alias for creating a hash map with an FNV hasher.
+pub(crate) type HashMap<K, V> =
+    std::collections::HashMap<K, V, std::hash::BuildHasherDefault<Hasher>>;
+
+/// A hasher that implements the Fowler–Noll–Vo (FNV) hash.
+pub(crate) struct Hasher(u64);
+
+impl Hasher {
+    const OFFSET_BASIS: u64 = 0xcbf29ce484222325;
+    const PRIME: u64 = 0x100000001b3;
+}
+
+impl Default for Hasher {
+    fn default() -> Hasher {
+        Hasher(Hasher::OFFSET_BASIS)
+    }
+}
+
+impl std::hash::Hasher for Hasher {
+    fn finish(&self) -> u64 {
+        self.0
+    }
+
+    fn write(&mut self, bytes: &[u8]) {
+        for &byte in bytes.iter() {
+            self.0 = self.0 ^ u64::from(byte);
+            self.0 = self.0.wrapping_mul(Hasher::PRIME);
+        }
+    }
+}