Merge branch 'master' into leebenson/tap2

lib/vrl/compiler/Cargo.toml

@@ -28,3 +28,7 @@ criterion = "0.3"
 [[bench]]
 name = "path"
 harness = false
+
+[[bench]]
+name = "kind"
+harness = false

lib/vrl/compiler/benches/kind.rs

@@ -0,0 +1,34 @@
+use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
+use std::fmt;
+use vrl_compiler::value::Kind;
+
+struct Parameters {
+    basis: Kind,
+}
+
+static PARAMETERS: [Parameters; 4] = [
+    Parameters { basis: Kind::Bytes },
+    Parameters { basis: Kind::Array },
+    Parameters { basis: Kind::Regex },
+    Parameters { basis: Kind::Null },
+];
+
+impl fmt::Display for Parameters {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.basis)
+    }
+}
+
+fn benchmark_kind_display(c: &mut Criterion) {
+    let mut group = c.benchmark_group("vrl_compiler::value::kind::display");
+    for param in &PARAMETERS {
+        group.bench_with_input(BenchmarkId::from_parameter(param), &param, |b, &param| {
+            b.iter(|| format!("{}", param.basis))
+        });
+    }
+}
+
+criterion_group!(name = vrl_compiler_kind;
+                 config = Criterion::default();
+                 targets = benchmark_kind_display);
+criterion_main!(vrl_compiler_kind);

lib/vrl/compiler/src/value/kind.rs

@@ -68,8 +68,29 @@ impl Kind {
         self == self.scalar()
     }
 
-    pub(crate) fn quoted(self) -> String {
-        format!(r#""{}""#, self.as_str())
+    /// Returns a quoted variant of `as_str`
+    ///
+    /// This function is a close duplicate of `as_str`, returning the same
+    /// underlying str but with quotes. We avoid the obvious `format!("{}",
+    /// self.as_str())` here as that incurs an allocation cost and the `Display`
+    /// of `Kind` is sometimes in the hot path.
+    ///
+    /// See https://github.com/timberio/vector/pull/6878 for details.
+    pub(crate) fn quoted(self) -> &'static str {
+        match self {
+            Kind::Bytes => "\"string\"",
+            Kind::Integer => "\"integer\"",
+            Kind::Float => "\"float\"",
+            Kind::Boolean => "\"boolean\"",
+            Kind::Object => "\"object\"",
+            Kind::Array => "\"array\"",
+            Kind::Timestamp => "\"timestamp\"",
+            Kind::Regex => "\"regex\"",
+            Kind::Null => "\"null\"",
+            _ if self.is_all() => "\"unknown type\"",
+            _ if self.is_empty() => "\"none\"",
+            _ => "\"multiple\"",
+        }
     }
 
     pub fn as_str(self) -> &'static str {
@@ -137,7 +158,7 @@ macro_rules! impl_kind {
                     return write!(f, "{}", self.quoted())
                 }
 
-                let mut kinds = vec![];
+                let mut kinds = Vec::with_capacity(16);
                 $(paste::paste! {
                 if self.[<contains_ $name>]() {
                     kinds.push(Kind::$kind.quoted())
@@ -229,6 +250,14 @@ impl From<&Value> for Kind {
 mod tests {
     use super::*;
 
+    #[test]
+    fn quoted() {
+        for i in 0..u16::MAX {
+            let kind = Kind::new(i);
+            assert_eq!(kind.quoted(), format!(r#""{}""#, kind.as_str()));
+        }
+    }
+
     #[test]
     fn kind_is_scalar() {
         let scalars = vec![