perf: prefer smaller possibly stack allocated strings

Cargo.toml

@@ -16,7 +16,9 @@ serde = { version = "1.0.130", features = ["derive", "rc"] }
 thiserror = "2"
 url = "2.5.3"
 deno_error = "0.5.1"
-capacity_builder = "0.4.0"
+capacity_builder = { version = "0.5.0", features = ["ecow", "hipstr"] }
+hipstr = "0.6"
+ecow = { version = "0.2.3", features = ["serde"] }
 
 [dev-dependencies]
 divan = "0.1.17"

rust-toolchain.toml

@@ -1,4 +1,4 @@
 [toolchain]
-channel = "1.80.0"
+channel = "1.83.0"
 components = ["clippy", "rustfmt"]
 profile = "minimal"

src/jsr.rs

@@ -2,7 +2,7 @@
 
 use std::borrow::Cow;
 
-use capacity_builder::FastDisplay;
+use capacity_builder::CapacityDisplay;
 use capacity_builder::StringAppendable;
 use capacity_builder::StringType;
 use serde::Deserialize;
@@ -18,13 +18,14 @@ use crate::package::PackageReq;
 use crate::package::PackageReqParseError;
 use crate::package::PackageReqReference;
 use crate::package::PackageReqReferenceParseError;
+use crate::StackString;
 
 /// A reference to a JSR package's name, version constraint, and potential sub path.
 /// This contains all the information found in an npm specifier.
 ///
 /// This wraps PackageReqReference in order to prevent accidentally
 /// mixing this with other schemes.
-#[derive(Clone, Debug, PartialEq, Eq, Hash, FastDisplay)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, CapacityDisplay)]
 pub struct JsrPackageReqReference(PackageReqReference);
 
 impl<'a> StringAppendable<'a> for &'a JsrPackageReqReference {
@@ -77,7 +78,9 @@ impl JsrPackageReqReference {
 ///
 /// This wraps PackageNvReference in order to prevent accidentally
 /// mixing this with other schemes.
-#[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash, FastDisplay)]
+#[derive(
+  Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash, CapacityDisplay,
+)]
 pub struct JsrPackageNvReference(PackageNvReference);
 
 impl JsrPackageNvReference {
@@ -142,7 +145,7 @@ impl<'de> Deserialize<'de> for JsrPackageNvReference {
   where
     D: serde::Deserializer<'de>,
   {
-    let text = String::deserialize(deserializer)?;
+    let text: Cow<'de, str> = Deserialize::deserialize(deserializer)?;
     match Self::from_str(&text) {
       Ok(req) => Ok(req),
       Err(err) => Err(serde::de::Error::custom(err)),
@@ -178,7 +181,9 @@ pub enum JsrDepPackageReqParseError {
 }
 
 /// A package constraint for a JSR dependency which could be from npm or JSR.
-#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, FastDisplay)]
+#[derive(
+  Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, CapacityDisplay,
+)]
 pub struct JsrDepPackageReq {
   pub kind: PackageKind,
   pub req: PackageReq,
@@ -208,7 +213,7 @@ impl<'de> Deserialize<'de> for JsrDepPackageReq {
   where
     D: serde::Deserializer<'de>,
   {
-    let text = String::deserialize(deserializer)?;
+    let text: Cow<'de, str> = Deserialize::deserialize(deserializer)?;
     match Self::from_str_loose(&text) {
       Ok(req) => Ok(req),
       Err(err) => Err(serde::de::Error::custom(err)),
@@ -265,13 +270,14 @@ impl JsrDepPackageReq {
   /// Outputs a normalized string representation of this dependency.
   ///
   /// Note: The normalized string is not safe for a URL. It's best used for serialization.
-  pub fn to_string_normalized(&self) -> String {
-    format!(
-      "{}{}@{}",
-      self.kind.scheme_with_colon(),
-      self.req.name,
-      self.req.version_req.inner()
-    )
+  pub fn to_string_normalized(&self) -> StackString {
+    capacity_builder::StringBuilder::build(|builder| {
+      builder.append(self.kind.scheme_with_colon());
+      builder.append(&self.req.name);
+      builder.append('@');
+      builder.append(self.req.version_req.inner());
+    })
+    .unwrap()
   }
 }
 

src/lib.rs

@@ -3,11 +3,12 @@
 #![deny(clippy::print_stderr)]
 #![deny(clippy::print_stdout)]
 
+use std::borrow::Cow;
 use std::cmp::Ordering;
 use std::fmt;
 use std::hash::Hash;
 
-use capacity_builder::FastDisplay;
+use capacity_builder::CapacityDisplay;
 use capacity_builder::StringAppendable;
 use capacity_builder::StringBuilder;
 use capacity_builder::StringType;
@@ -21,6 +22,12 @@ pub mod npm;
 pub mod package;
 mod range;
 mod specifier;
+mod string;
+
+/// A smaller two-byte vector.
+pub type SmallVec<T> = ecow::EcoVec<T>;
+pub use string::SmallStackString;
+pub use string::StackString;
 
 pub use self::specifier::VersionReqSpecifierParseError;
 
@@ -44,13 +51,15 @@ pub struct VersionParseError {
   source: monch::ParseErrorFailureError,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Default, Hash, FastDisplay)]
+pub type VersionPreOrBuild = SmallStackString;
+
+#[derive(Clone, Debug, PartialEq, Eq, Default, Hash, CapacityDisplay)]
 pub struct Version {
   pub major: u64,
   pub minor: u64,
   pub patch: u64,
-  pub pre: Vec<String>,
-  pub build: Vec<String>,
+  pub pre: SmallVec<VersionPreOrBuild>,
+  pub build: SmallVec<VersionPreOrBuild>,
 }
 
 impl<'a> StringAppendable<'a> for &'a Version {
@@ -98,7 +107,7 @@ impl<'de> Deserialize<'de> for Version {
   where
     D: serde::Deserializer<'de>,
   {
-    let text = String::deserialize(deserializer)?;
+    let text: Cow<'de, str> = Deserialize::deserialize(deserializer)?;
     match Version::parse_standard(&text) {
       Ok(version) => Ok(version),
       Err(err) => Err(serde::de::Error::custom(err)),
@@ -197,12 +206,14 @@ pub(crate) fn is_valid_tag(value: &str) -> bool {
   npm::is_valid_npm_tag(value)
 }
 
+pub type PackageTag = SmallStackString;
+
 #[derive(
-  Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize, FastDisplay,
+  Clone, Debug, PartialEq, Eq, Hash, Serialize, Deserialize, CapacityDisplay,
 )]
 pub enum RangeSetOrTag {
   RangeSet(VersionRangeSet),
-  Tag(String),
+  Tag(PackageTag),
 }
 
 impl<'a> StringAppendable<'a> for &'a RangeSetOrTag {
@@ -233,7 +244,7 @@ impl RangeSetOrTag {
 /// A version constraint.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct VersionReq {
-  raw_text: String,
+  raw_text: SmallStackString,
   inner: RangeSetOrTag,
 }
 
@@ -254,7 +265,7 @@ impl Hash for VersionReq {
 impl VersionReq {
   /// Creates a version requirement without examining the raw text.
   pub fn from_raw_text_and_inner(
-    raw_text: String,
+    raw_text: SmallStackString,
     inner: RangeSetOrTag,
   ) -> Self {
     Self { raw_text, inner }