Merge branch 'master' into faster-1-ascii-replace

Author: alexheretic

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 - Optimise `StrExt::replace_smolstr`, `StrExt::replacen_smolstr` for single ascii replace,
   ~3x speedup inline & heap.
+- Optimise `StrExt::to_ascii_lowercase_smolstr`, `StrExt::to_ascii_uppercase_smolstr` 
+  ~2x speedup inline, ~4-22x for heap.
 
 ## 0.3.2 - 2024-10-23
 

Cargo.toml

@@ -12,7 +12,7 @@ rustdoc-args = ["--cfg", "docsrs"]
 all-features = true
 
 [dependencies]
-serde = { version = "1.0", optional = true, default-features = false }
+serde_core = { version = "1.0.220", optional = true, default-features = false }
 borsh = { version = "1.4.0", optional = true, default-features = false }
 arbitrary = { version = "1.3", optional = true }
 
@@ -23,4 +23,5 @@ serde = { version = "1.0", features = ["derive"] }
 
 [features]
 default = ["std"]
-std = ["serde?/std", "borsh?/std"]
+std = ["serde_core?/std", "borsh?/std"]
+serde = ["dep:serde_core"]

src/lib.rs

@@ -644,12 +644,36 @@ impl StrExt for str {
 
     #[inline]
     fn to_ascii_lowercase_smolstr(&self) -> SmolStr {
-        from_char_iter(self.chars().map(|c| c.to_ascii_lowercase()))
+        let len = self.len();
+        if len <= INLINE_CAP {
+            let mut buf = [0u8; INLINE_CAP];
+            buf[..len].copy_from_slice(self.as_bytes());
+            buf[..len].make_ascii_lowercase();
+            SmolStr(Repr::Inline {
+                // SAFETY: `len` is in bounds
+                len: unsafe { InlineSize::transmute_from_u8(len as u8) },
+                buf,
+            })
+        } else {
+            self.to_ascii_lowercase().into()
+        }
     }
 
     #[inline]
     fn to_ascii_uppercase_smolstr(&self) -> SmolStr {
-        from_char_iter(self.chars().map(|c| c.to_ascii_uppercase()))
+        let len = self.len();
+        if len <= INLINE_CAP {
+            let mut buf = [0u8; INLINE_CAP];
+            buf[..len].copy_from_slice(self.as_bytes());
+            buf[..len].make_ascii_uppercase();
+            SmolStr(Repr::Inline {
+                // SAFETY: `len` is in bounds
+                len: unsafe { InlineSize::transmute_from_u8(len as u8) },
+                buf,
+            })
+        } else {
+            self.to_ascii_uppercase().into()
+        }
     }
 
     #[inline]

src/serde.rs

@@ -2,6 +2,7 @@ use alloc::{string::String, vec::Vec};
 use core::fmt;
 
 use serde::de::{Deserializer, Error, Unexpected, Visitor};
+use serde_core as serde;
 
 use crate::SmolStr;