From 166695d09ab3c30a0147ac74aa856bae1f5542a8 Mon Sep 17 00:00:00 2001
From: iximeow <me@iximeow.net>
Date: Tue, 18 Jun 2024 14:58:05 -0700
Subject: write_fixed_size impls for string and BigEnoughString
---
src/long_mode/display.rs | 69 +++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 63 insertions(+), 6 deletions(-)
(limited to 'src/long_mode')
diff --git a/src/long_mode/display.rs b/src/long_mode/display.rs
index d7a80cb..575765c 100644
--- a/src/long_mode/display.rs
+++ b/src/long_mode/display.rs
@@ -371,14 +371,10 @@ pub enum TokenType {
}
pub trait DisplaySink: fmt::Write {
- // /// may be optimized for writing strings of variable length.
- // fn write_str(&mut self, s: &str) -> Result<(), core::fmt::Error>;
fn write_fixed_size(&mut self, s: &str) -> Result<(), core::fmt::Error> {
- for c in s.as_bytes().iter() {
- self.write_char(*c as char)?;
- }
- Ok(())
+ self.write_str(s)
}
+
/// write a string to this sink that is less than 32 bytes. this is provided for optimization
/// opportunities when writing a variable-length string with known max size.
///
@@ -472,6 +468,37 @@ impl fmt::Write for BigEnoughString {
// TODO: delete this whole thing? maybe?
impl DisplaySink for alloc::string::String {
+ fn write_fixed_size(&mut self, s: &str) -> Result<(), core::fmt::Error> {
+ self.reserve(s.len());
+ let buf = unsafe { self.as_mut_vec() };
+ let new_bytes = s.as_bytes();
+
+ if new_bytes.len() == 0 {
+ unsafe { core::hint::unreachable_unchecked() }
+ }
+
+ if new_bytes.len() >= 16 {
+ unsafe { core::hint::unreachable_unchecked() }
+ }
+
+ unsafe {
+ let dest = buf.as_mut_ptr().offset(buf.len() as isize);
+ let src = new_bytes.as_ptr();
+
+ let mut rem = new_bytes.len() as isize;
+
+ dest.offset(0 as isize).write(new_bytes[0]);
+ for i in 1..new_bytes.len() {
+ unsafe {
+ dest.offset(i as isize).write(new_bytes[i]);
+ }
+ }
+
+ buf.set_len(buf.len() + new_bytes.len());
+ }
+
+ Ok(())
+ }
unsafe fn write_lt_32(&mut self, s: &str) -> Result<(), fmt::Error> {
self.reserve(s.len());
@@ -686,6 +713,36 @@ impl DisplaySink for alloc::string::String {
}
impl DisplaySink for BigEnoughString {
+ fn write_fixed_size(&mut self, s: &str) -> Result<(), core::fmt::Error> {
+ let buf = unsafe { self.content.as_mut_vec() };
+ let new_bytes = s.as_bytes();
+
+ if new_bytes.len() == 0 {
+ unsafe { core::hint::unreachable_unchecked() }
+ }
+
+ if new_bytes.len() >= 16 {
+ unsafe { core::hint::unreachable_unchecked() }
+ }
+
+ unsafe {
+ let dest = buf.as_mut_ptr().offset(buf.len() as isize);
+ let src = new_bytes.as_ptr();
+
+ let mut rem = new_bytes.len() as isize;
+
+ dest.offset(0 as isize).write(new_bytes[0]);
+ for i in 1..new_bytes.len() {
+ unsafe {
+ dest.offset(i as isize).write(new_bytes[i]);
+ }
+ }
+
+ buf.set_len(buf.len() + new_bytes.len());
+ }
+
+ Ok(())
+ }
unsafe fn write_lt_32(&mut self, s: &str) -> Result<(), fmt::Error> {
// SAFETY: todo
let buf = unsafe { self.content.as_mut_vec() };
--
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