From a78dfd8ecc68b9aabe6f5ea20d92daf5f44bd800 Mon Sep 17 00:00:00 2001
From: neetdai <>
Date: Sun, 19 Jan 2025 22:51:37 +0800
Subject: [PATCH] Add memchr and optimize resp2 decode

---
 Cargo.toml          |  7 ++++---
 src/resp2/decode.rs | 15 ++++++++++++---
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 6f54978..5f9e18c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -33,6 +33,7 @@ nom = { version = "7.1", default-features = false }
 libm = { version = "0.2", optional = true }
 hashbrown = { version = "0.14", optional = true }
 tokio-util = { version = "0.7", features = ["codec"], optional = true }
+memchr = "2.7.4"
 
 [dev-dependencies]
 rand = "0.8"
@@ -60,9 +61,9 @@ doctest = true
 name = "redis_protocol"
 test = true
 
-#[[bench]]
-#name = "resp2_decode"
-#harness = false
+[[bench]]
+name = "resp2_decode"
+harness = false
 
 #[[bench]]
 #name = "resp2_encode"
diff --git a/src/resp2/decode.rs b/src/resp2/decode.rs
index d88c777..a76c92f 100644
--- a/src/resp2/decode.rs
+++ b/src/resp2/decode.rs
@@ -9,7 +9,8 @@ use crate::{
   utils,
 };
 use alloc::vec::Vec;
-use core::str;
+use memchr::memchr;
+use core::{num::NonZero, str};
 use nom::{
   bytes::streaming::{take as nom_take, take_until as nom_take_until},
   multi::count as nom_count,
@@ -39,13 +40,20 @@ fn to_i64(s: &[u8]) -> Result<i64, RedisParseError<&[u8]>> {
 
 fn d_read_to_crlf(input: (&[u8], usize)) -> DResult<usize> {
   decode_log_str!(input.0, _input, "Parsing to CRLF. Remaining: {:?}", _input);
-  let (input_bytes, data) = nom_terminated(nom_take_until(CRLF.as_bytes()), nom_take(2_usize))(input.0)?;
+  // let (input_bytes, data) = nom_terminated(nom_take_until(CRLF.as_bytes()), nom_take(2_usize))(input.0)?;
+  let position = memchr(b'\r', input.0).ok_or_else(|| NomErr::Error(RedisParseError::Nom(input.0, nom::error::ErrorKind::CrLf)))?;
+  let (data, input_bytes) = input.0.split_at(position);
+  let (_, input_bytes) = input_bytes.split_at_checked(2).ok_or_else(|| NomErr::Error(RedisParseError::Nom(input.0, nom::error::ErrorKind::Eof)))?;
   Ok(((input_bytes, input.1 + data.len() + 2), data.len()))
 }
 
+#[inline]
 fn d_read_to_crlf_take(input: (&[u8], usize)) -> DResult<&[u8]> {
   decode_log_str!(input.0, _input, "Parsing to CRLF. Remaining: {:?}", _input);
-  let (input_bytes, data) = nom_terminated(nom_take_until(CRLF.as_bytes()), nom_take(2_usize))(input.0)?;
+  // let (input_bytes, data) = nom_terminated(nom_take_until(CRLF.as_bytes()), nom_take(2_usize))(input.0)?;
+  let position = memchr(b'\r', input.0).ok_or_else(|| NomErr::Error(RedisParseError::Nom(input.0, nom::error::ErrorKind::CrLf)))?;
+  let (data, input_bytes) = input.0.split_at(position);
+  let (_, input_bytes) = input_bytes.split_at_checked(2).ok_or_else(|| NomErr::Error(RedisParseError::Nom(input.0, nom::error::ErrorKind::Eof)))?;
   Ok(((input_bytes, input.1 + data.len() + 2), data))
 }
 
@@ -100,6 +108,7 @@ fn d_parse_error(input: (&[u8], usize)) -> DResult<RangeFrame> {
   Ok(((input, next_offset), RangeFrame::Error((offset, offset + len))))
 }
 
+#[inline]
 fn d_parse_bulkstring(input: (&[u8], usize), len: usize) -> DResult<RangeFrame> {
   let offset = input.1;
   let (input, data) = nom_terminated(nom_take(len), nom_take(2_usize))(input.0)?;