refactor: improve integer performance

benches/resp.rs

@@ -3,7 +3,18 @@ use bytes::BytesMut;
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 use simple_redis::{parse_frame, parse_frame_length, RespFrame};
 
-const DATA: &str = "+OK\r\n-ERR\r\n:1000\r\n$6\r\nfoobar\r\n$-1\r\n*2\r\n+hello\r\n$5\r\nworld\r\n+foo\r\n$3\r\nbar\r\n%2\r\n+foo\r\n,-123456.789\r\n+hello\r\n$5\r\nworld\r\n*3\r\n$3\r\nset\r\n$5\r\nhello\r\n$5\r\nworld\r\n%2\r\n+hello\r\n$5\r\nworld\r\n+foo\r\n$3\r\nbar\r\n";
+// resp frames covers all kinds of real-world redis requests and responses
+// cmd 1: set key value
+// cmd 1 response: OK
+// cmd 2: get key
+// cmd 2 response: value
+// cmd 3: hset key field value
+// cmd 3 response: ERR
+// cmd 4: hget key field
+// cmd 4 response: value
+// cmd 5: sadd key member
+// cmd 5 response: 1
+const DATA: &str = "*3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$5\r\nvalue\r\n*1\r\n+OK\r\n*2\r\n$3\r\nGET\r\n$3\r\nkey\r\n$5\r\nvalue\r\n*4\r\n$4\r\nHSET\r\n$3\r\nkey\r\n$5\r\nfield\r\n$5\r\nvalue\r\n*1\r\n-ERR\r\n*3\r\n$4\r\nHGET\r\n$3\r\nkey\r\n$5\r\nfield\r\n$5\r\nvalue\r\n*3\r\n$4\r\nSADD\r\n$3\r\nkey\r\n$6\r\nmember\r\n:1\r\n";
 
 fn v1_decode(buf: &mut BytesMut) -> Result<Vec<RespFrame>> {
     use simple_redis::RespDecode;

src/respv2/parser.rs

@@ -75,12 +75,11 @@ fn error(input: &mut &[u8]) -> PResult<SimpleError> {
     parse_string.map(SimpleError).parse_next(input)
 }
 
-// - integer: ":1234\r\n"
+// - integer: ":-1234\r\n", need to take care of the sign
 fn integer(input: &mut &[u8]) -> PResult<i64> {
-    let sign = opt(alt(('+', '-'))).parse_next(input)?.unwrap_or('+');
-    let sign: i64 = if sign == '+' { 1 } else { -1 };
+    let sign = opt('-').parse_next(input)?.is_some();
     let v: i64 = terminated(digit1.parse_to(), CRLF).parse_next(input)?;
-    Ok(sign * v)
+    Ok(if sign { -v } else { v })
 }
 
 // - null bulk string: "$-1\r\n"