diff --git a/README.md b/README.md
index 0b7733a..0b36d89 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,14 @@
 - pre-commit install
 - git remote add origin https://github.com/kindywu/03-simple-redis.git
 
+# RESP
+
+- Redis serialization protocol specification
+
+# 技术架构
+
+- tokio-util::codec::Framed -> bytes -> encode/decode frame
+
 # 设置日志级别(windows)
 
 - $env:RUST_LOG="info"
diff --git a/src/resp/array.rs b/src/resp/array.rs
index 0e4be98..2914369 100644
--- a/src/resp/array.rs
+++ b/src/resp/array.rs
@@ -4,11 +4,12 @@ use bytes::{Buf, BytesMut};
 
 use crate::{RespDecode, RespEncode, RespError, RespFrame};
 
-use super::{calc_total_length, parse_length, BUF_CAP, CRLF_LEN};
+use super::{calc_total_length, parse_length, CRLF_LEN};
 
 #[derive(Debug, Clone, PartialEq, PartialOrd)]
 pub struct RespArray(pub(crate) Vec<RespFrame>);
 
+// const BUF_CAP: usize = 4096;
 const NULL_ARRAY_STRING: &[u8; 5] = b"*-1\r\n";
 
 // - array: "*<number-of-elements>\r\n<element-1>...<element-n>"
@@ -17,7 +18,8 @@ impl RespEncode for RespArray {
         if self.0.is_empty() {
             NULL_ARRAY_STRING.to_vec()
         } else {
-            let mut buf = Vec::with_capacity(BUF_CAP);
+            // let mut buf = Vec::with_capacity(BUF_CAP);
+            let mut buf = Vec::new();
             buf.extend_from_slice(&format!("*{}\r\n", self.0.len()).into_bytes());
             for frame in self.0 {
                 buf.extend_from_slice(&frame.encode());
diff --git a/src/resp/mod.rs b/src/resp/mod.rs
index eabd15d..33edd61 100644
--- a/src/resp/mod.rs
+++ b/src/resp/mod.rs
@@ -12,7 +12,6 @@ pub use resp_frame::*;
 pub use simple_error::*;
 pub use simple_string::*;
 
-const BUF_CAP: usize = 4096;
 const CRLF: &[u8] = b"\r\n";
 const CRLF_LEN: usize = CRLF.len();
 
@@ -74,7 +73,7 @@ fn parse_length(buf: &[u8], prefix: &str) -> Result<(usize, usize), RespError> {
     let end = extract_simple_frame_data(buf, prefix)?;
     let s = String::from_utf8_lossy(&buf[prefix.len()..end]);
     if s == "-1" {
-        Ok((end, 0usize))
+        Ok((end, 0))
     } else {
         Ok((end, s.parse()?))
     }