Look at BufMut usage

.claude/settings.local.json

@@ -0,0 +1,13 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(cargo test)",
+      "Bash(cargo test:*)",
+      "Bash(cargo clippy:*)",
+      "Bash(cargo fmt:*)",
+      "Bash(cargo:*)",
+      "Bash(gh pr view:*)"
+    ],
+    "deny": []
+  }
+}

.gitignore

@@ -12,3 +12,4 @@ Cargo.lock
 examples/debug-file.rs
 
 .env
+.claude

CHANGELOG.md

@@ -14,6 +14,12 @@ All notable changes to this project will be documented in this file.
 
 ### Code improvements
 
+* optimized BytesMut buffer allocation patterns for better memory efficiency
+    * replaced `BytesMut::with_capacity() + resize()` with `BytesMut::zeroed()` for cleaner initialization
+    * added capacity pre-allocation in ASN encoding to avoid reallocations
+    * replaced unnecessary BytesMut allocations with direct slice references in MRT header parsing
+    * added capacity pre-allocation in MRT record encoding for optimal buffer sizing
+    * fixed non-canonical PartialOrd implementation for ASN type to follow Rust idioms
 * added BGP Flow-Spec parsing support following RFC 8955 and RFC 8956
     * implemented complete Flow-Spec NLRI parsing for IPv4 and IPv6 Flow Specification rules
     * added support for all Flow-Spec component types (destination/source prefix, protocol, ports, ICMP, TCP flags, packet length, DSCP, fragment, flow label)

src/models/network/asn.rs

@@ -52,7 +52,7 @@ impl PartialEq for Asn {
 
 impl PartialOrd for Asn {
     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        Some(self.asn.cmp(&other.asn))
+        Some(self.cmp(other))
     }
 }
 
@@ -278,7 +278,7 @@ impl FromStr for Asn {
 #[cfg(feature = "parser")]
 impl Asn {
     pub fn encode(&self) -> Bytes {
-        let mut bytes = BytesMut::new();
+        let mut bytes = BytesMut::with_capacity(if self.four_byte { 4 } else { 2 });
         match self.four_byte {
             true => bytes.put_u32(self.asn),
             false => bytes.put_u16(self.asn as u16),

src/parser/mrt/mrt_header.rs

@@ -42,7 +42,7 @@ use std::io::Read;
 pub fn parse_common_header<T: Read>(input: &mut T) -> Result<CommonHeader, ParserError> {
     let mut raw_bytes = [0u8; 12];
     input.read_exact(&mut raw_bytes)?;
-    let mut data = BytesMut::from(&raw_bytes[..]);
+    let mut data = &raw_bytes[..];
 
     let timestamp = data.get_u32();
     let entry_type_raw = data.get_u16();
@@ -56,7 +56,7 @@ pub fn parse_common_header<T: Read>(input: &mut T) -> Result<CommonHeader, Parse
             length -= 4;
             let mut raw_bytes: [u8; 4] = [0; 4];
             input.read_exact(&mut raw_bytes)?;
-            Some(BytesMut::from(&raw_bytes[..]).get_u32())
+            Some((&raw_bytes[..]).get_u32())
         }
         _ => None,
     };

src/parser/mrt/mrt_record.rs

@@ -31,8 +31,7 @@ pub fn parse_mrt_record(input: &mut impl Read) -> Result<MrtRecord, ParserErrorW
     };
 
     // read the whole message bytes to buffer
-    let mut buffer = BytesMut::with_capacity(common_header.length as usize);
-    buffer.resize(common_header.length as usize, 0);
+    let mut buffer = BytesMut::zeroed(common_header.length as usize);
     match input
         .take(common_header.length as u64)
         .read_exact(&mut buffer)
@@ -127,7 +126,6 @@ pub fn parse_mrt_body(
 
 impl MrtRecord {
     pub fn encode(&self) -> Bytes {
-        let mut bytes = BytesMut::new();
         let message_bytes = self.message.encode(self.common_header.entry_subtype);
         let mut new_header = self.common_header;
         if message_bytes.len() < new_header.length as usize {
@@ -146,6 +144,7 @@ impl MrtRecord {
         // assert!(self.message == parsed_body);
         // // debug ends
 
+        let mut bytes = BytesMut::with_capacity(header_bytes.len() + message_bytes.len());
         bytes.put_slice(&header_bytes);
         bytes.put_slice(&message_bytes);
         bytes.freeze()