From ad20e656b4098774993498858ae585b762be1543 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Fri, 23 Jan 2026 05:46:13 +0000
Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Bolt:=20Optimize=20socket=20parsing?=
 =?UTF-8?q?=20allocations=20in=20proc/net?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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- Replaced `string(byteSlice)` allocation in loop comparison with direct usage (compiler optimized).
- Replaced `make([]byte, ...)` in `decodeAddr` with stack-allocated arrays.
---
 .jules/bolt.md |  3 +++
 proc/net.go    | 11 ++++++-----
 2 files changed, 9 insertions(+), 5 deletions(-)
 create mode 100644 .jules/bolt.md

diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 00000000..7a728351
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2025-01-23 - Stack Allocation for Temporary Buffers
+**Learning:** Using `make([]byte, n)` for small, temporary buffers (like IP parsing) in hot loops causes significant allocation overhead. Replacing them with stack-allocated arrays (e.g., `var buf [16]byte; slice := buf[:]`) eliminates these allocations entirely.
+**Action:** Look for small `make` calls in hot paths (especially in `proc` parsing) and replace them with stack buffers where the size is bounded and small.
diff --git a/proc/net.go b/proc/net.go
index 70d6039d..3ab42141 100644
--- a/proc/net.go
+++ b/proc/net.go
@@ -58,8 +58,7 @@ func readSockets(src string) ([]Sock, error) {
 		local, b := nextField(b)
 		remote, b := nextField(b)
 		st, b := nextField(b)
-		state := string(st)
-		if state != stateEstablished && state != stateListen {
+		if string(st) != stateEstablished && string(st) != stateListen {
 			continue
 		}
 		_, b = nextField(b)
@@ -68,7 +67,7 @@ func readSockets(src string) ([]Sock, error) {
 		_, b = nextField(b)
 		_, b = nextField(b)
 		inode, _ := nextField(b)
-		res = append(res, Sock{SAddr: decodeAddr(local), DAddr: decodeAddr(remote), Listen: state == stateListen, Inode: string(inode)})
+		res = append(res, Sock{SAddr: decodeAddr(local), DAddr: decodeAddr(remote), Listen: string(st) == stateListen, Inode: string(inode)})
 	}
 	return res, nil
 }
@@ -93,11 +92,13 @@ func decodeAddr(src []byte) netaddr.IPPort {
 	if col == -1 || (col != 8 && col != 32) {
 		return netaddr.IPPort{}
 	}
-	ip := make([]byte, col/2)
+	var ipBuf [16]byte
+	ip := ipBuf[:col/2]
 	if _, err := hex.Decode(ip, src[:col]); err != nil {
 		return netaddr.IPPort{}
 	}
-	port := make([]byte, 2)
+	var portBuf [2]byte
+	port := portBuf[:]
 	if _, err := hex.Decode(port, src[col+1:]); err != nil {
 		return netaddr.IPPort{}
 	}