From 14554521770f857899ab512b0de107fc714ae490 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Sat, 4 Nov 2023 16:20:51 +0000 Subject: [PATCH] Pre-allocate send buffer when forwarding gossip When forwarding gossip, rather than relying on Vec doubling, pre-allocate the message encoding buffer. --- lightning/src/ln/peer_channel_encryptor.rs | 6 +++++- lightning/src/ln/peer_handler.rs | 4 ++-- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/lightning/src/ln/peer_channel_encryptor.rs b/lightning/src/ln/peer_channel_encryptor.rs index 071ef8a9d..a34b31a1b 100644 --- a/lightning/src/ln/peer_channel_encryptor.rs +++ b/lightning/src/ln/peer_channel_encryptor.rs @@ -34,6 +34,10 @@ use core::ops::Deref; /// and [BOLT-1](https://github.com/lightning/bolts/blob/master/01-messaging.md#lightning-message-format): pub const LN_MAX_MSG_LEN: usize = ::core::u16::MAX as usize; // Must be equal to 65535 +/// The (rough) size buffer to pre-allocate when encoding a message. Messages should reliably be +/// smaller than this size by at least 32 bytes or so. +pub const MSG_BUF_ALLOC_SIZE: usize = 2048; + // Sha256("Noise_XK_secp256k1_ChaChaPoly_SHA256") const NOISE_CK: [u8; 32] = [0x26, 0x40, 0xf5, 0x2e, 0xeb, 0xcd, 0x9e, 0x88, 0x29, 0x58, 0x95, 0x1c, 0x79, 0x42, 0x50, 0xee, 0xdb, 0x28, 0x00, 0x2c, 0x05, 0xd7, 0xdc, 0x2e, 0xa0, 0xf1, 0x95, 0x40, 0x60, 0x42, 0xca, 0xf1]; // Sha256(NOISE_CK || "lightning") @@ -448,7 +452,7 @@ impl PeerChannelEncryptor { pub fn encrypt_message(&mut self, message: &M) -> Vec { // Allocate a buffer with 2KB, fitting most common messages. Reserve the first 16+2 bytes // for the 2-byte message type prefix and its MAC. - let mut res = VecWriter(Vec::with_capacity(2048)); + let mut res = VecWriter(Vec::with_capacity(MSG_BUF_ALLOC_SIZE)); res.0.resize(16 + 2, 0); wire::write(message, &mut res).expect("In-memory messages must never fail to serialize"); diff --git a/lightning/src/ln/peer_handler.rs b/lightning/src/ln/peer_handler.rs index ba3a733d2..5f0d88a95 100644 --- a/lightning/src/ln/peer_handler.rs +++ b/lightning/src/ln/peer_handler.rs @@ -27,7 +27,7 @@ use crate::ln::msgs::{ChannelMessageHandler, LightningError, SocketAddress, Onio #[cfg(not(c_bindings))] use crate::ln::channelmanager::{SimpleArcChannelManager, SimpleRefChannelManager}; use crate::util::ser::{VecWriter, Writeable, Writer}; -use crate::ln::peer_channel_encryptor::{PeerChannelEncryptor,NextNoiseStep}; +use crate::ln::peer_channel_encryptor::{PeerChannelEncryptor, NextNoiseStep, MSG_BUF_ALLOC_SIZE}; use crate::ln::wire; use crate::ln::wire::{Encode, Type}; #[cfg(not(c_bindings))] @@ -785,7 +785,7 @@ impl From for MessageHandlingError { macro_rules! encode_msg { ($msg: expr) => {{ - let mut buffer = VecWriter(Vec::new()); + let mut buffer = VecWriter(Vec::with_capacity(MSG_BUF_ALLOC_SIZE)); wire::write($msg, &mut buffer).unwrap(); buffer.0 }} -- 2.39.5