From: Valentine Wallace <vwallace@protonmail.com>
Date: Fri, 10 Nov 2023 22:01:52 +0000 (-0500)
Subject: Make MAX_PATH_LENGTH_ESTIMATE const pub and expand doc comment.
X-Git-Tag: v0.0.124-beta~116^2~7
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=2de600b984fbd9c54bc1341177ac821e259078a3;p=rust-lightning

Make MAX_PATH_LENGTH_ESTIMATE const pub and expand doc comment.

Will be used in the next commit when we make this configurable in
PaymentParameters.
---

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index 8744761e7..420f6d5d8 100644
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -654,6 +654,8 @@ const DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF: u8 = 2;
 // The median hop CLTV expiry delta currently seen in the network.
 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
 
+/// Estimated maximum number of hops that can be included in a payment path. May be inaccurate if
+/// payment metadata, custom TLVs, or blinded paths are included in the payment.
 // During routing, we only consider paths shorter than our maximum length estimate.
 // In the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
 // field is always 1300 bytes. As the `tlv_payload` for each hop may vary in length, we have to
@@ -665,7 +667,7 @@ const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
 // (payment_secret and total_msat) = 93 bytes for the final hop.
 // Since the length of the potentially included `payment_metadata` is unknown to us, we round
 // down from (1300-93) / 61 = 19.78... to arrive at a conservative estimate of 19.
-const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
+pub const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
 
 /// Information used to route a payment.
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]