From e513057eae7e6924f0340c34f1c51b43692755f3 Mon Sep 17 00:00:00 2001
From: yyforyongyu <yy2452@columbia.edu>
Date: Thu, 22 Jul 2021 20:40:36 +0800
Subject: [PATCH] htlcswitch: add docs for circuit bucket hierarchy

---
 htlcswitch/circuit_map.go | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/htlcswitch/circuit_map.go b/htlcswitch/circuit_map.go
index 3e4968bc7..b1099a966 100644
--- a/htlcswitch/circuit_map.go
+++ b/htlcswitch/circuit_map.go
@@ -137,11 +137,31 @@ var (
 	// a packet to the source link, potentially including an error
 	// encrypter for applying this hop's encryption to the payload in the
 	// reverse direction.
+	//
+	// Bucket hierarchy:
+	//
+	// circuitAddKey(root-bucket)
+	//     	|
+	//     	|-- <incoming-circuit-key>: <encoded bytes of PaymentCircuit>
+	//     	|-- <incoming-circuit-key>: <encoded bytes of PaymentCircuit>
+	//     	|
+	//     	...
+	//
 	circuitAddKey = []byte("circuit-adds")
 
 	// circuitKeystoneKey is used to retrieve the bucket containing circuit
 	// keystones, which are set in place once a forwarded packet is
 	// assigned an index on an outgoing commitment txn.
+	//
+	// Bucket hierarchy:
+	//
+	// circuitKeystoneKey(root-bucket)
+	//     	|
+	//     	|-- <outgoing-circuit-key>: <incoming-circuit-key>
+	//     	|-- <outgoing-circuit-key>: <incoming-circuit-key>
+	//     	|
+	//     	...
+	//
 	circuitKeystoneKey = []byte("circuit-keystones")
 )