From 5e03d751ebb6b6f94fafbc800f34ad2bc7f09cc9 Mon Sep 17 00:00:00 2001
From: bitromortac <bitromortac@protonmail.com>
Date: Fri, 9 Apr 2021 09:40:33 +0200
Subject: [PATCH] lnrouter: add hint timestamp

---
 electrum/commands.py |  4 ++++
 electrum/lnrouter.py | 21 +++++++++++++++++----
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/electrum/commands.py b/electrum/commands.py
index 96fca6ca6..91b2e10b2 100644
--- a/electrum/commands.py
+++ b/electrum/commands.py
@@ -1091,6 +1091,10 @@ class Commands:
     async def clear_ln_blacklist(self):
         self.network.path_finder.liquidity_hints.clear_blacklist()
 
+    @command('n')
+    async def reset_liquidity_hints(self):
+        self.network.path_finder.liquidity_hints.reset_liquidity_hints()
+
     @command('w')
     async def list_invoices(self, wallet: Abstract_Wallet = None):
         l = wallet.get_invoices()
diff --git a/electrum/lnrouter.py b/electrum/lnrouter.py
index e691766f3..0cb73b264 100644
--- a/electrum/lnrouter.py
+++ b/electrum/lnrouter.py
@@ -43,6 +43,7 @@ if TYPE_CHECKING:
 DEFAULT_PENALTY_BASE_MSAT = 500  # how much base fee we apply for unknown sending capability of a channel
 DEFAULT_PENALTY_PROPORTIONAL_MILLIONTH = 100  # how much relative fee we apply for unknown sending capability of a channel
 BLACKLIST_DURATION = 3600  # how long (in seconds) a channel remains blacklisted
+HINT_DURATION = 3600  # how long (in seconds) a liquidity hint remains valid
 
 
 class NoChannelPolicy(Exception):
@@ -181,10 +182,15 @@ class LiquidityHint:
         self._can_send_backward = None
         self._cannot_send_backward = None
         self.blacklist_timestamp = 0
+        self.hint_timestamp = 0
+
+    def is_hint_invalid(self) -> bool:
+        now = int(time.time())
+        return now - self.hint_timestamp > HINT_DURATION
 
     @property
     def can_send_forward(self):
-        return self._can_send_forward
+        return None if self.is_hint_invalid() else self._can_send_forward
 
     @can_send_forward.setter
     def can_send_forward(self, amount):
@@ -199,7 +205,7 @@ class LiquidityHint:
 
     @property
     def can_send_backward(self):
-        return self._can_send_backward
+        return None if self.is_hint_invalid() else self._can_send_backward
 
     @can_send_backward.setter
     def can_send_backward(self, amount):
@@ -211,7 +217,7 @@ class LiquidityHint:
 
     @property
     def cannot_send_forward(self):
-        return self._cannot_send_forward
+        return None if self.is_hint_invalid() else self._cannot_send_forward
 
     @cannot_send_forward.setter
     def cannot_send_forward(self, amount):
@@ -228,7 +234,7 @@ class LiquidityHint:
 
     @property
     def cannot_send_backward(self):
-        return self._cannot_send_backward
+        return None if self.is_hint_invalid() else self._cannot_send_backward
 
     @cannot_send_backward.setter
     def cannot_send_backward(self, amount):
@@ -254,12 +260,14 @@ class LiquidityHint:
             return self.cannot_send_backward
 
     def update_can_send(self, is_forward_direction: bool, amount: int):
+        self.hint_timestamp = int(time.time())
         if is_forward_direction:
             self.can_send_forward = amount
         else:
             self.can_send_backward = amount
 
     def update_cannot_send(self, is_forward_direction: bool, amount: int):
+        self.hint_timestamp = int(time.time())
         if is_forward_direction:
             self.cannot_send_forward = amount
         else:
@@ -356,6 +364,11 @@ class LiquidityHintMgr:
         for k, v in self._liquidity_hints.items():
             v.blacklist_timestamp = 0
 
+    @with_lock
+    def reset_liquidity_hints(self):
+        for k, v in self._liquidity_hints.items():
+            v.hint_timestamp = 0
+
     def __repr__(self):
         string = "liquidity hints:\n"
         if self._liquidity_hints: