From f80d8b02ca9dfea6c6dc4256d560be608685a5a2 Mon Sep 17 00:00:00 2001
From: SomberNight <SomberNight@users.noreply.github.com>
Date: Thu, 21 Sep 2017 01:19:05 +0200
Subject: [PATCH] Periodically poll fee estimates from server.

---
 lib/network.py       | 13 ++++++++++---
 lib/simple_config.py | 21 +++++++++++++++++++++
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/lib/network.py b/lib/network.py
index bf537222..e85eba24 100644
--- a/lib/network.py
+++ b/lib/network.py
@@ -314,12 +314,16 @@ class Network(util.DaemonThread):
         self.queue_request('server.banner', [])
         self.queue_request('server.donation_address', [])
         self.queue_request('server.peers.subscribe', [])
-        for i in bitcoin.FEE_TARGETS:
-            self.queue_request('blockchain.estimatefee', [i])
+        self.request_fee_estimates()
         self.queue_request('blockchain.relayfee', [])
         for h in self.subscribed_addresses:
             self.queue_request('blockchain.scripthash.subscribe', [h])
 
+    def request_fee_estimates(self):
+        self.config.requested_fee_estimates()
+        for i in bitcoin.FEE_TARGETS:
+            self.queue_request('blockchain.estimatefee', [i])
+
     def get_status_value(self, key):
         if key == 'status':
             value = self.connection_status
@@ -542,7 +546,7 @@ class Network(util.DaemonThread):
             if error is None and result > 0:
                 i = params[0]
                 fee = int(result*COIN)
-                self.config.fee_estimates[i] = fee
+                self.config.update_fee_estimates(i, fee)
                 self.print_error("fee_estimates[%d]" % i, fee)
                 self.notify('fee')
         elif method == 'blockchain.relayfee':
@@ -746,6 +750,9 @@ class Network(util.DaemonThread):
                         self.server_retry_time = now
                 else:
                     self.switch_to_interface(self.default_server)
+        else:
+            if self.config.is_fee_estimates_update_required():
+                self.request_fee_estimates()
 
     def request_chunk(self, interface, idx):
         interface.print_error("requesting chunk %d" % idx)
diff --git a/lib/simple_config.py b/lib/simple_config.py
index 18d7fe23..90d77b47 100644
--- a/lib/simple_config.py
+++ b/lib/simple_config.py
@@ -6,6 +6,7 @@ from __future__ import unicode_literals
 import ast
 import json
 import threading
+import time
 import os
 
 from copy import deepcopy
@@ -48,6 +49,8 @@ class SimpleConfig(PrintError):
         self.lock = threading.RLock()
 
         self.fee_estimates = {}
+        self.fee_estimates_last_updated = {}
+        self.last_time_fee_estimates_requested = 0  # zero ensures immediate fees
 
         # The following two functions are there for dependency injection when
         # testing.
@@ -243,6 +246,24 @@ class SimpleConfig(PrintError):
             fee_rate = self.get('fee_per_kb', self.max_fee_rate()/2)
         return fee_rate
 
+    def update_fee_estimates(self, key, value):
+        self.fee_estimates[key] = value
+        self.fee_estimates_last_updated[key] = time.time()
+
+    def is_fee_estimates_update_required(self):
+        """Checks time since last requested and updated fee estimates.
+        Returns True if an update should be requested.
+        """
+        now = time.time()
+        prev_updates = self.fee_estimates_last_updated.values()
+        oldest_fee_time = min(prev_updates) if prev_updates else 0
+        stale_fees = now - oldest_fee_time > 7200
+        old_request = now - self.last_time_fee_estimates_requested > 60
+        return stale_fees and old_request
+
+    def requested_fee_estimates(self):
+        self.last_time_fee_estimates_requested = time.time()
+
     def get_video_device(self):
         device = self.get("video_device", "default")
         if device == 'default':