Add fee slider class with network callback.

lib/simple_config.py

@@ -6,6 +6,8 @@ import os
 from copy import deepcopy
 from util import user_dir, print_error, print_msg, print_stderr, PrintError
 
+from bitcoin import MAX_FEE_RATE, FEE_TARGETS
+
 SYSTEM_CONFIG_PATH = "/etc/electrum.conf"
 
 config = None
@@ -40,6 +42,8 @@ class SimpleConfig(PrintError):
         # a thread-safe way.
         self.lock = threading.RLock()
 
+        self.fee_estimates = {}
+
         # The following two functions are there for dependency injection when
         # testing.
         if read_system_config_function is None:
@@ -190,6 +194,43 @@ class SimpleConfig(PrintError):
             path = wallet.storage.path
             self.set_key('gui_last_wallet', path)
 
+    def max_fee_rate(self):
+        return self.get('max_fee_rate', MAX_FEE_RATE)
+
+    def dynfee(self, i):
+        if i < 4:
+            j = FEE_TARGETS[i]
+            fee = self.fee_estimates.get(j)
+        else:
+            assert i == 4
+            fee = self.fee_estimates.get(2)
+            if fee is not None:
+                fee += fee/2
+        if fee is not None:
+            fee = min(5*MAX_FEE_RATE, fee)
+        return fee
+
+    def reverse_dynfee(self, fee_per_kb):
+        import operator
+        dist = map(lambda x: (x[0], abs(x[1] - fee_per_kb)), self.fee_estimates.items())
+        min_target, min_value = min(dist, key=operator.itemgetter(1))
+        if fee_per_kb < self.fee_estimates.get(25)/2:
+            min_target = -1
+        return min_target
+
+    def has_fee_estimates(self):
+        return len(self.fee_estimates)==4
+
+    def is_dynfee(self):
+        return self.get('dynamic_fees') and self.has_fee_estimates()
+
+    def fee_per_kb(self):
+        dyn = self.is_dynfee()
+        if dyn:
+            fee_rate = self.dynfee(self.get('fee_level', 2))
+        else:
+            fee_rate = self.get('fee_per_kb', self.max_fee_rate()/2)
+        return fee_rate
 
 def read_system_config(path=SYSTEM_CONFIG_PATH):
     """Parse and return the system config settings in /etc/electrum.conf."""