wallet history fees: only calculate fees when exporting history

it's expensive, and it slows down startup of large wallets a lot

electrum/address_synchronizer.py

@@ -722,9 +722,8 @@ class AddressSynchronizer(PrintError):
             if fee is None:
                 txid = tx.txid()
                 fee = self.tx_fees.get(txid)
-            # cache fees. if wallet is synced, cache all;
+            # only cache non-None, as None can still change while syncing
-            # otherwise only cache non-None, as None can still change while syncing
+            if fee is not None:
-            if self.up_to_date or fee is not None:
                 tx._cached_fee = fee
         return fee
 

electrum/commands.py

@@ -520,9 +520,12 @@ class Commands:
         return tx.as_dict()
 
     @command('w')
-    def history(self, year=None, show_addresses=False, show_fiat=False):
+    def history(self, year=None, show_addresses=False, show_fiat=False, show_fees=False):
         """Wallet history. Returns the transaction history of your wallet."""
-        kwargs = {'show_addresses': show_addresses}
+        kwargs = {
+            'show_addresses': show_addresses,
+            'show_fees': show_fees,
+        }
         if year:
             import time
             start_date = datetime.datetime(year, 1, 1)
@@ -808,6 +811,7 @@ command_options = {
     'paid':        (None, "Show only paid requests."),
     'show_addresses': (None, "Show input and output addresses"),
     'show_fiat':   (None, "Show fiat value of transactions"),
+    'show_fees':   (None, "Show miner fees paid by transactions"),
     'year':        (None, "Show history for a given year"),
     'fee_method':  (None, "Fee estimation method to use"),
     'fee_level':   (None, "Float between 0.0 and 1.0, representing fee slider position")

electrum/gui/qt/history_list.py

@@ -555,10 +555,15 @@ class HistoryList(MyTreeView, AcceptFileDragDrop):
         self.parent.show_message(_("Your wallet history has been successfully exported."))
 
     def do_export_history(self, file_name, is_csv):
-        history = self.transactions.values()
+        hist = self.wallet.get_full_history(domain=self.get_domain(),
+                                            from_timestamp=None,
+                                            to_timestamp=None,
+                                            fx=self.parent.fx,
+                                            show_fees=True)
+        txns = hist['transactions']
         lines = []
         if is_csv:
-            for item in history:
+            for item in txns:
                 lines.append([item['txid'],
                               item.get('label', ''),
                               item['confirmations'],
@@ -583,4 +588,4 @@ class HistoryList(MyTreeView, AcceptFileDragDrop):
                     transaction.writerow(line)
             else:
                 from electrum.util import json_encode
-                f.write(json_encode(history))
+                f.write(json_encode(txns))

electrum/wallet.py

@@ -394,7 +394,8 @@ class Abstract_Wallet(AddressSynchronizer):
         return balance
 
     @profiler
-    def get_full_history(self, domain=None, from_timestamp=None, to_timestamp=None, fx=None, show_addresses=False):
+    def get_full_history(self, domain=None, from_timestamp=None, to_timestamp=None,
+                         fx=None, show_addresses=False, show_fees=False):
         out = []
         income = 0
         expenditures = 0
@@ -420,8 +421,10 @@ class Abstract_Wallet(AddressSynchronizer):
                 'date': timestamp_to_datetime(timestamp),
                 'label': self.get_label(tx_hash),
             }
-            tx_fee = self.get_tx_fee(tx)
+            tx_fee = None
-            item['fee'] = Satoshis(tx_fee) if tx_fee is not None else None
+            if show_fees:
+                tx_fee = self.get_tx_fee(tx)
+                item['fee'] = Satoshis(tx_fee) if tx_fee is not None else None
             if show_addresses:
                 item['inputs'] = list(map(lambda x: dict((k, x[k]) for k in ('prevout_hash', 'prevout_n')), tx.inputs()))
                 item['outputs'] = list(map(lambda x:{'address':x.address, 'value':Satoshis(x.value)},