commit a6ea9a0c71ccb30913ef60b39616326d50965d3a
parent 90dee439985c119028f38e7f8c1aa7ced6f244af
Author: Neil Booth <kyuupichan@gmail.com>
Date: Sat, 28 Nov 2015 22:08:00 +0900
Simplify interface to make_tx in coin chooser
Makes the coin chooser code simpler and easier to understand.
Diffstat:
2 files changed, 33 insertions(+), 29 deletions(-)
diff --git a/lib/coinchooser.py b/lib/coinchooser.py
@@ -27,21 +27,17 @@ class CoinChooser(PrintError):
def __init__(self, wallet):
self.wallet = wallet
- def fee(self, tx, fixed_fee, fee_per_kb):
- if fixed_fee is not None:
- return fixed_fee
- return tx.estimated_fee(fee_per_kb)
-
- def dust_threshold(self):
- return 182 * 3 * MIN_RELAY_TX_FEE/1000
-
- def make_tx(self, coins, outputs, change_addrs, fixed_fee, fee_per_kb):
- '''Select unspent coins to spend to pay outputs.'''
+ def make_tx(self, coins, outputs, change_addrs, fee_estimator,
+ dust_threshold):
+ '''Select unspent coins to spend to pay outputs. If the change is
+ greater than dust_threshold (after adding the change output to
+ the transaction) it is kept, otherwise none is sent and it is
+ added to the transaction fee.'''
amount = sum(map(lambda x: x[2], outputs))
total = 0
inputs = []
tx = Transaction.from_io(inputs, outputs)
- fee = self.fee(tx, fixed_fee, fee_per_kb)
+ fee = fee_estimator(tx)
# add inputs, sorted by age
for item in coins:
v = item.get('value')
@@ -51,7 +47,7 @@ class CoinChooser(PrintError):
# no need to estimate fee until we have reached desired amount
if total < amount + fee:
continue
- fee = self.fee(tx, fixed_fee, fee_per_kb)
+ fee = fee_estimator(tx)
if total >= amount + fee:
break
else:
@@ -69,13 +65,13 @@ class CoinChooser(PrintError):
else:
break
if removed:
- fee = self.fee(tx, fixed_fee, fee_per_kb)
+ fee = fee_estimator(tx)
for item in sorted(tx.inputs, key=itemgetter('value')):
v = item.get('value')
if total - v >= amount + fee:
tx.inputs.remove(item)
total -= v
- fee = self.fee(tx, fixed_fee, fee_per_kb)
+ fee = fee_estimator(tx)
continue
break
self.print_error("using %d inputs" % len(tx.inputs))
@@ -83,22 +79,21 @@ class CoinChooser(PrintError):
# if change is above dust threshold, add a change output.
change_addr = change_addrs[0]
change_amount = total - (amount + fee)
- if fixed_fee is not None and change_amount > 0:
- tx.outputs.append(('address', change_addr, change_amount))
- elif change_amount > self.dust_threshold():
+
+ # See if change would still be greater than dust after adding
+ # the change to the transaction
+ if change_amount > dust_threshold:
tx.outputs.append(('address', change_addr, change_amount))
- # recompute fee including change output
- fee = tx.estimated_fee(fee_per_kb)
+ fee = fee_estimator(tx)
# remove change output
tx.outputs.pop()
- # if change is still above dust threshold, re-add change output.
change_amount = total - (amount + fee)
- if change_amount > self.dust_threshold():
- tx.outputs.append(('address', change_addr, change_amount))
- self.print_error('change', change_amount)
- else:
- self.print_error('not keeping dust', change_amount)
- else:
+
+ # If change is still above dust threshold, keep the change.
+ if change_amount > dust_threshold:
+ tx.outputs.append(('address', change_addr, change_amount))
+ self.print_error('change', change_amount)
+ elif change_amount:
self.print_error('not keeping dust', change_amount)
return tx
diff --git a/lib/wallet.py b/lib/wallet.py
@@ -905,8 +905,6 @@ class Abstract_Wallet(PrintError):
if type == 'address':
assert is_address(data), "Address " + data + " is invalid!"
- fee_per_kb = self.fee_per_kb(config)
-
# change address
if change_addr:
change_addrs = [change_addr]
@@ -926,9 +924,20 @@ class Abstract_Wallet(PrintError):
else:
change_addrs = [address]
+ fee_per_kb = self.fee_per_kb(config)
+ def fee_estimator(tx):
+ if fixed_fee is not None:
+ return fixed_fee
+ return tx.estimated_fee(fee_per_kb)
+
+ # If a fixed fee is specified, keep even dust change
+ dust_threshold = 182 * 3 * MIN_RELAY_TX_FEE / 1000
+ if fixed_fee is None:
+ dust_threshold = 0
+
# Let the coin chooser select the coins to spend
tx = self.coin_chooser.make_tx(coins, outputs, change_addrs,
- fixed_fee, fee_per_kb)
+ fee_estimator, dust_threshold)
# Sort the inputs and outputs deterministically
tx.BIP_LI01_sort()
