Additional method changemixdepth in wallet-tool

This commit adds a method 'changemixdepth' to the list
of methods that can be invoked with the wallet-tool.py script.
It is a noscan method, so doesn't require sync, and uses the
value of the -m option as the new *number* of mixdepths, and
updates the wallet's storage for future runs.
Users are advised not to reduce this number, but increasing it
should always be fine.
Running tumbler with insufficient mixdepths quits with warning.

jmclient/jmclient/wallet.py

@@ -1074,6 +1074,8 @@ class BIP32Wallet(BaseWallet):
 
         for md, data in self._storage.data[self._STORAGE_INDEX_CACHE].items():
             md = int(md)
+            if md > self.max_mixdepth:
+                continue
             md_map = self._index_cache[md]
             for t, k in data.items():
                 md_map[int(t)] = k

jmclient/jmclient/wallet_utils.py

@@ -31,7 +31,10 @@ def get_wallettool_parser():
         '(importprivkey) Adds privkeys to this wallet, privkeys are spaces or commas separated.\n'
         '(dumpprivkey) Export a single private key, specify an hd wallet path\n'
         '(signmessage) Sign a message with the private key from an address in \n'
-        'the wallet. Use with -H and specify an HD wallet path for the address.')
+        'the wallet. Use with -H and specify an HD wallet path for the address.\n'
+        '(changemixdepth) Use with -m to change the *maximum* number of mixdepths\n'
+        'in the wallet; you are advised to only increase, not decrease this \n'
+        'number from the current value (initially 5).')
     parser = OptionParser(usage='usage: %prog [options] [wallet file] [method]',
                           description=description)
     parser.add_option('-p',
@@ -851,6 +854,11 @@ def get_wallet_cls(wtype=None):
     return cls
 
 
+def change_wallet_mixdepth(wallet, max_mixdepth):
+    wallet.max_mixdepth = max_mixdepth
+    wallet.save()
+    return "Maximum mixdepth successfully updated."
+
 def create_wallet(path, password, max_mixdepth, wallet_cls=None, **kwargs):
     storage = Storage(path, password, create=True)
     wallet_cls = wallet_cls or get_wallet_cls()
@@ -977,7 +985,8 @@ def wallet_tool_main(wallet_root_path):
     methods = ['display', 'displayall', 'summary', 'showseed', 'importprivkey',
                'history', 'showutxos']
     methods.extend(noseed_methods)
-    noscan_methods = ['showseed', 'importprivkey', 'dumpprivkey', 'signmessage']
+    noscan_methods = ['showseed', 'importprivkey', 'dumpprivkey',
+                      'signmessage', 'changemixdepth']
     readonly_methods = ['display', 'displayall', 'summary', 'showseed',
                         'history', 'showutxos', 'dumpprivkey', 'signmessage']
 
@@ -1044,6 +1053,8 @@ def wallet_tool_main(wallet_root_path):
         return "Key import completed."
     elif method == "signmessage":
         return wallet_signmessage(wallet, options.hd_path, args[2])
+    elif method == 'changemixdepth':
+        return change_wallet_mixdepth(wallet, options.mixdepth-1)
 
 
 #Testing (can port to test modules, TODO)

scripts/tumbler.py

@@ -34,7 +34,13 @@ def main():
     max_mix_depth = options['mixdepthsrc'] + options['mixdepthcount']
     wallet_path = get_wallet_path(wallet_name, None)
     wallet = open_test_wallet_maybe(wallet_path, wallet_name, max_mix_depth)
-
+    if wallet.max_mixdepth < max_mix_depth:
+        print("Your wallet does not contain the required number of mixdepths: ",
+              max_mix_depth)
+        print("Increase using this command: `python wallet-tool.py -m ",
+              max_mix_depth, " (yourwalletname) changemixdepth")
+        print("Then start the tumbler again with the same settings.")
+        sys.exit(0)
     if jm_single().config.get("BLOCKCHAIN",
                               "blockchain_source") == "electrum-server":
         jm_single().bc_interface.synctype = "with-script"