Delaying keyring import as long as possible

mercurial_keyring.py

@@ -46,65 +46,72 b' except:'
 from mercurial import mail
 from mercurial.mail import SMTPS, STARTTLS
 from mercurial import encoding
-from urllib2 import AbstractBasicAuthHandler, AbstractDigestAuthHandler
+from urlparse import urlparse
+import urllib2
+import smtplib
+import socket
+import os
+import sys
+
 
-# mercurial.demandimport incompatibility workaround.
-# various keyring backends fail as they can't properly import helper
-# modules (as demandimport modifies python import behaviour).
-# If you get import errors with demandimport in backtrace, try
-# guessing what to block and extending the list below.
-from mercurial import demandimport
-for blocked_module in [
-    "gobject._gobject",
-    "configparser",
-    "json",
-    "abc",
-    "io",
-    "keyring",
-    "gdata.docs.service",
-    "gdata.service",
-    "types",
-    "atom.http",
-    "atom.http_interface",
-    "atom.service",
-    "atom.token_store",
-    "ctypes",
-    "secretstorage.exceptions",
-    "fs.opener",
+def import_keyring():
+    """
+    Importing keyring happens to be costly if wallet is slow, so we delay it
+    until really needed.
+    """
+    if 'keyring' in sys.modules:
+        return
+    # mercurial.demandimport incompatibility workaround.
+    # various keyring backends fail as they can't properly import helper
+    # modules (as demandimport modifies python import behaviour).
+    # If you get import errors with demandimport in backtrace, try
+    # guessing what to block and extending the list below.
+    from mercurial import demandimport
+    for blocked_module in [
+            "gobject._gobject",
+            "configparser",
+            "json",
+            "abc",
+            "io",
+            "keyring",
+            "gdata.docs.service",
+            "gdata.service",
+            "types",
+            "atom.http",
+            "atom.http_interface",
+            "atom.service",
+            "atom.token_store",
+            "ctypes",
+            "secretstorage.exceptions",
+            "fs.opener",
     ]:
     if blocked_module not in demandimport.ignore:
         demandimport.ignore.append(blocked_module)
-
-try:
-    is_demandimport_enabled = demandimport.isenabled
-except AttributeError:
-    # Mercurial < 2.9.1
     try:
-        orig_demandimport = demandimport.demandimport
+        is_demandimport_enabled = demandimport.isenabled
     except AttributeError:
-        orig_demandimport = demandimport._demandimport
-    def is_demandimport_enabled():
-        return __import__ == orig_demandimport
-
-# Shut up warning about uninitialized logging for new keyring versions
-import logging
-logging.getLogger("keyring").addHandler(logging.NullHandler())
+        # Mercurial < 2.9.1
+        try:
+            orig_demandimport = demandimport.demandimport
+        except AttributeError:
+            orig_demandimport = demandimport._demandimport
+        def is_demandimport_enabled():
+            return __import__ == orig_demandimport
 
-# Temporarily disable demandimport to make the need of extending
-# the list above less likely.
-if is_demandimport_enabled():
-    demandimport.disable()
-    try:
+    # Shut up warning about uninitialized logging for new keyring versions
+    import logging
+    logging.getLogger("keyring").addHandler(logging.NullHandler())
+
+    # Temporarily disable demandimport to make the need of extending
+    # the list above less likely.
+    if is_demandimport_enabled():
+        demandimport.disable()
+        try:
+            import keyring
+        finally:
+            demandimport.enable()
+    else:
         import keyring
-    finally:
-        demandimport.enable()
-else:
-    import keyring
-
-from urlparse import urlparse
-import urllib2
-import smtplib, socket
-import os
 
 KEYRING_SERVICE = "Mercurial"
 
@@ -152,12 +159,14 b' class PasswordStore(object):'
     def _format_smtp_key(self, machine, port, username):
         return "%s@@%s:%s" % (username, machine, str(port))
     def _read_password_from_keyring(self, pwdkey):
+        import_keyring()
         password = keyring.get_password(KEYRING_SERVICE, pwdkey)
         # Reverse recoding from next routine
         if isinstance(password, unicode):
             return encoding.tolocal(password.encode('utf-8'))
         return password
     def _save_password_to_keyring(self, pwdkey, password):
+        import_keyring()
         # keyring in general expects unicode. Mercurial provides "local" encoding. See #33
         password = encoding.fromlocal(password).decode('utf-8')
         keyring.set_password(KEYRING_SERVICE,
@@ -409,7 +418,7 b' def find_user_password(self, realm, auth'
 
     return self._pwd_handler.find_auth(self, realm, authuri, req)
 
-@monkeypatch_method(AbstractBasicAuthHandler, "http_error_auth_reqed")
+@monkeypatch_method(urllib2.AbstractBasicAuthHandler, "http_error_auth_reqed")
 def basic_http_error_auth_reqed(self, authreq, host, req, headers):
     self.passwd._http_req = req
     try:
@@ -417,7 +426,7 b' def basic_http_error_auth_reqed(self, au'
     finally:
         self.passwd._http_req = None
 
-@monkeypatch_method(AbstractDigestAuthHandler, "http_error_auth_reqed")
+@monkeypatch_method(urllib2.AbstractDigestAuthHandler, "http_error_auth_reqed")
 def digest_http_error_auth_reqed(self, authreq, host, req, headers):
     self.passwd._http_req = req
     try: