Rev 3531: Make bzrlib.smart use lazy imports. in http://bzr.arbash-meinel.com/branches/bzr/1.6-dev/lazy_medium

[John Arbash Meinel]

At http://bzr.arbash-meinel.com/branches/bzr/1.6-dev/lazy_medium

------------------------------------------------------------
revno: 3531
revision-id: john at arbash-meinel.com-20080712180848-34lm6j0zthd8k3t9
parent: pqm at pqm.ubuntu.com-20080707230506-82h5w03vc72dyf1a
committer: John Arbash Meinel <john at arbash-meinel.com>
branch nick: lazy_medium
timestamp: Sat 2008-07-12 13:08:48 -0500
message:
  Make bzrlib.smart use lazy imports.
  
  It saves us an import of ssh.py that we aren't using, which
  on windows saves us an import of paramiko, which saves us from
  creating a Crypto.util.randompool.RandomPool, which spends
  1.5s measuring the delta between ticks of time.time()
  
  Mostly, this just means when you run a single test, it takes 100ms,
  rather than 1.5s of setup time, to spend 100ms running the actual
  test.
-------------- next part --------------
=== modified file 'bzrlib/smart/medium.py'
--- a/bzrlib/smart/medium.py	2008-06-25 05:21:31 +0000
+++ b/bzrlib/smart/medium.py	2008-07-12 18:08:48 +0000
@@ -29,21 +29,17 @@
 import sys
 import urllib
 
+from bzrlib.lazy_import import lazy_import
+lazy_import(globals(), """
 from bzrlib import (
     errors,
     osutils,
     symbol_versioning,
     urlutils,
     )
-from bzrlib.smart.protocol import (
-    MESSAGE_VERSION_THREE,
-    REQUEST_VERSION_TWO,
-    SmartClientRequestProtocolOne,
-    SmartServerRequestProtocolOne,
-    SmartServerRequestProtocolTwo,
-    build_server_protocol_three
-    )
+from bzrlib.smart import protocol
 from bzrlib.transport import ssh
+""")
 
 
 def _get_protocol_factory_for_bytes(bytes):
@@ -67,14 +63,14 @@
         root_client_path.  unused_bytes are any bytes that were not part of a
         protocol version marker.
     """
-    if bytes.startswith(MESSAGE_VERSION_THREE):
-        protocol_factory = build_server_protocol_three
-        bytes = bytes[len(MESSAGE_VERSION_THREE):]
-    elif bytes.startswith(REQUEST_VERSION_TWO):
-        protocol_factory = SmartServerRequestProtocolTwo
-        bytes = bytes[len(REQUEST_VERSION_TWO):]
+    if bytes.startswith(protocol.MESSAGE_VERSION_THREE):
+        protocol_factory = protocol.build_server_protocol_three
+        bytes = bytes[len(protocol.MESSAGE_VERSION_THREE):]
+    elif bytes.startswith(protocol.REQUEST_VERSION_TWO):
+        protocol_factory = protocol.SmartServerRequestProtocolTwo
+        bytes = bytes[len(protocol.REQUEST_VERSION_TWO):]
     else:
-        protocol_factory = SmartServerRequestProtocolOne
+        protocol_factory = protocol.SmartServerRequestProtocolOne
     return protocol_factory, bytes