Add benchmark for an object with a list.

Current timing on cpython2.7:

.....................
__main__: toExternalObject: Mean +- std dev: 405 us +- 9 us
.....................
__main__: fromExternalObject: Mean +- std dev: 1.37 ms +- 0.03 ms

src/nti/externalization/__base_interfaces.pxd

@@ -12,7 +12,7 @@ cdef class LocatedExternalDict(dict):
     cdef public __name__
     cdef public __parent__
     cdef public __acl__
-    cdef readonly mimeType
+    cdef public mimeType
 
     cdef update_from_other(self, other)
 

src/nti/externalization/tests/benchmarks/bm_simple_iface.py

@@ -8,17 +8,20 @@
 from __future__ import division
 from __future__ import print_function
 
+
 import sys
 
 import perf
 from perf import perf_counter
 
 from zope.configuration import xmlconfig
 
+from nti.externalization.representation import JsonRepresenter
 from nti.externalization.externalization import toExternalObject
 from nti.externalization.interfaces import StandardExternalFields
 from nti.externalization.internalization import default_externalized_object_factory_finder
 from nti.externalization.internalization import update_from_external_object
+
 import nti.externalization.tests.benchmarks
 from nti.externalization.tests.benchmarks.objects import DerivedWithOneTextField
 
@@ -42,21 +45,26 @@ def find_factory_time_func(loops, ext):
 
 def update_from_external_object_time_func(loops, ext):
     factory = default_externalized_object_factory_finder(ext)
+    # Updating *may* modify the object in place, so we need to
+    # make deep copies of it.
+    rep = JsonRepresenter()
+    json = rep.dump(ext)
+    exts = [rep.load(json) for x in range(loops * INNER_LOOPS)]
     begin = perf_counter()
-    for _ in range(loops):
-        for _ in range(INNER_LOOPS):
-            obj = factory()
-            update_from_external_object(obj, ext)
+    for x in exts:
+        obj = factory()
+        update_from_external_object(obj, x)
     end = perf_counter()
     return end - begin
 
 
-def profile():
+def profile(loops=1000, obj=None):
     from cProfile import Profile
     import pstats
 
-    obj = DerivedWithOneTextField()
-    obj.text = u'This is some text'
+    if obj is None:
+        obj = DerivedWithOneTextField()
+        obj.text = u'This is some text'
 
     ext = toExternalObject(obj)
 
@@ -68,7 +76,7 @@ def profile():
 
         prof = Profile()
         prof.enable()
-        func(1000, arg)
+        func(loops, arg)
         prof.disable()
         stats = pstats.Stats(prof)
         stats.strip_dirs()

src/nti/externalization/tests/benchmarks/bm_simple_iface_list.py

@@ -0,0 +1,67 @@
+# -*- coding: utf-8 -*-
+"""
+Extends bm_simple_iface to add a list.
+
+"""
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import sys
+
+import perf
+
+
+from zope.configuration import xmlconfig
+
+from nti.externalization.externalization import toExternalObject
+from nti.externalization.interfaces import StandardExternalFields
+
+import nti.externalization.tests.benchmarks
+
+from nti.externalization.tests.benchmarks.objects import DerivedWithOneTextField
+from nti.externalization.tests.benchmarks.objects import HasListOfDerived
+
+from nti.externalization.tests.benchmarks.bm_simple_iface import (
+    INNER_LOOPS,
+    to_external_object_time_func,
+    update_from_external_object_time_func,
+    profile
+)
+
+logger = __import__('logging').getLogger(__name__)
+
+
+def main(runner=None):
+
+    xmlconfig.file('configure.zcml', nti.externalization.tests.benchmarks)
+
+    obj = HasListOfDerived()
+    obj.the_objects = [DerivedWithOneTextField(text=u"This is some text " + str(i))
+                       for i in range(10)]
+
+
+    if '--profile' in sys.argv:
+        profile(100, obj)
+        return
+
+    mt = getattr(obj, 'mimeType')
+    assert mt == 'application/vnd.nextthought.benchmarks.haslistofderived', mt
+
+    runner = runner or perf.Runner()
+    runner.bench_time_func(__name__ + ": toExternalObject",
+                           to_external_object_time_func,
+                           obj,
+                           inner_loops=INNER_LOOPS)
+
+    ext = toExternalObject(obj)
+    assert StandardExternalFields.MIMETYPE in ext
+
+
+    runner.bench_time_func(__name__ + ": fromExternalObject",
+                           update_from_external_object_time_func,
+                           ext,
+                           inner_loops=INNER_LOOPS)
+
+if __name__ == '__main__':
+    main()

src/nti/externalization/tests/benchmarks/interfaces.py

@@ -10,6 +10,9 @@
 from zope.interface import Interface
 from zope.interface import taggedValue
 
+from zope.schema import List
+from zope.schema import Object
+
 from nti.schema.field import TextLine
 
 class ISimplestPossibleObject(Interface):
@@ -29,3 +32,11 @@ class IDerivedWithOneTextField(IRootInterface):
 
     taggedValue('__external_class_name__',
                 'DerivedWithOneTextField')
+
+
+class IHasListOfDerived(IRootInterface):
+
+    the_objects = List(Object(IDerivedWithOneTextField))
+
+    taggedValue('__external_class_name__',
+                'HasListOfDerived')

src/nti/externalization/tests/benchmarks/objects.py

@@ -24,3 +24,10 @@ class SimplestPossibleObject(ExternalizableInstanceDict):
 @interface.implementer(interfaces.IDerivedWithOneTextField)
 class DerivedWithOneTextField(object):
     createDirectFieldProperties(interfaces.IDerivedWithOneTextField)
+
+    def __init__(self, text=u''):
+        self.text = text
+
+@interface.implementer(interfaces.IHasListOfDerived)
+class HasListOfDerived(object):
+    createDirectFieldProperties(interfaces.IHasListOfDerived)