big_file: py3

bt5/erp5_big_file/DocumentTemplateItem/portal_components/document.erp5.BigFile.py

@@ -23,14 +23,17 @@ from erp5.component.module.BTreeData import BTreeData
 from ZPublisher.HTTPRequest import FileUpload
 from ZPublisher import HTTPRangeSupport
 from zope.datetime import rfc1123_date
-from mimetools import choose_boundary
 from Products.CMFCore.utils import _setCacheHeaders, _ViewEmulator
 from DateTime import DateTime
 import re
+import io
 import six
 
 if six.PY3:
   long = int  # pylint:disable=redefined-builtin
+  from email.generator import _make_boundary as choose_boundary
+else:
+  from mimetools import choose_boundary
 
 class BigFile(File):
   """
@@ -43,10 +46,10 @@ class BigFile(File):
     data property is either
 
       - BTreeData instance,  or
-      - str(*),  or
+      - bytes(*),  or
       - None.
 
-    (*) str has to be supported because '' is a default value for `data` field
+    (*) bytes has to be supported because b'' is a default value for `data` field
         from Data property sheet.
 
         Even more - for
@@ -55,7 +58,7 @@ class BigFile(File):
             b) desire to support automatic migration of File-based documents
                from document_module to BigFiles
 
-        non-empty str for data also have to be supported.
+        non-empty bytes for data also have to be supported.
 
         XXX(kirr) I'm not sure supporting non-empty str is a good idea (it
             would be simpler if .data could be either BTreeData or "empty"),
@@ -64,6 +67,8 @@ class BigFile(File):
 
             We discussed with Romain and settled on "None or str or BTreeData"
             invariant for now.
+        notes: for python3 port "str" becomes "bytes", but kirr message was not modified.
+
   """
 
   meta_type = 'ERP5 Big File'
@@ -115,9 +120,9 @@ class BigFile(File):
     # of memory.
     n=1 << 16
 
-    if isinstance(file, str):
+    if isinstance(file, bytes):
       # Big string: cut it into smaller chunks
-      file = StringIO(file)
+      file = io.BytesIO(file)
 
     if isinstance(file, FileUpload) and not file:
       raise ValueError('File not specified')
@@ -130,9 +135,9 @@ class BigFile(File):
 
     if data is None:
       btree = BTreeData()
-    elif isinstance(data, str):
+    elif isinstance(data, bytes):
       # we'll want to append content to this file -
-      # - automatically convert str (empty or not) to BTreeData
+      # - automatically convert bytes (empty or not) to BTreeData
       btree = BTreeData()
       btree.write(data, 0)
     else:
@@ -236,7 +241,7 @@ class BigFile(File):
           RESPONSE.setStatus(206) # Partial content
 
           # NOTE data cannot be None here (if it is - ranges are not satisfiable)
-          if isinstance(data, str):
+          if isinstance(data, bytes):
             RESPONSE.write(data[start:end])
             return True
           for chunk in data.iterate(start, end-start):
@@ -271,22 +276,22 @@ class BigFile(File):
           RESPONSE.setStatus(206) # Partial content
 
           for start, end in ranges:
-            RESPONSE.write('\r\n--%s\r\n' % boundary)
-            RESPONSE.write('Content-Type: %s\r\n' %
-                self.content_type)
+            RESPONSE.write(('\r\n--%s\r\n' % boundary).encode())
+            RESPONSE.write(('Content-Type: %s\r\n' %
+                self.content_type).encode())
             RESPONSE.write(
-                'Content-Range: bytes %d-%d/%d\r\n\r\n' % (
-                    start, end - 1, self.getSize()))
+                ('Content-Range: bytes %d-%d/%d\r\n\r\n' % (
+                    start, end - 1, self.getSize())).encode())
 
             # NOTE data cannot be None here (if it is - ranges are not satisfiable)
-            if isinstance(data, str):
+            if isinstance(data, bytes):
               RESPONSE.write(data[start:end])
 
             else:
               for chunk in data.iterate(start, end-start):
                 RESPONSE.write(chunk)
 
-          RESPONSE.write('\r\n--%s--\r\n' % boundary)
+          RESPONSE.write(('\r\n--%s--\r\n' % boundary).encode())
           return True
 
   security.declareProtected(Permissions.View, 'index_html')
@@ -296,7 +301,7 @@ class BigFile(File):
     """
     if self._range_request_handler(REQUEST, RESPONSE):
       # we served a chunk of content in response to a range request.
-      return ''
+      return b''
 
     web_cache_kw = kw.copy()
     if format is not _MARKER:
@@ -327,13 +332,13 @@ class BigFile(File):
 
 
     if data is None:
-      return ''
-    if isinstance(data, str):
+      return b''
+    if isinstance(data, bytes):
       RESPONSE.setBase(None)
       return data
     for chunk in data.iterate():
       RESPONSE.write(chunk)
-    return ''
+    return b''
 
   security.declareProtected(Permissions.ModifyPortalContent,'PUT')
   def PUT(self, REQUEST, RESPONSE):

bt5/erp5_big_file/ModuleComponentTemplateItem/portal_components/module.erp5.BTreeData.py

@@ -3,6 +3,7 @@ from BTrees.LOBTree import LOBTree
 from persistent import Persistent
 import itertools
 from six.moves import range
+import six
 
 # Maximum memory to allocate for sparse-induced padding.
 MAX_PADDING_CHUNK = 2 ** 20
@@ -11,11 +12,13 @@ class PersistentString(Persistent):
   def __init__(self, value):
     self.value = value
 
-  def __str__(self):
+  def __bytes__(self):
     return self.value
+  if six.PY2:
+    __str__ = __bytes__
 
   # Save place when storing this data in zodb
-  __getstate__ = __str__
+  __getstate__ = __bytes__
   __setstate__ = __init__
 
 negative_offset_error = ValueError('Negative offset')
@@ -110,7 +113,7 @@ class BTreeData(Persistent):
         chunk = tree[lower_key]
         chunk_end = lower_key + len(chunk.value)
         if chunk_end > offset or (
-              len(chunk.value) < self._chunk_size and
+              len(chunk.value) < (self._chunk_size or 0) and
               chunk_end == offset
             ):
           key = lower_key
@@ -137,7 +140,7 @@ class BTreeData(Persistent):
       try:
         chunk = tree[key]
       except KeyError:
-        tree[key] = chunk = PersistentString('')
+        tree[key] = chunk = PersistentString(b'')
       entry_size = len(chunk.value)
       if entry_size < to_write_len:
         to_write_len = min(to_write_len, max_to_write_len)
@@ -158,9 +161,9 @@ class BTreeData(Persistent):
     size (int)
      Number of bytes to read.
 
-    Returns string of read data.
+    Returns bytes of read data.
     """
-    return ''.join(self.iterate(offset, size))
+    return b''.join(self.iterate(offset, size))
 
   def iterate(self, offset=0, size=None):
     """
@@ -243,7 +246,7 @@ class BTreeData(Persistent):
         except ValueError:
           break
         del tree[key]
-    self.write('', offset)
+    self.write(b'', offset)
 
   # XXX: Various batch_size values need to be benchmarked, and a saner
   # default is likely to be applied.
@@ -314,12 +317,11 @@ class BTreeData(Persistent):
         tree[key] = next_chunk
 
 if __name__ == '__main__':
-
   def check(tree, length, read_offset, read_length, data_, keys=None):
     print(list(tree._tree.items()))
     tree_length = len(tree)
     tree_data = tree.read(read_offset, read_length)
-    tree_iterator_data = ''.join(tree.iterate(read_offset, read_length))
+    tree_iterator_data = b''.join(tree.iterate(read_offset, read_length))
     assert tree_length == length, tree_length
     assert tree_data == data_, repr(tree_data)
     assert tree_iterator_data == data_, repr(tree_iterator_data)

bt5/erp5_big_file/TestTemplateItem/portal_components/test.erp5.testBigFile.py

@@ -24,8 +24,7 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
-from six.moves import cStringIO as StringIO
-
+import io
 from ZPublisher.HTTPRequest import HTTPRequest
 from ZPublisher.HTTPResponse import HTTPResponse
 from Products.ERP5Type.tests.ERP5TypeTestCase import ERP5TypeTestCase
@@ -35,15 +34,15 @@ from erp5.component.module.BTreeData import BTreeData
 
 # like Testing.makerequest, but
 #
-#   1. always redirects stdout to stringio,
+#   1. always redirects stdout to BytesIO,
 #   2. stdin content can be specified and is processed,
 #   3. returns actual request object (not wrapped portal).
 #
 # see also: Products.CMFCore.tests.test_CookieCrumbler.makerequest()
 # TODO makerequest() is generic enough and deserves moving to testing utils
-def makerequest(environ=None, stdin=''):
-  stdout = StringIO()
-  stdin  = StringIO(stdin)
+def makerequest(environ=None, stdin=b''):
+  stdout = io.BytesIO()
+  stdin  = io.BytesIO(stdin)
   if environ is None:
     environ = {}
 
@@ -65,7 +64,7 @@ def makerequest(environ=None, stdin=''):
 # generate makerequest-like function for http method
 def request_function(method_name):
   method_name = method_name.upper()
-  def method_func(environ=None, stdin=''):
+  def method_func(environ=None, stdin=b''):
     if environ is None:
       environ = {}
     environ.setdefault('REQUEST_METHOD', method_name)
@@ -112,7 +111,7 @@ class TestBigFile(ERP5TypeTestCase):
     ret = method (request, request.RESPONSE, **kw)
     # like in ZPublisher - returned RESPONSE means empty
     if ret is request.RESPONSE:
-      ret = ''
+      ret = b''
     self.assertEqual(ret,       result)
     self.assertEqual(status,    request.RESPONSE.getStatus())
     for h,v in header_dict.items():
@@ -120,9 +119,9 @@ class TestBigFile(ERP5TypeTestCase):
       self.assertEqual(v, rv, '%s: %r != %r' % (h, v, rv))
 
     # force response flush to its stdout
-    request.RESPONSE.write('')
+    request.RESPONSE.write(b'')
     # body and headers are delimited by empty line (RFC 2616, 4.1)
-    response_body = request.RESPONSE.stdout.getvalue().split('\r\n\r\n', 1)[1]
+    response_body = request.RESPONSE.stdout.getvalue().split(b'\r\n\r\n', 1)[1]
     self.assertEqual(body, response_body)
 
 
@@ -135,90 +134,90 @@ class TestBigFile(ERP5TypeTestCase):
 
     # after creation file is empty and get(0-0) returns 416
     self.assertEqual(f.getSize(), 0)
-    self.assertEqual(f.getData(), '')
+    self.assertEqual(f.getData(), b'')
 
                                              #  result body status headers
-    check(get(), {'format': 'raw'},                 '', '', 200, {'Content-Length': '0'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',R308, {                                  'Range': 'bytes 0--1'})  # XXX 0--1 ok?
-    check(get({        'Range': 'bytes=0-0'}),{},   '', '', 416, {'Content-Length': '0',    'Content-Range': 'bytes */0'})
+    check(get(), {'format': 'raw'},                 b'', b'', 200, {'Content-Length': '0'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',R308, {                                  'Range': 'bytes 0--1'})  # XXX 0--1 ok?
+    check(get({        'Range': 'bytes=0-0'}),{},   b'', b'', 416, {'Content-Length': '0',    'Content-Range': 'bytes */0'})
 
 
     # append empty chunk - the same
-    f._appendData('')
+    f._appendData(b'')
     self.assertEqual(f.getSize(), 0)
-    self.assertEqual(f.getData(), '')
+    self.assertEqual(f.getData(), b'')
 
-    check(get(), {'format': 'raw'},                 '', '', 200, {'Content-Length': '0'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',R308, {                                  'Range': 'bytes 0--1'})  # XXX 0--1 ok?
-    check(get({        'Range': 'bytes=0-0'}),{},   '', '', 416, {                          'Content-Range': 'bytes */0'})
+    check(get(), {'format': 'raw'},                 b'', b'', 200, {'Content-Length': '0'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',R308, {                                  'Range': 'bytes 0--1'})  # XXX 0--1 ok?
+    check(get({        'Range': 'bytes=0-0'}),{},   b'', b'', 416, {                          'Content-Range': 'bytes */0'})
 
 
     # append 1 byte - file should grow up and get(0-0) returns 206
-    f._appendData('x')
+    f._appendData(b'x')
     self.assertEqual(f.getSize(), 1)
-    self.assertEqual(f.getData(), 'x')
+    self.assertEqual(f.getData(), b'x')
 
-    check(get(), {'format': 'raw'},                 '', 'x', 200, {'Content-Length': '1'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '', R308, {                                'Range': 'bytes 0-0'})
-    check(get({        'Range': 'bytes=0-0'}),{},   '', 'x', 206, {'Content-Length': '1',  'Content-Range': 'bytes 0-0/1'})
+    check(get(), {'format': 'raw'},                 b'', b'x', 200, {'Content-Length': '1'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'', R308, {                                'Range': 'bytes 0-0'})
+    check(get({        'Range': 'bytes=0-0'}),{},   b'', b'x', 206, {'Content-Length': '1',  'Content-Range': 'bytes 0-0/1'})
 
 
     # append another 2 bytes and try to get whole file and partial contents
-    f._appendData('yz')
+    f._appendData(b'yz')
     self.assertEqual(f.getSize(), 3)
-    self.assertEqual(f.getData(), 'xyz')
+    self.assertEqual(f.getData(), b'xyz')
 
-    check(get(), {'format': 'raw'},                 '', 'xyz',  200, {'Content-Length': '3'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',    R308, {                                'Range': 'bytes 0-2'})
-    check(get({        'Range': 'bytes=0-0'}),{},   '', 'x'  ,  206, {'Content-Length': '1',  'Content-Range': 'bytes 0-0/3'})
-    check(get({        'Range': 'bytes=1-1'}),{},   '',  'y' ,  206, {'Content-Length': '1',  'Content-Range': 'bytes 1-1/3'})
-    check(get({        'Range': 'bytes=2-2'}),{},   '',   'z',  206, {'Content-Length': '1',  'Content-Range': 'bytes 2-2/3'})
-    check(get({        'Range': 'bytes=0-1'}),{},   '', 'xy' ,  206, {'Content-Length': '2',  'Content-Range': 'bytes 0-1/3'})
-    check(get({        'Range': 'bytes=1-2'}),{},   '',  'yz',  206, {'Content-Length': '2',  'Content-Range': 'bytes 1-2/3'})
-    check(get({        'Range': 'bytes=0-2'}),{},   '', 'xyz',  206, {'Content-Length': '3',  'Content-Range': 'bytes 0-2/3'})
+    check(get(), {'format': 'raw'},                 b'', b'xyz',  200, {'Content-Length': '3'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',    R308, {                                'Range': 'bytes 0-2'})
+    check(get({        'Range': 'bytes=0-0'}),{},   b'', b'x'  ,  206, {'Content-Length': '1',  'Content-Range': 'bytes 0-0/3'})
+    check(get({        'Range': 'bytes=1-1'}),{},   b'',  b'y' ,  206, {'Content-Length': '1',  'Content-Range': 'bytes 1-1/3'})
+    check(get({        'Range': 'bytes=2-2'}),{},   b'',   b'z',  206, {'Content-Length': '1',  'Content-Range': 'bytes 2-2/3'})
+    check(get({        'Range': 'bytes=0-1'}),{},   b'', b'xy' ,  206, {'Content-Length': '2',  'Content-Range': 'bytes 0-1/3'})
+    check(get({        'Range': 'bytes=1-2'}),{},   b'',  b'yz',  206, {'Content-Length': '2',  'Content-Range': 'bytes 1-2/3'})
+    check(get({        'Range': 'bytes=0-2'}),{},   b'', b'xyz',  206, {'Content-Length': '3',  'Content-Range': 'bytes 0-2/3'})
 
     # append via PUT with range
-    check(put({'Content-Range': 'bytes 3-4/5', 'Content-Length': '2'}, '01'),{},  '', '', 204, {})
+    check(put({'Content-Range': 'bytes 3-4/5', 'Content-Length': '2'}, b'01'),{},  b'', b'', 204, {})
     self.assertEqual(f.getSize(), 5)
-    self.assertEqual(f.getData(), 'xyz01')
-    check(get(), {'format': 'raw'},                 '', 'xyz01',200, {'Content-Length': '5'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',    R308, {                                'Range': 'bytes 0-4'})
-    check(get({        'Range': 'bytes=0-4'}),{},   '', 'xyz01',206, {'Content-Length': '5',  'Content-Range': 'bytes 0-4/5'})
-    check(get({        'Range': 'bytes=1-3'}),{},   '',  'yz0' ,206, {'Content-Length': '3',  'Content-Range': 'bytes 1-3/5'})
-    check(get({        'Range': 'bytes=1-2'}),{},   '',  'yz'  ,206, {'Content-Length': '2',  'Content-Range': 'bytes 1-2/5'})
-    check(get({        'Range': 'bytes=2-2'}),{},   '',   'z'  ,206, {'Content-Length': '1',  'Content-Range': 'bytes 2-2/5'})
+    self.assertEqual(f.getData(), b'xyz01')
+    check(get(), {'format': 'raw'},                 b'', b'xyz01',200, {'Content-Length': '5'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',    R308, {                                'Range': 'bytes 0-4'})
+    check(get({        'Range': 'bytes=0-4'}),{},   b'', b'xyz01',206, {'Content-Length': '5',  'Content-Range': 'bytes 0-4/5'})
+    check(get({        'Range': 'bytes=1-3'}),{},   b'',  b'yz0' ,206, {'Content-Length': '3',  'Content-Range': 'bytes 1-3/5'})
+    check(get({        'Range': 'bytes=1-2'}),{},   b'',  b'yz'  ,206, {'Content-Length': '2',  'Content-Range': 'bytes 1-2/5'})
+    check(get({        'Range': 'bytes=2-2'}),{},   b'',   b'z'  ,206, {'Content-Length': '1',  'Content-Range': 'bytes 2-2/5'})
 
     # replace whole content via PUT without range
     # (and we won't exercise GET with range routinely further)
-    check(put({'Content-Length': '3'}, 'abc'),{},  '', '', 204, {})
+    check(put({'Content-Length': '3'}, b'abc'),{},  b'', b'', 204, {})
     self.assertEqual(f.getSize(), 3)
-    self.assertEqual(f.getData(), 'abc')
-    check(get(), {'format': 'raw'},                 '', 'abc',  200, {'Content-Length': '3'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',    R308, {                                'Range': 'bytes 0-2'})
+    self.assertEqual(f.getData(), b'abc')
+    check(get(), {'format': 'raw'},                 b'', b'abc',  200, {'Content-Length': '3'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',    R308, {                                'Range': 'bytes 0-2'})
 
     # append via PUT with range (again)
-    check(put({'Content-Range': 'bytes 3-7/8', 'Content-Length': '5'}, 'defgh'),{},  '', '', 204, {})
+    check(put({'Content-Range': 'bytes 3-7/8', 'Content-Length': '5'}, b'defgh'),{},  b'', b'', 204, {})
     self.assertEqual(f.getSize(), 8)
-    self.assertEqual(f.getData(), 'abcdefgh')
-    check(get(), {'format': 'raw'},                 '', 'abcdefgh', 200, {'Content-Length': '8'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',        R308, {                            'Range': 'bytes 0-7'})
+    self.assertEqual(f.getData(), b'abcdefgh')
+    check(get(), {'format': 'raw'},                 b'', b'abcdefgh', 200, {'Content-Length': '8'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',        R308, {                            'Range': 'bytes 0-7'})
 
     # append via ._appendData()  (again)
-    f._appendData('ij')
+    f._appendData(b'ij')
     self.assertEqual(f.getSize(), 10)
-    self.assertEqual(f.getData(), 'abcdefghij')
-    check(get(), {'format': 'raw'},                 '', 'abcdefghij', 200, {'Content-Length': '10'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',          R308, {                          'Range': 'bytes 0-9'})
+    self.assertEqual(f.getData(), b'abcdefghij')
+    check(get(), {'format': 'raw'},                 b'', b'abcdefghij', 200, {'Content-Length': '10'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',          R308, {                          'Range': 'bytes 0-9'})
 
     # make sure PUT with incorrect/non-append range is rejected
-    check(put({'Content-Range': 'bytes 10-10/10', 'Content-Length': '1'}, 'k'),{}, '', '', 400, {'X-Explanation': 'Total size unexpected'})
-    self.assertEqual(f.getData(), 'abcdefghij')
-    check(put({'Content-Range': 'bytes 10-10/11', 'Content-Length': '2'}, 'k'),{}, '', '', 400, {'X-Explanation': 'Content length unexpected'})
-    self.assertEqual(f.getData(), 'abcdefghij')
-    check(put({'Content-Range': 'bytes 8-8/10',   'Content-Length': '1'}, '?'),{}, '', '', 400, {'X-Explanation': 'Can only append data'})
-    check(put({'Content-Range': 'bytes 9-9/10',   'Content-Length': '1'}, '?'),{}, '', '', 400, {'X-Explanation': 'Can only append data'})
-    check(put({'Content-Range': 'bytes 9-10/11',  'Content-Length': '2'},'??'),{}, '', '', 400, {'X-Explanation': 'Can only append data'})
-    check(put({'Content-Range': 'bytes 11-11/12', 'Content-Length': '1'}, '?'),{}, '', '', 400, {'X-Explanation': 'Can only append data'})
+    check(put({'Content-Range': 'bytes 10-10/10', 'Content-Length': '1'}, b'k'),{}, b'', b'', 400, {'X-Explanation': 'Total size unexpected'})
+    self.assertEqual(f.getData(), b'abcdefghij')
+    check(put({'Content-Range': 'bytes 10-10/11', 'Content-Length': '2'}, b'k'),{}, b'', b'', 400, {'X-Explanation': 'Content length unexpected'})
+    self.assertEqual(f.getData(), b'abcdefghij')
+    check(put({'Content-Range': 'bytes 8-8/10',   'Content-Length': '1'}, b'?'),{}, b'', b'', 400, {'X-Explanation': 'Can only append data'})
+    check(put({'Content-Range': 'bytes 9-9/10',   'Content-Length': '1'}, b'?'),{}, b'', b'', 400, {'X-Explanation': 'Can only append data'})
+    check(put({'Content-Range': 'bytes 9-10/11',  'Content-Length': '2'},b'??'),{}, b'', b'', 400, {'X-Explanation': 'Can only append data'})
+    check(put({'Content-Range': 'bytes 11-11/12', 'Content-Length': '1'}, b'?'),{}, b'', b'', 400, {'X-Explanation': 'Can only append data'})
 
     # TODO test 'If-Range' with GET
     # TODO test multiple ranges in 'Range' with GET
@@ -229,11 +228,11 @@ class TestBigFile(ERP5TypeTestCase):
   # (called from under testBigFile_02_DataVarious driver)
   def _testBigFile_02_DataVarious(self):
     # BigFile's .data can be:
-    # str       - because data comes from Data property sheet and default value is ''
+    # bytes       - because data comes from Data property sheet and default value is b''
     # None      - because it can be changed
     # BTreeData - because it is scalable way to work with large content
     #
-    # str can be possibly non-empty because we could want to transparently
+    # bytes can be possibly non-empty because we could want to transparently
     # migrate plain File documents to BigFiles.
     #
     # make sure BigFile correctly works in all those situations.
@@ -242,47 +241,47 @@ class TestBigFile(ERP5TypeTestCase):
     f = big_file_module.newContent(portal_type='Big File')
     check = lambda *args: self.checkRequest(f, *args)
 
-    # after creation .data is ''  (as per default from Data property sheet)
+    # after creation .data is b''  (as per default from Data property sheet)
     _ = f._baseGetData()
-    self.assertIsInstance(_, str)
-    self.assertEqual(_, '')
+    self.assertIsInstance(_, bytes)
+    self.assertEqual(_, b'')
 
     # make sure we can get empty content through all ways
     # (already covered in testBigFile_01_Basic, but still)
     self.assertEqual(f.getSize(), 0)
-    self.assertEqual(f.getData(), '')
-    check(get(), {'format': 'raw'},                 '', '', 200, {'Content-Length': '0'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',R308, {                                'Range': 'bytes 0--1'})  # XXX 0--1 ok?
-    check(get({        'Range': 'bytes=0-0'}),{},   '', '', 416, {'Content-Length': '0',  'Content-Range': 'bytes */0'})
+    self.assertEqual(f.getData(), b'')
+    check(get(), {'format': 'raw'},                 b'', b'', 200, {'Content-Length': '0'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',R308, {                                'Range': 'bytes 0--1'})  # XXX 0--1 ok?
+    check(get({        'Range': 'bytes=0-0'}),{},   b'', b'', 416, {'Content-Length': '0',  'Content-Range': 'bytes */0'})
 
 
     # set .data to non-empty str and make sure we can get content through all ways
-    f._baseSetData('abc')
+    f._baseSetData(b'abc')
     _ = f._baseGetData()
-    self.assertIsInstance(_, str)
-    self.assertEqual(_, 'abc')
+    self.assertIsInstance(_, bytes)
+    self.assertEqual(_, b'abc')
     self.assertEqual(f.getSize(), 3)
-    self.assertEqual(f.getData(), 'abc')
-    check(get(), {'format': 'raw'},                 'abc', '',    200, {'Content-Length': '3'})
-    check(put({'Content-Range': 'bytes */*'}),{},   ''   , '',   R308, {                                'Range': 'bytes 0-2'})
-    check(get({        'Range': 'bytes=0-2'}),{},   ''   , 'abc', 206, {'Content-Length': '3',  'Content-Range': 'bytes 0-2/3'})
+    self.assertEqual(f.getData(), b'abc')
+    check(get(), {'format': 'raw'},                 b'abc', b'',    200, {'Content-Length': '3'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b''   , b'',   R308, {                                'Range': 'bytes 0-2'})
+    check(get({        'Range': 'bytes=0-2'}),{},   b''   , b'abc', 206, {'Content-Length': '3',  'Content-Range': 'bytes 0-2/3'})
 
     # and .data should remain str after access (though later this could be
     # changed to transparently migrate to BTreeData)
     _ = f._baseGetData()
-    self.assertIsInstance(_, str)
-    self.assertEqual(_, 'abc')
+    self.assertIsInstance(_, bytes)
+    self.assertEqual(_, b'abc')
 
 
     # on append .data should migrate to BTreeData
-    f._appendData('d')
+    f._appendData(b'd')
     _ = f._baseGetData()
     self.assertIsInstance(_, BTreeData)
     self.assertEqual(f.getSize(), 4)
-    self.assertEqual(f.getData(), 'abcd')
-    check(get(), {'format': 'raw'},                 '', 'abcd', 200, {'Content-Length': '4'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',    R308, {                                'Range': 'bytes 0-3'})
-    check(get({        'Range': 'bytes=0-3'}),{},   '', 'abcd', 206, {'Content-Length': '4',  'Content-Range': 'bytes 0-3/4'})
+    self.assertEqual(f.getData(), b'abcd')
+    check(get(), {'format': 'raw'},                 b'', b'abcd', 200, {'Content-Length': '4'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',    R308, {                                'Range': 'bytes 0-3'})
+    check(get({        'Range': 'bytes=0-3'}),{},   b'', b'abcd', 206, {'Content-Length': '4',  'Content-Range': 'bytes 0-3/4'})
 
 
 
@@ -292,39 +291,39 @@ class TestBigFile(ERP5TypeTestCase):
     #
     #      see ERP5.Document.File._setSize() for details.
     f._setData(None)
-    # NOTE still '' because it is default value specified in Data property
+    # NOTE still b'' because it is default value specified in Data property
     #      sheet for .data field
     _ = f._baseGetData()
-    self.assertIsInstance(_, str)
-    self.assertEqual(_, '')
+    self.assertIsInstance(_, bytes)
+    self.assertEqual(_, b'')
     # but we can change property sheet default on the fly
     # XXX ( only for this particular getter _baseGetData -
     #       - because property type information is not stored in one place,
     #       but is copied on getter/setter initialization - see Getter/Setter
     #       in ERP5Type.Accessor.Base )
     # NOTE this change is automatically reverted back in calling helper
-    self.assertIsInstance(f._baseGetData._default, str)
-    self.assertEqual(f._baseGetData._default, '')
+    self.assertIsInstance(f._baseGetData._default, bytes)
+    self.assertEqual(f._baseGetData._default, b'')
     f._baseGetData.__func__._default = None  # NOTE not possible to do on just f._baseGetData
     self.assertIs(f._baseGetData._default, None)
     self.assertIs(f._baseGetData(), None)   # <- oops
 
     self.assertEqual(f.getSize(), 0)
     self.assertIs   (f.getData(), None)
-    check(get(), {'format': 'raw'},                 '', '', 200, {'Content-Length': '0'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',R308, {                                'Range': 'bytes 0--1'})  # XXX 0--1 ok?
-    check(get({        'Range': 'bytes=0-0'}),{},   '', '', 416, {'Content-Length': '0',  'Content-Range': 'bytes */0'})
+    check(get(), {'format': 'raw'},                 b'', b'', 200, {'Content-Length': '0'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',R308, {                                'Range': 'bytes 0--1'})  # XXX 0--1 ok?
+    check(get({        'Range': 'bytes=0-0'}),{},   b'', b'', 416, {'Content-Length': '0',  'Content-Range': 'bytes */0'})
 
 
     # on append .data should become BTreeData
-    f._appendData('x')
+    f._appendData(b'x')
     _ = f._baseGetData()
     self.assertIsInstance(_, BTreeData)
     self.assertEqual(f.getSize(), 1)
-    self.assertEqual(f.getData(), 'x')
-    check(get(), {'format': 'raw'},                 '', 'x',    200, {'Content-Length': '1'})
-    check(put({'Content-Range': 'bytes */*'}),{},   '', '',    R308, {                                'Range': 'bytes 0-0'})
-    check(get({        'Range': 'bytes=0-3'}),{},   '', 'x',    206, {'Content-Length': '1',  'Content-Range': 'bytes 0-0/1'})
+    self.assertEqual(f.getData(), b'x')
+    check(get(), {'format': 'raw'},                 b'', b'x',    200, {'Content-Length': '1'})
+    check(put({'Content-Range': 'bytes */*'}),{},   b'', b'',    R308, {                                'Range': 'bytes 0-0'})
+    check(get({        'Range': 'bytes=0-3'}),{},   b'', b'x',    206, {'Content-Length': '1',  'Content-Range': 'bytes 0-0/1'})
 
 
 
@@ -333,26 +332,26 @@ class TestBigFile(ERP5TypeTestCase):
     big_file_module = self.getPortal().big_file_module
     f = big_file_module.newContent(portal_type='Big File')
 
-    # Data property sheet specifies .data default to ''
+    # Data property sheet specifies .data default to b''
     _ = f._baseGetData()
-    self.assertIsInstance(_, str)
-    self.assertEqual(_, '')
+    self.assertIsInstance(_, bytes)
+    self.assertEqual(_, b'')
 
     # NOTE obtaining getter is not possible via BigFile._baseGetData
     g = f._baseGetData.__func__
-    self.assertIsInstance(g._default, str)
-    self.assertEqual(g._default, '')
+    self.assertIsInstance(g._default, bytes)
+    self.assertEqual(g._default, b'')
 
     try:
       self._testBigFile_02_DataVarious()
 
     # restore ._baseGetData._default and make sure restoration really worked
     finally:
-      g._default = ''
+      g._default = b''
       f._baseSetData(None)    # so that we are sure getter returns class defaults
       _ = f._baseGetData()
-      self.assertIsInstance(_, str)
-      self.assertEqual(_, '')
+      self.assertIsInstance(_, bytes)
+      self.assertEqual(_, b'')