DataArray: get array slice by HTTP Range Request

bt5/erp5_wendelin/DocumentTemplateItem/portal_components/document.erp5.DataArray.py

@@ -30,6 +30,11 @@ from AccessControl import ClassSecurityInfo
 from Products.ERP5Type import Permissions, PropertySheet
 from Products.ERP5.Document.BigFile import BigFile
 from wendelin.bigarray.array_zodb import ZBigArray
+from Products.ERP5.Document.File import _MARKER
+from ZPublisher import HTTPRangeSupport
+from webdav.common import rfc1123_date
+from DateTime import DateTime
+from mimetools import choose_boundary
 import transaction
 
 class DataArray(BigFile):
@@ -82,3 +87,138 @@ class DataArray(BigFile):
       array reference directly.
     """
     return self.getArray()[start:end]
+  
+  security.declareProtected(Permissions.AccessContentsInformation, 'getSize')
+  def getSize(self, default=None):
+    """
+       Implement getSize interface for ndarray
+    """
+    return self.getArray().nbytes
+    
+  security.declareProtected(Permissions.View, 'index_html')
+  def index_html(self, REQUEST, RESPONSE, format=_MARKER, inline=_MARKER, **kw):
+    """
+      Support streaming
+    """
+    if self._range_request_handler(REQUEST, RESPONSE):
+      # we served a chunk of content in response to a range request.
+      return ''
+
+    # XXX: what we do? We can not transmit entire Big Array?
+    return ''
+    
+  def _range_request_handler(self, REQUEST, RESPONSE):
+    # HTTP Range header handling: return True if we've served a range
+    # chunk out of our data.
+    range = REQUEST.get_header('Range', None)
+    request_range = REQUEST.get_header('Request-Range', None)
+    if request_range is not None:
+      # Netscape 2 through 4 and MSIE 3 implement a draft version
+      # Later on, we need to serve a different mime-type as well.
+      range = request_range
+    if_range = REQUEST.get_header('If-Range', None)
+    if range is not None:
+      ranges = HTTPRangeSupport.parseRange(range)
+
+      # get byte view of array because we interpret ranges in bytes
+      data = self.getArray()[:].view("uint8").ravel()
+      
+      if if_range is not None:
+        # Only send ranges if the data isn't modified, otherwise send
+        # the whole object. Support both ETags and Last-Modified dates!
+        if len(if_range) > 1 and if_range[:2] == 'ts':
+          # ETag:
+          if if_range != self.http__etag():
+            # Modified, so send a normal response. We delete
+            # the ranges, which causes us to skip to the 200
+            # response.
+            ranges = None
+        else:
+          # Date
+          date = if_range.split( ';')[0]
+          try: mod_since=long(DateTime(date).timeTime())
+          except: mod_since=None
+          if mod_since is not None:
+            last_mod = self._data_mtime()
+            if last_mod is None:
+              last_mod = 0
+            last_mod = long(last_mod)
+            if last_mod > mod_since:
+              # Modified, so send a normal response. We delete
+              # the ranges, which causes us to skip to the 200
+              # response.
+              ranges = None
+
+      if ranges:
+        # Search for satisfiable ranges.
+        satisfiable = 0
+        for start, end in ranges:
+          if start < self.getSize():
+            satisfiable = 1
+            break
+
+        if not satisfiable:
+          RESPONSE.setHeader('Content-Range',
+              'bytes */%d' % self.getSize())
+          RESPONSE.setHeader('Accept-Ranges', 'bytes')
+          RESPONSE.setHeader('Last-Modified', rfc1123_date(self._data_mtime()))
+          RESPONSE.setHeader('Content-Type', self.content_type)
+          RESPONSE.setHeader('Content-Length', self.getSize())
+          RESPONSE.setStatus(416)
+          return True
+
+        ranges = HTTPRangeSupport.expandRanges(ranges, self.getSize())
+
+
+        if len(ranges) == 1:
+          # Easy case, set extra header and return partial set.
+          start, end = ranges[0]
+          size = end - start
+
+          RESPONSE.setHeader('Last-Modified', rfc1123_date(self._data_mtime()))
+          RESPONSE.setHeader('Content-Type', self.content_type)
+          RESPONSE.setHeader('Content-Length', size)
+          RESPONSE.setHeader('Accept-Ranges', 'bytes')
+          RESPONSE.setHeader('Content-Range',
+              'bytes %d-%d/%d' % (start, end - 1, self.getSize()))
+          RESPONSE.setStatus(206) # Partial content
+          
+          self.log(data[start:end].tobytes())
+          RESPONSE.write(data[start:end].tobytes())
+        else:
+          boundary = choose_boundary()
+
+          # Calculate the content length
+          size = (8 + len(boundary) + # End marker length
+              len(ranges) * (         # Constant lenght per set
+                  49 + len(boundary) + len(self.content_type) +
+                  len('%d' % self.getSize())))
+          for start, end in ranges:
+            # Variable length per set
+            size = (size + len('%d%d' % (start, end - 1)) +
+                end - start)
+
+          # Some clients implement an earlier draft of the spec, they
+          # will only accept x-byteranges.
+          draftprefix = (request_range is not None) and 'x-' or ''
+
+          RESPONSE.setHeader('Content-Length', size)
+          RESPONSE.setHeader('Accept-Ranges', 'bytes')
+          RESPONSE.setHeader('Last-Modified', rfc1123_date(self._data_mtime()))
+          RESPONSE.setHeader('Content-Type',
+              'multipart/%sbyteranges; boundary=%s' % (
+                  draftprefix, boundary))
+          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(
+                'Content-Range: bytes %d-%d/%d\r\n\r\n' % (
+                    start, end - 1, self.getSize()))
+
+            RESPONSE.write(data[start:end].tobytes())
+
+          RESPONSE.write('\r\n--%s--\r\n' % boundary)
+          return True

bt5/erp5_wendelin/DocumentTemplateItem/portal_components/document.erp5.DataArray.xml

@@ -45,7 +45,11 @@
         <item>
             <key> <string>text_content_warning_message</string> </key>
             <value>
-              <tuple/>
+              <tuple>
+                <string>W: 99, 42: Redefining built-in \'format\' (redefined-builtin)</string>
+                <string>W:113,  4: Redefining built-in \'range\' (redefined-builtin)</string>
+                <string>W:140, 10: No exception type(s) specified (bare-except)</string>
+              </tuple>
             </value>
         </item>
         <item>