Added no_file_check to sendfile for remote proxy case

sendfile/__init__.py

@@ -32,9 +32,9 @@ def _get_sendfile():
 
 
 
-def sendfile(request, filename, attachment=False, attachment_filename=None, mimetype=None, encoding=None):
-    '''
-    create a response to send file using backend configured in SENDFILE_BACKEND
+def sendfile(request, filename, attachment=False, attachment_filename=None, mimetype=None, encoding=None, no_file_check = False):
+    '''create a response to send file using backend configured in
+    SENDFILE_BACKEND
 
     If attachment is True the content-disposition header will be set.
     This will typically prompt the user to download the file, rather
@@ -45,23 +45,38 @@ def sendfile(request, filename, attachment=False, attachment_filename=None, mime
         False: No content-disposition filename
         String: Value used as filename
 
-    If no mimetype or encoding are specified, then they will be guessed via the
-    filename (using the standard python mimetypes module)
+    If no mimetype or encoding are specified, then they will be
+    guessed via the filename (using the standard python mimetypes
+    module)
+
+    If no_file_Check is true, sendfile() will check that the file
+    exists on the filesystem where stated.  If no_file_check is False,
+    then sendfile() will simply encode the path without checking for
+    its existence.  In this case it also won't set the Content-Length
+    or Content-Encoding header, so your surrounding proxy will need to
+    do that as needed.  This mode can be useful when using sendfile()
+    under a proxy atop a remote store (eg S3).
+
     '''
     _sendfile = _get_sendfile()
 
-    if not os.path.exists(filename):
+    if not no_file_check and not os.path.exists(filename):
         from django.http import Http404
         raise Http404('"%s" does not exist' % filename)
 
-    guessed_mimetype, guessed_encoding = guess_type(filename)
-    if mimetype is None:
-        if guessed_mimetype:
-            mimetype = guessed_mimetype
-        else:
-            mimetype = 'application/octet-stream'
-
-    response = _sendfile(request, filename, mimetype=mimetype)
+
+    if not no_file_check:
+        guessed_mimetype, guessed_encoding = guess_type(filename)
+        if mimetype is None:
+            if guessed_mimetype:
+                mimetype = guessed_mimetype
+            else:
+                mimetype = 'application/octet-stream'
+    else:
+        mimetype = 'application/octet-stream'
+
+    response = _sendfile(request, filename, mimetype=mimetype,
+                         no_file_check=no_file_check)
     if attachment:
         if attachment_filename is None:
             attachment_filename = os.path.basename(filename)
@@ -82,9 +97,10 @@ def sendfile(request, filename, attachment=False, attachment_filename=None, mime
                 parts.append('filename*=UTF-8\'\'%s' % quoted_filename)
         response['Content-Disposition'] = '; '.join(parts)
 
-    response['Content-length'] = os.path.getsize(filename)
+    if not no_file_check:
+        response['Content-length'] = os.path.getsize(filename)
     response['Content-Type'] = mimetype
-    if not encoding:
+    if not encoding and not no_file_check:
         encoding = guessed_encoding
     if encoding:
         response['Content-Encoding'] = encoding

sendfile/backends/_internalredirect.py

@@ -1,14 +1,22 @@
 from django.conf import settings
 import os.path
 
-def _convert_file_to_url(filename):
+def _convert_file_to_url(filename, no_file_check = False):
+    """In the normal case (no_file_check is False) reduce the filepath
+    against the filesystem and content root.  If no_file_check is
+    True, then don't do any of that and instead assume that the path
+    passed is correct and in its ultimate form.
+
+    """
+    if no_file_check: # We already a priori know that the path is
+                      # correct and in its final form.
+        return filename
     relpath = os.path.relpath(filename, settings.SENDFILE_ROOT)
-    
+
     url = [settings.SENDFILE_URL]
 
     while relpath:
         relpath, head = os.path.split(relpath)
         url.insert(1, head)
 
-    return u'/'.join(url)
-
+    return u'/'.join(url) # Note: xlates from os.path.sep to '/'

sendfile/backends/mod_wsgi.py

@@ -4,11 +4,11 @@
 
 def sendfile(request, filename, **kwargs):
     response = HttpResponse()
-    response['Location'] = _convert_file_to_url(filename)
+    response['Location'] = _convert_file_to_url(
+        filename, no_file_check = kwargs.get ("no_file_check", False))
     # need to destroy get_host() to stop django
     # rewriting our location to include http, so that
     # mod_wsgi is able to do the internal redirect
     request.get_host = lambda: ''
 
     return response
-

sendfile/backends/nginx.py

@@ -4,7 +4,8 @@
 
 def sendfile(request, filename, **kwargs):
     response = HttpResponse()
-    url = _convert_file_to_url(filename)
+    url = _convert_file_to_url(
+        filename, no_file_check = kwargs.get ("no_file_check", False))
     response['X-Accel-Redirect'] = url.encode('utf-8')
 
     return response

sendfile/backends/simple.py

@@ -11,16 +11,17 @@ def sendfile(request, filename, **kwargs):
     # Respect the If-Modified-Since header.
     statobj = os.stat(filename)
 
-    if not was_modified_since(request.META.get('HTTP_IF_MODIFIED_SINCE'),
-                              statobj[stat.ST_MTIME], statobj[stat.ST_SIZE]):
+    if not was_modified_since(
+            request.META.get('HTTP_IF_MODIFIED_SINCE'),
+            statobj[stat.ST_MTIME], statobj[stat.ST_SIZE]):
         return HttpResponseNotModified()
-    
-    
+
+
     response = HttpResponse(File(file(filename, 'rb')))
 
     response["Last-Modified"] = http_date(statobj[stat.ST_MTIME])
     return response
-    
+
 def was_modified_since(header=None, mtime=0, size=0):
     """
     Was something modified since the user last downloaded it?
@@ -52,4 +53,3 @@ def was_modified_since(header=None, mtime=0, size=0):
     except (AttributeError, ValueError, OverflowError):
         return True
     return False
-

sendfile/backends/xsendfile.py

@@ -3,6 +3,4 @@
 def sendfile(request, filename, **kwargs):
     response = HttpResponse()
     response['X-Sendfile'] = unicode(filename).encode('utf-8')
-
     return response
-