Refs #1 - Experimental support for Nginx X-Accel. Work in progress

demo/demoproject/download/tests.py

@@ -10,6 +10,8 @@
 from django.test import TestCase
 from django.test.utils import override_settings
 
+from django_downloadview.nginx import XAccelRedirectResponse
+
 from demoproject.download.models import Document
 
 
@@ -98,3 +100,24 @@ def test_download_hello_world(self):
                           'attachment; filename=hello-world.txt')
         self.assertEqual(open(self.files['hello-world.txt']).read(),
                          response.content)
+
+
+class XAccelRedirectDecoratorTestCase(DownloadTestCase):
+    @temporary_media_root()
+    def test_response(self):
+        document = Document.objects.create(
+            slug='hello-world',
+            file=File(open(self.files['hello-world.txt'])),
+        )
+        download_url = reverse('download_document_nginx',
+                               kwargs={'slug': 'hello-world'})
+        response = self.client.get(download_url)
+        self.assertEquals(response.status_code, 200)
+        self.assertTrue(isinstance(response, XAccelRedirectResponse))
+        self.assertEquals(response['Content-Type'],
+                          'text/plain; charset=utf-8')
+        self.assertFalse('ContentEncoding' in response)
+        self.assertEquals(response['Content-Disposition'],
+                          'attachment; filename=hello-world.txt')
+        self.assertEquals(response['X-Accel-Redirect'],
+                          '/download-optimized/document/hello-world.txt') 

demo/demoproject/download/urls.py

@@ -7,4 +7,6 @@
         name='download_hello_world'),
     url(r'^document/(?P<slug>[a-zA-Z0-9_-]+)/$', 'download_document',
         name='download_document'),
+    url(r'^document-nginx/(?P<slug>[a-zA-Z0-9_-]+)/$',
+        'download_document_nginx', name='download_document_nginx'),
 )

demo/demoproject/download/views.py

@@ -1,6 +1,7 @@
 from os.path import abspath, dirname, join
 
 from django_downloadview import DownloadView, ObjectDownloadView
+from django_downloadview.nginx import x_accel_redirect
 
 from demoproject.download.models import Document
 
@@ -14,3 +15,7 @@
                                             storage=None)
 
 download_document = ObjectDownloadView.as_view(model=Document)
+
+download_document_nginx = x_accel_redirect(download_document,
+                                           media_root='/var/www/files',
+                                           media_url='/download-optimized')

django_downloadview/nginx.py

@@ -6,10 +6,12 @@
 from datetime import datetime, timedelta
 
 from django.conf import settings
+from django.core.exceptions import ImproperlyConfigured
 from django.http import HttpResponse
 
-from django_downloadview.middlewares import BaseDownloadMiddleware
 from django_downloadview.decorators import DownloadDecorator
+from django_downloadview.middlewares import BaseDownloadMiddleware
+from django_downloadview.utils import content_type_to_charset
 
 
 #: Default value for X-Accel-Buffering header.
@@ -24,19 +26,15 @@
     setattr(settings, 'NGINX_DOWNLOAD_MIDDLEWARE_LIMIT', DEFAULT_LIMIT_RATE)
 
 
-def content_type_to_charset(content_type):
-    return 'utf-8'
-
-
 class XAccelRedirectResponse(HttpResponse):
     """Http response that delegate serving file to Nginx."""
-    def __init__(self, url, content_type, basename=None, expires=None,
+    def __init__(self, redirect_url, content_type, basename=None, expires=None,
                  with_buffering=None, limit_rate=None):
         """Return a HttpResponse with headers for Nginx X-Accel-Redirect."""
         super(XAccelRedirectResponse, self).__init__(content_type=content_type)
-        basename = basename or url.split('/')[-1]
+        basename = basename or redirect_url.split('/')[-1]
         self['Content-Disposition'] = 'attachment; filename=%s' % basename
-        self['X-Accel-Redirect'] = url
+        self['X-Accel-Redirect'] = redirect_url
         self['X-Accel-Charset'] = content_type_to_charset(content_type)
         if with_buffering is not None:
             self['X-Accel-Buffering'] = with_buffering and 'yes' or 'no'
@@ -52,27 +50,34 @@ def __init__(self, url, content_type, basename=None, expires=None,
 
 class BaseXAccelRedirectMiddleware(BaseDownloadMiddleware):
     """Looks like a middleware, but configurable."""
-    def __init__(self, expires=None, with_buffering=None, limit_rate=None):
+    def __init__(self, media_root, media_url, expires=None,
+                 with_buffering=None, limit_rate=None):
         """Constructor."""
+        self.media_root = media_root
+        self.media_url = media_url
         self.expires = expires
         self.with_buffering = with_buffering
         self.limit_rate = limit_rate
 
-    def file_to_url(response):
-        return response.filename
+    def get_redirect_url(self, response):
+        """Return redirect URL for file wrapped into response."""
+        absolute_filename = response.filename
+        relative_filename = absolute_filename[len(self.media_root):]
+        return '/'.join((self.media_url.rstrip('/'),
+                         relative_filename.strip('/')))
 
     def process_download_response(self, request, response):
         """Replace DownloadResponse instances by NginxDownloadResponse ones."""
-        url = self.file_to_url(response)
+        redirect_url = self.get_redirect_url(response)
         if self.expires:
             expires = self.expires
         else:
             try:
                 expires = response.expires
             except AttributeError:
                 expires = None
-        return XAccelRedirectResponse(url=url,
-                                      content_type=response.content_type,
+        return XAccelRedirectResponse(redirect_url=redirect_url,
+                                      content_type=response['Content-Type'],
                                       basename=response.basename,
                                       expires=expires,
                                       with_buffering=self.with_buffering,
@@ -87,8 +92,22 @@ class XAccelRedirectMiddleware():
     """
     def __init__(self):
         """Use Django settings as configuration."""
+        try:
+            media_root = settings.NGINX_DOWNLOAD_MIDDLEWARE_MEDIA_ROOT
+        except AttributeError:
+            raise ImproperlyConfigured(
+                'settings.NGINX_DOWNLOAD_MIDDLEWARE_MEDIA_ROOT is required by '
+                '%s middleware' % self.__class__.name)
+        try:
+            media_url = settings.NGINX_DOWNLOAD_MIDDLEWARE_MEDIA_URL
+        except AttributeError:
+            raise ImproperlyConfigured(
+                'settings.NGINX_DOWNLOAD_MIDDLEWARE_MEDIA_URL is required by '
+                '%s middleware' % self.__class__.name)
         super(XAccelRedirectMiddleware, self).__init__(
-            expires=settings.NGINX_DOWNLOAD_MIDDLEWARE_EXPIRESS,
+            media_root,
+            media_url,
+            expires=settings.NGINX_DOWNLOAD_MIDDLEWARE_EXPIRES,
             with_buffering=settings.NGINX_DOWNLOAD_MIDDLEWARE_WITH_BUFFERING,
             limit_rate=settings.NGINX_DOWNLOAD_MIDDLEWARE_LIMIT_RATE)
 

django_downloadview/utils.py

@@ -0,0 +1,18 @@
+"""Utility functions."""
+import re
+
+
+charset_pattern = re.compile(r'charset=(?P<charset>.+)$', re.I | re.U)
+
+
+def content_type_to_charset(content_type):
+    """Return charset part of content-type header.
+
+    >>> from django_downloadview.utils import content_type_to_charset
+    >>> content_type_to_charset('text/html; charset=utf-8')
+    'utf-8'
+
+    """
+    match = re.search(charset_pattern, content_type)
+    if match:
+        return match.group('charset')

docs/api/django_downloadview.txt

@@ -17,6 +17,14 @@ django_downloadview Package
     :undoc-members:
     :show-inheritance:
 
+:mod:`file` Module
+------------------
+
+.. automodule:: django_downloadview.file
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
 :mod:`middlewares` Module
 -------------------------
 
@@ -41,6 +49,14 @@ django_downloadview Package
     :undoc-members:
     :show-inheritance:
 
+:mod:`utils` Module
+-------------------
+
+.. automodule:: django_downloadview.utils
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
 :mod:`views` Module
 -------------------
 

docs/nginx.txt

@@ -19,14 +19,10 @@ As an example, let's consider the following download view:
 
 * mapped on ``/document/<object-slug>/download``
 * returns DownloadResponse corresponding to Document's model FileField
-* Document storage root is :file:`/var/www/files/`.
+* Document storage root is :file:`/var/www/files/`
+* FileField's ``upload_to`` is "document".
 
-Configure Document storage:
-
-.. code-block:: python
-
-   storage = FileSystemStorage(location='var/www/files',
-                               url='/optimized-download')
+Files live in ``/var/www/files/document/`` folder.
 
 As is, Django is to serve the files, i.e. load chunks into memory and stream
 them.
@@ -82,6 +78,8 @@ Optionally customize configuration (default is "use Nginx's defaults").
 
 .. code-block:: python
 
+   NGINX_DOWNLOAD_MIDDLEWARE_MEDIA_ROOT = MEDIA_ROOT
+   NGINX_DOWNLOAD_MIDDLEWARE_MEDIA_URL = '/optimized-download'
    NGINX_DOWNLOAD_MIDDLEWARE_EXPIRES = False  # Force no expiration.
    NGINX_DOWNLOAD_MIDDLEWARE_WITH_BUFFERING = False  # Force buffering off.
    NGINX_DOWNLOAD_MIDDLEWARE_LIMIT_RATE = False  # Force limit rate off.
@@ -104,7 +102,9 @@ In some urls.py:
    from django_downloadview.nginx import x_accel_redirect
 
 
-   download = x_accel_redirect(ObjectDownloadView.as_view(model=Document))
+   download = x_accel_redirect(ObjectDownloadView.as_view(model=Document),
+                               media_root=settings.MEDIA_ROOT,
+                               media_url='/optimized-download')
 
    # ... URL patterns using ``download``