Add support for HTTP redirects

src/calibre/srv/errors.py

@@ -6,9 +6,25 @@ from __future__ import (unicode_literals, division, absolute_import,
 __license__ = 'GPL v3'
 __copyright__ = '2015, Kovid Goyal <kovid at kovidgoyal.net>'
 
-
-class HTTP404(Exception):
-    pass
+import httplib
 
 class JobQueueFull(Exception):
     pass
+
+class HTTPSimpleResponse(Exception):
+
+    def __init__(self, http_code, http_message='', close_connection=False, location=None):
+        Exception.__init__(self, http_message)
+        self.http_code = http_code
+        self.close_connection = close_connection
+        self.location = location
+
+class HTTPRedirect(HTTPSimpleResponse):
+
+    def __init__(self, location, http_code=httplib.MOVED_PERMANENTLY, http_message='', close_connection=False):
+        HTTPSimpleResponse.__init__(self, http_code, http_message, close_connection, location)
+
+class HTTPNotFound(HTTPSimpleResponse):
+
+    def __init__(self, http_message='', close_connection=False):
+        HTTPSimpleResponse.__init__(self, httplib.NOT_FOUND, http_message, close_connection)

src/calibre/srv/http_response.py

@@ -16,7 +16,7 @@ from functools import wraps
 from calibre import guess_type, force_unicode
 from calibre.constants import __version__
 from calibre.srv.loop import WRITE
-from calibre.srv.errors import HTTP404
+from calibre.srv.errors import HTTPSimpleResponse
 from calibre.srv.http_request import HTTPRequest, read_headers
 from calibre.srv.sendfile import file_metadata, sendfile_to_socket_async, CannotSendfile, SendfileInterrupted
 from calibre.srv.utils import MultiDict, http_date, HTTP1, HTTP11, socket_errors_socket_closed
@@ -284,10 +284,15 @@ class HTTPConnection(HTTPRequest):
         buf.seek(pos + sent)
         return buf.tell() == end
 
-    def simple_response(self, status_code, msg='', close_after_response=True):
-        if self.response_protocol is HTTP1 and status_code in (httplib.REQUEST_ENTITY_TOO_LARGE, httplib.REQUEST_URI_TOO_LONG):
-            # HTTP/1.0 has no 413/414 codes
-            status_code = httplib.BAD_REQUEST
+    def simple_response(self, status_code, msg='', close_after_response=True, extra_headers=None):
+        if self.response_protocol is HTTP1:
+            # HTTP/1.0 has no 413/414/303 codes
+            status_code = {
+                httplib.REQUEST_ENTITY_TOO_LARGE:httplib.BAD_REQUEST,
+                httplib.REQUEST_URI_TOO_LONG:httplib.BAD_REQUEST,
+                httplib.SEE_OTHER:httplib.FOUND
+            }.get(status_code, status_code)
+
         self.close_after_response = close_after_response
         msg = msg.encode('utf-8')
         ct = 'http' if self.method == 'TRACE' else 'plain'
@@ -299,6 +304,9 @@ class HTTPConnection(HTTPRequest):
         ]
         if self.close_after_response and self.response_protocol is HTTP11:
             buf.append("Connection: close")
+        if extra_headers is not None:
+            for h, v in extra_headers.iteritems():
+                buf.append('%s: %s' % (h, v))
         buf.append('')
         buf = [(x + '\r\n').encode('ascii') for x in buf]
         if self.method != 'HEAD':
@@ -346,8 +354,11 @@ class HTTPConnection(HTTPRequest):
     def job_done(self, ok, result):
         if not ok:
             etype, e, tb = result
-            if isinstance(e, HTTP404):
-                return self.simple_response(httplib.NOT_FOUND, msg=e.message or '', close_after_response=False)
+            if isinstance(e, HTTPSimpleResponse):
+                eh = {}
+                if e.location:
+                    eh['Location'] = e.location
+                return self.simple_response(e.http_code, msg=e.message or '', close_after_response=e.close_connection, extra_headers=eh)
             raise e, None, tb
 
         data, output = result

src/calibre/srv/tests/http.py

@@ -89,10 +89,10 @@ class TestHTTP(BaseTest):
 
     def test_http_basic(self):  # {{{
         'Test basic HTTP protocol conformance'
-        from calibre.srv.errors import HTTP404
+        from calibre.srv.errors import HTTPNotFound, HTTPRedirect
         body = 'Requested resource not found'
         def handler(data):
-            raise HTTP404(body)
+            raise HTTPNotFound(body)
         def raw_send(conn, raw):
             conn.send(raw)
             conn._HTTPConnection__state = httplib._CS_REQ_SENT
@@ -146,6 +146,17 @@ class TestHTTP(BaseTest):
             self.ae(r.status, httplib.INTERNAL_SERVER_ERROR)
             server.loop.log.filter_level = orig
 
+            # Test 301
+            def handler(data):
+                raise HTTPRedirect('/somewhere-else')
+            server.change_handler(handler)
+            conn = server.connect()
+            conn.request('GET', '/')
+            r = conn.getresponse()
+            self.ae(r.status, httplib.MOVED_PERMANENTLY)
+            self.ae(r.getheader('Location'), '/somewhere-else')
+            self.ae('', r.read())
+
             server.change_handler(lambda data:data.path[0] + data.read().decode('ascii'))
             conn = server.connect()