From 072befe3c8bd16de32362592edd8d6a24da7877c Mon Sep 17 00:00:00 2001
From: Ilya Kreymer <ilya@archive.org>
Date: Fri, 20 Dec 2013 15:10:12 -0800
Subject: [PATCH] archivalrouter: support handler chaining, using call
 convention and pass prev response

---
 pywb/archivalrouter.py    | 18 +++++++++++++-----
 pywb/wbapp.py             | 12 ++++++------
 pywb/wbrequestresponse.py | 10 +++++-----
 3 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/pywb/archivalrouter.py b/pywb/archivalrouter.py
index 1e3afe57..da122a9e 100644
--- a/pywb/archivalrouter.py
+++ b/pywb/archivalrouter.py
@@ -27,11 +27,19 @@ class ArchivalRequestRouter:
 
                 return handler, req
 
-        return self.fallback, WbRequest(env)
+        return self.fallback, WbRequest.from_uri(request_uri, env)
 
     def handleRequest(self, env):
         handler, wbrequest = self._parseRequest(env)
-        return handler.run(wbrequest)
+        resp = None
+
+        if isinstance(handler, list):
+            for x in handler:
+                resp = x(wbrequest, resp)
+        else:
+            resp = handler(wbrequest, resp)
+
+        return resp
 
     def getPrefix(self, env, rel_prefix):
         if self.abs_path:
@@ -75,7 +83,7 @@ class ReferRedirect:
             self.matchPrefixs = [matchPrefixs]
 
 
-    def run(self, wbrequest):
+    def __call__(self, wbrequest, _):
         if wbrequest.referrer is None:
             return None
 
@@ -109,8 +117,8 @@ if __name__ == "__main__":
         env = {'REQUEST_URI': request_uri, 'HTTP_REFERER': referrer}
 
         redir = ReferRedirect(matchHost)
-        req = WbRequest.parse(env)
-        rep = redir.run(req)
+        req = WbRequest.from_uri(request_uri, env)
+        rep = redir(req, None)
         if not rep:
             return False
 
diff --git a/pywb/wbapp.py b/pywb/wbapp.py
index 125a820d..53edd319 100644
--- a/pywb/wbapp.py
+++ b/pywb/wbapp.py
@@ -7,11 +7,11 @@ from wbrequestresponse import WbResponse
 from archivalrouter import ArchivalRequestRouter
 
 class EchoEnv:
-    def run(self, wbrequest):
+    def __call__(self, wbrequest, _):
         return WbResponse.text_response(str(wbrequest.env))
 
 class WBHandler:
-    def run(self, wbrequest):
+    def __call__(self, wbrequest, _):
         return WbResponse.text_response(str(wbrequest))
 
 class QueryHandler:
@@ -19,7 +19,7 @@ class QueryHandler:
         self.cdxserver = indexreader.RemoteCDXServer('http://web.archive.org/cdx/search/cdx')
 
 
-    def run(self, wbrequest):
+    def __call__(self, wbrequest, prev_wbresponse):
         wburl = wbrequest.wb_url
 
         params = self.cdxserver.getQueryParams(wburl)
@@ -38,9 +38,9 @@ class QueryHandler:
 ## ===========
 parser = ArchivalRequestRouter(
     {
-     't0' : EchoEnv(),
-     't1' : WBHandler(),
-     't2' : QueryHandler()
+     't0' : [EchoEnv()],
+     't1' : [WBHandler()],
+     't2' : [QueryHandler()]
     },
     hostpaths = ['http://localhost:9090/'])
 ## ===========
diff --git a/pywb/wbrequestresponse.py b/pywb/wbrequestresponse.py
index 51f81b63..a045edd5 100644
--- a/pywb/wbrequestresponse.py
+++ b/pywb/wbrequestresponse.py
@@ -3,21 +3,21 @@ from wbarchivalurl import ArchivalUrl
 
 class WbRequest:
     """
-    >>> WbRequest.parse({'REQUEST_URI': '/save/_embed/example.com/?a=b'})
+    >>> WbRequest.from_uri('/save/_embed/example.com/?a=b')
     {'wb_url': ('latest_replay', '', '', 'http://_embed/example.com/?a=b', '/http://_embed/example.com/?a=b'), 'coll': 'save', 'wb_prefix': '/save/', 'request_uri': '/save/_embed/example.com/?a=b'}
 
-    >>> WbRequest.parse({'REQUEST_URI': '/2345/20101024101112im_/example.com/?b=c'})
+    >>> WbRequest.from_uri('/2345/20101024101112im_/example.com/?b=c')
     {'wb_url': ('replay', '20101024101112', 'im_', 'http://example.com/?b=c', '/20101024101112im_/http://example.com/?b=c'), 'coll': '2345', 'wb_prefix': '/2345/', 'request_uri': '/2345/20101024101112im_/example.com/?b=c'}
 
-    >>> WbRequest.parse({'REQUEST_URI': '/2010/example.com'})
+    >>> WbRequest.from_uri('/2010/example.com')
     {'wb_url': ('latest_replay', '', '', 'http://example.com', '/http://example.com'), 'coll': '2010', 'wb_prefix': '/2010/', 'request_uri': '/2010/example.com'}
 
-    >>> WbRequest.parse({'REQUEST_URI': '../example.com'})
+    >>> WbRequest.from_uri('../example.com')
     {'wb_url': ('latest_replay', '', '', 'http://example.com', '/http://example.com'), 'coll': '', 'wb_prefix': '/', 'request_uri': '../example.com'}
     """
 
     @staticmethod
-    def parse(env, request_uri = ''):
+    def from_uri(request_uri, env = {}):
         if not request_uri:
             request_uri = env.get('REQUEST_URI')