initial implementation of selective output caching

the PackageCmd and PatchCmd classes are now cached on their
first request.

note that this is incomplete, as the PackageCmd is also currently
used to print non-static information as well (when a package name
doesn't find an exact match and it does a query).

1 files changed, 26 insertions, 2 deletions

diff --git a/patchtracker/ReqHandler.py b/patchtracker/ReqHandler.py
index a87fd68..59e0f53 100755
--- a/patchtracker/ReqHandler.py
+++ b/patchtracker/ReqHandler.py
@@ -7,6 +7,7 @@ import sys
 import patchtracker.Conf as Conf
 from patchtracker.Templates import ErrorTemplate, PatchTemplate, PackageVersTemplate, LetterTocTemplate, FrontPageTemplate, SearchResultsTemplate
 from patchtracker.DiffGzHandler import DiffGzHandler, DiffGzException
+from patchtracker.CacheObject import CacheObject, CacheMissException
 import patchtracker.DB as DB
 from patchtracker.DB import PatchTrackerDB
 import pygments
@@ -158,14 +159,19 @@ class FrontPageCmd(Cmd):
 class CmdHandler:
   def __init__(self, env):
     self.headers = []
-    uri=Conf.root_url+env['PATH_INFO']
+    uri = Conf.root_url+env['PATH_INFO']
+    self.cacheobj = None
+    #print "Accept:",env['HTTP_ACCEPT']
 
     args = uri[len(Conf.root_url)+1:].split("/")
     cmdarg = args[0]
+    cacheable = False
     if cmdarg == "patch":
       self.cmd = PatchCmd(args[1:])
+      cacheable = True
     elif cmdarg == "package":
       self.cmd = PackageCmd(args[1:]) 
+      cacheable = True
     elif cmdarg == "index":
       self.cmd = IndexCmd(args[1:]) 
     elif cmdarg == "jump":
@@ -178,11 +184,29 @@ class CmdHandler:
     else:
       self.cmd = ErrorCmd("invalid command/location '%s'"%(cmdarg), "404 Not found")
 
+    if Conf.caching and cacheable:
+      self.cacheobj = CacheObject(key=uri)
+
     self.headers.append( ('Content-type', self.cmd.content_type) )
     self.status = self.cmd.status
 
   def output(self):
+    result = None
     try:
-      return self.cmd.output()
+      if self.cacheobj:
+        result = self.cacheobj.get()
+      else:
+        result = self.cmd.output()
+    except CacheMissException:
+      result = self.cmd.output()
+      self.cacheobj.put(result)
     except DiffGzException, e:
       return ErrorCmd(str(e), "500 Oh Noez!!1!").output()
+
+    return result
+
+if __name__ == '__main__':
+  fake_env = { 'PATH_INFO': sys.argv[1] }
+  cmdh = CmdHandler(fake_env)
+  print "Status: %s\nHeaders: %s"%(cmdh.status, cmdh.headers)
+  print cmdh.output()