From b81dd300382cd78babe3421a994f4745e4a6f085 Mon Sep 17 00:00:00 2001
From: Thomas Leonard <talex5@gmail.com>
Date: Tue, 29 Jan 2008 18:46:55 +0000
Subject: [PATCH] Don't use tasks system if nothing needs to be downloaded.

---
 zeroinstall/injector/autopolicy.py  |  3 ++-
 zeroinstall/injector/iface_cache.py |  9 ++++++++-
 zeroinstall/injector/policy.py      | 20 +++++++++++++++-----
 3 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/zeroinstall/injector/autopolicy.py b/zeroinstall/injector/autopolicy.py
index 97559a2..15483a6 100644
--- a/zeroinstall/injector/autopolicy.py
+++ b/zeroinstall/injector/autopolicy.py
@@ -41,7 +41,8 @@ class AutoPolicy(policy.Policy):
 
 	def execute(self, prog_args, main = None, wrapper = None):
 		downloaded = self.download_impls()
-		self.handler.wait_for_blocker(downloaded)
+		if downloaded:
+			self.handler.wait_for_blocker(downloaded)
 		if not self.download_only:
 			run.execute(self, prog_args, dry_run = self.dry_run, main = main, wrapper = wrapper)
 		else:
diff --git a/zeroinstall/injector/iface_cache.py b/zeroinstall/injector/iface_cache.py
index 8aea746..00253dd 100644
--- a/zeroinstall/injector/iface_cache.py
+++ b/zeroinstall/injector/iface_cache.py
@@ -348,9 +348,16 @@ class IfaceCache(object):
 		reader.update_from_cache(interface)
 
 	def get_feed(self, url):
+		"""Get a feed from the cache.
+		@param url: the URL of the feed
+		@return: the feed, or None if it isn't cached
+		@rtype: L{model.ZeroInstallFeed}"""
 		# TODO: This isn't a good implementation
 		iface = self.get_interface(url)
-		return iface._main_feed
+		feed = iface._main_feed
+		if not isinstance(feed, model.DummyFeed):
+			return feed
+		return None
 
 	def get_interface(self, uri):
 		"""Get the interface for uri, creating a new one if required.
diff --git a/zeroinstall/injector/policy.py b/zeroinstall/injector/policy.py
index 55dd47f..38c2327 100644
--- a/zeroinstall/injector/policy.py
+++ b/zeroinstall/injector/policy.py
@@ -224,7 +224,12 @@ class Policy(object):
 
 	def is_stale(self, feed):
 		"""Check whether feed needs updating, based on the configured L{freshness}.
+		None is considered to be stale.
 		@return: true if feed is stale or missing."""
+		if feed is None:
+			return True
+		if feed.url.startswith('/'):
+			return False		# Local feeds are never stale
 		if feed.last_modified is None:
 			return True		# Don't even have it yet
 		now = time.time()
@@ -558,7 +563,6 @@ class Policy(object):
 
 		return False
 	
-	@tasks.async
 	def download_impls(self):
 		"""Download all implementations that are missing from the cache."""
 		blockers = []
@@ -573,8 +577,14 @@ class Policy(object):
 					"interface!)")
 			blockers.append(self.download_impl(impl, source))
 
-		while blockers:
-			yield blockers
-			tasks.check(blockers)
+		if not blockers:
+			return None
+
+		@tasks.async
+		def download_impls(blockers):
+			while blockers:
+				yield blockers
+				tasks.check(blockers)
 
-			blockers = [b for b in blockers if not b.happened]
+				blockers = [b for b in blockers if not b.happened]
+		return download_impls(blockers)
-- 
2.11.4.GIT