Create multiple sources per stratum morphology

Building per-artifact results in undesirable behaviour,
as multiple artifacts are produced for every chunk build.
It therefore makes more sense to build per-source.

This implies that actually, the model of one source per
morphology is wrong and we should move the dependencies
into the source.

Unlike chunks however, where every chunk artifact has the
same dependencies, stratum artifacts can have different
dependencies.

So before we can move the dependencies into the Source,
we need to have as many Sources as Stratum Artifacts.

1 files changed, 8 insertions, 5 deletions

diff --git a/morphlib/sourcepool.py b/morphlib/sourcepool.py
index ec134c0a..6dfcb2c3 100644
--- a/morphlib/sourcepool.py
+++ b/morphlib/sourcepool.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2012  Codethink Limited
+# Copyright (C) 2012-2014  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -14,12 +14,15 @@
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 
+import collections
+
+
 class SourcePool(object):
 
     '''Manage a collection of Source objects.'''
 
     def __init__(self):
-        self._sources = {}
+        self._sources = collections.defaultdict(dict)
         self._order = []
 
     def _key(self, repo_name, original_ref, filename):
@@ -30,8 +33,8 @@ class SourcePool(object):
         key = self._key(source.repo_name,
                         source.original_ref,
                         source.filename)
-        if key not in self._sources:
-            self._sources[key] = source
+        if key not in self._sources or source.name not in self._sources[key]:
+            self._sources[key][source.name] = source
             self._order.append(source)
 
     def lookup(self, repo_name, original_ref, filename):
@@ -42,7 +45,7 @@ class SourcePool(object):
         '''
 
         key = self._key(repo_name, original_ref, filename)
-        return self._sources[key]
+        return self._sources[key].values()
 
     def __iter__(self):
         '''Iterate over sources in the pool, in the order they were added.'''