Add a Source class

This will eventually replace the Blob class we are currently using.
It is somewhat simpler, because the envisioned usage of Source will
be different from Blob: we'll be rewriting the build ordering class,
and the builder classes, in ways that simplify things, and thus a
simpler Source class will hopefully suffice.

1 files changed, 54 insertions, 0 deletions

diff --git a/morphlib/source.py b/morphlib/source.py
new file mode 100644
index 00000000..399d9e0c
--- /dev/null
+++ b/morphlib/source.py
@@ -0,0 +1,54 @@
+# Copyright (C) 2012  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
+# the Free Software Foundation; version 2 of the License.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import morphlib
+
+
+class Source(object):
+
+    '''Represent the source to be built.
+    
+    Has the following properties:
+    
+    * ``repo`` -- the git repository which contains the source
+    * ``sha1`` -- the absolute git commit id for the revision we use
+    * ``morphology`` -- the in-memory representation of the morphology we use
+    * ``dependencies`` -- list of Sources for build dependencies for us
+    * ``dependents`` -- list of Source for whom we are a build dependency
+    
+    The ``dependencies`` and ``dependents`` lists MUST be modified by
+    the ``add_dependencies`` and ``add_dependent`` methods only.
+    
+    '''
+    
+    def __init__(self, repo, sha1, morphology):
+        assert type(morphology) == morphlib.morph2.Morphology
+        self.repo = repo
+        self.sha1 = sha1
+        self.morphology = morphology
+        self.dependencies = []
+        self.dependents = []
+
+    def add_dependency(self, source):
+        '''Add ``source`` to the dependency list.'''
+        if source not in self.dependencies:
+            self.dependencies.append(source)
+            source.dependents.append(self)
+
+    def depends_on(self, source):
+        '''Do we depend on ``source``?'''
+        return source in self.dependencies
+