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.

3 files changed, 125 insertions, 0 deletions

diff --git a/morphlib/__init__.py b/morphlib/__init__.py
index f6b8ccb4..fbfc3b31 100644
--- a/morphlib/__init__.py
+++ b/morphlib/__init__.py
@@ -34,6 +34,7 @@ import morph2
 import morphology
 import morphologyloader
 import savefile
+import source
 import sourcemanager
 import stopwatch
 import tempdir
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
+
diff --git a/morphlib/source_tests.py b/morphlib/source_tests.py
new file mode 100644
index 00000000..79ccf408
--- /dev/null
+++ b/morphlib/source_tests.py
@@ -0,0 +1,70 @@
+# 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 unittest
+
+import morphlib
+
+
+class SourceTests(unittest.TestCase):
+
+    morphology_text = '''
+        {
+            "name": "foo",
+            "kind": "chunk"
+        }
+    '''
+
+    def setUp(self):
+        self.repo = 'foo.repo'
+        self.sha1 = 'CAFEF00D'
+        self.morphology = morphlib.morph2.Morphology(self.morphology_text)
+        self.source = morphlib.source.Source(self.repo, self.sha1,
+                                             self.morphology)
+        self.other = morphlib.source.Source(self.repo, self.sha1, 
+                                            self.morphology)
+                                             
+    def test_sets_repo(self):
+        self.assertEqual(self.source.repo, self.repo)
+                                             
+    def test_sets_sha1(self):
+        self.assertEqual(self.source.sha1, self.sha1)
+                                             
+    def test_sets_morphology(self):
+        self.assertEqual(self.source.morphology, self.morphology)
+                                             
+    def test_sets_dependencies_to_empty(self):
+        self.assertEqual(self.source.dependencies, [])
+                                             
+    def test_sets_dependents_to_empty(self):
+        self.assertEqual(self.source.dependents, [])
+
+    def test_does_not_depend_on_other_initially(self):
+        self.assertFalse(self.source.depends_on(self.other))
+
+    def test_adds_dependency(self):
+        self.source.add_dependency(self.other)
+        self.assertEqual(self.source.dependencies, [self.other])
+        self.assertEqual(self.other.dependents, [self.source])
+        self.assertTrue(self.source.depends_on(self.other))
+
+    def test_does_not_add_dependency_twice(self):
+        self.source.add_dependency(self.other)
+        self.source.add_dependency(self.other)
+        self.assertEqual(self.source.dependencies, [self.other])
+        self.assertEqual(self.other.dependents, [self.source])
+        self.assertTrue(self.source.depends_on(self.other))
+