Add a new morphology parser class

The old morphlib.morphology.Morphlogy class is entangled by having
treeish and requires reading from an open file. This is a bad design
for the class: the treeish is unnecessary coupling, and the open file
makes is harder than necessary to parse a morphology which we don't
have as a file on disk.

The new class gets the text of the morphology and does not care about
treeishes at all. It also acts more like a dictionary, giving more
uniform access to the various items, while reducing the amount of
code we have in the class.

The old class will remain until all uses of it have been eradicated.

1 files changed, 83 insertions, 0 deletions

diff --git a/morphlib/morph2.py b/morphlib/morph2.py
new file mode 100644
index 00000000..8987b848
--- /dev/null
+++ b/morphlib/morph2.py
@@ -0,0 +1,83 @@
+# 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 json
+
+
+class Morphology(object):
+
+    '''An in-memory representation of a morphology.
+    
+    This is a parsed version of the morphology, with rules for default
+    values applied. No other processing.
+    
+    '''
+    
+    static_defaults = [
+        ('configure-commands', []),
+        ('build-commands', []),
+        ('test-commands', []),
+        ('install-commands', []),
+        ('sources', []),
+        ('max-jobs', None),
+        ('description', ''),
+        ('build-depends', None),
+        ('build-system', 'manual'),
+    ]
+    
+    def __init__(self, text):
+        self._dict = json.loads(text)
+        self._set_defaults()
+        
+    def __getitem__(self, key):
+        return self._dict[key]
+        
+    def __contains__(self, key):
+        return key in self._dict
+        
+    def _set_defaults(self):
+        if 'max-jobs' in self:
+            self._dict['max-jobs'] = int(self['max-jobs'])
+
+        if 'disk-size' in self:
+            size = self['disk-size']
+            size = size.lower()
+            if size.endswith('g'):
+                size = int(size[:-1]) * 1024**3
+            elif size.endswith('m'): # pragma: no cover
+                size = int(size[:-1]) * 1024**2
+            elif size.endswith('k'): # pragma: no cover
+                size = int(size[:-1]) * 1024
+            else: # pragma: no cover
+                size = int(size)
+            self._dict['disk-size'] = size
+    
+        for name, value in self.static_defaults:
+            if name not in self._dict:
+                self._dict[name] = value
+
+        if self['kind'] == 'stratum':
+            self._set_stratum_defaults()
+            
+    def _set_stratum_defaults(self):
+        for source in self['sources']:
+            if 'repo' not in source:
+                source['repo'] = source['name']
+            if 'morph' not in source:
+                source['morph'] = source['name']
+            if 'build-depends' not in source:
+                source['build-depends'] = None
+