Morph: index component morphologies by name

This requires that we enforce uniqueness.

New method: Morphology.lookup_morphology_by_name()

1 files changed, 25 insertions, 0 deletions

diff --git a/morphlib/morph2.py b/morphlib/morph2.py
index d4d9fe07..ffb05660 100644
--- a/morphlib/morph2.py
+++ b/morphlib/morph2.py
@@ -44,6 +44,7 @@ class Morphology(object):
     def __init__(self, text):
         self._dict = json.loads(text)
         self._set_defaults()
+        self._create_child_index()
 
     def __getitem__(self, key):
         return self._dict[key]
@@ -54,6 +55,11 @@ class Morphology(object):
     def keys(self):
         return self._dict.keys()
 
+    def lookup_morphology_by_name(self, name):
+        '''Find child morphology by its morphology name, honouring aliases
+        defined within this stratum.'''
+        return self._child_dict[name]
+
     def _set_defaults(self):
         if 'max-jobs' in self:
             self._dict['max-jobs'] = int(self['max-jobs'])
@@ -86,3 +92,22 @@ class Morphology(object):
                 source['morph'] = source['name']
             if 'build-depends' not in source:
                 source['build-depends'] = None
+
+    def _get_valid_triple(self, info):
+        return (info['repo'], info['ref'], "%s.morph" % info['morph'])
+
+    def _create_child_index(self):
+        self._child_dict = {}
+        if self['kind'] == 'system':
+            for info in self['strata']:
+                source_name = info.get('alias', info['morph'])
+                if source_name in self._child_dict:
+                    raise ValueError("duplicate stratum name: " + source_name)
+                self._child_dict[source_name] = self._get_valid_triple(info)
+        elif self['kind'] == 'stratum':
+            for info in self['chunks']:
+                # FIXME: in the future, chunks will have an 'alias' field too
+                source_name = info['name']
+                if source_name in self._child_dict:
+                    raise ValueError("duplicate chunk name: " + source_name)
+                self._child_dict[source_name] = self._get_valid_triple(info)