Revert of [package.proto] convert deps from list to map.

recipe_engine/package.py

Index: recipe_engine/package.py
diff --git a/recipe_engine/package.py b/recipe_engine/package.py
index 52a3b6eab66704fc4afc73490e9f6fd8cf75221c..bd0ebf1ea48842beaa5bc6257c35721ac116ab03 100644
--- a/recipe_engine/package.py
+++ b/recipe_engine/package.py
@@ -60,12 +60,7 @@
   """A collection of functions operating on a proto path.
 
   This is an object so that it can be mocked in the tests.
-
-  Proto files read will always be upconverted to the current proto in
-  package.proto, and will be written back in their original format.
   """
-  API_VERSIONS = (1, 2)
-
   def __init__(self, path):
     self._path = path
 
@@ -78,32 +73,13 @@
       return fh.read()
 
   def read(self):
-    obj = json.loads(self.read_raw())
-
-    vers = obj.get('api_version')
-    assert vers in self.API_VERSIONS, (
-      'expected %r to be one of %r' % (vers, self.API_VERSIONS)
-    )
-
-    # upconvert old deps-as-a-list to deps-as-a-dict
-    if 'deps' in obj and vers == 1:
-      obj['deps'] = {d.pop('project_id'): d for d in obj['deps']}
-
+    text = self.read_raw()
     buf = package_pb2.Package()
-    json_format.ParseDict(obj, buf, ignore_unknown_fields=True)
+    json_format.Parse(text, buf, ignore_unknown_fields=True)
     return buf
 
   def to_raw(self, buf):
     obj = json_format.MessageToDict(buf, preserving_proto_field_name=True)
-
-    # downconvert if api_version is 1
-    if buf.deps and buf.api_version < 2:
-      deps = []
-      for pid, d in sorted(obj['deps'].iteritems()):
-        d['project_id'] = pid
-        deps.append(d)
-      obj['deps'] = deps
-
     return json.dumps(obj, indent=2, sort_keys=True).replace(' \n', '\n')
 
   def write(self, buf):
@@ -229,6 +205,7 @@
 
   def dump(self):
     buf = package_pb2.DepSpec(
+        project_id=self.project_id,
         url=self.repo,
         branch=self.branch,
         revision=self.revision)
@@ -353,6 +330,7 @@
   def dump(self):
     """Returns the package.proto DepSpec form of this RepoSpec."""
     return package_pb2.DepSpec(
+        project_id=self.project_id,
         url="file://"+self.path)
 
   def __eq__(self, other):
@@ -484,12 +462,12 @@
 
   def get_rolled_spec(self):
     """Returns a PackageSpec with all the deps updates from this roll."""
+    # TODO(phajdan.jr): does this preserve comments? should it?
     new_deps = _updated(
         self._package_spec.deps,
         { project_id: spec for project_id, spec in
           self._updates.iteritems() })
     return PackageSpec(
-        self._package_spec.api_version,
         self._package_spec.project_id,
         self._package_spec.recipes_path,
         new_deps)
@@ -521,8 +499,9 @@
 
 
 class PackageSpec(object):
-  def __init__(self, api_version, project_id, recipes_path, deps):
-    self._api_version = api_version
+  API_VERSION = 1
+
+  def __init__(self, project_id, recipes_path, deps):
     self._project_id = project_id
     self._recipes_path = recipes_path
     self._deps = deps
@@ -534,25 +513,25 @@
   @classmethod
   def load_proto(cls, proto_file):
     buf = proto_file.read()
-
-    deps = { pid: cls.spec_for_dep(pid, dep)
-             for pid, dep in buf.deps.iteritems() }
-    return cls(buf.api_version, str(buf.project_id), str(buf.recipes_path),
-               deps)
+    assert buf.api_version == cls.API_VERSION
+
+    deps = { str(dep.project_id): cls.spec_for_dep(dep)
+             for dep in buf.deps }
+    return cls(str(buf.project_id), str(buf.recipes_path), deps)
 
   @classmethod
-  def spec_for_dep(cls, project_id, dep):
+  def spec_for_dep(cls, dep):
     """Returns a RepoSpec for the given dependency protobuf."""
     url = str(dep.url)
     if url.startswith("file://"):
-      return PathRepoSpec(str(project_id), url[len("file://"):])
+      return PathRepoSpec(str(dep.project_id), url[len("file://"):])
 
     if dep.repo_type in (package_pb2.DepSpec.GIT, package_pb2.DepSpec.GITILES):
       if dep.repo_type == package_pb2.DepSpec.GIT:
         backend = fetch.GitBackend()
       elif dep.repo_type == package_pb2.DepSpec.GITILES:
         backend = fetch.GitilesBackend()
-      return GitRepoSpec(str(project_id),
+      return GitRepoSpec(str(dep.project_id),
                          url,
                          str(dep.branch),
                          str(dep.revision),
@@ -573,16 +552,12 @@
   def deps(self):
     return self._deps
 
-  @property
-  def api_version(self):
-    return self._api_version
-
   def dump(self):
     return package_pb2.Package(
-        api_version=self._api_version,
+        api_version=self.API_VERSION,
         project_id=self._project_id,
         recipes_path=self._recipes_path,
-        deps={k: v.dump() for k, v in self._deps.iteritems()})
+        deps=[ self._deps[dep].dump() for dep in sorted(self._deps.keys()) ])
 
   def roll_candidates(self, root_spec, context):
     """Returns list of consistent roll candidates, and rejected roll candidates.