Cleanup

generator/vocabulary.py

@@ -2,12 +2,14 @@
 from __future__ import annotations
 import contextlib
 import contextvars
+import copy
 import dataclasses
+import fractions
 import functools
 import hashlib
 import json
 import pathlib
-import fractions
+import types
 
 ROOT = pathlib.Path(__file__).resolve().parents[1] / 'data' / 'composition'
 ACTIVE = contextvars.ContextVar('composition_vocabulary', default=None)
@@ -16,7 +18,7 @@ def load(root=ROOT):
   # Content, not just the directory, keys memoization. Long-lived individual
   # role builds must observe edited production data without restarting Python.
   names = ('roles', 'harmony', 'lead_ins', 'accompaniment')
-  return _load(tuple((name, (pathlib.Path(root) / (name + '.json')).read_text()) for name in names))
+  return copy.deepcopy(_load(tuple((name, (pathlib.Path(root) / (name + '.json')).read_text()) for name in names)))
 
 @functools.lru_cache(maxsize=16)
 def _load(contents):
@@ -105,26 +107,54 @@ def _load(contents):
 
 @functools.lru_cache(maxsize=1)
 def _default():
-  return {'data': load(), 'role': '', 'settings': {}}
+  return CompositionContext.create(load())
+
+def _freeze(value):
+  if isinstance(value, dict):
+    return types.MappingProxyType({key: _freeze(item) for key, item in value.items()})
+  if isinstance(value, list):
+    return tuple(_freeze(item) for item in value)
+  return value
+
+@functools.lru_cache(maxsize=32)
+def _frozen_json(contents):
+  return _freeze(json.loads(contents))
+
+@dataclasses.dataclass(frozen=True)
+class CompositionContext:
+  """Owned, immutable, pickleable policy inputs with stable iteration order."""
+  resources_json: str
+  name: str = ''
+  settings_json: str = '{}'
+  @classmethod
+  def create(cls, resources, name='', settings=None):
+    return cls(json.dumps(resources), name, json.dumps(settings or {}))
+  def data(self, name):
+    return _frozen_json(self.resources_json)[name]
+  def role(self, name=None):
+    return {**self.data('roles')['roles'].get(name or self.name, {}), **_frozen_json(self.settings_json)}
+  def accompaniment(self, part):
+    value = self.data('accompaniment')
+    return {**{key: item for key, item in value.items() if key != 'instruments'}, **value['instruments'][part]}
 
 def current():
   return ACTIVE.get() or _default()
 
 def data(name):
-  return current()['data'][name]
+  return current().data(name)
 
 def accompaniment(part, resources=None):
-  value = (resources or current()['data'])['accompaniment']
+  if resources is None:
+    return current().accompaniment(part)
+  value = resources['accompaniment']
   return {**{k: v for k, v in value.items() if k != 'instruments'}, **value['instruments'][part]}
 
 def role(name=None):
-  active = current()
-  name = name or active['role']
-  return {**active['data']['roles']['roles'].get(name, {}), **active['settings']}
+  return current().role(name)
 
 @contextlib.contextmanager
 def using(resources, name, settings=None):
-  token = ACTIVE.set({'data': resources, 'role': name, 'settings': settings or {}})
+  token = ACTIVE.set(CompositionContext.create(resources, name, settings))
   try:
     yield
   finally: