Speed up language def loading.

lute/language/service.py

@@ -8,49 +8,79 @@
 from lute.book.model import Book, Repository
 
 
-class Service:
-    "Service."
+class LangDef:
+    "Language, built from language definition.yml, and .txt book files."
 
-    def __init__(self, session):
-        self.session = session
+    def __init__(self, directory):
+        "Build from files."
+        self.language = self._load_lang_def(directory)
+        self.books = self._get_books(directory, self.language.name)
 
-    def get_supported_defs(self):
-        "Return supported language definitions."
-        ret = []
-        def_glob = os.path.join(self._language_defs_path(), "**", "definition.yaml")
-        for f in glob(def_glob):
-            lang = None
-            with open(f, "r", encoding="utf-8") as df:
-                d = yaml.safe_load(df)
-                lang = Language.from_dict(d)
-            if lang.is_supported:
-                entry = {"language": lang, "books": self._get_books(f, lang.name)}
-                ret.append(entry)
-        ret.sort(key=lambda x: x["language"].name)
-        return ret
+    def _load_lang_def(self, directory):
+        "Load from file, must exist."
+        def_file = os.path.join(directory, "definition.yaml")
+        with open(def_file, "r", encoding="utf-8") as df:
+            d = yaml.safe_load(df)
+            return Language.from_dict(d)
 
-    def predefined_languages(self):
-        "Languages defined in yaml files."
-        return [d["language"] for d in self.get_supported_defs()]
-
-    def _get_books(self, lang_definition_filename, lang_name):
-        "Get the stories in the same directory as the definition.yaml."
+    def _get_books(self, directory, language_name):
+        "Get the stories."
         books = []
-        d, f = os.path.split(lang_definition_filename)
-        story_glob = os.path.join(d, "*.txt")
+        story_glob = os.path.join(directory, "*.txt")
         for filename in glob(story_glob):
             with open(filename, "r", encoding="utf-8") as f:
                 content = f.read()
             title_match = re.search(r"title:\s*(.*)\n", content)
             title = title_match.group(1).strip()
             content = re.sub(r"#.*\n", "", content)
             b = Book()
-            b.language_name = lang_name
+            b.language_name = language_name
             b.title = title
             b.text = content
             books.append(b)
         return books
 
+
+class Service:
+    "Service."
+
+    def __init__(self, session):
+        self.session = session
+        self.language_from_lang_defs_cache = None
+
+    def _language_defs_path(self):
+        "Path to the definitions and stories."
+        thisdir = os.path.dirname(__file__)
+        d = os.path.join(thisdir, "..", "db", "language_defs")
+        return os.path.abspath(d)
+
+    def _load_lang_defs_cache(self):
+        "Cache Languages build from lang defs."
+        if self.language_from_lang_defs_cache is not None:
+            return
+        cache = {}
+        def_glob = os.path.join(self._language_defs_path(), "**", "definition.yaml")
+        for f in glob(def_glob):
+            lang_dir, def_yaml = os.path.split(f)
+            ld = LangDef(lang_dir)
+            cache[ld.language.name] = ld
+        self.language_from_lang_defs_cache = cache
+
+    def get_supported_defs(self):
+        "Return supported language definitions."
+        self._load_lang_defs_cache()
+        ret = [
+            {"language": ld.language, "books": ld.books}
+            for _, ld in self.language_from_lang_defs_cache.items()
+            if ld.language.is_supported
+        ]
+        ret.sort(key=lambda x: x["language"].name)
+        return ret
+
+    def predefined_languages(self):
+        "Languages defined in yaml files."
+        return [d["language"] for d in self.get_supported_defs()]
+
     def get_language_def(self, lang_name):
         "Get a lang def and its stories."
         defs = self.get_supported_defs()
@@ -72,9 +102,3 @@ def load_language_def(self, lang_name):
         r.commit()
 
         return lang.id
-
-    def _language_defs_path(self):
-        "Path to the definitions and stories."
-        thisdir = os.path.dirname(__file__)
-        d = os.path.join(thisdir, "..", "db", "language_defs")
-        return os.path.abspath(d)