First commit

core/json_io.py

@@ -0,0 +1,46 @@
+import functools
+import json
+import os
+import asyncio
+import logging
+from uuid import uuid4
+
+# This is basically our old DataIO, except that it's now threadsafe
+# and just a base for much more elaborate classes
+
+
+log = logging.getLogger("red")
+
+PRETTY = {"indent": 4, "sort_keys": True, "separators": (',', ' : ')}
+MINIFIED = {"sort_keys": True, "separators": (',', ':')}
+
+
+class JsonIO:
+    """Basic functions for atomic saving / loading of json files
+
+    This is inherited by the flusher and db helpers"""
+
+    def _save_json(self, path, data, settings=PRETTY):
+        log.debug("Saving file {}".format(path))
+        filename, _ = os.path.splitext(path)
+        tmp_file = "{}-{}.tmp".format(filename, uuid4().fields[0])
+        with open(tmp_file, encoding="utf-8", mode="w") as f:
+            json.dump(data, f, **settings)
+        os.replace(tmp_file, path)
+
+    async def _threadsafe_save_json(self, path, data, settings=PRETTY):
+        loop = asyncio.get_event_loop()
+        func = functools.partial(self._save_json, path, data, settings)
+        await loop.run_in_executor(None, func)
+
+    def _load_json(self, path):
+        log.debug("Reading file {}".format(path))
+        with open(path, encoding='utf-8', mode="r") as f:
+            data = json.load(f)
+        return data
+
+    async def _threadsafe_load_json(self, path):
+        loop = asyncio.get_event_loop()
+        func = functools.partial(self._load_json, path)
+        task = loop.run_in_executor(None, func)
+        return await asyncio.wait_for(task)