Experiment with adding a JSON serializer

1 files changed, 78 insertions, 0 deletions

diff --git a/requests_cache/serializers/json.py b/requests_cache/serializers/json.py
new file mode 100644
index 0000000..cc2975e
--- /dev/null
+++ b/requests_cache/serializers/json.py
@@ -0,0 +1,78 @@
+# TODO: Handle CachedHTTPResponse, PreparedRequest, RequestsCookieJar, CachedResponse (history)
+import json
+from base64 import b64decode, b64encode
+from datetime import datetime, timedelta
+from json import JSONDecoder, JSONEncoder
+from typing import Union
+
+from requests.cookies import RequestsCookieJar, cookiejar_from_dict
+from requests.structures import CaseInsensitiveDict
+
+from ..response import CachedResponse
+
+
+class ResponseJSONSerializer:
+    def dumps(self, response: CachedResponse) -> str:
+        """Serialize a CachedResponse into JSON"""
+        return json.dumps(response.to_dict(), cls=ResponseJSONEncoder, indent=2)
+
+    def loads(self, obj: str) -> CachedResponse:
+        """Deserialize a CachedResponse from JSON"""
+        response = json.loads(obj, cls=ResponseJSONDecoder)
+
+        response['_content'] = b64decode(response['_content'].encode())
+        response['_raw_response_attrs'] = response.pop('raw')
+        response['_request_attrs'] = response.pop('request')
+        response['cookies'] = cookiejar_from_dict(response.get('cookies', {}))
+        response['headers'] = CaseInsensitiveDict(response.get('headers', {}))
+        response['history'] = [self.loads(redirect) for redirect in response.get('history', [])]
+
+        return CachedResponse(**response)
+
+
+class ResponseJSONEncoder(JSONEncoder):
+    """Serialize a CachedResponse as JSON"""
+
+    def default(self, obj):
+        if isinstance(obj, bytes):
+            return b64encode(obj).decode()
+        if isinstance(obj, datetime):
+            return obj.isoformat()
+        elif isinstance(obj, RequestsCookieJar):
+            return dict(obj)
+        # elif isinstance(obj, CookieJar):
+        #     cookies = RequestsCookieJar()
+        #     cookies.update(obj)
+        #     return dict(cookies)
+        elif isinstance(obj, timedelta):
+            return {
+                '__type__': 'timedelta',
+                'days': obj.days,
+                'seconds': obj.seconds,
+                'microseconds': obj.microseconds,
+            }
+        return super().default(obj)
+
+
+class ResponseJSONDecoder(JSONDecoder):
+    """Deserialize a CachedResponse from JSON"""
+
+    def __init__(self, **kwargs):
+        super().__init__(object_hook=self.object_hook, **kwargs)
+
+    def object_hook(self, obj):
+        """Check for and handle custom types before they get deserialized by JSONDecoder"""
+        if isinstance(obj, str):
+            return try_parse_isoformat(obj)
+        elif isinstance(obj, dict) and obj.get('__type__', None) == 'timedelta':
+            obj.pop('__type__')
+            return timedelta(**obj)
+        return obj
+
+
+def try_parse_isoformat(obj: str) -> Union[datetime, str]:
+    """Attempt to parse an ISO-formatted datetime string; if it fails, just return the string"""
+    try:
+        return datetime.fromisoformat(obj)
+    except (AttributeError, TypeError, ValueError):
+        return obj