Merge pull request #508 from supertokens/adds-caching-to-querier

adds caching for querier

Author: rishabhpoddar

CHANGELOG.md

@@ -8,6 +8,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [unreleased]
 
+## [0.22.0] - 2024-06-05
+- Adds caching per API based on user context.
+
+### Breaking change:
+- Changes general error in querier to normal python error.
+
 ## [0.21.0] - 2024-05-23
 
 ### Breaking change

setup.py

@@ -83,7 +83,7 @@
 
 setup(
     name="supertokens_python",
-    version="0.21.0",
+    version="0.22.0",
     author="SuperTokens",
     license="Apache 2.0",
     author_email="[email protected]",

supertokens_python/constants.py

@@ -14,7 +14,7 @@
 from __future__ import annotations
 
 SUPPORTED_CDI_VERSIONS = ["3.0"]
-VERSION = "0.21.0"
+VERSION = "0.22.0"
 TELEMETRY = "/telemetry"
 USER_COUNT = "/users/count"
 USER_DELETE = "/user/remove"

supertokens_python/querier.py

@@ -35,11 +35,11 @@
 
 from typing import List, Set, Union
 
-from .exceptions import raise_general_exception
 from .process_state import AllowedProcessStates, ProcessState
 from .utils import find_max_version, is_4xx_error, is_5xx_error
 from sniffio import AsyncLibraryNotFoundError
 from supertokens_python.async_to_sync_wrapper import create_or_get_event_loop
+from supertokens_python.utils import get_timestamp_ms
 
 
 class Querier:
@@ -68,10 +68,13 @@ class Querier:
             ],
         ]
     ] = None
+    __global_cache_tag = get_timestamp_ms()
+    __disable_cache = False
 
     def __init__(self, hosts: List[Host], rid_to_core: Union[None, str] = None):
         self.__hosts = hosts
         self.__rid_to_core = None
+        self.__global_cache_tag = get_timestamp_ms()
         if rid_to_core is not None:
             self.__rid_to_core = rid_to_core
 
@@ -80,15 +83,15 @@ def reset():
         if ("SUPERTOKENS_ENV" not in environ) or (
             environ["SUPERTOKENS_ENV"] != "testing"
         ):
-            raise_general_exception("calling testing function in non testing env")
+            raise Exception("calling testing function in non testing env")
         Querier.__init_called = False
 
     @staticmethod
     def get_hosts_alive_for_testing():
         if ("SUPERTOKENS_ENV" not in environ) or (
             environ["SUPERTOKENS_ENV"] != "testing"
         ):
-            raise_general_exception("calling testing function in non testing env")
+            raise Exception("calling testing function in non testing env")
         return Querier.__hosts_alive_for_testing
 
     async def api_request(
@@ -100,7 +103,7 @@ async def api_request(
         **kwargs: Any,
     ) -> Response:
         if attempts_remaining == 0:
-            raise_general_exception("Retry request failed")
+            raise Exception("Retry request failed")
 
         try:
             async with AsyncClient() as client:
@@ -141,7 +144,7 @@ async def f(url: str, method: str) -> Response:
         api_version = find_max_version(cdi_supported_by_server, SUPPORTED_CDI_VERSIONS)
 
         if api_version is None:
-            raise_general_exception(
+            raise Exception(
                 "The running SuperTokens core version is not compatible with this python "
                 "SDK. Please visit https://supertokens.io/docs/community/compatibility-table "
                 "to find the right versions"
@@ -152,7 +155,7 @@ async def f(url: str, method: str) -> Response:
 
     @staticmethod
     def get_instance(rid_to_core: Union[str, None] = None):
-        if (not Querier.__init_called) or (Querier.__hosts is None):
+        if not Querier.__init_called:
             raise Exception(
                 "Please call the supertokens.init function before using SuperTokens"
             )
@@ -181,6 +184,7 @@ def init(
                 ],
             ]
         ] = None,
+        disable_cache: bool = False,
     ):
         if not Querier.__init_called:
             Querier.__init_called = True
@@ -190,6 +194,7 @@ def init(
             Querier.__last_tried_index = 0
             Querier.__hosts_alive_for_testing = set()
             Querier.network_interceptor = network_interceptor
+            Querier.__disable_cache = disable_cache
 
     async def __get_headers_with_api_version(self, path: NormalisedURLPath):
         headers = {API_VERSION_HEADER: await self.get_api_version()}
@@ -211,6 +216,41 @@ async def send_get_request(
         async def f(url: str, method: str) -> Response:
             headers = await self.__get_headers_with_api_version(path)
             nonlocal params
+
+            assert params is not None
+
+            # Sort the keys for deterministic order
+            sorted_keys = sorted(params.keys())
+            sorted_header_keys = sorted(headers.keys())
+
+            # Start with the path as the unique key
+            unique_key = path.get_as_string_dangerous()
+
+            # Append sorted params to the unique key
+            for key in sorted_keys:
+                value = params[key]
+                unique_key += f";{key}={value}"
+
+            # Append a separator for headers
+            unique_key += ";hdrs"
+
+            # Append sorted headers to the unique key
+            for key in sorted_header_keys:
+                value = headers[key]
+                unique_key += f";{key}={value}"
+
+            if user_context is not None:
+                if (
+                    user_context.get("_default", {}).get("global_cache_tag", -1)
+                    != self.__global_cache_tag
+                ):
+                    self.invalidate_core_call_cache(user_context, False)
+
+                if not Querier.__disable_cache and unique_key in user_context.get(
+                    "_default", {}
+                ).get("core_call_cache", {}):
+                    return user_context["_default"]["core_call_cache"][unique_key]
+
             if Querier.network_interceptor is not None:
                 (
                     url,
@@ -222,14 +262,30 @@ async def f(url: str, method: str) -> Response:
                     url, method, headers, params, {}, user_context
                 )
 
-            return await self.api_request(
+            response = await self.api_request(
                 url,
                 method,
                 2,
                 headers=headers,
                 params=params,
             )
 
+            if (
+                response.status_code == 200
+                and not Querier.__disable_cache
+                and user_context is not None
+            ):
+                user_context["_default"] = {
+                    **user_context.get("_default", {}),
+                    "core_call_cache": {
+                        **user_context.get("_default", {}).get("core_call_cache", {}),
+                        unique_key: response,
+                    },
+                    "global_cache_tag": self.__global_cache_tag,
+                }
+
+            return response
+
         return await self.__send_request_helper(path, "GET", f, len(self.__hosts))
 
     async def send_post_request(
@@ -239,6 +295,7 @@ async def send_post_request(
         user_context: Union[Dict[str, Any], None],
         test: bool = False,
     ) -> Dict[str, Any]:
+        self.invalidate_core_call_cache(user_context)
         if data is None:
             data = {}
 
@@ -280,6 +337,8 @@ async def send_delete_request(
         params: Union[Dict[str, Any], None],
         user_context: Union[Dict[str, Any], None],
     ) -> Dict[str, Any]:
+        if user_context is not None:
+            self.invalidate_core_call_cache(user_context)
         if params is None:
             params = {}
 
@@ -312,6 +371,7 @@ async def send_put_request(
         data: Union[Dict[str, Any], None],
         user_context: Union[Dict[str, Any], None],
     ) -> Dict[str, Any]:
+        self.invalidate_core_call_cache(user_context)
         if data is None:
             data = {}
 
@@ -334,10 +394,29 @@ async def f(url: str, method: str) -> Response:
 
         return await self.__send_request_helper(path, "PUT", f, len(self.__hosts))
 
-    def get_all_core_urls_for_path(self, path: str) -> List[str]:
-        if self.__hosts is None:
-            return []
+    def invalidate_core_call_cache(
+        self,
+        user_context: Union[Dict[str, Any], None],
+        upd_global_cache_tag_if_necessary: bool = True,
+    ):
+        if user_context is None:
+            # this is done so that the code below runs as expected.
+            # It will reset the __global_cache_tag if needed, and the
+            # stuff we assign to the user_context will just be ignored (as expected)
+            user_context = {}
+
+        if upd_global_cache_tag_if_necessary and (
+            user_context.get("_default", {}).get("keep_cache_alive", False) is not True
+        ):
+            # there can be race conditions here, but i think we can ignore them.
+            self.__global_cache_tag = get_timestamp_ms()
 
+        user_context["_default"] = {
+            **user_context.get("_default", {}),
+            "core_call_cache": {},
+        }
+
+    def get_all_core_urls_for_path(self, path: str) -> List[str]:
         normalized_path = NormalisedURLPath(path)
 
         result: List[str] = []
@@ -362,7 +441,7 @@ async def __send_request_helper(
         retry_info_map: Optional[Dict[str, int]] = None,
     ) -> Dict[str, Any]:
         if no_of_tries == 0:
-            raise_general_exception("No SuperTokens core available to query")
+            raise Exception("No SuperTokens core available to query")
 
         try:
             current_host_domain = self.__hosts[
@@ -408,7 +487,7 @@ async def __send_request_helper(
                     )
 
             if is_4xx_error(response.status_code) or is_5xx_error(response.status_code):  # type: ignore
-                raise_general_exception(
+                raise Exception(
                     "SuperTokens core threw an error for a "
                     + method
                     + " request to path: "
@@ -432,5 +511,3 @@ async def __send_request_helper(
             return await self.__send_request_helper(
                 path, method, http_function, no_of_tries - 1, retry_info_map
             )
-        except Exception as e:
-            raise_general_exception(e)

supertokens_python/supertokens.py

@@ -86,10 +86,12 @@ def __init__(
                 ],
             ]
         ] = None,
+        disable_core_call_cache: bool = False,
     ):  # We keep this = None here because this is directly used by the user.
         self.connection_uri = connection_uri
         self.api_key = api_key
         self.network_interceptor = network_interceptor
+        self.disable_core_call_cache = disable_core_call_cache
 
 
 class Host:
@@ -243,7 +245,10 @@ def __init__(
             )
         )
         Querier.init(
-            hosts, supertokens_config.api_key, supertokens_config.network_interceptor
+            hosts,
+            supertokens_config.api_key,
+            supertokens_config.network_interceptor,
+            supertokens_config.disable_core_call_cache,
         )
 
         if len(recipe_list) == 0:

supertokens_python/utils.py

@@ -250,6 +250,7 @@ def set_request_in_user_context_if_not_defined(
 
     if isinstance(user_context["_default"], dict):
         user_context["_default"]["request"] = request
+        user_context["_default"]["keep_cache_alive"] = True
 
     return user_context