From 6f2b5ce6d8d8e51e3b85ded59ad7ff7ae5f235c3 Mon Sep 17 00:00:00 2001
From: Christopher Sande <christopher.sande@canvasmedical.com>
Date: Wed, 29 Jan 2025 11:36:51 -0600
Subject: [PATCH] Http helper method to execute HTTP requests in parallel

---
 canvas_sdk/utils/http.py | 60 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 58 insertions(+), 2 deletions(-)

diff --git a/canvas_sdk/utils/http.py b/canvas_sdk/utils/http.py
index 7e374a7b..d4cb148d 100644
--- a/canvas_sdk/utils/http.py
+++ b/canvas_sdk/utils/http.py
@@ -1,7 +1,10 @@
+import concurrent
+import functools
 import time
-from collections.abc import Callable, Mapping
+from collections.abc import Callable, Iterable, Mapping
+from concurrent.futures import ThreadPoolExecutor
 from functools import wraps
-from typing import Any, TypeVar, cast
+from typing import Any, Literal, TypeVar, cast
 
 import requests
 import statsd
@@ -9,6 +12,38 @@
 F = TypeVar("F", bound=Callable)
 
 
+class BatchedRequest:
+    """Representation of a request that will be executed in parallel with other requests."""
+
+    def __init__(
+        self, method: Literal["GET", "POST", "PUT", "PATCH"], url: str, *args: Any, **kwargs: Any
+    ) -> None:
+        self._method = method
+        self._url = url
+        self._args = args
+        self._kwargs = kwargs
+
+    def fn(self, session: requests.Session) -> Callable:
+        """
+        Return a callable constructed from the session object, method, URL, args, and kwargs.
+
+        This callable is passed to the ThreadPoolExecutor.
+        """
+        match self._method:
+            case "GET":
+                instance_method = session.get
+            case "POST":
+                instance_method = session.post
+            case "PUT":
+                instance_method = session.put
+            case "PATCH":
+                instance_method = session.patch
+            case _:
+                raise RuntimeError(f"HTTP method {self._method} is not supported")
+
+        return functools.partial(instance_method, self._url, *self._args, **self._kwargs)
+
+
 class Http:
     """A helper class for completing HTTP calls with metrics tracking."""
 
@@ -72,3 +107,24 @@ def patch(
     ) -> requests.Response:
         """Sends a PATCH request."""
         return self.session.patch(url, json=json, data=data, headers=headers)
+
+    def batch_requests(
+        self,
+        batched_requests: Iterable[BatchedRequest],
+        max_workers: int | None = None,
+        timeout: int | None = None,
+    ) -> list[requests.Response]:
+        """
+        Execute requests in parallel.
+
+        Wait for the responses to complete, and then return a list of the responses.
+        """
+        futures = []
+        with ThreadPoolExecutor(max_workers=max_workers) as executor:
+            for request in batched_requests:
+                futures.append(executor.submit(request.fn(self.session)))
+
+            # TODO: Is there a need to expose return_when or specify a different default value? https://docs.python.org/3.12/library/concurrent.futures.html#concurrent.futures.wait
+            concurrent.futures.wait(futures, timeout=timeout)
+
+        return [future.result() for future in futures]