Karlburke/stash large descendants resp in s3

entity-api-spec.yaml

@@ -324,7 +324,7 @@ components:
           properties:
             organ_donor_data:
               type: array
-              description: "Information about the donor who's organ(s) was/were used.  The organ was obtained via an organ donation program from a deceaced donor. Only living_donor_data or organ_donor_data, not both can be defined for a single donor."
+              description: "Information about the donor who's organ(s) was/were used.  The organ was obtained via an organ donation program from a deceased donor. Only living_donor_data or organ_donor_data, not both can be defined for a single donor."
               items:
                 $ref: '#/components/schemas/DonorMetadata'
             living_donor_data:
@@ -2100,6 +2100,8 @@ paths:
               examples:
                 ancestorsarray:
                   $ref: '#/components/examples/DatasetArrayExample'
+        '303':
+          description: If the total response payload exceeds 10 MB, the response is returned via an S3 bucket.  A 303 HTTP response code will be returned with the redirect URL where the query can be retrieved.
         '400':
           description: Invalid or misformatted entity identifier
         '401':

src/app.py

@@ -1664,6 +1664,8 @@ def get_ancestors(id):
 """
 @app.route('/descendants/<id>', methods = ['GET'])
 def get_descendants(id):
+    global anS3Worker
+
     final_result = []
 
     # Get user token from Authorization header
@@ -1718,6 +1720,25 @@ def get_descendants(id):
         # Final result after normalization
         final_result = schema_manager.normalize_entities_list_for_response(complete_entities_list)
 
+    # Check the size of what is to be returned through the AWS Gateway, and replace it with
+    # a response that links to an Object in the AWS S3 Bucket, if appropriate.
+    try:
+        resp_body = json.dumps(final_result).encode('utf-8')
+        s3_url = anS3Worker.stash_response_body_if_big(resp_body)
+        if s3_url is not None:
+            return Response(response=s3_url
+                            , status=303)  # See Other
+        # The HuBMAP Commons S3Worker will return None for a URL when the response body is
+        # smaller than it is configured to store, so the response should be returned through
+        # the AWS Gateway
+    except Exception as s3exception:
+        logger.error(f"Error using anS3Worker to handle len(resp_body)="
+                     f"{len(resp_body)}.")
+        logger.error(s3exception, exc_info=True)
+        return Response(response=f"Unexpected error storing large results in S3. See logs."
+                        , status=500)
+
+    # Return a regular response through the AWS Gateway
     return jsonify(final_result)