API: compress call parameters to reduce rule size

api.py

@@ -1,10 +1,12 @@
 #!/usr/bin/env python3
 
-__copyright__ = 'Copyright (c) 2021-2022, Utrecht University'
+__copyright__ = 'Copyright (c) 2021-2023, Utrecht University'
 __license__   = 'GPLv3, see LICENSE'
 
+import base64
 import json
 import sys
+import zlib
 from timeit import default_timer as timer
 from typing import Any, Dict, Optional
 
@@ -52,7 +54,7 @@ def break_strings(N: int, m: int) -> int:
         return (N - 1) // m + 1
 
     def nrep_string_expr(s: str, m: int = 64) -> str:
-        return ' ++\n'.join('"{}"'.format(escape_quotes(s[i * m:i * m + m])) for i in range(break_strings(len(s), m) + 1))
+        return '++\n'.join('"{}"'.format(escape_quotes(s[i * m:i * m + m])) for i in range(break_strings(len(s), m) + 1))
 
     if app.config.get('LOG_API_CALL_DURATION', False):
         begintime = timer()
@@ -61,7 +63,11 @@ def nrep_string_expr(s: str, m: int = 64) -> str:
         data = {}
 
     params = json.dumps(data)
-    arg_str_expr = nrep_string_expr(params)
+
+    # Compress params and encode as base64 to reduce size (max rule length in iRODS is 20KB)
+    compressed_params = zlib.compress(params.encode())
+    base64_encoded_params = base64.b64encode(compressed_params)
+    arg_str_expr = nrep_string_expr(base64_encoded_params.decode('utf-8'))
 
     # Set parameters as variable instead of parameter input to circumvent iRODS string limits.
     rule_body = ''' *x={}