feat(trigger): Some attribte caching

Author: Michael Brewer

aws_lambda_powertools/utilities/trigger/cloud_watch_logs_event.py

@@ -1,7 +1,7 @@
 import base64
 import json
 import zlib
-from typing import Dict, List, Optional
+from typing import Any, Dict, List, Optional
 
 from aws_lambda_powertools.utilities.trigger.common import DictWrapper
 
@@ -78,17 +78,26 @@ class CloudWatchLogsEvent(dict):
     - https://docs.aws.amazon.com/lambda/latest/dg/services-cloudwatchlogs.html
     """
 
+    def __init__(self, event: Dict[str, Any]):
+        super().__init__(event)
+        self._decompressed_logs_data = None
+        self._json_logs_data = None
+
     @property
-    def aws_logs_data(self) -> str:
+    def raw_logs_data(self) -> str:
         """The value of the `data` field is a Base64 encoded ZIP archive."""
         return self["awslogs"]["data"]
 
     @property
     def decompress_logs_data(self) -> bytes:
         """Decode and decompress log data"""
-        payload = base64.b64decode(self.aws_logs_data)
-        return zlib.decompress(payload, zlib.MAX_WBITS | 32)
+        if self._decompressed_logs_data is None:
+            payload = base64.b64decode(self.raw_logs_data)
+            self._decompressed_logs_data = zlib.decompress(payload, zlib.MAX_WBITS | 32)
+        return self._decompressed_logs_data
 
     def parse_logs_data(self) -> CloudWatchLogsDecodedData:
         """Decode, decompress and parse json data as CloudWatchLogsDecodedData"""
-        return CloudWatchLogsDecodedData(json.loads(self.decompress_logs_data.decode("UTF-8")))
+        if self._json_logs_data is None:
+            self._json_logs_data = json.loads(self.decompress_logs_data.decode("UTF-8"))
+        return CloudWatchLogsDecodedData(self._json_logs_data)

tests/functional/test_lambda_trigger_events.py

@@ -42,15 +42,19 @@ def load_event(file_name: str) -> dict:
 def test_cloud_watch_trigger_event():
     event = CloudWatchLogsEvent(load_event("cloudWatchLogEvent.json"))
 
-    decoded_data = event.parse_logs_data()
-    log_events = decoded_data.log_events
+    decompressed_logs_data = event.decompress_logs_data
+    assert event.decompress_logs_data == decompressed_logs_data
+
+    json_logs_data = event.parse_logs_data()
+    assert event.parse_logs_data() == json_logs_data
+    log_events = json_logs_data.log_events
     log_event = log_events[0]
 
-    assert decoded_data.owner == "123456789123"
-    assert decoded_data.log_group == "testLogGroup"
-    assert decoded_data.log_stream == "testLogStream"
-    assert decoded_data.subscription_filters == ["testFilter"]
-    assert decoded_data.message_type == "DATA_MESSAGE"
+    assert json_logs_data.owner == "123456789123"
+    assert json_logs_data.log_group == "testLogGroup"
+    assert json_logs_data.log_stream == "testLogStream"
+    assert json_logs_data.subscription_filters == ["testFilter"]
+    assert json_logs_data.message_type == "DATA_MESSAGE"
 
     assert log_event.get_id == "eventId1"
     assert log_event.timestamp == 1440442987000