feat: Add option to enable event payload compression (#300)

contract-tests/client_entity.py

@@ -41,6 +41,7 @@ def __init__(self, tag, config):
 
         if config.get("events") is not None:
             events = config["events"]
+            opts["enable_event_compression"] = events.get("enableGzip", False)
             if events.get("baseUri") is not None:
                 opts["events_uri"] = events["baseUri"]
             if events.get("capacity") is not None:

contract-tests/service.py

@@ -70,6 +70,8 @@ def status():
             'secure-mode-hash',
             'tags',
             'migrations',
+            'event-gzip',
+            'optional-event-gzip',
             'event-sampling',
             'polling-gzip',
             'inline-context',

ldclient/config.py

@@ -175,7 +175,8 @@ def __init__(self,
                  http: HTTPConfig=HTTPConfig(),
                  big_segments: Optional[BigSegmentsConfig]=None,
                  application: Optional[dict]=None,
-                 hooks: Optional[List[Hook]]=None):
+                 hooks: Optional[List[Hook]]=None,
+                 enable_event_compression: bool=False):
         """
         :param sdk_key: The SDK key for your LaunchDarkly account. This is always required.
         :param base_uri: The base URL for the LaunchDarkly server. Most users should use the default
@@ -241,6 +242,7 @@ def __init__(self,
           :class:`HTTPConfig`.
         :param application: Optional properties for setting application metadata. See :py:attr:`~application`
         :param hooks: Hooks provide entrypoints which allow for observation of SDK functions.
+        :param enable_event_compression: Whether or not to enable GZIP compression for outgoing events.
         """
         self.__sdk_key = sdk_key
 
@@ -274,6 +276,7 @@ def __init__(self,
         self.__big_segments = BigSegmentsConfig() if not big_segments else big_segments
         self.__application = validate_application_info(application or {}, log)
         self.__hooks = [hook for hook in hooks if isinstance(hook, Hook)] if hooks else []
+        self.__enable_event_compression = enable_event_compression
         self._data_source_update_sink: Optional[DataSourceUpdateSink] = None
 
     def copy_with_new_sdk_key(self, new_sdk_key: str) -> 'Config':
@@ -459,6 +462,10 @@ def hooks(self) -> List[Hook]:
         """
         return self.__hooks
 
+    @property
+    def enable_event_compression(self) -> bool:
+        return self.__enable_event_compression
+
     @property
     def data_source_update_sink(self) -> Optional[DataSourceUpdateSink]:
         """

ldclient/impl/events/event_processor.py

@@ -12,6 +12,7 @@
 import uuid
 import queue
 import urllib3
+import gzip
 from ldclient.config import Config
 from datetime import timedelta
 from random import Random
@@ -559,19 +560,23 @@ def _post_events_with_retry(
 ):
     hdrs = _headers(config)
     hdrs['Content-Type'] = 'application/json'
+    if config.enable_event_compression:
+        hdrs['Content-Encoding'] = 'gzip'
+
     if payload_id:
         hdrs['X-LaunchDarkly-Event-Schema'] = str(__CURRENT_EVENT_SCHEMA__)
         hdrs['X-LaunchDarkly-Payload-ID'] = payload_id
     can_retry = True
     context = "posting %s" % events_description
+    data = gzip.compress(bytes(body, 'utf-8')) if config.enable_event_compression else body
     while True:
         next_action_message = "will retry" if can_retry else "some events were dropped"
         try:
             r = http_client.request(
                 'POST',
                 uri,
                 headers=hdrs,
-                body=body,
+                body=data,
                 timeout=urllib3.Timeout(connect=config.http.connect_timeout, read=config.http.read_timeout),
                 retries=0
             )