chore: Updated change log and readme (#194)

Author: mnoman09

CHANGELOG.md

@@ -1,3 +1,23 @@
+# Optimizely C# SDK Changelog
+
+## 3.3.0
+September 26th, 2019
+
+### New Features:
+- Configuration manager is set to PollingProjectConfigManager and for datafile will be started by default. Requests to download and update datafile are made in a separate thread and are scheduled with fixed delay.
+- Added support for event batching via the event processor.
+- Events generated by methods like `Activate`, `Track`, and `IsFeatureEnabled` will be held in a queue until the configured batch size is reached, or the configured flush interval has elapsed. Then, they will be combined into a request and sent to the event dispatcher.
+- To configure event batching, set the `MaxEventBatchSize` and `MaxEventFlushInterval` properties in the `OptimizelyFactory` using `OptimizelyFactory.SetBatchSize(int batchSize)` and `OptimizelyFactory.SetFlushInterval(TimeSpan flushInterval)` and then creating using `OptimizelyFactory.NewDefaultInstance`.
+- Event batching is enabled by default. `eventBatchSize` defaults to `10`. `eventFlushInterval` defaults to `30000` milliseconds.
+- Updated the `Dispose` method representing the process of closing the instance. When `Dispose` is called, any events waiting to be sent as part of a batched event request will be immediately batched and sent to the event dispatcher.
+- If any such requests were sent to the event dispatcher, `Stop` waits for provided `TimeoutInterval` before stoping, so that events get successfully dispatched.
+- `OptimizelyFactory` now provides support of setting configuration variables from ***App.config***, User will now be able to provide configuration variables of `HttpConfigManager` and `BatchEventProcessor` in ***App.config***. Steps of usage are provided in [README.md](https://github.com/optimizely/csharp-sdk#using-appconfig-in-optimizelyfactory).
+
+### Deprecated
+- `EventBuilder` was deprecated and now we will be using `UserEventFactory` and `EventFactory` to create LogEvent Object.
+- Deprecated `Track` notifications in favor of explicit `LogEvent` notification.
+- New features will no longer be supported on `.net standard 1.6` and `.net 3.5`
+
 ## 3.2.0
 July 22nd, 2019
 

README.md

@@ -68,7 +68,7 @@ The Optimizely client object accepts the following plug-ins:
 2. `ILogger` exposes a single method, Log, to record activity in the SDK.  An example of a class to bridge the SDK's Log to Log4Net is provided in the Demo Application.
 3. `IErrorHandler` allows you to implement custom logic when Exceptions are thrown.  Note that Exception information is already included in the Log.
 4. `ProjectConfigManager` exposes method for retrieving ProjectConfig instance. Examples include `FallbackProjectConfigManager` and `HttpProjectConfigManager`.
-
+5. `EventProcessor` provides an intermediary processing stage within event production. It's assumed that the EventProcessor dispatches events via a provided EventDispatcher. Examples include `ForwardingEventProcessor` and `BatchEventProcessor`.
 These are optional plug-ins and default behavior is implement if none are provided.
 
 #### OptimizelyFactory
@@ -127,6 +127,37 @@ User can provide variables using following procedure:
 Optimizely optimizely = OptimizelyFactory.newDefaultInstance();
 ```
 
+#### BatchEventProcessor
+[BatchEventProcessor](https://github.com/optimizely/csharp-sdk/blob/master/OptimizelySDK/Event/BatchEventProcessor.cs) is a batched implementation of the [EventProcessor](https://github.com/optimizely/csharp-sdk/blob/master/OptimizelySDK/Event/EventProcessor.cs)
+     * Events passed to the BatchEventProcessor are immediately added to a BlockingQueue.
+     * The BatchEventProcessor maintains a single consumer thread that pulls events off of the BlockingQueue and buffers them for either a configured batch size or for a maximum duration before the resulting LogEvent is sent to the NotificationManager.
+##### Use BatchEventProcessor
+
+```
+EventProcessor eventProcessor = new BatchEventProcessor.Builder()
+                .WithMaxBatchSize(MaxEventBatchSize)
+                .WithFlushInterval(MaxEventFlushInterval)
+                .WithEventDispatcher(eventDispatcher)
+                .WithNotificationCenter(notificationCenter)
+                .Build();
+```
+
+##### Max Event Batch Size
+
+The Max event batch size is used to limit eventQueue batch size and events will be dispatched when limit reaches.
+
+##### Flush Interval
+
+The FlushInterval is used to specify a delay between consecutive flush events call. Event batch will be dispatched after meeting this specified timeSpan.
+
+##### Event Dispatcher 
+
+Custom EventDispatcher can be passed.
+
+##### Notification Center
+
+Custom NotificationCenter can be passed. 
+
 #### HttpProjectConfigManager
 
 [`HttpProjectConfigManager`](https://github.com/optimizely/csharp-sdk/blob/master/OptimizelySDK/Config/HttpProjectConfigManager.cs)