Additional docs for RequestContext

Hummingbird.docc/Articles/RequestContexts.md

@@ -56,6 +56,10 @@ struct MyRequestContext: RequestContext {
 }
 ```
 
+### Limiting memory usage
+
+You can limit the amount of memory uploaded to your server when decoding requests by setting the value ``Hummingbird/RequestContext/maxUploadSize`` in your `RequestContext`. If someone sends a request larger than the `maxUploadSize` value defined the server will respond with a response with status code `(413) Content too large`. The `maxUploadSize` value defaults to 2MB. The request decoders provided with Hummingbird for JSON and URL Encoded Forms both use this limit.
+
 You can find out more about request decoding and response encoding in <doc:RequestDecoding> and <doc:ResponseEncoding>.
 
 ## Passing data forward
@@ -116,6 +120,30 @@ router.get("ip") { _, context in
 }
 ```
 
+### RequestContext transformation
+
+The `RequestContext` can be transformed for the routes in a route group. The `RequestContext` you are converting to needs to conform to ``ChildRequestContext``. This requires a parent context ie the `RequestContext` you are converting from and a ``ChildRequestContext/init(context:)`` function to perform the conversion.
+
+```swift
+struct MyNewRequestContext: ChildRequestContext {
+    typealias ParentContext = MyRequestContext
+    init(context: ParentContext) throws {
+        self.coreContext = context.coreContext
+        ...
+    }
+}
+```
+Once you have defined how to perform the transform from your original `RequestContext` the conversion is added as follows
+
+```swift
+let app = Application(context: MyRequestContext.self)
+router.group("/todos", context: MyNewRequestContext.self)
+    .put(use: createTodo)
+    .get(use: listTodos)
+```
+
+Transforming the `RequestContext` is a powerful way of enforcing compile-time guarantees that requests adhere to certain requirements. And by expressing these requirements as protocol conformances, you can compose these properties and flexibly express those requirements.
+
 ## Authentication Middleware
 
 The most obvious example of this is passing user authentication information forward. The authentication framework from ``HummingbirdAuth`` makes use of this. If you want to use the authentication and sessions middleware your context will also need to conform to ``HummingbirdAuth/AuthRequestContext``. 

Hummingbird.docc/Articles/RouterGuide.md

@@ -172,28 +172,6 @@ router.group("/todos")
     .delete("{id}", deleteTodo)
 ```
 
-### RequestContext transformation
-
-The `RequestContext` can be transformed for the routes in a route group. The `RequestContext` you are converting to needs to conform to ``ChildRequestContext``. This requires a parent context ie the `RequestContext` you are converting from and a ``ChildRequestContext/init(context:)`` function to perform the conversion.
-
-```swift
-struct MyNewRequestContext: ChildRequestContext {
-    typealias ParentContext = MyRequestContext
-    init(context: ParentContext) throws {
-        self.coreContext = context.coreContext
-        ...
-    }
-}
-```
-Once you have defined how to perform the transform from your original `RequestContext` the conversion is added as follows
-
-```swift
-let app = Application(context: MyRequestContext.self)
-router.group("/todos", context: MyNewRequestContext.self)
-    .put(use: createTodo)
-    .get(use: listTodos)
-```
-
 ### Route Collections
 
 A ``RouteCollection`` is a collection of routes and middleware that can be added to a `Router` in one go. It has the same API as `RouterGroup`, so can have groups internal to the collection to allow for Middleware to applied to only sub-sections of the `RouteCollection`.