WebSocket Compression

sdk/lib/io/websocket.dart

Index: sdk/lib/io/websocket.dart
diff --git a/sdk/lib/io/websocket.dart b/sdk/lib/io/websocket.dart
index 599e295c60ac92923dc620303830b986b8522f96..3a65685259c89df5d92999645ca84c3c1fa846d4 100644
--- a/sdk/lib/io/websocket.dart
+++ b/sdk/lib/io/websocket.dart
@@ -24,6 +24,93 @@ abstract class WebSocketStatus {
 }
 
 /**
+ * The [CompressionOptions] class allows you to control
+ * the options of WebSocket compression.
+ */
+class CompressionOptions {
+  /**
+   * Default WebSocket Compression options.
+   * Compression will be enabled with the following options:
+   * clientNoContextTakeover: false
+   * serverNoContextTakeover: false
+   * clientMaxWindowBits: 15
+   * serverMaxWindowBits: 15
+   */
+  static const CompressionOptions DEFAULT = const CompressionOptions();
+
+  /**
+   * Disables WebSocket Compression.
+   */
+  static const CompressionOptions OFF = const CompressionOptions(enabled: false);

[Søren Gjesse, 2015/06/25 15:41:26]

Long line, see
https://www.dartlang.org/articles/style-guide/#avoid-lines-longer-than-80-cha....

+
+  /**
+   * Control whether the client will reuse it's compression instances.
+   */
+  final bool clientNoContextTakeover;
+
+  /**
+   * Control whether the server will reuse it's compression instances.
+   */
+  final bool serverNoContextTakeover;
+
+  /**
+   * Sets the Max Window Bits for the Client.
+   */
+  final int clientMaxWindowBits;
+
+  /**
+   * Sets the Max Window Bits for the Server.
+   */
+  final int serverMaxWindowBits;
+
+  /**
+   * Enables or disables WebSocket compression.
+   */
+  final bool enabled;
+
+  const CompressionOptions({this.clientNoContextTakeover: false,

[Søren Gjesse, 2015/06/25 15:41:26]

Please reformat the arguments, see
https://www.dartlang.org/articles/style-guide/#do-indent-continued-lines-with....

+    this.serverNoContextTakeover: false, this.clientMaxWindowBits,
+                           this.serverMaxWindowBits, this.enabled: true});
+
+  /**
+   * Create a Compression Header
+   */
+  String _createHeader([List<String> requested]) {
+    if (!enabled) {
+      return "";
+    }
+
+    var header = "permessage-deflate";
+
+    if (requested == null) {
+      header += "; client_max_window_bits";
+    } else {
+      if (requested.contains("client_max_window_bits")) {
+        var myMaxWindowBits = clientMaxWindowBits == null ? 15 : clientMaxWindowBits;

[Søren Gjesse, 2015/06/25 15:41:26]

Long line.

+        header += "; client_max_window_bits=${myMaxWindowBits}";
+      }
+    }
+
+    if (clientNoContextTakeover && (requested != null

[Søren Gjesse, 2015/06/25 15:41:27]

Please look at
https://www.dartlang.org/articles/style-guide/#do-place-binary-operators-on-t...
regarding formatting of binary operators.

+      && requested.contains("client_no_context_takeover"))) {
+      header += "; client_no_context_takeover";
+    }
+
+    if (serverNoContextTakeover && (requested != null
+      && requested.contains("server_no_context_takeover"))) {
+      header += "; server_no_context_takeover";
+    }
+
+    if (requested != null) {
+      var mwb = serverMaxWindowBits == null ? 15 : serverMaxWindowBits;
+      header += "; server_max_window_bits=${mwb}";
+    }
+
+    return header;
+  }
+}
+
+/**
  * The [WebSocketTransformer] provides the ability to upgrade a
  * [HttpRequest] to a [WebSocket] connection. It supports both
  * upgrading a single [HttpRequest] and upgrading a stream of
@@ -63,8 +150,9 @@ abstract class WebSocketTransformer
    * completing with a [String]. The [String] must exist in the list of
    * protocols.
    */
-  factory WebSocketTransformer({protocolSelector(List<String> protocols)})
-      => new _WebSocketTransformerImpl(protocolSelector);
+  factory WebSocketTransformer({protocolSelector(List<String> protocols),
+    CompressionOptions compression: CompressionOptions.DEFAULT})
+      => new _WebSocketTransformerImpl(protocolSelector, compression);
 
   /**
    * Upgrades a [HttpRequest] to a [WebSocket] connection. If the
@@ -80,8 +168,9 @@ abstract class WebSocketTransformer
    * protocols.
    */
   static Future<WebSocket> upgrade(HttpRequest request,
-                                   {protocolSelector(List<String> protocols)}) {
-    return _WebSocketTransformerImpl._upgrade(request, protocolSelector);
+                                   {protocolSelector(List<String> protocols),
+                                    CompressionOptions compression: CompressionOptions.DEFAULT}) {
+    return _WebSocketTransformerImpl._upgrade(request, protocolSelector, compression);
   }
 
   /**
@@ -176,12 +265,12 @@ abstract class WebSocket implements Stream, StreamSink {
    * act as the server and will not mask its messages.
    */
   factory WebSocket.fromUpgradedSocket(Socket socket, {String protocol,
-        bool serverSide}) {
+        bool serverSide, CompressionOptions compression: CompressionOptions.DEFAULT}) {
     if (serverSide == null) {
       throw new ArgumentError("The serverSide argument must be passed "
           "explicitly to WebSocket.fromUpgradedSocket.");
     }
-    return new _WebSocketImpl._fromSocket(socket, protocol, serverSide);
+    return new _WebSocketImpl._fromSocket(socket, protocol, compression, serverSide);
   }
 
   /**