WIP.

Author: ioquatix

lib/protocol/http2/window_update_frame.rb

@@ -8,8 +8,11 @@
 module Protocol
 	module HTTP2
 		class Window
+			# 
+			DEFAULT_CAPACITY = 0xFFFF
+			
 			# @param capacity [Integer] The initial window size, typically from the settings.
-			def initialize(capacity = 0xFFFF)
+			def initialize(capacity = DEFAULT_CAPACITY)
 				# This is the main field required:
 				@available = capacity
 
@@ -70,14 +73,22 @@ def limited?
 				@available < (@capacity / 2)
 			end
 
+			def as_json(...)
+				{used: @used, available: @available, capacity: @capacity}
+			end
+			
+			def to_json(...)
+				as_json.to_json(...)
+			end
+			
 			def inspect
 				"\#<#{self.class} used=#{@used} available=#{@available} capacity=#{@capacity}>"
 			end
 		end
 
 		# This is a window which efficiently maintains a desired capacity.
 		class LocalWindow < Window
-			def initialize(capacity = 0xFFFF, desired: nil)
+			def initialize(capacity = DEFAULT_CAPACITY, desired: nil)
 				super(capacity)
 
 				@desired = desired
@@ -90,17 +101,22 @@ def wanted
 					# We must send an update which allows at least @desired bytes to be sent.
 					(@desired - @capacity) + @used
 				else
-					@used
+					super
 				end
 			end
 
 			def limited?
 				if @desired
-					@available < @desired
+					# Do not send window updates until we are less than half the desired capacity:
+					@available < (@desired / 2)
 				else
 					super
 				end
 			end
+			
+			def as_json(...)
+				super.merge(desired: @desired)
+			end
 		end
 
 		# The WINDOW_UPDATE frame is used to implement flow control.

test/protocol/http2/window.rb

@@ -55,4 +55,15 @@
 			expect(window.wanted).to be == 200
 		end
 	end
+	
+	with "#limited?" do
+		it "becomes limited after half the capacity is consumed" do
+			expect(window).not.to be(:limited?)
+			
+			# Consume a little more than half:
+			window.consume(window.capacity / 2 + 2)
+			
+			expect(window).to be(:limited?)
+		end
+	end
 end

test/protocol/http2/window_update_frame.rb

@@ -203,8 +203,12 @@ def before
 					expect(frame).to be_a Protocol::HTTP2::WindowUpdateFrame
 				end
 
-				expect(client).to receive(:receive_window_update)
+				expect(client).to receive(:receive_window_update).twice
 
+				stream.send_data("*" * client.available_size)
+				expect(server.read_frame).to be_a Protocol::HTTP2::DataFrame
+				
+				frame = client.read_frame
 				expect(frame).to be_a(Protocol::HTTP2::WindowUpdateFrame)
 				expect(frame).to be(:connection?) # stream_id = 0