window_update_frame.rb in protocol-http2-0.15.0

- old
+ new

@@ -1,25 +1,10 @@
-# Copyright, 2018, by Samuel G. D. Williams. <http://www.codeotaku.com>
-# 
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-# 
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-# 
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-# THE SOFTWARE.
+# frozen_string_literal: true
 
+# Released under the MIT License.
+# Copyright, 2019-2023, by Samuel Williams.
+
 require_relative 'frame'
 
 module Protocol
 	module HTTP2
 		class Window
@@ -42,10 +27,16 @@
 			attr :capacity
 			
 			# When the value of SETTINGS_INITIAL_WINDOW_SIZE changes, a receiver MUST adjust the size of all stream flow-control windows that it maintains by the difference between the new value and the old value.
 			def capacity= value
 				difference = value - @capacity
+				
+				# An endpoint MUST treat a change to SETTINGS_INITIAL_WINDOW_SIZE that causes any flow-control window to exceed the maximum size as a connection error of type FLOW_CONTROL_ERROR.
+				if (@available + difference) > MAXIMUM_ALLOWED_WINDOW_SIZE
+					raise FlowControlError, "Changing window size by #{difference} caused overflow: #{@available + difference} > #{MAXIMUM_ALLOWED_WINDOW_SIZE}!"
+				end
+				
 				@available += difference
 				@capacity = value
 			end
 			
 			def consume(amount)
@@ -58,29 +49,31 @@
 			def available?
 				@available > 0
 			end
 			
 			def expand(amount)
+				available = @available + amount
+				
+				if available > MAXIMUM_ALLOWED_WINDOW_SIZE
+					raise FlowControlError, "Expanding window by #{amount} caused overflow: #{available} > #{MAXIMUM_ALLOWED_WINDOW_SIZE}!"
+				end
+				
 				# puts "expand(#{amount}) @available=#{@available}"
 				@available += amount
 				@used -= amount
-				
-				if @available > MAXIMUM_ALLOWED_WINDOW_SIZE
-					raise FlowControlError, "Expanding window by #{amount} caused overflow: #{@available} > #{MAXIMUM_ALLOWED_WINDOW_SIZE}!"
-				end
 			end
 			
 			def wanted
 				@used
 			end
 			
 			def limited?
 				@available < (@capacity / 2)
 			end
 			
-			def to_s
-				"\#<Window used=#{@used} available=#{@available} capacity=#{@capacity}>"
+			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
@@ -100,10 +93,14 @@
 					@used
 				end
 			end
 			
 			def limited?
-				@available < ((@desired || @capacity) / 2)
+				if @desired
+					@available < @desired
+				else
+					super
+				end
 			end
 		end
 		
 		# The WINDOW_UPDATE frame is used to implement flow control.
 		#