eager-decode-then reorder received frames

the immediate benefit of eager-decoding frames is that one can push PING
frames to the top of the stack, thereby prioritizing its processing.

Author: HoneyryderChuck

lib/http/2/framer.rb

@@ -119,6 +119,7 @@ def initialize(local_max_frame_size = DEFAULT_MAX_FRAME_SIZE,
                    remote_max_frame_size = DEFAULT_MAX_FRAME_SIZE)
       @local_max_frame_size = local_max_frame_size
       @remote_max_frame_size = remote_max_frame_size
+      @frames = []
     end
 
     # Generates common 9-byte frame header.
@@ -371,6 +372,21 @@ def generate(frame)
     #
     # @param buf [Buffer]
     def parse(buf)
+      while (frame = decode_frame(buf))
+        if frame[:type] == :ping
+          # PING responses SHOULD be given higher priority than any other frame.
+          @frames.unshift(frame)
+        else
+          @frames << frame
+        end
+      end
+
+      @frames.shift
+    end
+
+    private
+
+    def decode_frame(buf)
       return if buf.size < 9
 
       frame = read_common_header(buf)
@@ -491,8 +507,6 @@ def parse(buf)
       frame
     end
 
-    private
-
     def pack_error(error, buffer:)
       unless error.is_a? Integer
         error = DEFINED_ERRORS[error]

sig/framer.rbs

@@ -34,6 +34,7 @@ module HTTP2
 
     @local_max_frame_size: Integer
     @remote_max_frame_size: Integer
+    @streams: Hash[Integer, Stream]
 
     attr_accessor local_max_frame_size: Integer
 
@@ -47,12 +48,14 @@ module HTTP2
 
     def generate: (frame) -> String
 
-    def parse: (String) -> frame?
+    def parse: (String buf) -> frame?
 
     private
 
     def initialize: (?Integer local_max_frame_size, ?Integer remote_max_frame_size) -> untyped
 
+    def decode_frame: (String buf) -> frame?
+
     def pack_error: (Integer | Symbol error, buffer: String) -> String
 
     def unpack_error: (Integer) -> (Symbol | Integer)