SwiftQUIC: Reduce CPU overhead in getting inbound stream data delivered to the stream

Author: agnosticdev

Sources/SwiftNetwork/Protocols/ManyToManyProtocol.swift

@@ -1388,6 +1388,15 @@ extension ManyToManyApplicationStreamProtocol where Flow: AutomaticUpperStreamPr
         guard let flow = self.flow(for: flowID) else { throw NetworkError.posix(EINVAL) }
         flow.serviceUpperReceiveQueue()
     }
+    // Enqueue and delivery the stream data all in one shot
+    public func deliverInboundStreamData(
+        flow flowID: MultiplexedFlowIdentifier,
+        streamData: consuming FrameArray
+    ) throws(NetworkError) {
+        guard var flow = self.flow(for: flowID) else { throw NetworkError.posix(EINVAL) }
+        try flow.addToUpperReceiveQueue(streamData)
+        flow.serviceUpperReceiveQueue()
+    }
 }
 
 @_spi(ProtocolProvider)

Sources/SwiftNetwork/QUIC/QUICConnection.swift

@@ -2374,8 +2374,7 @@ public final class QUICConnection: ManyToManyApplicationStreamProtocol,
                 continue
             }
 
-            try? enqueueInboundStreamData(flow: flowID, streamData: frameArray)
-            try? deliverEnqueuedInboundStreamData(flow: flowID)
+            try? deliverInboundStreamData(flow: flowID, streamData: frameArray)
 
             // When the stream is already in `resetReceived` state,
             // it should be closed when we receive STOP_SENDING, so we
@@ -4317,8 +4316,7 @@ public final class QUICConnection: ManyToManyApplicationStreamProtocol,
         }
         if let frameArray = stream.dequeueReassembledData(connection: self) {
             do {
-                try enqueueInboundStreamData(flow: flowID, streamData: frameArray)
-                try deliverEnqueuedInboundStreamData(flow: flowID)
+                try deliverInboundStreamData(flow: flowID, streamData: frameArray)
                 sendFrames()
             } catch {
                 log.error("Error sending frames on stream close: \(error)")

Sources/SwiftNetwork/QUIC/QUICStream.swift

@@ -328,7 +328,7 @@ struct StreamListMembership: OptionSet {
 // Also note that a flow identifier can exist in multiple lists at one time.
 @available(Network 0.1.0, *)
 struct QUICStreamList: ~Copyable {
-    private var list: [MultiplexedFlowIdentifier] = []
+    private var list: Deque<MultiplexedFlowIdentifier> = []
     private let name: StaticString
     private let listType: StreamListMembership