Remove unused ability to disable flow control in QUIC

net/quic/quic_flow_controller.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/quic_flow_controller.h"
 
 #include "base/basictypes.h"
 #include "net/quic/quic_connection.h"
 #include "net/quic/quic_flags.h"
 #include "net/quic/quic_protocol.h"
 
 namespace net {
 
 #define ENDPOINT (is_server_ ? "Server: " : " Client: ")
 
 QuicFlowController::QuicFlowController(QuicConnection* connection,
                                        QuicStreamId id,
                                        bool is_server,
                                        QuicStreamOffset send_window_offset,
                                        QuicStreamOffset receive_window_offset,
                                        QuicByteCount max_receive_window)
     : connection_(connection),
       id_(id),
-      is_enabled_(true),
       is_server_(is_server),
       bytes_consumed_(0),
       highest_received_byte_offset_(0),
       bytes_sent_(0),
       send_window_offset_(send_window_offset),
       receive_window_offset_(receive_window_offset),
       max_receive_window_(max_receive_window),
       last_blocked_send_window_offset_(0) {
   DVLOG(1) << ENDPOINT << "Created flow controller for stream " << id_
            << ", setting initial receive window offset to: "
            << receive_window_offset_
            << ", max receive window to: "
            << max_receive_window_
            << ", setting send window offset to: " << send_window_offset_;
 }
 
 void QuicFlowController::AddBytesConsumed(QuicByteCount bytes_consumed) {
-  if (!IsEnabled()) {
-    return;
-  }
-
   bytes_consumed_ += bytes_consumed;
   DVLOG(1) << ENDPOINT << "Stream " << id_ << " consumed: " << bytes_consumed_;
 
   MaybeSendWindowUpdate();
 }
 
 bool QuicFlowController::UpdateHighestReceivedOffset(
     QuicStreamOffset new_offset) {
-  if (!IsEnabled()) {
-    return false;
-  }
-
   // Only update if offset has increased.
   if (new_offset <= highest_received_byte_offset_) {
     return false;
   }
 
   DVLOG(1) << ENDPOINT << "Stream " << id_
            << " highest byte offset increased from: "
            << highest_received_byte_offset_ << " to " << new_offset;
   highest_received_byte_offset_ = new_offset;
   return true;
 }
 
 void QuicFlowController::AddBytesSent(QuicByteCount bytes_sent) {
-  if (!IsEnabled()) {
-    return;
-  }
-
   if (bytes_sent_ + bytes_sent > send_window_offset_) {
     LOG(DFATAL) << ENDPOINT << "Stream " << id_ << " Trying to send an extra "
                 << bytes_sent << " bytes, when bytes_sent = " << bytes_sent_
                 << ", and send_window_offset_ = " << send_window_offset_;
     bytes_sent_ = send_window_offset_;
 
     // This is an error on our side, close the connection as soon as possible.
     connection_->SendConnectionClose(QUIC_FLOW_CONTROL_SENT_TOO_MUCH_DATA);
     return;
   }
 
   bytes_sent_ += bytes_sent;
   DVLOG(1) << ENDPOINT << "Stream " << id_ << " sent: " << bytes_sent_;
 }
 
 bool QuicFlowController::FlowControlViolation() {
-  if (!IsEnabled()) {
-    return false;
-  }
-
   if (highest_received_byte_offset_ > receive_window_offset_) {
     LOG(ERROR) << ENDPOINT << "Flow control violation on stream "
                << id_ << ", receive window offset: "
                << receive_window_offset_
                << ", highest received byte offset: "
                << highest_received_byte_offset_;
     return true;
   }
   return false;
 }
 
 void QuicFlowController::MaybeSendWindowUpdate() {
-  if (!IsEnabled()) {
-    return;
-  }
-
   // Send WindowUpdate to increase receive window if
   // (receive window offset - consumed bytes) < (max window / 2).
   // This is behaviour copied from SPDY.
   DCHECK_LT(bytes_consumed_, receive_window_offset_);
   QuicStreamOffset consumed_window = receive_window_offset_ - bytes_consumed_;
   QuicByteCount threshold = (max_receive_window_ / 2);
 
   if (consumed_window < threshold) {
     // Update our receive window.
     receive_window_offset_ += (max_receive_window_ - consumed_window);
 
     DVLOG(1) << ENDPOINT << "Sending WindowUpdate frame for stream " << id_
              << ", consumed bytes: " << bytes_consumed_
              << ", consumed window: " << consumed_window
              << ", and threshold: " << threshold
              << ", and max recvw: " << max_receive_window_
              << ". New receive window offset is: " << receive_window_offset_;
 
     // Inform the peer of our new receive window.
     connection_->SendWindowUpdate(id_, receive_window_offset_);
   }
 }
 
 void QuicFlowController::MaybeSendBlocked() {
-  if (!IsEnabled()) {
-    return;
-  }
-
   if (SendWindowSize() == 0 &&
       last_blocked_send_window_offset_ < send_window_offset_) {
     DVLOG(1) << ENDPOINT << "Stream " << id_ << " is flow control blocked. "
              << "Send window: " << SendWindowSize()
              << ", bytes sent: " << bytes_sent_
              << ", send limit: " << send_window_offset_;
     // The entire send_window has been consumed, we are now flow control
     // blocked.
     connection_->SendBlocked(id_);
 
     // Keep track of when we last sent a BLOCKED frame so that we only send one
     // at a given send offset.
     last_blocked_send_window_offset_ = send_window_offset_;
   }
 }
 
 bool QuicFlowController::UpdateSendWindowOffset(
     QuicStreamOffset new_send_window_offset) {
-  if (!IsEnabled()) {
-    return false;
-  }
-
   // Only update if send window has increased.
   if (new_send_window_offset <= send_window_offset_) {
     return false;
   }
 
   DVLOG(1) << ENDPOINT << "UpdateSendWindowOffset for stream " << id_
            << " with new offset " << new_send_window_offset
            << " current offset: " << send_window_offset_
            << " bytes_sent: " << bytes_sent_;
 
   const bool blocked = IsBlocked();
   send_window_offset_ = new_send_window_offset;
   return blocked;
 }
 
-void QuicFlowController::Disable() {
-  is_enabled_ = false;
-}
-
-bool QuicFlowController::IsEnabled() const {
-  return is_enabled_;
-}
-
 bool QuicFlowController::IsBlocked() const {
-  return IsEnabled() && SendWindowSize() == 0;
+  return SendWindowSize() == 0;
 }
 
 uint64 QuicFlowController::SendWindowSize() const {
   if (bytes_sent_ > send_window_offset_) {
     return 0;
   }
   return send_window_offset_ - bytes_sent_;
 }
 
 }  // namespace net