Reduce number of redundant map lookups in QuicStreamFactory::OnJobComplete

net/quic/chromium/quic_stream_factory.cc

 // Copyright (c) 2012 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/chromium/quic_stream_factory.h"
 
 #include <algorithm>
 #include <tuple>
 #include <utility>
 
@@ skipping 1130 matching lines @@
     JobSet* jobs = &(active_jobs_[server_id]);
     if (jobs->size() > 1) {
       // If there is another pending job, then we can delete this job and let
       // the other job handle the request.
       job->Cancel();
       jobs->erase(job);
       return;
     }
   }
 
+  ServerIDRequestsMap::iterator requests_iter =
+      job_requests_map_.find(server_id);
+  DCHECK(requests_iter != job_requests_map_.end());
   if (rv == OK) {
     if (!always_require_handshake_confirmation_)
       set_require_confirmation(false);
 
-    if (!job_requests_map_[server_id].empty()) {
+    if (!requests_iter->second.empty()) {
       SessionMap::iterator session_it = active_sessions_.find(server_id);
       DCHECK(session_it != active_sessions_.end());
       QuicChromiumClientSession* session = session_it->second;
-      for (QuicStreamRequest* request : job_requests_map_[server_id]) {
+      for (QuicStreamRequest* request : requests_iter->second) {
         DCHECK(request->server_id() == server_id);
         // Do not notify |request| yet.
         request->SetSession(session);
       }
     }
   }
 
-  while (!job_requests_map_[server_id].empty()) {
-    RequestSet::iterator it = job_requests_map_[server_id].begin();
-    QuicStreamRequest* request = *it;
-    job_requests_map_[server_id].erase(it);
+  // It's okay not to erase |request| from |requests_iter->second| because the
+  // entire RequestSet will be erased from |job_requests_map_|.
+  for (auto* request : requests_iter->second) {
     // Even though we're invoking callbacks here, we don't need to worry
     // about |this| being deleted, because the factory is owned by the
     // profile which can not be deleted via callbacks.
     request->OnRequestComplete(rv);
   }
 
   for (auto& other_job : active_jobs_[server_id]) {
     if (other_job.first != job)
       other_job.first->Cancel();
   }
 
   active_jobs_[server_id].clear();
   active_jobs_.erase(server_id);
-  job_requests_map_.erase(server_id);
+  job_requests_map_.erase(requests_iter);
 }
 
 void QuicStreamFactory::OnCertVerifyJobComplete(CertVerifierJob* job, int rv) {
   active_cert_verifier_jobs_.erase(job->server_id());
 }
 
 std::unique_ptr<QuicHttpStream> QuicStreamFactory::CreateFromSession(
     QuicChromiumClientSession* session) {
   return std::unique_ptr<QuicHttpStream>(
       new QuicHttpStream(session->GetWeakPtr(), http_server_properties_));
@@ skipping 790 matching lines @@
 void QuicStreamFactory::OpenFactory() {
   status_ = OPEN;
 }
 
 void QuicStreamFactory::MaybeClearConsecutiveDisabledCount() {
   if (status_ == OPEN)
     consecutive_disabled_count_ = 0;
 }
 
 }  // namespace net