Improve the display of LoadLogs when truncation occurs....

net/base/load_log_util_unittest.cc

 // Copyright (c) 2009 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/base/load_log_unittest.h"
 #include "net/base/load_log_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
 namespace {
 
 TEST(LoadLogUtilTest, Basic) {
-  scoped_refptr<LoadLog> log(new LoadLog);
+  scoped_refptr<LoadLog> log(new LoadLog(10));
 
   log->Add(MakeTime(1), LoadLog::TYPE_HOST_RESOLVER_IMPL, LoadLog::PHASE_BEGIN);
   log->Add(MakeTime(5), LoadLog::TYPE_HOST_RESOLVER_IMPL_OBSERVER_ONSTART,
       LoadLog::PHASE_BEGIN);
   log->Add(MakeTime(8), LoadLog::TYPE_HOST_RESOLVER_IMPL_OBSERVER_ONSTART,
       LoadLog::PHASE_END);
   log->Add(MakeTime(12), LoadLog::TYPE_CANCELLED, LoadLog::PHASE_NONE);
   log->Add(MakeTime(131), LoadLog::TYPE_HOST_RESOLVER_IMPL, LoadLog::PHASE_END);
 
   EXPECT_EQ(
     "t=  1: +HOST_RESOLVER_IMPL                    [dt=130]\n"
     "t=  5:   +HOST_RESOLVER_IMPL_OBSERVER_ONSTART [dt=  3]\n"
     "t=  8:   -HOST_RESOLVER_IMPL_OBSERVER_ONSTART\n"
     "t= 12:    CANCELLED\n"
     "t=131: -HOST_RESOLVER_IMPL",
     LoadLogUtil::PrettyPrintAsEventTree(log));
 }
 
 TEST(LoadLogUtilTest, UnmatchedOpen) {
-  scoped_refptr<LoadLog> log(new LoadLog);
+  scoped_refptr<LoadLog> log(new LoadLog(10));
 
   log->Add(MakeTime(3), LoadLog::TYPE_HOST_RESOLVER_IMPL, LoadLog::PHASE_BEGIN);
   // Note that there is no matching call to PHASE_END for all of the following.
   log->Add(MakeTime(6), LoadLog::TYPE_HOST_RESOLVER_IMPL_OBSERVER_ONSTART,
       LoadLog::PHASE_BEGIN);
   log->Add(MakeTime(7), LoadLog::TYPE_HOST_RESOLVER_IMPL_OBSERVER_ONSTART,
       LoadLog::PHASE_BEGIN);
   log->Add(MakeTime(8), LoadLog::TYPE_HOST_RESOLVER_IMPL_OBSERVER_ONSTART,
       LoadLog::PHASE_BEGIN);
   log->Add(MakeTime(10), LoadLog::TYPE_CANCELLED, LoadLog::PHASE_NONE);
   log->Add(MakeTime(16), LoadLog::TYPE_HOST_RESOLVER_IMPL, LoadLog::PHASE_END);
 
   EXPECT_EQ(
     "t= 3: +HOST_RESOLVER_IMPL                          [dt=13]\n"
     "t= 6:   +HOST_RESOLVER_IMPL_OBSERVER_ONSTART       [dt=10]\n"
     "t= 7:     +HOST_RESOLVER_IMPL_OBSERVER_ONSTART     [dt= 9]\n"
     "t= 8:       +HOST_RESOLVER_IMPL_OBSERVER_ONSTART   [dt= 8]\n"
     "t=10:          CANCELLED\n"
     "t=16: -HOST_RESOLVER_IMPL",
     LoadLogUtil::PrettyPrintAsEventTree(log));
 }
 
+TEST(LoadLogUtilTest, DisplayOfTruncated) {
+  size_t kMaxNumEntries = 5;
+  scoped_refptr<LoadLog> log(new LoadLog(kMaxNumEntries));
+
+  // Add a total of 10 events. This means that 5 will be truncated.
+  log->Add(MakeTime(0), LoadLog::TYPE_TCP_CONNECT, LoadLog::PHASE_BEGIN);
+  for (size_t i = 1; i < 8; ++i) {
+    log->Add(MakeTime(i), LoadLog::TYPE_CANCELLED, LoadLog::PHASE_NONE);
+  }
+  log->Add(MakeTime(9), LoadLog::TYPE_TCP_CONNECT, LoadLog::PHASE_END);
+
+  EXPECT_EQ(
+    "t=0: +TCP_CONNECT   [dt=9]\n"
+    "t=1:    CANCELLED\n"
+    "t=2:    CANCELLED\n"
+    "t=3:    CANCELLED\n"
+    " ... Truncated 4 entries ...\n"
+    "t=9: -TCP_CONNECT",
+    LoadLogUtil::PrettyPrintAsEventTree(log));
+}
+
 }  // namespace
 }  // namespace net