Collect some disk statistics.

metrics_daemon_test.cc

 // Copyright (c) 2010 The Chromium OS 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 <utime.h>
 
 #include <string>
 #include <vector>
 
 #include <base/file_util.h>
+#include <base/stringprintf.h>
 #include <gtest/gtest.h>
 
 #include "counter_mock.h"
 #include "metrics_daemon.h"
 #include "metrics_library_mock.h"
 
 using base::Time;
 using base::TimeTicks;
 using chromeos_metrics::FrequencyCounter;
 using chromeos_metrics::FrequencyCounterMock;
 using chromeos_metrics::TaggedCounterMock;
 using chromeos_metrics::TaggedCounterReporter;
 using chromeos_metrics::TaggedCounterReporterMock;
 using std::string;
 using std::vector;
 using ::testing::_;
 using ::testing::Return;
 using ::testing::StrictMock;
 
 static const int kSecondsPerDay = 24 * 60 * 60;
 
 static const char kTestDir[] = "test";
 static const char kLastFile[] = "test/last";
 static const char kCurrentFile[] = "test/current";
+static const char kFakeDiskStatsPath[] = "fake-disk-stats";
+static const char kFakeDiskStatsFormat[] =
+    "    1793     1788    %d   105580    "
+    "    196      175     %d    30290    "
+    "    0    44060   135850\n";
+static string kFakeDiskStats[2];
+static const int kFakeReadSectors[] = {80000, 100000};
+static const int kFakeWriteSectors[] = {3000, 4000};
 
 // This class allows a TimeTicks object to be initialized with seconds
 // (rather than microseconds) through the protected TimeTicks(int64)
 // constructor.
 class TestTicks : public TimeTicks {
  public:
   TestTicks(int64 seconds)
       : TimeTicks(seconds * Time::kMicrosecondsPerSecond) {}
 };
 
 // Overloaded for test failure printing purposes.
 static std::ostream& operator<<(std::ostream& o, const Time& time) {
   o << time.ToInternalValue() << "us";
   return o;
 };
 
 class MetricsDaemonTest : public testing::Test {
  protected:
   virtual void SetUp() {
     EXPECT_EQ(NULL, daemon_.daily_use_.get());
     EXPECT_EQ(NULL, daemon_.kernel_crash_interval_.get());
     EXPECT_EQ(NULL, daemon_.user_crash_interval_.get());
-    daemon_.Init(true, &metrics_lib_);
+    kFakeDiskStats[0] = StringPrintf(kFakeDiskStatsFormat,
+                                     kFakeReadSectors[0], kFakeWriteSectors[0]);
+    kFakeDiskStats[1] = StringPrintf(kFakeDiskStatsFormat,
+                                     kFakeReadSectors[1], kFakeWriteSectors[1]);
+    CreateFakeDiskStatsFile(kFakeDiskStats[0].c_str());
+    daemon_.Init(true, &metrics_lib_, kFakeDiskStatsPath);
 
     // Check configuration of a few histograms.
     FrequencyCounter* frequency_counter =
         daemon_.frequency_counters_[MetricsDaemon::kMetricAnyCrashesDailyName];
     const TaggedCounterReporter* reporter = GetReporter(frequency_counter);
     EXPECT_EQ(MetricsDaemon::kMetricAnyCrashesDailyName,
               reporter->histogram_name());
     EXPECT_EQ(chromeos_metrics::kSecondsPerDay,
               frequency_counter->cycle_duration());
     EXPECT_EQ(MetricsDaemon::kMetricCrashFrequencyMin, reporter->min());
@@ skipping 45 matching lines @@
 
     EXPECT_FALSE(daemon_.user_active_);
     EXPECT_TRUE(daemon_.user_active_last_.is_null());
     EXPECT_EQ(MetricsDaemon::kUnknownPowerState, daemon_.power_state_);
     EXPECT_EQ(MetricsDaemon::kUnknownSessionState, daemon_.session_state_);
 
     file_util::Delete(FilePath(kTestDir), true);
     file_util::CreateDirectory(FilePath(kTestDir));
   }
 
-  virtual void TearDown() {}
+  virtual void TearDown() {
+    EXPECT_EQ(unlink(kFakeDiskStatsPath), 0);
+  }
 
   const TaggedCounterReporter*
   GetReporter(FrequencyCounter* frequency_counter) const {
     return static_cast<const TaggedCounterReporter*>(
         &frequency_counter->tagged_counter());
   }
 
   void ExpectFrequencyFlushCalls() {
     MetricsDaemon::FrequencyCounters::iterator i;
     for (i = daemon_.frequency_counters_.begin();
@@ skipping 81 matching lines @@
     }
     return msg;
   }
 
   // Deallocates the DBus message |msg| previously allocated through
   // dbus_message_new*.
   void DeleteDBusMessage(DBusMessage* msg) {
     dbus_message_unref(msg);
   }
 
-  // Get the frequency counter for the given name.
+  // Gets the frequency counter for the given name.
   FrequencyCounterMock& GetFrequencyMock(const char* histogram_name) {
     return *static_cast<FrequencyCounterMock*>(
         daemon_.frequency_counters_[histogram_name]);
   }
 
+  // Creates or overwrites an input file containing fake disk stats.
+  void CreateFakeDiskStatsFile(const char* fake_stats) {
+    if (unlink(kFakeDiskStatsPath) < 0) {
+      EXPECT_EQ(errno, ENOENT);
+    }
+    FILE* f = fopen(kFakeDiskStatsPath, "w");
+    EXPECT_EQ(1, fwrite(fake_stats, strlen(fake_stats), 1, f));
+    EXPECT_EQ(0, fclose(f));
+  }
+
   // The MetricsDaemon under test.
   MetricsDaemon daemon_;
 
   // Metrics library mock. It's a strict mock so that all unexpected
   // metric generation calls are marked as failures.
   StrictMock<MetricsLibraryMock> metrics_lib_;
 
   // Counter mocks. They are strict mocks so that all unexpected
   // update calls are marked as failures. They are pointers so that
   // they can replace the scoped_ptr's allocated by the daemon.
@@ skipping 285 matching lines @@
   EXPECT_TRUE(daemon_.user_active_);
   EXPECT_EQ(TestTime(10 * kSecondsPerDay + 1000), daemon_.user_active_last_);
 }
 
 TEST_F(MetricsDaemonTest, GetHistogramPath) {
   EXPECT_EQ("/var/log/metrics/Logging.AnyCrashesDaily",
             daemon_.GetHistogramPath(
                 MetricsDaemon::kMetricAnyCrashesDailyName).value());
 }
 
+TEST_F(MetricsDaemonTest, ReportDiskStats) {
+  long int read_sectors_now, write_sectors_now;
+
+  CreateFakeDiskStatsFile(kFakeDiskStats[1].c_str());
+  daemon_.DiskStatsReadStats(&read_sectors_now, &write_sectors_now);
+  EXPECT_EQ(read_sectors_now, kFakeReadSectors[1]);
+  EXPECT_EQ(write_sectors_now, kFakeWriteSectors[1]);
+
+  MetricsDaemon::DiskStatsState ds_state = daemon_.diskstats_state_;
+  EXPECT_CALL(metrics_lib_,
+              SendToUMA(_, (kFakeReadSectors[1] - kFakeReadSectors[0]) / 30,

[petkov, 2011/02/14 23:39:16]

any reason for not matching the rest of the arguments?

[Luigi Semenzato, 2011/02/15 17:45:47]

Yes.  The other arguments are passed as literal constants.  It doesn't seem that
I'd be testing anything of substance.  (I would verify that 4 == 4 and 4 != 5,
for instance).  OTOH it may make the test fail unnecessarily upon changes. 
Unless you feel it's safer to type each numeric constant twice.

+                        _, _, _));
+  EXPECT_CALL(metrics_lib_,
+              SendToUMA(_, (kFakeWriteSectors[1] - kFakeWriteSectors[0]) / 30,
+                        _, _, _));
+  daemon_.DiskStatsCallback();
+  EXPECT_TRUE(ds_state != daemon_.diskstats_state_);
+}
+
 int main(int argc, char** argv) {
   testing::InitGoogleTest(&argc, argv);
   return RUN_ALL_TESTS();
 }