Create a histogram serialization mechanism in components/metrics

components/metrics/export/metrics_utils_unittest.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 "components/metrics/export/metrics_utils.h"
+
+#include "base/file_util.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/logging.h"
+#include "base/strings/stringprintf.h"
+#include "components/metrics/export/crash_sample.h"
+#include "components/metrics/export/histogram_sample.h"
+#include "components/metrics/export/linearhistogram_sample.h"
+#include "components/metrics/export/metric_sample.h"
+#include "components/metrics/export/sparsehistogram_sample.h"
+#include "components/metrics/export/useraction_sample.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace metrics {
+namespace {
+
+void AreEqHistogram(HistogramSample* a, HistogramSample* b) {
+  EXPECT_EQ(a->name(), b->name());
+  EXPECT_EQ(a->sample(), b->sample());
+  EXPECT_EQ(a->min(), b->min());
+  EXPECT_EQ(a->max(), b->max());
+  EXPECT_EQ(a->nbucket(), b->nbucket());
+}
+
+void AreEqCrash(CrashSample* a, CrashSample* b) {
+  EXPECT_EQ(a->name(), b->name());
+}
+
+void AreEqLinear(LinearHistogramSample* a, LinearHistogramSample* b) {
+  EXPECT_EQ(a->name(), b->name());
+  EXPECT_EQ(a->sample(), b->sample());
+  EXPECT_EQ(a->max(), b->max());
+}
+
+void AreEqSparse(SparseHistogramSample* a, SparseHistogramSample* b) {
+  EXPECT_EQ(a->name(), b->name());
+  EXPECT_EQ(a->sample(), b->sample());
+}
+
+void AreEqAction(UserActionSample* a, UserActionSample* b) {
+  EXPECT_EQ(a->name(), b->name());
+}
+
+void AreEq(MetricSample* a, MetricSample* b) {
+  ASSERT_TRUE(a);
+  ASSERT_TRUE(b);
+  MetricSample::SampleType type = a->type();
+  ASSERT_EQ(a->type(), b->type());
+  if (type == MetricSample::CRASH) {
+    AreEqCrash(reinterpret_cast<CrashSample*>(a),
+               reinterpret_cast<CrashSample*>(b));
+  } else if (type == MetricSample::HISTOGRAM) {
+    AreEqHistogram(reinterpret_cast<HistogramSample*>(a),
+                   reinterpret_cast<HistogramSample*>(b));
+  } else if (type == MetricSample::SPARSE_HISTOGRAM) {
+    AreEqSparse(reinterpret_cast<SparseHistogramSample*>(a),
+                reinterpret_cast<SparseHistogramSample*>(b));
+  } else if (type == MetricSample::LINEAR_HISTOGRAM) {
+    AreEqLinear(reinterpret_cast<LinearHistogramSample*>(a),
+                reinterpret_cast<LinearHistogramSample*>(b));
+  } else if (type == MetricSample::USER_ACTION) {
+    AreEqAction(reinterpret_cast<UserActionSample*>(a),
+                reinterpret_cast<UserActionSample*>(b));
+  } else {
+    DLOG(ERROR) << "could not recognize type";
+    FAIL();
+  }
+}
+
+class MetricsUtilsChromeOSTest : public testing::Test {
+ protected:
+  static const int buff_size = 1024;
+
+  MetricsUtilsChromeOSTest() {
+    bool success = temporary_dir.CreateUniqueTempDir();
+    if (success) {
+      base::FilePath dir_path = temporary_dir.path();
+      filename = dir_path.value() + "chromeossampletest";
+      filepath = base::FilePath(filename);
+    }
+  }

[Alexei Svitkine (slow), 2014/05/01 15:57:09]

Add empty line after this.

+  virtual void SetUp() {
+    base::DeleteFile(filepath, false);

[Alexei Svitkine (slow), 2014/05/01 15:57:09]

What's this call for?

[bsimonnet, 2014/05/01 20:34:21]

To make sure the file is not here and therefore no metrics are currently stored.

+    buffer.reset(new char[buff_size]);
+  }
+
+  void TestSerialization(MetricSample* sample) {
+    std::string serialized(sample->ToString());
+    ASSERT_EQ('\0', serialized[serialized.length() - 1]);
+    AreEq(sample, MetricsUtils::ReadSample(serialized).get());
+  }
+
+  scoped_ptr<char[]> buffer;

[Alexei Svitkine (slow), 2014/05/01 15:57:09]

Is this used somewhere?

[bsimonnet, 2014/05/01 20:34:21]

no I forgot to delete it.

+  std::string filename;
+  base::ScopedTempDir temporary_dir;
+  base::FilePath filepath;
+};
+
+TEST_F(MetricsUtilsChromeOSTest, CrashSerializeTest) {
+  CrashSample crash("test");
+  TestSerialization(&crash);
+}
+
+TEST_F(MetricsUtilsChromeOSTest, HistogramSerializeTest) {
+  HistogramSample hist("myhist", 13, 1, 100, 10);
+  TestSerialization(&hist);
+}
+
+TEST_F(MetricsUtilsChromeOSTest, LinearSerializeTest) {
+  LinearHistogramSample lhist("linearhist", 12, 30);
+  TestSerialization(&lhist);
+}
+
+TEST_F(MetricsUtilsChromeOSTest, SparseSerializeTest) {
+  SparseHistogramSample shist("mysparse", 30);
+  TestSerialization(&shist);
+}
+
+TEST_F(MetricsUtilsChromeOSTest, UserActionSerializeTest) {
+  TestSerialization(new UserActionSample("myaction"));
+}
+
+TEST_F(MetricsUtilsChromeOSTest, IllegalNameAreFilteredTest) {
+  SparseHistogramSample sample1("no space", 10);
+  LinearHistogramSample sample2(base::StringPrintf("here%cbhe", '\0'), 1, 3);
+  EXPECT_FALSE(MetricsUtils::WriteMetricToFile(sample1, filename));
+  EXPECT_FALSE(MetricsUtils::WriteMetricToFile(sample2, filename));
+  int64 size = 0;
+
+  ASSERT_TRUE(!PathExists(filepath) || base::GetFileSize(filepath, &size));
+
+  EXPECT_EQ(0, size);
+}
+
+TEST_F(MetricsUtilsChromeOSTest, BadInputIsCaughtTest) {
+  std::string input(
+      base::StringPrintf("sparsehistogram%cname foo%c", '\0', '\0'));
+  EXPECT_EQ(NULL, SparseHistogramSample::ReadSparseHistogram(input).get());
+}
+
+TEST_F(MetricsUtilsChromeOSTest, MessageSeparatedByZero) {
+  CrashSample crash("crash");
+
+  MetricsUtils::WriteMetricToFile(crash, filename);
+  int64 size = 0;
+  ASSERT_TRUE(base::GetFileSize(filepath, &size));
+  EXPECT_EQ(size, 16);
+}
+
+TEST_F(MetricsUtilsChromeOSTest, MessagesTooLongAreDiscardedTest) {
+  // Creates a message that is bigger than the maximum allowed size.
+  // As we are adding extra character (crash, \0s, etc), if the name is
+  // kMessageMaxLength long, it will be too long.
+  std::string name(MetricsUtils::kMessageMaxLength, 'c');
+
+  CrashSample crash(name);
+  EXPECT_FALSE(MetricsUtils::WriteMetricToFile(crash, filename));
+  int64 size = 0;
+  ASSERT_TRUE(base::GetFileSize(filepath, &size));
+  EXPECT_EQ(0, size);
+}
+
+TEST_F(MetricsUtilsChromeOSTest, ReadLongMessageTest) {
+  base::File test_file(filepath,
+                       base::File::FLAG_OPEN_ALWAYS | base::File::FLAG_APPEND);
+  std::string message(MetricsUtils::kMessageMaxLength + 1, 'c');
+
+  int32_t message_size = message.length() + sizeof(int32_t);
+  test_file.WriteAtCurrentPos(reinterpret_cast<const char*>(&message_size),
+                              sizeof(message_size));
+  test_file.WriteAtCurrentPos(message.c_str(), message.length());
+  test_file.Close();
+
+  CrashSample crash("test");
+  MetricsUtils::WriteMetricToFile(crash, filename);
+
+  ScopedVector<MetricSample> samples;
+  MetricsUtils::ReadAndTruncateMetricsFromFile(filename, &samples);
+  ASSERT_EQ(size_t(1), samples.size());
+  AreEq(&crash, samples[0]);
+}
+
+TEST_F(MetricsUtilsChromeOSTest, WriteReadTest) {
+  HistogramSample hist("myhist", 1, 2, 3, 4);
+  CrashSample crash("crash");
+  LinearHistogramSample lhist("linear", 1, 10);
+  SparseHistogramSample shist("mysparse", 30);
+  UserActionSample action("myaction");
+
+  MetricsUtils::WriteMetricToFile(hist, filename);
+  MetricsUtils::WriteMetricToFile(crash, filename);
+  MetricsUtils::WriteMetricToFile(lhist, filename);
+  MetricsUtils::WriteMetricToFile(shist, filename);
+  MetricsUtils::WriteMetricToFile(action, filename);
+  ScopedVector<MetricSample> vect;
+  MetricsUtils::ReadAndTruncateMetricsFromFile(filename, &vect);
+  ASSERT_EQ(vect.size(), size_t(5));
+  AreEq(&hist, vect[0]);
+  AreEq(&crash, vect[1]);
+  AreEq(&lhist, vect[2]);
+  AreEq(&shist, vect[3]);
+  AreEq(&action, vect[4]);
+
+  int64 size = 0;
+  ASSERT_TRUE(base::GetFileSize(filepath, &size));
+  ASSERT_EQ(0, size);
+}
+
+}  // namespace
+}  // namespace metrics