Export of internal Abseil changes

--
f825cf3feb6db06522b2b4ee785de7dfa325780d by Martijn Vels <mvels@google.com>:

Move Cordz test helpers to cordz_test_helpers library

PiperOrigin-RevId: 370059941

--
5080249da6a4f5cc2b546aed48503fd028670379 by Martijn Vels <mvels@google.com>:

Add new Cordz instrumentation on AppendTree.

PiperOrigin-RevId: 369968167

--
21092b889fad34ec605894e311b436d5f417456f by Benjamin Barenblat <bbaren@google.com>:

Round floats using round(x), not static_cast<int>(x + 0.5)

Adding 0.5 to an IEEE float may cause one bit of precision loss, which
is enough to change the result in certain cases. For example,

    static_cast<int>(std::round(0.49999999999999994)) == 0
    static_cast<int>(0.49999999999999994 + 0.5) == 1

PiperOrigin-RevId: 369926519
GitOrigin-RevId: f825cf3feb6db06522b2b4ee785de7dfa325780d
Change-Id: Ib78ce1faec79f06578933db5dc6fc05de043ead1

1 files changed, 92 insertions, 0 deletions

diff --git a/absl/strings/cordz_test.cc b/absl/strings/cordz_test.cc
new file mode 100644
index 00000000..6e8deefd
--- /dev/null
+++ b/absl/strings/cordz_test.cc
@@ -0,0 +1,92 @@
+// Copyright 2021 The Abseil Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <string>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/base/config.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/base/macros.h"
+#include "absl/strings/cord.h"
+#include "absl/strings/cordz_test_helpers.h"
+#include "absl/strings/internal/cordz_functions.h"
+#include "absl/strings/internal/cordz_info.h"
+#include "absl/strings/internal/cordz_sample_token.h"
+#include "absl/strings/internal/cordz_statistics.h"
+#include "absl/strings/internal/cordz_update_tracker.h"
+#include "absl/strings/str_cat.h"
+#include "absl/strings/string_view.h"
+
+#ifdef ABSL_INTERNAL_CORDZ_ENABLED
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+
+using cord_internal::CordzInfo;
+using cord_internal::CordzSampleToken;
+using cord_internal::CordzStatistics;
+using cord_internal::CordzUpdateTracker;
+using Method = CordzUpdateTracker::MethodIdentifier;
+
+namespace {
+
+std::string MakeString(int length) {
+  std::string s(length, '.');
+  for (int i = 4; i < length; i += 2) {
+    s[i] = '\b';
+  }
+  return s;
+}
+
+TEST(CordzTest, ConstructSmallStringView) {
+  CordzSamplingIntervalHelper sample_every(1);
+  Cord cord(absl::string_view(MakeString(50)));
+  EXPECT_THAT(cord, HasValidCordzInfoOf(Method::kConstructorString));
+}
+
+TEST(CordzTest, ConstructLargeStringView) {
+  CordzSamplingIntervalHelper sample_every(1);
+  Cord cord(absl::string_view(MakeString(5000)));
+  EXPECT_THAT(cord, HasValidCordzInfoOf(Method::kConstructorString));
+}
+
+TEST(CordzTest, CopyConstruct) {
+  CordzSamplingIntervalHelper sample_every(1);
+  Cord src = UnsampledCord(MakeString(5000));
+  Cord cord(src);
+  EXPECT_THAT(cord, HasValidCordzInfoOf(Method::kConstructorCord));
+}
+
+TEST(CordzTest, AppendLargeCordToEmpty) {
+  CordzSamplingIntervalHelper sample_every(1);
+  Cord cord;
+  Cord src = UnsampledCord(MakeString(5000));
+  cord.Append(src);
+  EXPECT_THAT(cord, HasValidCordzInfoOf(Method::kAppendCord));
+}
+
+TEST(CordzTest, MoveAppendLargeCordToEmpty) {
+  CordzSamplingIntervalHelper sample_every(1);
+  Cord cord;
+  cord.Append(UnsampledCord(MakeString(5000)));
+  EXPECT_THAT(cord, HasValidCordzInfoOf(Method::kAppendCord));
+}
+
+}  // namespace
+
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_INTERNAL_CORDZ_ENABLED