From b56cbdd23834a65682c0b46f367f8679e83bc894 Mon Sep 17 00:00:00 2001
From: Abseil Team <absl-team@google.com>
Date: Fri, 18 Sep 2020 15:55:15 -0700
Subject: Abseil LTS 20200923

What's New:
* `absl::StatusOr<T>` has been released. See our [blog
  post](https://abseil.io/blog/2020-091021-status) for more
  information.
* Abseil Flags reflection interfaces have been released.
* Abseil Flags memory usage has been significantly optimized.
* Abseil now supports a "hardened" build mode. This build mode enables
  runtime checks that guard against programming errors that may lead
  to security vulnerabilities.

Notable Fixes:
* Sanitizer dynamic annotations like `AnnotateRWLockCreate` that are
  also defined by the compiler sanitizer implementation are no longer
  also defined by Abseil.
* Sanitizer macros are now prefixed with `ABSL_` to avoid naming collisions.
* Sanitizer usage is now automatically detected and no longer requires
  macros like `ADDRESS_SANITIZER` to be defined on the command line.

Breaking Changes:
* Abseil no longer contains a `dynamic_annotations` library. Users
  using a supported build system (Bazel or CMake) are unaffected by
  this, but users manually specifying link libraries may get an error
  about a missing linker input.

Baseline: 7680a5f8efe32de4753baadbd63e74e59d95bac1
Cherry picks: None
---
 absl/strings/str_cat_benchmark.cc | 49 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

(limited to 'absl/strings/str_cat_benchmark.cc')

diff --git a/absl/strings/str_cat_benchmark.cc b/absl/strings/str_cat_benchmark.cc
index 14c63b3f..02c4dbe6 100644
--- a/absl/strings/str_cat_benchmark.cc
+++ b/absl/strings/str_cat_benchmark.cc
@@ -23,7 +23,7 @@
 namespace {
 
 const char kStringOne[] = "Once Upon A Time, ";
-const char kStringTwo[] = "There was a std::string benchmark";
+const char kStringTwo[] = "There was a string benchmark";
 
 // We want to include negative numbers in the benchmark, so this function
 // is used to count 0, 1, -1, 2, -2, 3, -3, ...
@@ -137,4 +137,51 @@ void BM_DoubleToString_By_SixDigits(benchmark::State& state) {
 }
 BENCHMARK(BM_DoubleToString_By_SixDigits);
 
+template <typename... Chunks>
+void BM_StrAppendImpl(benchmark::State& state, size_t total_bytes,
+                      Chunks... chunks) {
+  for (auto s : state) {
+    std::string result;
+    while (result.size() < total_bytes) {
+      absl::StrAppend(&result, chunks...);
+      benchmark::DoNotOptimize(result);
+    }
+  }
+}
+
+void BM_StrAppend(benchmark::State& state) {
+  const int total_bytes = state.range(0);
+  const int chunks_at_a_time = state.range(1);
+  const absl::string_view kChunk = "0123456789";
+
+  switch (chunks_at_a_time) {
+    case 1:
+      return BM_StrAppendImpl(state, total_bytes, kChunk);
+    case 2:
+      return BM_StrAppendImpl(state, total_bytes, kChunk, kChunk);
+    case 4:
+      return BM_StrAppendImpl(state, total_bytes, kChunk, kChunk, kChunk,
+                              kChunk);
+    case 8:
+      return BM_StrAppendImpl(state, total_bytes, kChunk, kChunk, kChunk,
+                              kChunk, kChunk, kChunk, kChunk, kChunk);
+    default:
+      std::abort();
+  }
+}
+
+template <typename B>
+void StrAppendConfig(B* benchmark) {
+  for (int bytes : {10, 100, 1000, 10000}) {
+    for (int chunks : {1, 2, 4, 8}) {
+      // Only add the ones that divide properly. Otherwise we are over counting.
+      if (bytes % (10 * chunks) == 0) {
+        benchmark->Args({bytes, chunks});
+      }
+    }
+  }
+}
+
+BENCHMARK(BM_StrAppend)->Apply(StrAppendConfig);
+
 }  // namespace
-- 
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