- a4e14440b870dbf7b36975eaebf783a70a7fcee4 Release string_view microbenchmarks. by Alex Strelnikov <strel@google.com>

  - 7cec68e37e16fb4e266368236ae1de6419f6946a Increase Abseil's minimum supported cmake version to 3.1.... by Jon Cohen <cohenjon@google.com>
  - b977456175c8db380676bd56c44b32efbfc6f606 Fix a typo in the mutex.h comments. by Abseil Team <absl-team@google.com>
  - 3d30cec131d08b066bc1cf877e4f661e8ee0584c Release StrSplit microbenchmarks. by Alex Strelnikov <strel@google.com>
  - dddece6031feac1cca4689e623462f895f28d019 Release StrReplace microbenchmarks. by Alex Strelnikov <strel@google.com>
  - ac3b40e1694f74bdcf31b8d1152481e92edfd441 Internal Change by Abseil Team <absl-team@google.com>
  - d0e69ad6ddf0e59596a02ccab0253967f2909cdb Release StrCat microbenchmarks. by Alex Strelnikov <strel@google.com>
  - db4d471030fa320d2b9d2ce241610333f0eb7a50 Release StrJoin microbenchmarks. by Alex Strelnikov <strel@google.com>

GitOrigin-RevId: a4e14440b870dbf7b36975eaebf783a70a7fcee4
Change-Id: I3f12700aafce677049f4d1a6e09ea821963a8c9e

1 files changed, 124 insertions, 0 deletions

diff --git a/absl/strings/str_replace_benchmark.cc b/absl/strings/str_replace_benchmark.cc
new file mode 100644
index 000000000000..9dd72eb6e77c
--- /dev/null
+++ b/absl/strings/str_replace_benchmark.cc
@@ -0,0 +1,124 @@
+// Copyright 2018 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
+//
+//      http://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 "absl/strings/str_replace.h"
+
+#include <cstring>
+#include <string>
+
+#include "benchmark/benchmark.h"
+#include "absl/base/internal/raw_logging.h"
+
+namespace {
+
+std::string* big_string;
+std::string* after_replacing_the;
+std::string* after_replacing_many;
+
+struct Replacement {
+  const char* needle;
+  const char* replacement;
+} replacements[] = {
+    {"the", "box"},          //
+    {"brown", "quick"},      //
+    {"jumped", "liquored"},  //
+    {"dozen", "brown"},      //
+    {"lazy", "pack"},        //
+    {"liquor", "shakes"},    //
+};
+
+// Here, we set up a std::string for use in global-replace benchmarks.
+// We started with a million blanks, and then deterministically insert
+// 10,000 copies each of two pangrams.  The result is a std::string that is
+// 40% blank space and 60% these words.  'the' occurs 18,247 times and
+// all the substitutions together occur 49,004 times.
+//
+// We then create "after_replacing_the" to be a std::string that is a result of
+// replacing "the" with "box" in big_string.
+//
+// And then we create "after_replacing_many" to be a std::string that is result
+// of preferring several substitutions.
+void SetUpStrings() {
+  if (big_string == nullptr) {
+    size_t r = 0;
+    big_string = new std::string(1000 * 1000, ' ');
+    for (std::string phrase : {"the quick brown fox jumped over the lazy dogs",
+                          "pack my box with the five dozen liquor jugs"}) {
+      for (int i = 0; i < 10 * 1000; ++i) {
+        r = r * 237 + 41;  // not very random.
+        memcpy(&(*big_string)[r % (big_string->size() - phrase.size())],
+               phrase.data(), phrase.size());
+      }
+    }
+    // big_string->resize(50);
+    // OK, we've set up the std::string, now let's set up expectations - first by
+    // just replacing "the" with "box"
+    after_replacing_the = new std::string(*big_string);
+    for (size_t pos = 0;
+         (pos = after_replacing_the->find("the", pos)) != std::string::npos;) {
+      memcpy(&(*after_replacing_the)[pos], "box", 3);
+    }
+    // And then with all the replacements.
+    after_replacing_many = new std::string(*big_string);
+    for (size_t pos = 0;;) {
+      size_t next_pos = static_cast<size_t>(-1);
+      const char* needle_string = nullptr;
+      const char* replacement_string = nullptr;
+      for (const auto& r : replacements) {
+        auto needlepos = after_replacing_many->find(r.needle, pos);
+        if (needlepos != std::string::npos && needlepos < next_pos) {
+          next_pos = needlepos;
+          needle_string = r.needle;
+          replacement_string = r.replacement;
+        }
+      }
+      if (next_pos > after_replacing_many->size()) break;
+      after_replacing_many->replace(next_pos, strlen(needle_string),
+                                    replacement_string);
+      next_pos += strlen(replacement_string);
+      pos = next_pos;
+    }
+  }
+}
+
+void BM_StrReplaceAllOneReplacement(benchmark::State& state) {
+  SetUpStrings();
+  std::string src = *big_string;
+  for (auto _ : state) {
+    std::string dest = absl::StrReplaceAll(src, {{"the", "box"}});
+    ABSL_RAW_CHECK(dest == *after_replacing_the,
+                   "not benchmarking intended behavior");
+  }
+}
+BENCHMARK(BM_StrReplaceAllOneReplacement);
+
+void BM_StrReplaceAll(benchmark::State& state) {
+  SetUpStrings();
+  std::string src = *big_string;
+  for (auto _ : state) {
+    std::string dest = absl::StrReplaceAll(src, {{"the", "box"},
+                                            {"brown", "quick"},
+                                            {"jumped", "liquored"},
+                                            {"dozen", "brown"},
+                                            {"lazy", "pack"},
+                                            {"liquor", "shakes"}});
+    ABSL_RAW_CHECK(dest == *after_replacing_many,
+                   "not benchmarking intended behavior");
+  }
+}
+BENCHMARK(BM_StrReplaceAll);
+
+}  // namespace
+
+BENCHMARK_MAIN();