Simple google3-compatible benchmarking.
Based on our open-source RE2 benchmarking code.
Includes benchmarks for a handful of <string.h> functions.
Change-Id: I30eb70d25dbf4ad5f2ca44976a8ce3b1ff7dad01
diff --git a/tests/benchmark_main.cpp b/tests/benchmark_main.cpp
new file mode 100644
index 0000000..4fbeb07
--- /dev/null
+++ b/tests/benchmark_main.cpp
@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * 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 "benchmark.h"
+
+#include <regex.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <string>
+#include <map>
+
+static int64_t gBytesProcessed;
+static int64_t gBenchmarkTotalTimeNs;
+static int64_t gBenchmarkStartTimeNs;
+
+typedef std::map<std::string, ::testing::Benchmark*> BenchmarkMap;
+typedef BenchmarkMap::iterator BenchmarkMapIt;
+static BenchmarkMap gBenchmarks;
+
+static int Round(int n) {
+ int base = 1;
+ while (base*10 < n) {
+ base *= 10;
+ }
+ if (n < 2*base) {
+ return 2*base;
+ }
+ if (n < 5*base) {
+ return 5*base;
+ }
+ return 10*base;
+}
+
+static int64_t NanoTime() {
+ struct timespec t;
+ t.tv_sec = t.tv_nsec = 0;
+ clock_gettime(CLOCK_MONOTONIC, &t);
+ return static_cast<int64_t>(t.tv_sec) * 1000000000LL + t.tv_nsec;
+}
+
+namespace testing {
+
+Benchmark* Benchmark::Arg(int arg) {
+ args_.push_back(arg);
+ return this;
+}
+
+bool Benchmark::ShouldRun(int argc, char* argv[]) {
+ if (argc == 1) {
+ return true; // With no arguments, we run all benchmarks.
+ }
+ // Otherwise, we interpret each argument as a regular expression and
+ // see if any of our benchmarks match.
+ for (int i = 1; i < argc; i++) {
+ regex_t re;
+ if (regcomp(&re, argv[i], 0) != 0) {
+ fprintf(stderr, "couldn't compile \"%s\" as a regular expression!\n", argv[i]);
+ exit(EXIT_FAILURE);
+ }
+ int match = regexec(&re, name_, 0, NULL, 0);
+ regfree(&re);
+ if (match != REG_NOMATCH) {
+ return true;
+ }
+ }
+ return false;
+}
+
+void Benchmark::Register(const char* name, void (*fn)(int), void (*fn_range)(int, int)) {
+ name_ = name;
+ fn_ = fn;
+ fn_range_ = fn_range;
+
+ if (fn_ == NULL && fn_range_ == NULL) {
+ fprintf(stderr, "%s: missing function\n", name_);
+ exit(EXIT_FAILURE);
+ }
+
+ gBenchmarks.insert(std::make_pair(name, this));
+}
+
+void Benchmark::Run() {
+ if (args_.empty()) {
+ fprintf(stderr, "%s: no args!\n", name_);
+ exit(EXIT_FAILURE);
+ }
+ for (size_t i = 0; i < args_.size(); ++i) {
+ RunWithArg(args_[i]);
+ }
+}
+
+void Benchmark::RunRepeatedlyWithArg(int iterations, int arg) {
+ gBytesProcessed = 0;
+ gBenchmarkTotalTimeNs = 0;
+ gBenchmarkStartTimeNs = NanoTime();
+ if (fn_ != NULL) {
+ fn_(iterations);
+ } else {
+ fn_range_(iterations, arg);
+ }
+ if (gBenchmarkStartTimeNs != 0) {
+ gBenchmarkTotalTimeNs += NanoTime() - gBenchmarkStartTimeNs;
+ }
+}
+
+void Benchmark::RunWithArg(int arg) {
+ // run once in case it's expensive
+ int iterations = 1;
+ RunRepeatedlyWithArg(iterations, arg);
+ while (gBenchmarkTotalTimeNs < 1e9 && iterations < 1e9) {
+ int last = iterations;
+ if (gBenchmarkTotalTimeNs/iterations == 0) {
+ iterations = 1e9;
+ } else {
+ iterations = 1e9 / (gBenchmarkTotalTimeNs/iterations);
+ }
+ iterations = std::max(last + 1, std::min(iterations + iterations/2, 100*last));
+ iterations = Round(iterations);
+ RunRepeatedlyWithArg(iterations, arg);
+ }
+
+ char throughput[100];
+ throughput[0] = '\0';
+ if (gBenchmarkTotalTimeNs > 0 && gBytesProcessed > 0) {
+ double mib_processed = static_cast<double>(gBytesProcessed)/1e6;
+ double seconds = static_cast<double>(gBenchmarkTotalTimeNs)/1e9;
+ snprintf(throughput, sizeof(throughput), " %8.2f MiB/s", mib_processed/seconds);
+ }
+
+ char full_name[100];
+ if (fn_range_ != NULL) {
+ if (arg >= (1<<20)) {
+ snprintf(full_name, sizeof(full_name), "%s/%dM", name_, arg/(1<<20));
+ } else if (arg >= (1<<10)) {
+ snprintf(full_name, sizeof(full_name), "%s/%dK", name_, arg/(1<<10));
+ } else {
+ snprintf(full_name, sizeof(full_name), "%s/%d", name_, arg);
+ }
+ } else {
+ snprintf(full_name, sizeof(full_name), "%s", name_);
+ }
+
+ printf("%-20s %10lld %10lld%s\n", full_name,
+ static_cast<int64_t>(iterations), gBenchmarkTotalTimeNs/iterations, throughput);
+ fflush(stdout);
+}
+
+} // namespace testing
+
+void SetBenchmarkBytesProcessed(int64_t x) {
+ gBytesProcessed = x;
+}
+
+void StopBenchmarkTiming() {
+ if (gBenchmarkStartTimeNs != 0) {
+ gBenchmarkTotalTimeNs += NanoTime() - gBenchmarkStartTimeNs;
+ }
+ gBenchmarkStartTimeNs = 0;
+}
+
+void StartBenchmarkTiming() {
+ if (gBenchmarkStartTimeNs == 0) {
+ gBenchmarkStartTimeNs = NanoTime();
+ }
+}
+
+int main(int argc, char* argv[]) {
+ if (gBenchmarks.empty()) {
+ fprintf(stderr, "no benchmarks!\n");
+ exit(EXIT_FAILURE);
+ }
+
+ printf("%-20s %10s %10s\n", "", "iterations", "ns/op");
+ fflush(stdout);
+
+ for (BenchmarkMapIt it = gBenchmarks.begin(); it != gBenchmarks.end(); ++it) {
+ ::testing::Benchmark* b = it->second;
+ if (b->ShouldRun(argc, argv)) {
+ b->Run();
+ }
+ }
+ return 0;
+}