Squashed 'third_party/google-benchmark/' content from commit 785e2c3
Change-Id: Iaaca5eca89f717081452e643a233e86425b03e89
git-subtree-dir: third_party/google-benchmark
git-subtree-split: 785e2c3158589e8ef48c59ba80e48d76bdbd8902
diff --git a/src/string_util.cc b/src/string_util.cc
new file mode 100644
index 0000000..05ac5b4
--- /dev/null
+++ b/src/string_util.cc
@@ -0,0 +1,261 @@
+#include "string_util.h"
+
+#include <array>
+#include <cmath>
+#include <cstdarg>
+#include <cstdio>
+#include <memory>
+#include <sstream>
+
+#include "arraysize.h"
+
+namespace benchmark {
+namespace {
+
+// kilo, Mega, Giga, Tera, Peta, Exa, Zetta, Yotta.
+const char kBigSIUnits[] = "kMGTPEZY";
+// Kibi, Mebi, Gibi, Tebi, Pebi, Exbi, Zebi, Yobi.
+const char kBigIECUnits[] = "KMGTPEZY";
+// milli, micro, nano, pico, femto, atto, zepto, yocto.
+const char kSmallSIUnits[] = "munpfazy";
+
+// We require that all three arrays have the same size.
+static_assert(arraysize(kBigSIUnits) == arraysize(kBigIECUnits),
+ "SI and IEC unit arrays must be the same size");
+static_assert(arraysize(kSmallSIUnits) == arraysize(kBigSIUnits),
+ "Small SI and Big SI unit arrays must be the same size");
+
+static const int64_t kUnitsSize = arraysize(kBigSIUnits);
+
+void ToExponentAndMantissa(double val, double thresh, int precision,
+ double one_k, std::string* mantissa,
+ int64_t* exponent) {
+ std::stringstream mantissa_stream;
+
+ if (val < 0) {
+ mantissa_stream << "-";
+ val = -val;
+ }
+
+ // Adjust threshold so that it never excludes things which can't be rendered
+ // in 'precision' digits.
+ const double adjusted_threshold =
+ std::max(thresh, 1.0 / std::pow(10.0, precision));
+ const double big_threshold = adjusted_threshold * one_k;
+ const double small_threshold = adjusted_threshold;
+ // Values in ]simple_threshold,small_threshold[ will be printed as-is
+ const double simple_threshold = 0.01;
+
+ if (val > big_threshold) {
+ // Positive powers
+ double scaled = val;
+ for (size_t i = 0; i < arraysize(kBigSIUnits); ++i) {
+ scaled /= one_k;
+ if (scaled <= big_threshold) {
+ mantissa_stream << scaled;
+ *exponent = i + 1;
+ *mantissa = mantissa_stream.str();
+ return;
+ }
+ }
+ mantissa_stream << val;
+ *exponent = 0;
+ } else if (val < small_threshold) {
+ // Negative powers
+ if (val < simple_threshold) {
+ double scaled = val;
+ for (size_t i = 0; i < arraysize(kSmallSIUnits); ++i) {
+ scaled *= one_k;
+ if (scaled >= small_threshold) {
+ mantissa_stream << scaled;
+ *exponent = -static_cast<int64_t>(i + 1);
+ *mantissa = mantissa_stream.str();
+ return;
+ }
+ }
+ }
+ mantissa_stream << val;
+ *exponent = 0;
+ } else {
+ mantissa_stream << val;
+ *exponent = 0;
+ }
+ *mantissa = mantissa_stream.str();
+}
+
+std::string ExponentToPrefix(int64_t exponent, bool iec) {
+ if (exponent == 0) return "";
+
+ const int64_t index = (exponent > 0 ? exponent - 1 : -exponent - 1);
+ if (index >= kUnitsSize) return "";
+
+ const char* array =
+ (exponent > 0 ? (iec ? kBigIECUnits : kBigSIUnits) : kSmallSIUnits);
+ if (iec)
+ return array[index] + std::string("i");
+ else
+ return std::string(1, array[index]);
+}
+
+std::string ToBinaryStringFullySpecified(double value, double threshold,
+ int precision, double one_k = 1024.0) {
+ std::string mantissa;
+ int64_t exponent;
+ ToExponentAndMantissa(value, threshold, precision, one_k, &mantissa,
+ &exponent);
+ return mantissa + ExponentToPrefix(exponent, false);
+}
+
+} // end namespace
+
+void AppendHumanReadable(int n, std::string* str) {
+ std::stringstream ss;
+ // Round down to the nearest SI prefix.
+ ss << ToBinaryStringFullySpecified(n, 1.0, 0);
+ *str += ss.str();
+}
+
+std::string HumanReadableNumber(double n, double one_k) {
+ // 1.1 means that figures up to 1.1k should be shown with the next unit down;
+ // this softens edge effects.
+ // 1 means that we should show one decimal place of precision.
+ return ToBinaryStringFullySpecified(n, 1.1, 1, one_k);
+}
+
+std::string StrFormatImp(const char* msg, va_list args) {
+ // we might need a second shot at this, so pre-emptivly make a copy
+ va_list args_cp;
+ va_copy(args_cp, args);
+
+ // TODO(ericwf): use std::array for first attempt to avoid one memory
+ // allocation guess what the size might be
+ std::array<char, 256> local_buff;
+ std::size_t size = local_buff.size();
+ // 2015-10-08: vsnprintf is used instead of snd::vsnprintf due to a limitation
+ // in the android-ndk
+ auto ret = vsnprintf(local_buff.data(), size, msg, args_cp);
+
+ va_end(args_cp);
+
+ // handle empty expansion
+ if (ret == 0) return std::string{};
+ if (static_cast<std::size_t>(ret) < size)
+ return std::string(local_buff.data());
+
+ // we did not provide a long enough buffer on our first attempt.
+ // add 1 to size to account for null-byte in size cast to prevent overflow
+ size = static_cast<std::size_t>(ret) + 1;
+ auto buff_ptr = std::unique_ptr<char[]>(new char[size]);
+ // 2015-10-08: vsnprintf is used instead of snd::vsnprintf due to a limitation
+ // in the android-ndk
+ ret = vsnprintf(buff_ptr.get(), size, msg, args);
+ return std::string(buff_ptr.get());
+}
+
+std::string StrFormat(const char* format, ...) {
+ va_list args;
+ va_start(args, format);
+ std::string tmp = StrFormatImp(format, args);
+ va_end(args);
+ return tmp;
+}
+
+void ReplaceAll(std::string* str, const std::string& from,
+ const std::string& to) {
+ std::size_t start = 0;
+ while ((start = str->find(from, start)) != std::string::npos) {
+ str->replace(start, from.length(), to);
+ start += to.length();
+ }
+}
+
+#ifdef BENCHMARK_STL_ANDROID_GNUSTL
+/*
+ * GNU STL in Android NDK lacks support for some C++11 functions, including
+ * stoul, stoi, stod. We reimplement them here using C functions strtoul,
+ * strtol, strtod. Note that reimplemented functions are in benchmark::
+ * namespace, not std:: namespace.
+ */
+unsigned long stoul(const std::string& str, size_t* pos, int base) {
+ /* Record previous errno */
+ const int oldErrno = errno;
+ errno = 0;
+
+ const char* strStart = str.c_str();
+ char* strEnd = const_cast<char*>(strStart);
+ const unsigned long result = strtoul(strStart, &strEnd, base);
+
+ const int strtoulErrno = errno;
+ /* Restore previous errno */
+ errno = oldErrno;
+
+ /* Check for errors and return */
+ if (strtoulErrno == ERANGE) {
+ throw std::out_of_range(
+ "stoul failed: " + str + " is outside of range of unsigned long");
+ } else if (strEnd == strStart || strtoulErrno != 0) {
+ throw std::invalid_argument(
+ "stoul failed: " + str + " is not an integer");
+ }
+ if (pos != nullptr) {
+ *pos = static_cast<size_t>(strEnd - strStart);
+ }
+ return result;
+}
+
+int stoi(const std::string& str, size_t* pos, int base) {
+ /* Record previous errno */
+ const int oldErrno = errno;
+ errno = 0;
+
+ const char* strStart = str.c_str();
+ char* strEnd = const_cast<char*>(strStart);
+ const long result = strtol(strStart, &strEnd, base);
+
+ const int strtolErrno = errno;
+ /* Restore previous errno */
+ errno = oldErrno;
+
+ /* Check for errors and return */
+ if (strtolErrno == ERANGE || long(int(result)) != result) {
+ throw std::out_of_range(
+ "stoul failed: " + str + " is outside of range of int");
+ } else if (strEnd == strStart || strtolErrno != 0) {
+ throw std::invalid_argument(
+ "stoul failed: " + str + " is not an integer");
+ }
+ if (pos != nullptr) {
+ *pos = static_cast<size_t>(strEnd - strStart);
+ }
+ return int(result);
+}
+
+double stod(const std::string& str, size_t* pos) {
+ /* Record previous errno */
+ const int oldErrno = errno;
+ errno = 0;
+
+ const char* strStart = str.c_str();
+ char* strEnd = const_cast<char*>(strStart);
+ const double result = strtod(strStart, &strEnd);
+
+ /* Restore previous errno */
+ const int strtodErrno = errno;
+ errno = oldErrno;
+
+ /* Check for errors and return */
+ if (strtodErrno == ERANGE) {
+ throw std::out_of_range(
+ "stoul failed: " + str + " is outside of range of int");
+ } else if (strEnd == strStart || strtodErrno != 0) {
+ throw std::invalid_argument(
+ "stoul failed: " + str + " is not an integer");
+ }
+ if (pos != nullptr) {
+ *pos = static_cast<size_t>(strEnd - strStart);
+ }
+ return result;
+}
+#endif
+
+} // end namespace benchmark