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carbon-lang/toolchain/base/timings.h
T
Jon Ross-Perkins 1d8c7ffe89 Add support for scoped timings. (#4533)
I think there are a few related ways to do this. I considered
llvm::make_scope_exit, but the return type is difficult to work with. I
particularly was thinking I could encapsulate the duration logic this
way.
2024-11-15 16:57:33 +00:00

78 lines
2.4 KiB
C++

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#ifndef CARBON_TOOLCHAIN_BASE_TIMINGS_H_
#define CARBON_TOOLCHAIN_BASE_TIMINGS_H_
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "toolchain/base/yaml.h"
namespace Carbon {
// Helps track timings for a compile.
class Timings {
public:
// Records a timing for a scope, if the timings object is valid.
class ScopedTiming {
public:
explicit ScopedTiming(std::optional<Timings>* timings,
llvm::StringRef label)
: timings(timings),
label(label),
start(*timings ? std::chrono::steady_clock::now()
: std::chrono::steady_clock::time_point::min()) {}
~ScopedTiming() {
if (*timings) {
(*timings)->Add(label, std::chrono::steady_clock::now() - start);
}
}
private:
std::optional<Timings>* timings;
llvm::StringRef label;
std::chrono::steady_clock::time_point start;
};
// Adds tracking for nanoseconds, paired with the given label.
auto Add(llvm::StringRef label, std::chrono::nanoseconds nanoseconds)
-> void {
timings_.push_back(
{.label = std::string(label), .nanoseconds = nanoseconds});
}
auto OutputYaml(llvm::StringRef filename) const -> Yaml::OutputMapping {
// Explicitly copy the filename.
return Yaml::OutputMapping([&, filename](Yaml::OutputMapping::Map map) {
map.Add("filename", filename);
map.Add("nanoseconds",
Yaml::OutputMapping([&](Yaml::OutputMapping::Map label_map) {
std::chrono::nanoseconds total_nanoseconds(0);
for (const auto& entry : timings_) {
total_nanoseconds += entry.nanoseconds;
label_map.Add(entry.label, static_cast<int64_t>(
entry.nanoseconds.count()));
}
label_map.Add("Total",
static_cast<int64_t>(total_nanoseconds.count()));
}));
});
}
private:
// Timing for a specific label.
struct Entry {
std::string label;
std::chrono::nanoseconds nanoseconds;
};
// The accumulated data on timings.
llvm::SmallVector<Entry> timings_;
};
} // namespace Carbon
#endif // CARBON_TOOLCHAIN_BASE_TIMINGS_H_