log_format.cc | Explore in Territory

//
// Copyright 2022 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
//
//      https://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/log/internal/log_format.h"

#include <string.h>

#ifdef _MSC_VER
#include <winsock2.h>  // For timeval
#else
#include <sys/time.h>
#endif

#include <cstddef>
#include <cstdint>
#include <limits>
#include <string>
#include <type_traits>

#include "absl/base/config.h"
#include "absl/base/log_severity.h"
#include "absl/base/optimization.h"
#include "absl/log/internal/append_truncated.h"
#include "absl/log/internal/config.h"
#include "absl/log/internal/globals.h"
#include "absl/strings/numbers.h"
#include "absl/strings/str_format.h"
#include "absl/strings/string_view.h"
#include "absl/time/civil_time.h"
#include "absl/time/time.h"
#include "absl/types/span.h"

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace log_internal {
namespace {

// This templated function avoids compiler warnings about tautological
// comparisons when log_internal::Tid is unsigned. It can be replaced with a
// constexpr if once the minimum C++ version Abseil supports is C++17.
template <typename T>
inline std::enable_if_t<!std::is_signed<T>::value>
PutLeadingWhitespace(T tid, char*& p) { … }

template <typename T>
inline std::enable_if_t<std::is_signed<T>::value>
PutLeadingWhitespace(T tid, char*& p) { … }

// The fields before the filename are all fixed-width except for the thread ID,
// which is of bounded width.
size_t FormatBoundedFields(absl::LogSeverity severity, absl::Time timestamp,
                           log_internal::Tid tid, absl::Span<char>& buf) { … }

size_t FormatLineNumber(int line, absl::Span<char>& buf) { … }

}  // namespace

std::string FormatLogMessage(absl::LogSeverity severity,
                             absl::CivilSecond civil_second,
                             absl::Duration subsecond, log_internal::Tid tid,
                             absl::string_view basename, int line,
                             PrefixFormat format, absl::string_view message) { … }

// This method is fairly hot, and the library always passes a huge `buf`, so we
// save some bounds-checking cycles by not trying to do precise truncation.
// Truncating at a field boundary is probably a better UX anyway.
//
// The prefix is written in three parts, each of which does a single
// bounds-check and truncation:
// 1. severity, timestamp, and thread ID
// 2. filename
// 3. line number and bracket
size_t FormatLogPrefix(absl::LogSeverity severity, absl::Time timestamp,
                       log_internal::Tid tid, absl::string_view basename,
                       int line, PrefixFormat format, absl::Span<char>& buf) { … }

}  // namespace log_internal
ABSL_NAMESPACE_END
}  // namespace absl
chromium/third_party/abseil-cpp/absl/log/internal/log_format.cc
