// 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. // // ----------------------------------------------------------------------------- // File: log/internal/log_format.h // ----------------------------------------------------------------------------- // // This file declares routines implementing formatting of log message and log // prefix. #ifndef ABSL_LOG_INTERNAL_LOG_FORMAT_H_ #define ABSL_LOG_INTERNAL_LOG_FORMAT_H_ #include <stddef.h> #include <string> #include "absl/base/config.h" #include "absl/base/log_severity.h" #include "absl/log/internal/config.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 { enum class PrefixFormat { … }; // Formats log message based on provided data. 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); // Formats various entry metadata into a text string meant for use as a // prefix on a log message string. Writes into `buf`, advances `buf` to point // at the remainder of the buffer (i.e. past any written bytes), and returns the // number of bytes written. // // In addition to calling `buf->remove_prefix()` (or the equivalent), this // function may also do `buf->remove_suffix(buf->size())` in cases where no more // bytes (i.e. no message data) should be written into the buffer. For example, // if the prefix ought to be: // I0926 09:00:00.000000 1234567 foo.cc:123] // `buf` is too small, the function might fill the whole buffer: // I0926 09:00:00.000000 1234 // (note the apparrently incorrect thread ID), or it might write less: // I0926 09:00:00.000000 // In this case, it might also empty `buf` prior to returning to prevent // message data from being written into the space where a reader would expect to // see a thread ID. 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 #endif // ABSL_LOG_INTERNAL_LOG_FORMAT_H_