rocksdb/logging/log_buffer.h
Levi Tamasi af7ae912e2 Fix potential ambiguities in/around port/sys_time.h (#10045)
Summary:
There are some time-related POSIX APIs that are not available on Windows
(e.g. `localtime_r`), which we have worked around by providing our own
implementations in `port/sys_time.h`. This workaround actually relies on
some ambiguity: on Windows, a call to `localtime_r` calls
`ROCKSDB_NAMESPACE::port::localtime_r` (which is pulled into
`ROCKSDB_NAMESPACE` by a using-declaration), while on other platforms
it calls the global `localtime_r`. This works fine as long as there is only one
candidate function; however, it breaks down when there is more than one
`localtime_r` visible in a scope.

The patch fixes this by introducing `ROCKSDB_NAMESPACE::port::{TimeVal, GetTimeOfDay, LocalTimeR}`
to eliminate any ambiguity.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10045

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D36639372

Pulled By: ltamasi

fbshipit-source-id: fc13dbfa421b7c8918111a6d9e24ce77e91a7c50
2022-05-24 18:20:17 -07:00

57 lines
1.8 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#include <ctime>
#include "memory/arena.h"
#include "port/sys_time.h"
#include "rocksdb/env.h"
#include "util/autovector.h"
namespace ROCKSDB_NAMESPACE {
class Logger;
// A class to buffer info log entries and flush them in the end.
class LogBuffer {
public:
// log_level: the log level for all the logs
// info_log: logger to write the logs to
LogBuffer(const InfoLogLevel log_level, Logger* info_log);
// Add a log entry to the buffer. Use default max_log_size.
// max_log_size indicates maximize log size, including some metadata.
void AddLogToBuffer(size_t max_log_size, const char* format, va_list ap);
size_t IsEmpty() const { return logs_.empty(); }
// Flush all buffered log to the info log.
void FlushBufferToLog();
static const size_t kDefaultMaxLogSize = 512;
private:
// One log entry with its timestamp
struct BufferedLog {
port::TimeVal now_tv; // Timestamp of the log
char message[1]; // Beginning of log message
};
const InfoLogLevel log_level_;
Logger* info_log_;
Arena arena_;
autovector<BufferedLog*> logs_;
};
// Add log to the LogBuffer for a delayed info logging. It can be used when
// we want to add some logs inside a mutex.
// max_log_size indicates maximize log size, including some metadata.
extern void LogToBuffer(LogBuffer* log_buffer, size_t max_log_size,
const char* format, ...);
// Same as previous function, but with default max log size.
extern void LogToBuffer(LogBuffer* log_buffer, const char* format, ...);
} // namespace ROCKSDB_NAMESPACE