libreoffice-online/common/Log.hpp
Ashod Nakashian 01138d7ae0 wsd: save errno before invoking any other functions
Most C and Posix API clobber errno. By failing to save
it immediately after invoking an API we risk simply
reporting the result of an arbitrary subsequent API call.

This adds LOG_SYS_ERRNO to take errno explicitly.
This is necessary because sometimes logging is not done
immediately after calling the function for which we
want to report errno. Similarly, log macros that log
errno need to save errno before calling any functions.
This is necessary as the argements might contain calls
that clobber errno.

This also converts some LOG_SYS entries to LOG_ERR
because there can be no relevant errno in that context
(f.e. in a catch clause).

A couple of LOG_ macros have been folded into others,
reducing redundancy.

Finally, both of these log macros append errno to the
log message, so there is little point in ending the
messages with a period.

Change-Id: Iecc656f67115fec78b65cad4e7c17a17623ecf43
Signed-off-by: Ashod Nakashian <ashod.nakashian@collabora.co.uk>
2020-12-29 11:40:17 +00:00

425 lines
18 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#pragma once
#include <sys/syscall.h>
#include <unistd.h>
#include <cerrno>
#include <cstddef>
#include <functional>
#include <iostream>
#include <thread>
#include <sstream>
#include <string>
#include <Poco/DateTime.h>
#include <Poco/DateTimeFormat.h>
#include <Poco/DateTimeFormatter.h>
#include <Poco/Logger.h>
#ifdef __ANDROID__
#include <android/log.h>
#endif
#include "Util.hpp"
inline std::ostream& operator<< (std::ostream& os, const std::chrono::system_clock::time_point& ts)
{
os << Util::getIso8601FracformatTime(ts);
return os;
}
/// Format seconds with the units suffix until we migrate to C++20.
inline std::ostream& operator<<(std::ostream& os, const std::chrono::seconds& s)
{
os << s.count() << 's';
return os;
}
/// Format milliseconds with the units suffix until we migrate to C++20.
inline std::ostream& operator<<(std::ostream& os, const std::chrono::milliseconds& ms)
{
os << ms.count() << "ms";
return os;
}
/// Format microseconds with the units suffix until we migrate to C++20.
inline std::ostream& operator<<(std::ostream& os, const std::chrono::microseconds& ms)
{
os << ms.count() << "us";
return os;
}
namespace Log
{
/// Initialize the logging system.
void initialize(const std::string& name,
const std::string& logLevel,
const bool withColor,
const bool logToFile,
const std::map<std::string, std::string>& config);
/// Returns the underlying logging system.
Poco::Logger& logger();
/// Shutdown and release the logging system.
void shutdown();
#if !MOBILEAPP
extern bool IsShutdown;
/// Was static shutdown() called? If so, producing more logs should be avoided.
inline bool isShutdownCalled() { return IsShutdown; }
#else
constexpr bool isShutdownCalled() { return false; }
#endif
/// Generates log entry prefix. Example follows (without the pipes).
/// |wsd-07272-07298 2020-04-25 17:29:28.928697 [ websrv_poll ] TRC |
/// This is fully signal-safe. Buffer must be at least 128 bytes.
char* prefix(const Poco::DateTime& time, char* buffer, const char* level);
template <int Size> inline char* prefix(char buffer[Size], const char* level)
{
static_assert(Size >= 128, "Buffer size must be at least 128 bytes.");
return prefix(Poco::DateTime(), buffer, level);
}
inline bool traceEnabled() { return logger().trace(); }
inline bool debugEnabled() { return logger().debug(); }
inline bool infoEnabled() { return logger().information(); }
inline bool warnEnabled() { return logger().warning(); }
inline bool errorEnabled() { return logger().error(); }
inline bool fatalEnabled() { return logger().fatal(); }
/// Signal safe prefix logging
void signalLogPrefix();
/// Signal safe logging
void signalLog(const char* message);
/// Signal log number
void signalLogNumber(std::size_t num);
/// The following is to write streaming logs.
/// Log::info() << "Value: 0x" << std::hex << value
/// << ", pointer: " << this << Log::end;
static const struct _end_marker
{
_end_marker()
{
}
} end;
/// Helper class to support implementing streaming
/// operator for logging.
class StreamLogger
{
public:
/// No-op instance.
StreamLogger()
: _enabled(false)
{
}
StreamLogger(std::function<void(const std::string&)> func, const char*level)
: _func(std::move(func)),
_enabled(true)
{
char buffer[1024];
_stream << prefix<sizeof(buffer) - 1>(buffer, level);
}
StreamLogger(StreamLogger&& sl) noexcept
: _stream(sl._stream.str()),
_func(std::move(sl._func)),
_enabled(sl._enabled)
{
}
bool enabled() const { return _enabled; }
void flush() const
{
if (_enabled)
{
_func(_stream.str());
}
}
std::ostringstream& getStream() { return _stream; }
private:
std::ostringstream _stream;
std::function<void(const std::string&)> _func;
const bool _enabled;
};
inline StreamLogger trace()
{
return traceEnabled()
? StreamLogger([](const std::string& msg) { logger().trace(msg); }, "TRC")
: StreamLogger();
}
inline StreamLogger debug()
{
return debugEnabled()
? StreamLogger([](const std::string& msg) { logger().debug(msg); }, "DBG")
: StreamLogger();
}
inline StreamLogger info()
{
return infoEnabled()
? StreamLogger([](const std::string& msg) { logger().information(msg); }, "INF")
: StreamLogger();
}
inline StreamLogger warn()
{
return warnEnabled()
? StreamLogger([](const std::string& msg) { logger().warning(msg); }, "WRN")
: StreamLogger();
}
inline StreamLogger error()
{
return errorEnabled()
? StreamLogger([](const std::string& msg) { logger().error(msg); }, "ERR")
: StreamLogger();
}
inline StreamLogger fatal()
{
return fatalEnabled()
? StreamLogger([](const std::string& msg) { logger().fatal(msg); }, "FTL")
: StreamLogger();
}
template <typename U>
StreamLogger& operator<<(StreamLogger& lhs, const U& rhs)
{
if (lhs.enabled())
{
lhs.getStream() << rhs;
}
return lhs;
}
template <typename U>
StreamLogger& operator<<(StreamLogger&& lhs, U&& rhs)
{
if (lhs.enabled())
{
lhs.getStream() << rhs;
}
return lhs;
}
inline StreamLogger& operator<<(StreamLogger& lhs, const std::chrono::system_clock::time_point& rhs)
{
if (lhs.enabled())
{
lhs.getStream() << Util::getIso8601FracformatTime(rhs);
}
return lhs;
}
inline void operator<<(StreamLogger& lhs, const _end_marker&)
{
(void)end;
lhs.flush();
}
/// Dump the invalid id as 0, otherwise dump in hex.
inline std::string to_string(const std::thread::id& id)
{
if (id != std::thread::id())
{
std::ostringstream os;
os << std::hex << "0x" << id;
return os.str();
}
return "0";
}
inline StreamLogger& operator<<(StreamLogger& lhs, const std::thread::id& rhs)
{
if (lhs.enabled())
{
lhs.getStream() << Log::to_string(rhs);
}
return lhs;
}
}
#ifndef IOS
#define LOG_FILE_NAME(f) f
#else
// We know that when building with Xcode, __FILE__ will always be a full path, with several slashes,
// so this will always work. We want just the file name, they are unique anyway.
#define LOG_FILE_NAME(f) (strrchr(f, '/') + 1)
#endif
#define LOG_END(LOG, FILEP) \
do \
{ \
if (FILEP) \
LOG << "| " << LOG_FILE_NAME(__FILE__) << ':' << __LINE__; \
LOG.flush(); \
} while (false)
#ifdef __ANDROID__
#define LOG_BODY_(LOG, PRIO, LVL, X, FILEP) \
char b_[1024]; \
std::ostringstream oss_(Log::prefix<sizeof(b_) - 1>(b_, LVL), std::ostringstream::ate); \
oss_ << std::boolalpha << X; \
LOG_END(oss_, FILEP); \
((void)__android_log_print(ANDROID_LOG_DEBUG, "loolwsd", "%s %s", LVL, oss_.str().c_str()))
#else
#define LOG_BODY_(LOG, PRIO, LVL, X, FILEP) \
char b_[1024]; \
std::ostringstream oss_(Log::prefix<sizeof(b_) - 1>(b_, LVL), std::ostringstream::ate); \
oss_ << std::boolalpha << X; \
LOG_END(oss_, FILEP); \
LOG.log(Poco::Message(LOG.name(), oss_.str(), Poco::Message::PRIO_##PRIO));
#endif
#define LOG_TRC(X) \
do \
{ \
auto& log_ = Log::logger(); \
if (log_.trace() && !Log::isShutdownCalled()) \
{ \
LOG_BODY_(log_, TRACE, "TRC", X, true); \
} \
} while (false)
#define LOG_TRC_NOFILE(X) \
do \
{ \
auto& log_ = Log::logger(); \
if (log_.trace() && !Log::isShutdownCalled()) \
{ \
LOG_BODY_(log_, TRACE, "TRC", X, false); \
} \
} while (false)
#define LOG_DBG(X) \
do \
{ \
auto& log_ = Log::logger(); \
if (log_.debug() && !Log::isShutdownCalled()) \
{ \
LOG_BODY_(log_, DEBUG, "DBG", X, true); \
} \
} while (false)
#define LOG_INF(X) \
do \
{ \
auto& log_ = Log::logger(); \
if (log_.information() && !Log::isShutdownCalled()) \
{ \
LOG_BODY_(log_, INFORMATION, "INF", X, true); \
} \
} while (false)
#define LOG_INF_NOFILE(X) \
do \
{ \
auto& log_ = Log::logger(); \
if (log_.information() && !Log::isShutdownCalled()) \
{ \
LOG_BODY_(log_, INFORMATION, "INF", X, false); \
} \
} while (false)
#define LOG_WRN(X) \
do \
{ \
auto& log_ = Log::logger(); \
if (!Log::isShutdownCalled() && log_.warning()) \
{ \
LOG_BODY_(log_, WARNING, "WRN", X, true); \
} \
} while (false)
#define LOG_ERR(X) \
do \
{ \
auto& log_ = Log::logger(); \
if (!Log::isShutdownCalled() && log_.error()) \
{ \
LOG_BODY_(log_, ERROR, "ERR", X, true); \
} \
} while (false)
/// Log an ERR entry with the given errno appended.
#define LOG_SYS_ERRNO(ERRNO, X) \
do \
{ \
const auto onrre = ERRNO; /* Save errno immediately while avoiding name clashes*/ \
LOG_ERR(X << " (" << Util::symbolicErrno(onrre) << ": " << std::strerror(onrre) << ')'); \
} while (false)
/// Log an ERR entry with errno appended.
/// NOTE: Must be called immediately after an API that sets errno.
/// Use LOG_SYS_ERRNO to pass errno explicitly.
#define LOG_SYS(X) LOG_SYS_ERRNO(errno, X)
#define LOG_FTL(X) \
do \
{ \
std::cerr << X << std::endl; \
auto& log_ = Log::logger(); \
if (!Log::isShutdownCalled() && log_.fatal()) \
{ \
LOG_BODY_(log_, FATAL, "FTL", X, true); \
} \
} while (false)
/// Log an FTL (fatal) entry with errno appended.
/// NOTE: Must be called immediately after an API that sets errno.
#define LOG_SFL(X) \
do \
{ \
const auto onrre = errno; /* Save errno immediately while avoiding name clashes*/ \
LOG_FTL(X << " (" << Util::symbolicErrno(onrre) << ": " << std::strerror(onrre) << ')'); \
} while (false)
#define LOG_CHECK(X) \
do \
{ \
if (!(X)) \
{ \
LOG_ERR("Check failed. Expected (" #X ")."); \
} \
} while (false)
#define LOG_CHECK_RET(X, RET) \
do \
{ \
if (!(X)) \
{ \
LOG_ERR("Check failed. Expected (" #X ")."); \
return RET; \
} \
} while (false)
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */