logging.h

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2020 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#ifndef BITCOIN_LOGGING_H
#define BITCOIN_LOGGING_H
 
#include <fs.h>
#include <tinyformat.h>
#include <threadsafety.h>
#include <util/string.h>
 
#include <atomic>
#include <cstdint>
#include <list>
#include <mutex>
#include <string>
#include <vector>
 
static const bool DEFAULT_LOGTIMEMICROS = false;
static const bool DEFAULT_LOGIPS        = false;
static const bool DEFAULT_LOGTIMESTAMPS = true;
static const bool DEFAULT_LOGTHREADNAMES = false;
static const bool DEFAULT_LOGSOURCELOCATIONS = false;
extern const char * const DEFAULT_DEBUGLOGFILE;
 
extern bool fLogIPs;
 
struct LogCategory {
    std::string category;
    bool active;
};
 
namespace BCLog {
    enum LogFlags : uint32_t {
        NONE        = 0,
        NET         = (1 <<  0),
        TOR         = (1 <<  1),
        MEMPOOL     = (1 <<  2),
        HTTP        = (1 <<  3),
        BENCH       = (1 <<  4),
        ZMQ         = (1 <<  5),
        WALLETDB    = (1 <<  6),
        RPC         = (1 <<  7),
        ESTIMATEFEE = (1 <<  8),
        ADDRMAN     = (1 <<  9),
        SELECTCOINS = (1 << 10),
        REINDEX     = (1 << 11),
        CMPCTBLOCK  = (1 << 12),
        RAND        = (1 << 13),
        PRUNE       = (1 << 14),
        PROXY       = (1 << 15),
        MEMPOOLREJ  = (1 << 16),
        LIBEVENT    = (1 << 17),
        COINDB      = (1 << 18),
        QT          = (1 << 19),
        LEVELDB     = (1 << 20),
        VALIDATION  = (1 << 21),
        I2P         = (1 << 22),
        IPC         = (1 << 23),
        ALL         = ~(uint32_t)0,
    };
 
    class Logger
    {
    private:
        mutable StdMutex m_cs; // Can not use Mutex from sync.h because in debug mode it would cause a deadlock when a potential deadlock was detected
 
        FILE* m_fileout GUARDED_BY(m_cs) = nullptr;
        std::list<std::string> m_msgs_before_open GUARDED_BY(m_cs);
        bool m_buffering GUARDED_BY(m_cs) = true; 
 
        std::atomic_bool m_started_new_line{true};
 
        std::atomic<uint32_t> m_categories{0};
 
        std::string LogTimestampStr(const std::string& str);
 
        std::list<std::function<void(const std::string&)>> m_print_callbacks GUARDED_BY(m_cs) {};
 
    public:
        bool m_print_to_console = false;
        bool m_print_to_file = false;
 
        bool m_log_timestamps = DEFAULT_LOGTIMESTAMPS;
        bool m_log_time_micros = DEFAULT_LOGTIMEMICROS;
        bool m_log_threadnames = DEFAULT_LOGTHREADNAMES;
        bool m_log_sourcelocations = DEFAULT_LOGSOURCELOCATIONS;
 
        fs::path m_file_path;
        std::atomic<bool> m_reopen_file{false};
 
        void LogPrintStr(const std::string& str, const std::string& logging_function, const std::string& source_file, const int source_line);
 
        bool Enabled() const
        {
            StdLockGuard scoped_lock(m_cs);
            return m_buffering || m_print_to_console || m_print_to_file || !m_print_callbacks.empty();
        }
 
        std::list<std::function<void(const std::string&)>>::iterator PushBackCallback(std::function<void(const std::string&)> fun)
        {
            StdLockGuard scoped_lock(m_cs);
            m_print_callbacks.push_back(std::move(fun));
            return --m_print_callbacks.end();
        }
 
        void DeleteCallback(std::list<std::function<void(const std::string&)>>::iterator it)
        {
            StdLockGuard scoped_lock(m_cs);
            m_print_callbacks.erase(it);
        }
 
        bool StartLogging();
        void DisconnectTestLogger();
 
        void ShrinkDebugFile();
 
        uint32_t GetCategoryMask() const { return m_categories.load(); }
 
        void EnableCategory(LogFlags flag);
        bool EnableCategory(const std::string& str);
        void DisableCategory(LogFlags flag);
        bool DisableCategory(const std::string& str);
 
        bool WillLogCategory(LogFlags category) const;
        std::vector<LogCategory> LogCategoriesList() const;
        std::string LogCategoriesString() const
        {
            return Join(LogCategoriesList(), ", ", [&](const LogCategory& i) { return i.category; });
        };
 
        bool DefaultShrinkDebugFile() const;
    };
 
} // namespace BCLog
 
BCLog::Logger& LogInstance();
 
static inline bool LogAcceptCategory(BCLog::LogFlags category)
{
    return LogInstance().WillLogCategory(category);
}
 
bool GetLogCategory(BCLog::LogFlags& flag, const std::string& str);
 
// Be conservative when using LogPrintf/error or other things which
// unconditionally log to debug.log! It should not be the case that an inbound
// peer can fill up a user's disk with debug.log entries.
 
template <typename... Args>
static inline void LogPrintf_(const std::string& logging_function, const std::string& source_file, const int source_line, const char* fmt, const Args&... args)
{
    if (LogInstance().Enabled()) {
        std::string log_msg;
        try {
            log_msg = tfm::format(fmt, args...);
        } catch (tinyformat::format_error& fmterr) {
            /* Original format string will have newline so don't add one here */
            log_msg = "Error \"" + std::string(fmterr.what()) + "\" while formatting log message: " + fmt;
        }
        LogInstance().LogPrintStr(log_msg, logging_function, source_file, source_line);
    }
}
 
#define LogPrintf(...) LogPrintf_(__func__, __FILE__, __LINE__, __VA_ARGS__)
 
// Use a macro instead of a function for conditional logging to prevent
// evaluating arguments when logging for the category is not enabled.
#define LogPrint(category, ...)              \
    do {                                     \
        if (LogAcceptCategory((category))) { \
            LogPrintf(__VA_ARGS__);          \
        }                                    \
    } while (0)
 
#endif // BITCOIN_LOGGING_H