log_internal.h

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// SPDX-License-Identifier: LGPL-2.1-or-later
 
#pragma once
 
#include <atomic>
#include <map>
#include <vector>
#include <string_view>
#include <fstream>
#include <thread>
#include <mutex>
#include "threading/mutex_auto_lock.h"
#include "util/basic_macros.h"
#include "irrlichttypes.h"
 
class ILogOutput;
 
enum LogLevel {
        LL_NONE, // Special level that is always printed
        LL_ERROR,
        LL_WARNING,
        LL_ACTION,  // In-game actions
        LL_INFO,
        LL_VERBOSE,
        LL_TRACE,
        LL_MAX,
};
 
enum LogColor : u8 {
        LOG_COLOR_NEVER,
        LOG_COLOR_ALWAYS,
        LOG_COLOR_AUTO,
};
 
enum LogTimestamp : u8 {
        LOG_TIMESTAMP_NONE,
        LOG_TIMESTAMP_WALL,
        LOG_TIMESTAMP_RELATIVE
};
 
typedef u8 LogLevelMask;
#define LOGLEVEL_TO_MASKLEVEL(x) (1 << x)
 
class Logger {
public:
        void addOutput(ILogOutput *out);
        void addOutput(ILogOutput *out, LogLevel lev);
        void addOutputMasked(ILogOutput *out, LogLevelMask mask);
        void addOutputMaxLevel(ILogOutput *out, LogLevel lev);
        LogLevelMask removeOutput(ILogOutput *out);
        void setLevelSilenced(LogLevel lev, bool silenced);
 
        void registerThread(std::string_view name);
        void deregisterThread();
 
        void log(LogLevel lev, std::string_view text);
        // Logs without a prefix
        void logRaw(LogLevel lev, std::string_view text);
 
        static LogLevel stringToLevel(std::string_view name);
        static const char *getLevelLabel(LogLevel lev);
 
        bool hasOutput(LogLevel level) {
                return m_has_outputs[level].load(std::memory_order_relaxed);
        }
 
        bool isLevelSilenced(LogLevel level) {
                return m_silenced_levels[level].load(std::memory_order_relaxed);
        }
 
        static LogColor color_mode;
        static LogTimestamp timestamp_mode;
 
private:
        void logToOutputsRaw(LogLevel, std::string_view line);
        void logToOutputs(LogLevel, const std::string &combined,
                const std::string &time, const std::string &thread_name,
                std::string_view payload_text);
 
        const std::string &getThreadName();
        static std::string getLogTimestamp();
 
        mutable std::mutex m_mutex;
        std::vector<ILogOutput *> m_outputs[LL_MAX];
        std::atomic<bool> m_has_outputs[LL_MAX];
        std::atomic<bool> m_silenced_levels[LL_MAX];
        std::map<std::thread::id, std::string> m_thread_names;
};
 
class ILogOutput {
public:
        virtual void logRaw(LogLevel, std::string_view line) = 0;
        virtual void log(LogLevel, const std::string &combined,
                const std::string &time, const std::string &thread_name,
                std::string_view payload_text) = 0;
};
 
class ICombinedLogOutput : public ILogOutput {
public:
        void log(LogLevel lev, const std::string &combined,
                const std::string &time, const std::string &thread_name,
                std::string_view payload_text)
        {
                logRaw(lev, combined);
        }
};
 
class StreamLogOutput : public ICombinedLogOutput {
public:
        StreamLogOutput(std::ostream &stream);
 
        void logRaw(LogLevel lev, std::string_view line);
 
private:
        std::ostream &m_stream;
        bool is_tty = false;
};
 
class FileLogOutput : public ICombinedLogOutput {
public:
        void setFile(const std::string &filename, s64 file_size_max);
 
        void logRaw(LogLevel lev, std::string_view line)
        {
                m_stream << line << std::endl;
        }
 
private:
        std::ofstream m_stream;
};
 
struct LogEntry {
        LogLevel level;
        std::string timestamp;
        std::string thread_name;
        std::string text;
        // "timestamp: level[thread_name]: text"
        std::string combined;
};
 
class CaptureLogOutput : public ILogOutput {
public:
        CaptureLogOutput() = delete;
        DISABLE_CLASS_COPY(CaptureLogOutput);
 
        CaptureLogOutput(Logger &logger) : m_logger(logger)
        {
                m_logger.addOutput(this);
        }
 
        ~CaptureLogOutput()
        {
                m_logger.removeOutput(this);
        }
 
        void setLogLevel(LogLevel level)
        {
                m_logger.removeOutput(this);
                m_logger.addOutputMaxLevel(this, level);
        }
 
        void logRaw(LogLevel lev, std::string_view line) override
        {
                MutexAutoLock lock(m_mutex);
                m_entries.emplace_back(LogEntry{lev, "", "", std::string(line), std::string(line)});
        }
 
        void log(LogLevel lev, const std::string &combined,
                const std::string &time, const std::string &thread_name,
                std::string_view payload_text) override
        {
                MutexAutoLock lock(m_mutex);
                m_entries.emplace_back(LogEntry{lev, time, thread_name, std::string(payload_text), combined});
        }
 
        // Take the log entries currently stored, clearing the buffer.
        std::vector<LogEntry> take()
        {
                std::vector<LogEntry> entries;
                MutexAutoLock lock(m_mutex);
                std::swap(m_entries, entries);
                return entries;
        }
 
private:
        Logger &m_logger;
        // g_logger serializes calls to log/logRaw with a mutex, but that
        // doesn't prevent take() from being called on top of it.
        // This mutex prevents that.
        std::mutex m_mutex;
        std::vector<LogEntry> m_entries;
};
 
 
#ifdef __ANDROID__
class AndroidLogOutput : public ICombinedLogOutput {
public:
        void logRaw(LogLevel lev, std::string_view line);
};
#endif
 
#ifdef __ANDROID__
extern AndroidLogOutput stdout_output;
extern AndroidLogOutput stderr_output;
#else
extern StreamLogOutput stdout_output;
extern StreamLogOutput stderr_output;
#endif
 
extern Logger g_logger;