ppsspp/Common/Log/LogManager.h

// Copyright (C) 2003 Dolphin Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0 or later versions.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/

#pragma once

#include "ppsspp_config.h"

#include <vector>
#include <cstdio>

#include "Common/Common.h"
#include "Common/CommonFuncs.h"
#include "Common/Log.h"
#include "Common/File/Path.h"
#include "Common/Thread/ParkingLot.h"

#define	MAX_MESSAGES 8000   

// The running PSP thread, for log headers. Thread local: only the thread running the PSP sets it.
extern thread_local const char *hleCurrentThreadName;

// Struct that listeners can output how they want. For example, on Android we don't want to add
// timestamp or write the level as a string, those already exist.
struct LogMessage {
	char timestamp[16];
	char header[64];  // Filename/thread/etc. in front.
	LogLevel level;
	const char *log;
	std::string msg;  // The actual log message.
};

enum class LogOutput {
	Stdio = (1 << 0),  // Also android log.
	DebugString = (1 << 1),
	RingBuffer = (1 << 2),
	File = (1 << 3),
	Printf = (1 << 5),
	ExternalCallback = (1 << 6),
};
ENUM_CLASS_BITOPS(LogOutput);

// Lock-free ring of recent messages. Writers claim a slot with fetch_add and
// guard it with a per-slot sequence (odd while being written). Readers that
// catch a slot mid-write get an empty string instead of waiting.
class RingbufferLog {
public:
	RingbufferLog();
	void Log(const LogMessage &msg);
	int GetCount() const;
	std::string TextAt(int i) const;
	LogLevel LevelAt(int i) const;
	void Clear();

private:
	enum { MAX_LOGS = 256, MAX_TEXT = 512, TEXT_WORDS = MAX_TEXT / sizeof(int) };
	static_assert(MAX_TEXT % sizeof(int) == 0, "Log text must fit whole atomic words");
	struct Slot {
		retro_atomic_int_t seq;
		retro_atomic_int_t level;
		// Sequence validation alone cannot legalize concurrent plain-byte access.
		retro_atomic_int_t text[TEXT_WORDS];
	};
	bool Read(int i, std::string *text, LogLevel *level) const;
	Slot slots_[MAX_LOGS];
	retro_atomic_int_t head_;
	retro_atomic_int_t count_;
};

class Section;

typedef void (*LogCallback)(const LogMessage &message, void *userdata);
extern bool *g_bLogEnabledSetting;

class LogManager {
public:
	LogManager();
	~LogManager();

	void SetOutputsEnabled(LogOutput outputs);
	LogOutput GetOutputsEnabled() const {
		return (LogOutput)retro_atomic_load_relaxed_int(const_cast<retro_atomic_int_t *>(&outputs_));
	}
	void EnableOutput(LogOutput output) {
		retro_atomic_fetch_or_int(&outputs_, (int)output);
		if (output & LogOutput::File)
			SetFileLogPath(logFilename_);
	}
	void DisableOutput(LogOutput output) {
		retro_atomic_fetch_and_int(&outputs_, ~(int)output);
	}
	void EnableOutput(LogOutput output, bool enabled) {
		if (enabled) {
			EnableOutput(output);
		} else {
			DisableOutput(output);
		}
	}

	static u32 GetMaxLevel() { return (u32)MAX_LOGLEVEL;	}
	static int GetNumChannels() { return (int)Log::NUMBER_OF_LOGS; }

	void LogLine(LogLevel level, Log type,
				 const char *file, int line, const char *fmt, va_list args);

	LogChannel *GetLogChannel(Log type) {
		return &g_log[(size_t)type];
	}

	void SetLogLevel(Log type, LogLevel level) {
		g_log[(size_t)type].SetLevel(level);
	}

	void SetAllLogLevels(LogLevel level) {
		for (int i = 0; i < (int)Log::NUMBER_OF_LOGS; ++i) {
			g_log[i].SetLevel(level);
		}
	}

	void SetAllLogEnable(bool enable) {
		for (int i = 0; i < (int)Log::NUMBER_OF_LOGS; ++i) {
			g_log[i].SetEnabled(enable);
		}
	}

	void SetEnabled(Log type, bool enable) {
		g_log[(size_t)type].SetEnabled(enable);
	}

	LogLevel GetLogLevel(Log type) {
		return g_log[(size_t)type].Level();
	}

	const RingbufferLog &GetRingbuffer() const {
		return ringLog_;
	}

	void Init(bool *enabledSetting, bool headless = false);
	void Shutdown();

	// A list rather than a single slot, because the WebSocket debugger registers one callback per
	// *connection* (LogBroadcaster is a local in the per-connection handler) and more than one
	// client can be attached at once - the bundled JS debugger in a browser alongside Tools/wsdbg,
	// say. With a single slot the second connection silently took the log stream away from the
	// first, and then the first one to disconnect cleared the slot and stopped delivery to the
	// other as well.
	// Returns a handle to hand back to RemoveExternalLogCallback(), or -1 if it wasn't added.
	// Add/Remove/SetFileLogPath/Shutdown are control-side calls: one thread at a time.
	// Logging itself may happen from any thread, concurrently with them.
	int AddExternalLogCallback(LogCallback callback, void *userdata);
	void RemoveExternalLogCallback(int handle);

	void SetFileLogPath(const Path &filename);
	const Path &GetLogFilePath() const { return logFilename_; }

	void SaveConfig(Section *section);
	void LoadConfig(const Section *section);

	// Channel level/enabled changes made through the WebSocket debugger (log.channel.set) are
	// meant as temporary, session-only diagnostic tweaks - call this so SaveConfig() skips
	// writing (and thus permanently overwriting) the user's real saved settings with them.
	void NotifyChannelsChangedByDebugger() { channelsChangedByDebugger_ = true; }

	static const char *GetLogTypeName(Log type);

	static u32 GetLevelColor(LogLevel level) {
		switch (level) {
		case LogLevel::LDEBUG: return 0xE0E0E0;
		case LogLevel::LWARNING: return 0x50FFFF;
		case LogLevel::LERROR: return 0x5050FF;
		case LogLevel::LNOTICE: return 0x30FF30;
		case LogLevel::LINFO: return 0xFFFF60;
		case LogLevel::LVERBOSE:
		default: return 0xC0C0C0;
		}
	}

private:
	// Prevent copies.
	LogManager(const LogManager &) = delete;
	void operator=(const LogManager &) = delete;

	bool initialized_ = false;
	bool channelsChangedByDebugger_ = false;

	// Stdio logging
	void StdioLog(const LogMessage &message);
	bool stdioUseColor_ = true;

	retro_atomic_int_t outputs_;

	// File logging. fp_ is published to loggers, closed only after a drain.
	void CloseLogFile();
	retro_atomic_ptr_t fp_;
	bool logFileOpenFailed_ = false;
	Path logFilename_;

	// Ring buffer
	RingbufferLog ringLog_;

	// Callbacks: published entries, freed only after a drain.
	struct ExternalCallbackEntry {
		LogCallback callback;
		void *userdata;
	};
	enum { MAX_EXTERNAL_CALLBACKS = 8 };
	retro_atomic_ptr_t externalCallbacks_[MAX_EXTERNAL_CALLBACKS];
	retro_atomic_int_t externalCount_;

	// Loggers hold this while touching fp_ or a callback entry.
	ReaderGate gate_;
};

extern LogManager g_logManager;