STDLogSink.cpp

/***********************************************************************************************************************
 * Copyright (C) 2016 Andrew Zonenberg and contributors                                                                *
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 *      following disclaimer.                                                                                          *
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 *      following disclaimer in the documentation and/or other materials provided with the distribution.               *
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 *      derived from this software without specific prior written permission.                                          *
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#include "log.h"
#include <cstdio>
#include <cstdarg>
#include <string>
#include <sstream>
#include <limits.h>
#ifdef _WIN32
#include <windows.h>
#else
#include <sys/ioctl.h>
#include <unistd.h>
#endif

using namespace std;

extern bool g_logToStdoutAlways;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Construction / destruction

STDLogSink::STDLogSink(Severity min_severity)
	: LogSink(min_severity)
{
	//Get the current display terminal width
#ifndef _WIN32
#ifndef __EMSCRIPTEN__
	if(isatty(STDOUT_FILENO))
	{
		struct winsize w;
		ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
		m_termWidth = w.ws_col;
	}
	else
	{
		m_termWidth = UINT_MAX;	//don't wrap text if logging to a file
	}
#else
	m_termWidth = 120;	//for now, force emscripten to always 120 char wrapping
#endif
#else
	HANDLE h;
	BOOL ret;
	ostringstream msg;
	CONSOLE_SCREEN_BUFFER_INFO csbi;

	m_termWidth = 80; //Pick a reasonable fallback value

	h = GetStdHandle(STD_OUTPUT_HANDLE);
	if (h == INVALID_HANDLE_VALUE)
	{
		msg << "GetStdHandle() failed (" << GetLastError() << ");\n";
		Log(Severity::WARNING, msg.str());
	}
	else if ((ret = GetConsoleScreenBufferInfo(h, &csbi)) == FALSE)
	{
		msg << "GetConsoleScreenBufferInfo() failed (" << GetLastError() << ");\n";
		Log(Severity::WARNING, msg.str());
	}
	else
	{
		m_termWidth = csbi.dwSize.X;
	}
#endif
}

STDLogSink::~STDLogSink()
{
	Flush();
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Logging

void STDLogSink::Flush()
{
	fflush(stdout);
	fflush(stderr);
}

void STDLogSink::Log(Severity severity, const string &msg)
{
	//Skip messages which aren't important enough
	if(severity > m_min_severity)
		return;

	//Prevent newer messages on stderr from appearing before older messages on stdout
	if(severity <= Severity::WARNING)
		Flush();

	//Wrap/print it
	string wrapped = WrapString(msg);
	if( (severity <= Severity::WARNING) && !g_logToStdoutAlways )
		fputs(wrapped.c_str(), stderr);
	else
		fputs(wrapped.c_str(), stdout);

	//Ensure that this message is displayed immediately even if we print lower severity stuff later
	if(severity <= Severity::WARNING)
		Flush();

	//See if we printed a \n
	if(wrapped.length() && (wrapped[wrapped.length() - 1] == '\n'))
		m_lastMessageWasNewline = true;
	else if(wrapped != "")
		m_lastMessageWasNewline = false;
}

void STDLogSink::Log(Severity severity, const char *format, va_list va)
{
	//Skip messages which aren't important enough
	if(severity > m_min_severity)
		return;

	//Prevent newer messages on stderr from appearing before older messages on stdout
	if(severity <= Severity::WARNING)
		Flush();

	//Wrap/print it
	string wrapped = WrapString(vstrprintf(format, va));
	if( (severity <= Severity::WARNING) && !g_logToStdoutAlways )
		fputs(wrapped.c_str(), stderr);
	else
		fputs(wrapped.c_str(), stdout);

	//Ensure that this message is displayed immediately even if we print lower severity stuff later
	if(severity <= Severity::WARNING)
		Flush();

	//See if we printed a \n
	if(wrapped.length() && (wrapped[wrapped.length() - 1] == '\n'))
		m_lastMessageWasNewline = true;
	else if(wrapped != "")
		m_lastMessageWasNewline = false;
}