barrier/lib/base/CLog.cpp

/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2002 Chris Schoeneman
 * 
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file COPYING that should have accompanied this file.
 * 
 * This package 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 for more details.
 */

#include "CLog.h"
#include "CString.h"
#include "CStringUtil.h"
#include "LogOutputters.h"
#include "CArch.h"
#include "Version.h"
#include <cstdio>
#include <cstring>

// names of priorities
static const char*		g_priority[] = {
								"FATAL",
								"ERROR",
								"WARNING",
								"NOTE",
								"INFO",
								"DEBUG",
								"DEBUG1",
								"DEBUG2"
							};

// number of priorities
static const int		g_numPriority = (int)(sizeof(g_priority) /
											sizeof(g_priority[0]));

// the default priority
#if defined(NDEBUG)
static const int		g_defaultMaxPriority = 4;
#else
static const int		g_defaultMaxPriority = 5;
#endif

// length of longest string in g_priority
static const int		g_maxPriorityLength = 7;

// length of suffix string (": ")
static const int		g_prioritySuffixLength = 2;

// amount of padded required to fill in the priority prefix
static const int		g_priorityPad = g_maxPriorityLength +
										g_prioritySuffixLength;


//
// CLog
//

CLog*					CLog::s_log = NULL;

CLog::CLog()
{
	assert(s_log == NULL);

	// create mutex for multithread safe operation
	m_mutex            = ARCH->newMutex();

	// other initalization
	m_maxPriority      = g_defaultMaxPriority;
	m_maxNewlineLength = 0;
	insert(new CConsoleLogOutputter);
}

CLog::~CLog()
{
	// clean up
	for (COutputterList::iterator index  = m_outputters.begin();
								  index != m_outputters.end(); ++index) {
		delete *index;
	}
	for (COutputterList::iterator index  = m_alwaysOutputters.begin();
								  index != m_alwaysOutputters.end(); ++index) {
		delete *index;
	}
	ARCH->closeMutex(m_mutex);
	s_log = NULL;
}

CLog*
CLog::getInstance()
{
	// note -- not thread safe;  client must initialize log safely
	if (s_log == NULL) {
		s_log = new CLog;
	}
	return s_log;
}

void
CLog::print(const char* file, int line, const char* fmt, ...) const
{
	// check if fmt begins with a priority argument
	int priority = 4;
	if (fmt[0] == '%' && fmt[1] == 'z') {
		priority = fmt[2] - '\060';
		fmt += 3;
	}

	// done if below priority threshold
	if (priority > getFilter()) {
		return;
	}

	// compute prefix padding length
	char stack[1024];
	int pPad = g_priorityPad;
	if (file != NULL) {
		sprintf(stack, "%d", line);
		pPad += strlen(file) + 1 /* comma */ +
				strlen(stack) + 1 /* colon */ + 1 /* space */;
	}

	// compute suffix padding length
	int sPad = m_maxNewlineLength;

	// print to buffer, leaving space for a newline at the end and prefix
	// at the beginning.
	char* buffer = stack;
	int len      = (int)(sizeof(stack) / sizeof(stack[0]));
	while (true) {
		// try printing into the buffer
		va_list args;
		va_start(args, fmt);
		int n = ARCH->vsnprintf(buffer + pPad, len - pPad - sPad, fmt, args);
		va_end(args);

		// if the buffer wasn't big enough then make it bigger and try again
		if (n < 0 || n > (int)len) {
			if (buffer != stack) {
				delete[] buffer;
			}
			len   *= 2;
			buffer = new char[len];
		}

		// if the buffer was big enough then continue
		else {
			break;
		}
	}

	// print the prefix to the buffer.  leave space for priority label.
	char* message = buffer;
	if (file != NULL) {
		sprintf(buffer + g_priorityPad, "%s,%d:", file, line);
		buffer[pPad - 1] = ' ';

		// discard file and line if priority < 0
		if (priority < 0) {
			message += pPad - g_priorityPad;
		}
	}

	// output buffer
	output(priority, message);

	// clean up
	if (buffer != stack) {
		delete[] buffer;
	}
}

void
CLog::insert(ILogOutputter* outputter, bool alwaysAtHead)
{
	assert(outputter               != NULL);
	assert(outputter->getNewline() != NULL);

	CArchMutexLock lock(m_mutex);
	if (alwaysAtHead) {
		m_alwaysOutputters.push_front(outputter);
	}
	else {
		m_outputters.push_front(outputter);
	}
	int newlineLength = strlen(outputter->getNewline());
	if (newlineLength > m_maxNewlineLength) {
		m_maxNewlineLength = newlineLength;
	}
	outputter->open(kAppVersion);
	outputter->show(false);
}

void
CLog::remove(ILogOutputter* outputter)
{
	CArchMutexLock lock(m_mutex);
	m_outputters.remove(outputter);
	m_alwaysOutputters.remove(outputter);
}

void
CLog::pop_front(bool alwaysAtHead)
{
	CArchMutexLock lock(m_mutex);
	COutputterList* list = alwaysAtHead ? &m_alwaysOutputters : &m_outputters;
	if (!list->empty()) {
		delete list->front();
		list->pop_front();
	}
}

bool
CLog::setFilter(const char* maxPriority)
{
	if (maxPriority != NULL) {
		for (int i = 0; i < g_numPriority; ++i) {
			if (strcmp(maxPriority, g_priority[i]) == 0) {
				setFilter(i);
				return true;
			}
		}
		return false;
	}
	return true;
}

void
CLog::setFilter(int maxPriority)
{
	CArchMutexLock lock(m_mutex);
	m_maxPriority = maxPriority;
}

int
CLog::getFilter() const
{
	CArchMutexLock lock(m_mutex);
	return m_maxPriority;
}

void
CLog::output(int priority, char* msg) const
{
	assert(priority >= -1 && priority < g_numPriority);
	assert(msg != NULL);

	// insert priority label
	int n = -g_prioritySuffixLength;
	if (priority >= 0) {
		n = strlen(g_priority[priority]);
		strcpy(msg + g_maxPriorityLength - n, g_priority[priority]);
		msg[g_maxPriorityLength + 0] = ':';
		msg[g_maxPriorityLength + 1] = ' ';
		msg[g_maxPriorityLength + 1] = ' ';
	}

	// find end of message
	char* end = msg + g_priorityPad + strlen(msg + g_priorityPad);

	// write to each outputter
	CArchMutexLock lock(m_mutex);
	for (COutputterList::const_iterator index  = m_alwaysOutputters.begin();
										index != m_alwaysOutputters.end();
										++index) {
		// get outputter
		ILogOutputter* outputter = *index;
		
		// put an appropriate newline at the end
		strcpy(end, outputter->getNewline());

		// write message
		outputter->write(static_cast<ILogOutputter::ELevel>(priority),
							msg + g_maxPriorityLength - n);
	}
	for (COutputterList::const_iterator index  = m_outputters.begin();
										index != m_outputters.end(); ++index) {
		// get outputter
		ILogOutputter* outputter = *index;
		
		// put an appropriate newline at the end
		strcpy(end, outputter->getNewline());

		// write message and break out of loop if it returns false
		if (!outputter->write(static_cast<ILogOutputter::ELevel>(priority),
							msg + g_maxPriorityLength - n)) {
			break;
		}
	}
}