Logger.cpp

   1 /*
   2  * This file is part of the vng project
   3  * Copyright (C) 2008 Thomas Zander <tzander@trolltech.com>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "Logger.h"
  20 #include "Logger_p.h"
  21 #include <QDebug>
  22
  23 LoggerPrivate::LoggerPrivate()
  24     : verbosity(Logger::Chatty),
  25     dummy(new NullDevice()),
  26     pagerStream(0),
  27     pager(0),
  28     colorPager(false)
  29 {
  30 }
  31
  32 LoggerPrivate::~LoggerPrivate() {
  33     removePager();
  34 }
  35
  36 void LoggerPrivate::insertPager()
  37 {
  38     if (pager)
  39         return; // already present.
  40     pager = new QProcess();
  41     connect(pager, SIGNAL(finished(int )), this, SLOT(pagerFinished()));
  42     pager->setProcessChannelMode(QProcess::ForwardedChannels);
  43     colorPager = true;
  44     if (! startPager("less", QStringList() << "-R" << "-E")) {
  45         colorPager = false;
  46         if (! startPager("less", QStringList() << "-E")) {
  47             if (! startPager("more")) {
  48                 delete pager;
  49                 pager = 0;
  50                 return;
  51             }
  52         }
  53     }
  54     pagerStream = new QTextStream(pager);
  55 }
  56
  57 void LoggerPrivate::removePager()
  58 {
  59     if (pager == 0)
  60         return;
  61     pagerStream->flush();
  62     pager->closeWriteChannel();
  63     pager->waitForFinished(-1);
  64     delete pager;
  65     pager = 0;
  66     delete pagerStream;
  67     pagerStream = 0;
  68 }
  69
  70 bool LoggerPrivate::startPager(const QString &program, const QStringList &arguments)
  71 {
  72     Q_ASSERT(pager);
  73     pager->start(program, arguments, QIODevice::ReadWrite);
  74     if (! pager->waitForStarted()) {
  75         if (pager->state() != QProcess::NotRunning) { // time out
  76             standardOut() << "ERROR: the pager failed to start" << endl;
  77             pager->kill();
  78         }
  79         return false;
  80     }
  81     if (pager->state() != QProcess::Running) // it already 'finished'
  82         return false;
  83     return true;
  84 }
  85
  86 void LoggerPrivate::pagerFinished()
  87 {
  88     if (! pager)
  89         return;
  90     pager->close();
  91 }
  92
  93 Q_GLOBAL_STATIC(LoggerPrivate, _vng_logger_private)
  94
  95
  96 Logger::Logger()
  97     : d(_vng_logger_private())
  98 {
  99 }
 100
 101 void Logger::setVerbosity(Verbosity verbosity)
 102 {
 103     _vng_logger_private()->verbosity = verbosity;
 104 }
 105
 106 Logger::Verbosity Logger::verbosity()
 107 {
 108     return _vng_logger_private()->verbosity;
 109 }
 110
 111 QTextStream & Logger::standardOut()
 112 {
 113     LoggerPrivate *self = _vng_logger_private();
 114     if (self->pagerStream)
 115         return *self->pagerStream;
 116     return self->standardOut();
 117 }
 118
 119 QTextStream &Logger::log(Verbosity verbosity)
 120 {
 121     LoggerPrivate *self = _vng_logger_private();
 122     if (self->verbosity >= verbosity) {
 123         if (self->pagerStream) {
 124             self->pager->waitForBytesWritten();
 125             return *self->pagerStream;
 126         }
 127         return self->standardOut();
 128     }
 129     return self->dummy;
 130 }
 131
 132
 133 QTextStream & Logger::debug()
 134 {
 135     return log(Debug);
 136 }
 137
 138 QTextStream & Logger::info()
 139 {
 140     return log(Verbose);
 141 }
 142
 143 QTextStream & Logger::warn()
 144 {
 145     return log(Chatty);
 146 }
 147
 148 QTextStream & Logger::error()
 149 {
 150     return log(Quiet);
 151 }
 152
 153 void Logger::startPager()
 154 {
 155     _vng_logger_private()->insertPager();
 156 }
 157
 158 void Logger::stopPager()
 159 {
 160     _vng_logger_private()->removePager();
 161 }
 162
 163 void Logger::flushPager()
 164 {
 165     QProcess *pager = _vng_logger_private()->pager;
 166     if (pager)
 167         pager->waitForBytesWritten();
 168 }
 169
 170
 171 bool Logger::hasNonColorPager()
 172 {
 173     if (_vng_logger_private()->pager == 0)
 174         return false;
 175     return ! _vng_logger_private()->colorPager;
 176 }