src/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 #include <QThread>
  23
  24 LoggerPrivate::LoggerPrivate()
  25     : verbosity(Logger::Chatty),
  26     dummy(new NullDevice()),
  27     pagerStream(0),
  28     pager(0),
  29     colorPager(false)
  30 {
  31 }
  32
  33 LoggerPrivate::~LoggerPrivate()
  34 {
  35     removePager();
  36 }
  37
  38 void LoggerPrivate::insertPager()
  39 {
  40     if (pager)
  41         return; // already present.
  42     pager = new QProcess();
  43     connect(pager, SIGNAL(finished(int )), this, SLOT(pagerFinished()));
  44     pager->setProcessChannelMode(QProcess::ForwardedChannels);
  45     colorPager = true;
  46     if (! startPager(QLatin1String("less"), QStringList() << QLatin1String("-R") << QLatin1String("-E"))) {
  47         colorPager = false;
  48         if (! startPager(QLatin1String("less"), QStringList() << QLatin1String("-E"))) {
  49             if (! startPager(QLatin1String("more"))) {
  50                 delete pager;
  51                 pager = 0;
  52                 return;
  53             }
  54         }
  55     }
  56     pagerStream = new QTextStream(pager);
  57 }
  58
  59 void LoggerPrivate::removePager()
  60 {
  61     if (pager == 0)
  62         return;
  63     pagerStream->flush();
  64     pager->closeWriteChannel();
  65     pager->waitForFinished(-1);
  66     delete pager;
  67     pager = 0;
  68     delete pagerStream;
  69     pagerStream = 0;
  70 }
  71
  72 bool LoggerPrivate::startPager(const QString &program, const QStringList &arguments)
  73 {
  74     Q_ASSERT(pager);
  75     pager->start(program, arguments, QIODevice::ReadWrite);
  76     if (! pager->waitForStarted()) {
  77         if (pager->state() != QProcess::NotRunning) { // time out
  78             standardOut() << "ERROR: the pager failed to start" << endl;
  79             pager->kill();
  80         }
  81         return false;
  82     }
  83     if (pager->state() != QProcess::Running) // it already 'finished'
  84         return false;
  85     return true;
  86 }
  87
  88 void LoggerPrivate::pagerFinished()
  89 {
  90     if (! pager)
  91         return;
  92     pager->close();
  93 }
  94
  95 Q_GLOBAL_STATIC(LoggerPrivate, _vng_logger_private)
  96
  97
  98 Logger::Logger()
  99     : d(_vng_logger_private())
 100 {
 101 }
 102
 103 void Logger::setVerbosity(Verbosity verbosity)
 104 {
 105     _vng_logger_private()->verbosity = verbosity;
 106 }
 107
 108 Logger::Verbosity Logger::verbosity()
 109 {
 110     return _vng_logger_private()->verbosity;
 111 }
 112
 113 QTextStream & Logger::standardOut()
 114 {
 115     LoggerPrivate *self = _vng_logger_private();
 116     if (self->pagerStream)
 117         return *self->pagerStream;
 118     return self->standardOut();
 119 }
 120
 121 QTextStream &Logger::log(Verbosity verbosity)
 122 {
 123     LoggerPrivate *self = _vng_logger_private();
 124     if (self->verbosity >= verbosity) {
 125         if (self->pagerStream && QThread::currentThread() == self->pager->thread()) {
 126             self->pager->waitForBytesWritten();
 127             return *self->pagerStream;
 128         }
 129         return self->standardOut();
 130     }
 131     return self->dummy;
 132 }
 133
 134 QTextStream & Logger::debug()
 135 {
 136     return log(Debug);
 137 }
 138
 139 QTextStream & Logger::info()
 140 {
 141     return log(Verbose);
 142 }
 143
 144 QTextStream & Logger::warn()
 145 {
 146     return log(Chatty);
 147 }
 148
 149 QTextStream & Logger::error()
 150 {
 151     return log(Quiet);
 152 }
 153
 154 void Logger::startPager()
 155 {
 156     _vng_logger_private()->insertPager();
 157 }
 158
 159 void Logger::stopPager()
 160 {
 161     _vng_logger_private()->removePager();
 162 }
 163
 164 void Logger::flushPager()
 165 {
 166     QProcess *pager = _vng_logger_private()->pager;
 167     if (pager)
 168         pager->waitForBytesWritten();
 169 }
 170
 171 bool Logger::hasNonColorPager()
 172 {
 173     if (_vng_logger_private()->pager == 0)
 174         return false;
 175     return ! _vng_logger_private()->colorPager;
 176 }