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     removePager();
  35 }
  36
  37 void LoggerPrivate::insertPager()
  38 {
  39     if (pager)
  40         return; // already present.
  41     pager = new QProcess();
  42     connect(pager, SIGNAL(finished(int )), this, SLOT(pagerFinished()));
  43     pager->setProcessChannelMode(QProcess::ForwardedChannels);
  44     colorPager = true;
  45     if (! startPager("less", QStringList() << "-R" << "-E")) {
  46         colorPager = false;
  47         if (! startPager("less", QStringList() << "-E")) {
  48             if (! startPager("more")) {
  49                 delete pager;
  50                 pager = 0;
  51                 return;
  52             }
  53         }
  54     }
  55     pagerStream = new QTextStream(pager);
  56 }
  57
  58 void LoggerPrivate::removePager()
  59 {
  60     if (pager == 0)
  61         return;
  62     pagerStream->flush();
  63     pager->closeWriteChannel();
  64     pager->waitForFinished(-1);
  65     delete pager;
  66     pager = 0;
  67     delete pagerStream;
  68     pagerStream = 0;
  69 }
  70
  71 bool LoggerPrivate::startPager(const QString &program, const QStringList &arguments)
  72 {
  73     Q_ASSERT(pager);
  74     pager->start(program, arguments, QIODevice::ReadWrite);
  75     if (! pager->waitForStarted()) {
  76         if (pager->state() != QProcess::NotRunning) { // time out
  77             standardOut() << "ERROR: the pager failed to start" << endl;
  78             pager->kill();
  79         }
  80         return false;
  81     }
  82     if (pager->state() != QProcess::Running) // it already 'finished'
  83         return false;
  84     return true;
  85 }
  86
  87 void LoggerPrivate::pagerFinished()
  88 {
  89     if (! pager)
  90         return;
  91     pager->close();
  92 }
  93
  94 Q_GLOBAL_STATIC(LoggerPrivate, _vng_logger_private)
  95
  96
  97 Logger::Logger()
  98     : d(_vng_logger_private())
  99 {
 100 }
 101
 102 void Logger::setVerbosity(Verbosity verbosity)
 103 {
 104     _vng_logger_private()->verbosity = verbosity;
 105 }
 106
 107 Logger::Verbosity Logger::verbosity()
 108 {
 109     return _vng_logger_private()->verbosity;
 110 }
 111
 112 QTextStream & Logger::standardOut()
 113 {
 114     LoggerPrivate *self = _vng_logger_private();
 115     if (self->pagerStream)
 116         return *self->pagerStream;
 117     return self->standardOut();
 118 }
 119
 120 QTextStream &Logger::log(Verbosity verbosity)
 121 {
 122     LoggerPrivate *self = _vng_logger_private();
 123     if (self->verbosity >= verbosity) {
 124         if (self->pagerStream && QThread::currentThread() == self->pager->thread()) {
 125             self->pager->waitForBytesWritten();
 126             return *self->pagerStream;
 127         }
 128         return self->standardOut();
 129     }
 130     return self->dummy;
 131 }
 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
 172 bool Logger::hasNonColorPager()
 173 {
 174     if (_vng_logger_private()->pager == 0)
 175         return false;
 176     return ! _vng_logger_private()->colorPager;
 177 }