kio Library API Documentation

kfilterdev.cpp

00001 /* This file is part of the KDE libraries
00002    Copyright (C) 2000 David Faure <faure@kde.org>
00003 
00004    This library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Library General Public
00006    License version 2 as published by the Free Software Foundation.
00007 
00008    This library is distributed in the hope that it will be useful,
00009    but WITHOUT ANY WARRANTY; without even the implied warranty of
00010    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00011    Library General Public License for more details.
00012 
00013    You should have received a copy of the GNU Library General Public License
00014    along with this library; see the file COPYING.LIB.  If not, write to
00015    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
00016    Boston, MA 02111-1307, USA.
00017 */
00018 
00019 #include "kfilterdev.h"
00020 #include "kfilterbase.h"
00021 #include <kdebug.h>
00022 #include <stdio.h> // for EOF
00023 #include <stdlib.h>
00024 #include <assert.h>
00025 #include <qfile.h>
00026 
00027 class KFilterDev::KFilterDevPrivate
00028 {
00029 public:
00030     KFilterDevPrivate() : bNeedHeader(true), bSkipHeaders(false),
00031                           autoDeleteFilterBase(false), bOpenedUnderlyingDevice(false) {}
00032     bool bNeedHeader;
00033     bool bSkipHeaders;
00034     bool autoDeleteFilterBase;
00035     bool bOpenedUnderlyingDevice;
00036     QByteArray buffer; // Used as 'input buffer' when reading, as 'output buffer' when writing
00037     QCString ungetchBuffer;
00038     QCString origFileName;
00039     KFilterBase::Result result;
00040 };
00041 
00042 KFilterDev::KFilterDev( KFilterBase * _filter, bool autoDeleteFilterBase )
00043     : filter(_filter)
00044 {
00045     assert(filter);
00046     d = new KFilterDevPrivate;
00047     d->autoDeleteFilterBase = autoDeleteFilterBase;
00048 }
00049 
00050 KFilterDev::~KFilterDev()
00051 {
00052     if ( isOpen() )
00053         close();
00054     if ( d->autoDeleteFilterBase )
00055         delete filter;
00056     delete d;
00057 }
00058 
00059 #ifndef KDE_NO_COMPAT
00060 //this one is static
00061 // Cumbersome API. To be removed in KDE 3.0.
00062 QIODevice* KFilterDev::createFilterDevice(KFilterBase* base, QFile* file)
00063 {
00064    if (file==0)
00065       return 0;
00066 
00067    //we don't need a filter
00068    if (base==0)
00069        return new QFile(file->name()); // A bit strange IMHO. We ask for a QFile but we create another one !?! (DF)
00070 
00071    base->setDevice(file);
00072    return new KFilterDev(base);
00073 }
00074 #endif
00075 
00076 //static
00077 QIODevice * KFilterDev::deviceForFile( const QString & fileName, const QString & mimetype,
00078                                        bool forceFilter )
00079 {
00080     QFile * f = new QFile( fileName );
00081     KFilterBase * base = mimetype.isEmpty() ? KFilterBase::findFilterByFileName( fileName )
00082                          : KFilterBase::findFilterByMimeType( mimetype );
00083     if ( base )
00084     {
00085         base->setDevice(f, true);
00086         return new KFilterDev(base, true);
00087     }
00088     if(!forceFilter)
00089         return f;
00090     else
00091     {
00092         delete f;
00093         return 0L;
00094     }
00095 }
00096 
00097 QIODevice * KFilterDev::device( QIODevice* inDevice, const QString & mimetype)
00098 {
00099     return device( inDevice, mimetype, true );
00100 }
00101 
00102 QIODevice * KFilterDev::device( QIODevice* inDevice, const QString & mimetype, bool autoDeleteInDevice )
00103 {
00104    if (inDevice==0)
00105       return 0;
00106    KFilterBase * base = KFilterBase::findFilterByMimeType(mimetype);
00107    if ( base )
00108    {
00109       base->setDevice(inDevice, autoDeleteInDevice);
00110       return new KFilterDev(base, true /* auto-delete "base" */);
00111    }
00112    return 0;
00113 }
00114 
00115 bool KFilterDev::open( int mode )
00116 {
00117     //kdDebug(7005) << "KFilterDev::open " << mode << endl;
00118     if ( mode == IO_ReadOnly )
00119     {
00120         d->buffer.resize(0);
00121         d->ungetchBuffer.resize(0);
00122     }
00123     else
00124     {
00125         d->buffer.resize( 8*1024 );
00126         filter->setOutBuffer( d->buffer.data(), d->buffer.size() );
00127     }
00128     d->bNeedHeader = !d->bSkipHeaders;
00129     filter->init( mode );
00130     d->bOpenedUnderlyingDevice = !filter->device()->isOpen();
00131     bool ret = d->bOpenedUnderlyingDevice ? filter->device()->open( mode ) : true;
00132     d->result = KFilterBase::OK;
00133 
00134     if ( !ret )
00135         kdWarning(7005) << "KFilterDev::open: Couldn't open underlying device" << endl;
00136     else
00137     {
00138         setState( IO_Open );
00139         setMode( mode );
00140     }
00141     ioIndex = 0;
00142     return ret;
00143 }
00144 
00145 void KFilterDev::close()
00146 {
00147     //kdDebug(7005) << "KFilterDev::close" << endl;
00148     if ( filter->mode() == IO_WriteOnly )
00149         writeBlock( 0L, 0 ); // finish writing
00150     //kdDebug(7005) << "KFilterDev::close. Calling terminate()." << endl;
00151 
00152     filter->terminate();
00153     if ( d->bOpenedUnderlyingDevice )
00154         filter->device()->close();
00155 
00156     setState( 0 ); // not IO_Open
00157 }
00158 
00159 void KFilterDev::flush()
00160 {
00161     //kdDebug(7005) << "KFilterDev::flush" << endl;
00162     filter->device()->flush();
00163     // Hmm, might not be enough...
00164 }
00165 
00166 QIODevice::Offset KFilterDev::size() const
00167 {
00168     // Well, hmm, Houston, we have a problem.
00169     // We can't know the size of the uncompressed data
00170     // before uncompressing it.......
00171 
00172     // But readAll, which is not virtual, needs the size.........
00173 
00174     kdWarning(7005) << "KFilterDev::size - can't be implemented !!!!!!!! Returning -1 " << endl;
00175     //abort();
00176     return (uint)-1;
00177 }
00178 
00179 QIODevice::Offset KFilterDev::at() const
00180 {
00181     return ioIndex;
00182 }
00183 
00184 bool KFilterDev::at( QIODevice::Offset pos )
00185 {
00186     Q_ASSERT ( filter->mode() == IO_ReadOnly );
00187     //kdDebug(7005) << "KFilterDev::at " << pos << "  currently at " << ioIndex << endl;
00188 
00189     if ( ioIndex == pos )
00190         return true;
00191 
00192     if ( pos == 0 )
00193     {
00194         ioIndex = 0;
00195         // We can forget about the cached data
00196         d->ungetchBuffer.resize(0);
00197         d->bNeedHeader = !d->bSkipHeaders;
00198         d->result = KFilterBase::OK;
00199         filter->setInBuffer(0L,0);
00200         filter->reset();
00201         return filter->device()->reset();
00202     }
00203 
00204     if ( ioIndex < pos ) // we can start from here
00205         pos = pos - ioIndex;
00206     else
00207     {
00208         // we have to start from 0 ! Ugly and slow, but better than the previous
00209         // solution (KTarGz was allocating everything into memory)
00210         if (!at(0)) // sets ioIndex to 0
00211             return false;
00212     }
00213 
00214     //kdDebug(7005) << "KFilterDev::at : reading " << pos << " dummy bytes" << endl;
00215     // #### Slow, and allocate a huge block of memory (potentially)
00216     // Maybe we could have a flag in the class to know we don't care about the
00217     // actual data
00218     QByteArray dummy( pos );
00219     return ( (QIODevice::Offset)readBlock( dummy.data(), pos ) == pos ) ;
00220 }
00221 
00222 bool KFilterDev::atEnd() const
00223 {
00224     return filter->device()->atEnd() && (d->result == KFilterBase::END);
00225 }
00226 
00227 Q_LONG KFilterDev::readBlock( char *data, Q_ULONG maxlen )
00228 {
00229     Q_ASSERT ( filter->mode() == IO_ReadOnly );
00230     //kdDebug(7005) << "KFilterDev::readBlock maxlen=" << maxlen << endl;
00231     // If we came to the end of the stream, return 0.
00232     if ( d->result == KFilterBase::END )
00233         return 0;
00234     // If we had an error, return -1.
00235     if ( d->result != KFilterBase::OK )
00236         return -1;
00237 
00238     filter->setOutBuffer( data, maxlen );
00239 
00240     bool readEverything = false;
00241     uint dataReceived = 0;
00242     uint availOut = maxlen;
00243     while ( dataReceived < maxlen )
00244     {
00245         if (filter->inBufferEmpty())
00246         {
00247             // Not sure about the best size to set there.
00248             // For sure, it should be bigger than the header size (see comment in readHeader)
00249             d->buffer.resize( 8*1024 );
00250             // Request data from underlying device
00251             int size = filter->device()->readBlock( d->buffer.data(),
00252                                                     d->buffer.size() );
00253             if ( size )
00254                 filter->setInBuffer( d->buffer.data(), size );
00255             else
00256                 readEverything = true;
00257             //kdDebug(7005) << "KFilterDev::readBlock got " << size << " bytes from device" << endl;
00258         }
00259         if (d->bNeedHeader)
00260         {
00261             (void) filter->readHeader();
00262             d->bNeedHeader = false;
00263         }
00264 
00265         d->result = filter->uncompress();
00266 
00267         if (d->result == KFilterBase::ERROR)
00268         {
00269             kdWarning(7005) << "KFilterDev: Error when uncompressing data" << endl;
00270             break;
00271         }
00272 
00273         // We got that much data since the last time we went here
00274         uint outReceived = availOut - filter->outBufferAvailable();
00275         //kdDebug(7005) << "avail_out = " << filter->outBufferAvailable() << " result=" << d->result << " outReceived=" << outReceived << endl;
00276         if( availOut < (uint)filter->outBufferAvailable() )
00277             kdWarning(7005) << " last availOut " << availOut << " smaller than new avail_out=" << filter->outBufferAvailable() << " !" << endl;
00278 
00279         // Move on in the output buffer
00280         data += outReceived;
00281         dataReceived += outReceived;
00282         ioIndex += outReceived;
00283         if (d->result == KFilterBase::END)
00284         {
00285             //kdDebug(7005) << "KFilterDev::readBlock got END. dataReceived=" << dataReceived << endl;
00286             break; // Finished.
00287         }
00288         if (readEverything && filter->inBufferEmpty() && filter->outBufferAvailable() != 0 )
00289         {
00290             // We decoded everything there was to decode. So -> done.
00291             //kdDebug(7005) << "Seems we're done. dataReceived=" << dataReceived << endl;
00292             d->result = KFilterBase::END;
00293             break;
00294         }
00295         availOut = maxlen - dataReceived;
00296         filter->setOutBuffer( data, availOut );
00297     }
00298 
00299     return dataReceived;
00300 }
00301 
00302 Q_LONG KFilterDev::writeBlock( const char *data /*0 to finish*/, Q_ULONG len )
00303 {
00304     Q_ASSERT ( filter->mode() == IO_WriteOnly );
00305     // If we had an error, return 0.
00306     if ( d->result != KFilterBase::OK )
00307         return 0;
00308 
00309     bool finish = (data == 0L);
00310     if (!finish)
00311     {
00312         filter->setInBuffer( data, len );
00313         if (d->bNeedHeader)
00314         {
00315             (void)filter->writeHeader( d->origFileName );
00316             d->bNeedHeader = false;
00317         }
00318     }
00319 
00320     uint dataWritten = 0;
00321     uint availIn = len;
00322     while ( dataWritten < len || finish )
00323     {
00324 
00325         d->result = filter->compress( finish );
00326 
00327         if (d->result == KFilterBase::ERROR)
00328         {
00329             kdWarning(7005) << "KFilterDev: Error when compressing data" << endl;
00330             // What to do ?
00331             break;
00332         }
00333 
00334         // Wrote everything ?
00335         if (filter->inBufferEmpty() || (d->result == KFilterBase::END))
00336         {
00337             // We got that much data since the last time we went here
00338             uint wrote = availIn - filter->inBufferAvailable();
00339 
00340             //kdDebug(7005) << " Wrote everything for now. avail_in = " << filter->inBufferAvailable() << " result=" << d->result << " wrote=" << wrote << endl;
00341 
00342             // Move on in the input buffer
00343             data += wrote;
00344             dataWritten += wrote;
00345             ioIndex += wrote;
00346 
00347             availIn = len - dataWritten;
00348             //kdDebug(7005) << " KFilterDev::writeBlock availIn=" << availIn << " dataWritten=" << dataWritten << " ioIndex=" << ioIndex << endl;
00349             if ( availIn > 0 ) // Not sure this will ever happen
00350                 filter->setInBuffer( data, availIn );
00351         }
00352 
00353         if (filter->outBufferFull() || (d->result == KFilterBase::END))
00354         {
00355             //kdDebug(7005) << " KFilterDev::writeBlock writing to underlying. avail_out=" << filter->outBufferAvailable() << endl;
00356             int towrite = d->buffer.size() - filter->outBufferAvailable();
00357             if ( towrite > 0 )
00358             {
00359                 // Write compressed data to underlying device
00360                 int size = filter->device()->writeBlock( d->buffer.data(), towrite );
00361                 if ( size != towrite )
00362                     kdWarning(7005) << "KFilterDev::writeBlock. Could only write " << size << " out of " << towrite << " bytes" << endl;
00363                 //else
00364                     //kdDebug(7005) << " KFilterDev::writeBlock wrote " << size << " bytes" << endl;
00365             }
00366             d->buffer.resize( 8*1024 );
00367             filter->setOutBuffer( d->buffer.data(), d->buffer.size() );
00368             if (d->result == KFilterBase::END)
00369             {
00370                 //kdDebug(7005) << " KFilterDev::writeBlock END" << endl;
00371                 Q_ASSERT(finish); // hopefully we don't get end before finishing
00372                 break;
00373             }
00374         }
00375     }
00376 
00377     return dataWritten;
00378 }
00379 
00380 int KFilterDev::getch()
00381 {
00382     Q_ASSERT ( filter->mode() == IO_ReadOnly );
00383     //kdDebug(7005) << "KFilterDev::getch" << endl;
00384     if ( !d->ungetchBuffer.isEmpty() ) {
00385         int len = d->ungetchBuffer.length();
00386         int ch = d->ungetchBuffer[ len-1 ];
00387         d->ungetchBuffer.truncate( len - 1 );
00388         //kdDebug(7005) << "KFilterDev::getch from ungetch: " << QString(QChar(ch)) << endl;
00389         return ch;
00390     }
00391     char buf[1];
00392     int ret = readBlock( buf, 1 ) == 1 ? buf[0] : EOF;
00393     //kdDebug(7005) << "KFilterDev::getch ret=" << QString(QChar(ret)) << endl;
00394     return ret;
00395 }
00396 
00397 int KFilterDev::putch( int c )
00398 {
00399     //kdDebug(7005) << "KFilterDev::putch" << endl;
00400     char buf[1];
00401     buf[0] = c;
00402     return writeBlock( buf, 1 ) == 1 ? c : -1;
00403 }
00404 
00405 int KFilterDev::ungetch( int ch )
00406 {
00407     //kdDebug(7005) << "KFilterDev::ungetch " << QString(QChar(ch)) << endl;
00408     if ( ch == EOF )                            // cannot unget EOF
00409         return ch;
00410 
00411     // pipe or similar => we cannot ungetch, so do it manually
00412     d->ungetchBuffer +=ch;
00413     return ch;
00414 }
00415 
00416 void KFilterDev::setOrigFileName( const QCString & fileName )
00417 {
00418     d->origFileName = fileName;
00419 }
00420 
00421 void KFilterDev::setSkipHeaders()
00422 {
00423     d->bSkipHeaders = true;
00424 }
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