kio

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., 51 Franklin Street, Fifth Floor,
00016    Boston, MA 02110-1301, 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 #define BUFFER_SIZE 8*1024
00028 
00029 class KFilterDev::KFilterDevPrivate
00030 {
00031 public:
00032     KFilterDevPrivate() : bNeedHeader(true), bSkipHeaders(false),
00033                           autoDeleteFilterBase(false), bOpenedUnderlyingDevice(false),
00034                           bIgnoreData(false){}
00035     bool bNeedHeader;
00036     bool bSkipHeaders;
00037     bool autoDeleteFilterBase;
00038     bool bOpenedUnderlyingDevice;
00039     bool bIgnoreData;
00040     QByteArray buffer; // Used as 'input buffer' when reading, as 'output buffer' when writing
00041     QCString ungetchBuffer;
00042     QCString origFileName;
00043     KFilterBase::Result result;
00044 };
00045 
00046 KFilterDev::KFilterDev( KFilterBase * _filter, bool autoDeleteFilterBase )
00047     : filter(_filter)
00048 {
00049     assert(filter);
00050     d = new KFilterDevPrivate;
00051     d->autoDeleteFilterBase = autoDeleteFilterBase;
00052 }
00053 
00054 KFilterDev::~KFilterDev()
00055 {
00056     if ( isOpen() )
00057         close();
00058     if ( d->autoDeleteFilterBase )
00059         delete filter;
00060     delete d;
00061 }
00062 
00063 #ifndef KDE_NO_COMPAT
00064 //this one is static
00065 // Cumbersome API. To be removed in KDE 3.0.
00066 QIODevice* KFilterDev::createFilterDevice(KFilterBase* base, QFile* file)
00067 {
00068    if (file==0)
00069       return 0;
00070 
00071    //we don't need a filter
00072    if (base==0)
00073        return new QFile(file->name()); // A bit strange IMHO. We ask for a QFile but we create another one !?! (DF)
00074 
00075    base->setDevice(file);
00076    return new KFilterDev(base);
00077 }
00078 #endif
00079 
00080 //static
00081 QIODevice * KFilterDev::deviceForFile( const QString & fileName, const QString & mimetype,
00082                                        bool forceFilter )
00083 {
00084     QFile * f = new QFile( fileName );
00085     KFilterBase * base = mimetype.isEmpty() ? KFilterBase::findFilterByFileName( fileName )
00086                          : KFilterBase::findFilterByMimeType( mimetype );
00087     if ( base )
00088     {
00089         base->setDevice(f, true);
00090         return new KFilterDev(base, true);
00091     }
00092     if(!forceFilter)
00093         return f;
00094     else
00095     {
00096         delete f;
00097         return 0L;
00098     }
00099 }
00100 
00101 QIODevice * KFilterDev::device( QIODevice* inDevice, const QString & mimetype)
00102 {
00103     return device( inDevice, mimetype, true );
00104 }
00105 
00106 QIODevice * KFilterDev::device( QIODevice* inDevice, const QString & mimetype, bool autoDeleteInDevice )
00107 {
00108    if (inDevice==0)
00109       return 0;
00110    KFilterBase * base = KFilterBase::findFilterByMimeType(mimetype);
00111    if ( base )
00112    {
00113       base->setDevice(inDevice, autoDeleteInDevice);
00114       return new KFilterDev(base, true /* auto-delete "base" */);
00115    }
00116    return 0;
00117 }
00118 
00119 bool KFilterDev::open( int mode )
00120 {
00121     //kdDebug(7005) << "KFilterDev::open " << mode << endl;
00122     if ( mode == IO_ReadOnly )
00123     {
00124         d->buffer.resize(0);
00125         d->ungetchBuffer.resize(0);
00126     }
00127     else
00128     {
00129         d->buffer.resize( BUFFER_SIZE );
00130         filter->setOutBuffer( d->buffer.data(), d->buffer.size() );
00131     }
00132     d->bNeedHeader = !d->bSkipHeaders;
00133     filter->init( mode );
00134     d->bOpenedUnderlyingDevice = !filter->device()->isOpen();
00135     bool ret = d->bOpenedUnderlyingDevice ? filter->device()->open( mode ) : true;
00136     d->result = KFilterBase::OK;
00137 
00138     if ( !ret )
00139         kdWarning(7005) << "KFilterDev::open: Couldn't open underlying device" << endl;
00140     else
00141     {
00142         setState( IO_Open );
00143         setMode( mode );
00144     }
00145     ioIndex = 0;
00146     return ret;
00147 }
00148 
00149 void KFilterDev::close()
00150 {
00151     if ( !isOpen() )
00152         return;
00153     //kdDebug(7005) << "KFilterDev::close" << endl;
00154     if ( filter->mode() == IO_WriteOnly )
00155         writeBlock( 0L, 0 ); // finish writing
00156     //kdDebug(7005) << "KFilterDev::close. Calling terminate()." << endl;
00157 
00158     filter->terminate();
00159     if ( d->bOpenedUnderlyingDevice )
00160         filter->device()->close();
00161 
00162     setState( 0 ); // not IO_Open
00163 }
00164 
00165 void KFilterDev::flush()
00166 {
00167     //kdDebug(7005) << "KFilterDev::flush" << endl;
00168     filter->device()->flush();
00169     // Hmm, might not be enough...
00170 }
00171 
00172 QIODevice::Offset KFilterDev::size() const
00173 {
00174     // Well, hmm, Houston, we have a problem.
00175     // We can't know the size of the uncompressed data
00176     // before uncompressing it.......
00177 
00178     // But readAll, which is not virtual, needs the size.........
00179 
00180     kdWarning(7005) << "KFilterDev::size - can't be implemented !!!!!!!! Returning -1 " << endl;
00181     //abort();
00182     return (uint)-1;
00183 }
00184 
00185 QIODevice::Offset KFilterDev::at() const
00186 {
00187     return ioIndex;
00188 }
00189 
00190 bool KFilterDev::at( QIODevice::Offset pos )
00191 {
00192     //kdDebug(7005) << "KFilterDev::at " << pos << "  currently at " << ioIndex << endl;
00193 
00194     if ( ioIndex == pos )
00195         return true;
00196 
00197     Q_ASSERT ( filter->mode() == IO_ReadOnly );
00198 
00199     if ( pos == 0 )
00200     {
00201         ioIndex = 0;
00202         // We can forget about the cached data
00203         d->ungetchBuffer.resize(0);
00204         d->bNeedHeader = !d->bSkipHeaders;
00205         d->result = KFilterBase::OK;
00206         filter->setInBuffer(0L,0);
00207         filter->reset();
00208         return filter->device()->reset();
00209     }
00210 
00211     if ( ioIndex < pos ) // we can start from here
00212         pos = pos - ioIndex;
00213     else
00214     {
00215         // we have to start from 0 ! Ugly and slow, but better than the previous
00216         // solution (KTarGz was allocating everything into memory)
00217         if (!at(0)) // sets ioIndex to 0
00218             return false;
00219     }
00220 
00221     //kdDebug(7005) << "KFilterDev::at : reading " << pos << " dummy bytes" << endl;
00222     QByteArray dummy( QMIN( pos, 3*BUFFER_SIZE ) );
00223     d->bIgnoreData = true;
00224     bool result = ( (QIODevice::Offset)readBlock( dummy.data(), pos ) == pos );
00225     d->bIgnoreData = false;
00226     return result;
00227 }
00228 
00229 bool KFilterDev::atEnd() const
00230 {
00231     return filter->device()->atEnd() && (d->result == KFilterBase::END)
00232                                      && d->ungetchBuffer.isEmpty();
00233 }
00234 
00235 Q_LONG KFilterDev::readBlock( char *data, Q_ULONG maxlen )
00236 {
00237     Q_ASSERT ( filter->mode() == IO_ReadOnly );
00238     //kdDebug(7005) << "KFilterDev::readBlock maxlen=" << maxlen << endl;
00239 
00240     uint dataReceived = 0;
00241     if ( !d->ungetchBuffer.isEmpty() )
00242     {
00243         uint len = d->ungetchBuffer.length();
00244         if ( !d->bIgnoreData )
00245         {
00246             while ( ( dataReceived < len ) && ( dataReceived < maxlen ) )
00247             {
00248                 *data = d->ungetchBuffer[ len - dataReceived - 1 ];
00249                 data++;
00250                 dataReceived++;
00251             }
00252         }
00253         else
00254         {
00255             dataReceived = QMIN( len, maxlen );
00256         }
00257         d->ungetchBuffer.truncate( len - dataReceived );
00258         ioIndex += dataReceived;
00259     }
00260 
00261     // If we came to the end of the stream
00262     // return what we got from the ungetchBuffer.
00263     if ( d->result == KFilterBase::END )
00264         return dataReceived;
00265 
00266     // If we had an error, return -1.
00267     if ( d->result != KFilterBase::OK )
00268         return -1;
00269 
00270 
00271     Q_ULONG outBufferSize;
00272     if ( d->bIgnoreData )
00273     {
00274         outBufferSize = QMIN( maxlen, 3*BUFFER_SIZE );
00275     }
00276     else
00277     {
00278         outBufferSize = maxlen;
00279     }
00280     outBufferSize -= dataReceived;
00281     Q_ULONG availOut = outBufferSize;
00282     filter->setOutBuffer( data, outBufferSize );
00283 
00284     bool decompressedAll = false;
00285     while ( dataReceived < maxlen )
00286     {
00287         if (filter->inBufferEmpty())
00288         {
00289             // Not sure about the best size to set there.
00290             // For sure, it should be bigger than the header size (see comment in readHeader)
00291             d->buffer.resize( BUFFER_SIZE );
00292             // Request data from underlying device
00293             int size = filter->device()->readBlock( d->buffer.data(),
00294                                                     d->buffer.size() );
00295             if ( size )
00296                 filter->setInBuffer( d->buffer.data(), size );
00297             else {
00298                 if ( decompressedAll )
00299                 {
00300                     // We decoded everything there was to decode. So -> done.
00301                     //kdDebug(7005) << "Seems we're done. dataReceived=" << dataReceived << endl;
00302                     d->result = KFilterBase::END;
00303                     break;
00304                 }
00305             }
00306             //kdDebug(7005) << "KFilterDev::readBlock got " << size << " bytes from device" << endl;
00307         }
00308         if (d->bNeedHeader)
00309         {
00310             (void) filter->readHeader();
00311             d->bNeedHeader = false;
00312         }
00313 
00314         d->result = filter->uncompress();
00315 
00316         if (d->result == KFilterBase::ERROR)
00317         {
00318             kdWarning(7005) << "KFilterDev: Error when uncompressing data" << endl;
00319             break;
00320         }
00321 
00322         // We got that much data since the last time we went here
00323         uint outReceived = availOut - filter->outBufferAvailable();
00324         //kdDebug(7005) << "avail_out = " << filter->outBufferAvailable() << " result=" << d->result << " outReceived=" << outReceived << endl;
00325         if( availOut < (uint)filter->outBufferAvailable() )
00326             kdWarning(7005) << " last availOut " << availOut << " smaller than new avail_out=" << filter->outBufferAvailable() << " !" << endl;
00327 
00328         dataReceived += outReceived;
00329         if ( !d->bIgnoreData )  // Move on in the output buffer
00330         {
00331             data += outReceived;
00332             availOut = maxlen - dataReceived;
00333         }
00334         else if ( maxlen - dataReceived < outBufferSize )
00335         {
00336             availOut = maxlen - dataReceived;
00337         }
00338         ioIndex += outReceived;
00339         if (d->result == KFilterBase::END)
00340         {
00341             //kdDebug(7005) << "KFilterDev::readBlock got END. dataReceived=" << dataReceived << endl;
00342             break; // Finished.
00343         }
00344         if (filter->inBufferEmpty() && filter->outBufferAvailable() != 0 )
00345         {
00346             decompressedAll = true;
00347         }
00348         filter->setOutBuffer( data, availOut );
00349     }
00350 
00351     return dataReceived;
00352 }
00353 
00354 Q_LONG KFilterDev::writeBlock( const char *data /*0 to finish*/, Q_ULONG len )
00355 {
00356     Q_ASSERT ( filter->mode() == IO_WriteOnly );
00357     // If we had an error, return 0.
00358     if ( d->result != KFilterBase::OK )
00359         return 0;
00360 
00361     bool finish = (data == 0L);
00362     if (!finish)
00363     {
00364         filter->setInBuffer( data, len );
00365         if (d->bNeedHeader)
00366         {
00367             (void)filter->writeHeader( d->origFileName );
00368             d->bNeedHeader = false;
00369         }
00370     }
00371 
00372     uint dataWritten = 0;
00373     uint availIn = len;
00374     while ( dataWritten < len || finish )
00375     {
00376 
00377         d->result = filter->compress( finish );
00378 
00379         if (d->result == KFilterBase::ERROR)
00380         {
00381             kdWarning(7005) << "KFilterDev: Error when compressing data" << endl;
00382             // What to do ?
00383             break;
00384         }
00385 
00386         // Wrote everything ?
00387         if (filter->inBufferEmpty() || (d->result == KFilterBase::END))
00388         {
00389             // We got that much data since the last time we went here
00390             uint wrote = availIn - filter->inBufferAvailable();
00391 
00392             //kdDebug(7005) << " Wrote everything for now. avail_in = " << filter->inBufferAvailable() << " result=" << d->result << " wrote=" << wrote << endl;
00393 
00394             // Move on in the input buffer
00395             data += wrote;
00396             dataWritten += wrote;
00397             ioIndex += wrote;
00398 
00399             availIn = len - dataWritten;
00400             //kdDebug(7005) << " KFilterDev::writeBlock availIn=" << availIn << " dataWritten=" << dataWritten << " ioIndex=" << ioIndex << endl;
00401             if ( availIn > 0 ) // Not sure this will ever happen
00402                 filter->setInBuffer( data, availIn );
00403         }
00404 
00405         if (filter->outBufferFull() || (d->result == KFilterBase::END))
00406         {
00407             //kdDebug(7005) << " KFilterDev::writeBlock writing to underlying. avail_out=" << filter->outBufferAvailable() << endl;
00408             int towrite = d->buffer.size() - filter->outBufferAvailable();
00409             if ( towrite > 0 )
00410             {
00411                 // Write compressed data to underlying device
00412                 int size = filter->device()->writeBlock( d->buffer.data(), towrite );
00413                 if ( size != towrite ) {
00414                     kdWarning(7005) << "KFilterDev::writeBlock. Could only write " << size << " out of " << towrite << " bytes" << endl;
00415                     return 0; // indicate an error (happens on disk full)
00416                 }
00417                 //else
00418                     //kdDebug(7005) << " KFilterDev::writeBlock wrote " << size << " bytes" << endl;
00419             }
00420             d->buffer.resize( 8*1024 );
00421             filter->setOutBuffer( d->buffer.data(), d->buffer.size() );
00422             if (d->result == KFilterBase::END)
00423             {
00424                 //kdDebug(7005) << " KFilterDev::writeBlock END" << endl;
00425                 Q_ASSERT(finish); // hopefully we don't get end before finishing
00426                 break;
00427             }
00428         }
00429     }
00430 
00431     return dataWritten;
00432 }
00433 
00434 int KFilterDev::getch()
00435 {
00436     Q_ASSERT ( filter->mode() == IO_ReadOnly );
00437     //kdDebug(7005) << "KFilterDev::getch" << endl;
00438     if ( !d->ungetchBuffer.isEmpty() ) {
00439         int len = d->ungetchBuffer.length();
00440         int ch = d->ungetchBuffer[ len-1 ];
00441         d->ungetchBuffer.truncate( len - 1 );
00442         ioIndex++;
00443         //kdDebug(7005) << "KFilterDev::getch from ungetch: " << QString(QChar(ch)) << endl;
00444         return ch;
00445     }
00446     char buf[1];
00447     int ret = readBlock( buf, 1 ) == 1 ? buf[0] : EOF;
00448     //kdDebug(7005) << "KFilterDev::getch ret=" << QString(QChar(ret)) << endl;
00449     return ret;
00450 }
00451 
00452 int KFilterDev::putch( int c )
00453 {
00454     //kdDebug(7005) << "KFilterDev::putch" << endl;
00455     char buf[1];
00456     buf[0] = c;
00457     return writeBlock( buf, 1 ) == 1 ? c : -1;
00458 }
00459 
00460 int KFilterDev::ungetch( int ch )
00461 {
00462     //kdDebug(7005) << "KFilterDev::ungetch " << QString(QChar(ch)) << endl;
00463     if ( ch == EOF )                            // cannot unget EOF
00464         return ch;
00465 
00466     // pipe or similar => we cannot ungetch, so do it manually
00467     d->ungetchBuffer +=ch;
00468     ioIndex--;
00469     return ch;
00470 }
00471 
00472 void KFilterDev::setOrigFileName( const QCString & fileName )
00473 {
00474     d->origFileName = fileName;
00475 }
00476 
00477 void KFilterDev::setSkipHeaders()
00478 {
00479     d->bSkipHeaders = true;
00480 }
kio

kfilterdev.cpp

kio

API Reference
