qgpluginmanager.cpp

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/****************************************************************************
** $Id: qgpluginmanager.cpp,v 1.2 2003/07/10 02:40:12 llornkcor Exp $
**
** Implementation of QGPluginManager class
**
** Copyright (C) 2000-2003 Trolltech AS.  All rights reserved.
**
** This file is part of the tools module of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
** licenses may use this file in accordance with the Qt Commercial License
** Agreement provided with the Software.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
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**   information about Qt Commercial License Agreements.
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**********************************************************************/

#include "qgpluginmanager_p.h"
#ifndef QT_NO_COMPONENT
#include "qcomlibrary_p.h"
#include "qmap.h"
#include "qdir.h"

/*
  The following co-occurrence code is borrowed from Qt Linguist.

  How similar are two texts? The approach used here relies on
  co-occurrence matrices and is very efficient.

  Let's see with an example: how similar are "here" and "hither"?  The
  co-occurrence matrix M for "here" is M[h,e] = 1, M[e,r] = 1,
  M[r,e] = 1 and 0 elsewhere; the matrix N for "hither" is N[h,i] = 1,
  N[i,t] = 1, ..., N[h,e] = 1, N[e,r] = 1 and 0 elsewhere.  The union
  U of both matrices is the matrix U[i,j] = max { M[i,j], N[i,j] },
  and the intersection V is V[i,j] = min { M[i,j], N[i,j] }. The score
  for a pair of texts is

      score = (sum of V[i,j] over all i, j) / (sum of U[i,j] over all i, j),

  a formula suggested by Arnt Gulbrandsen. Here we have

      score = 2 / 6,

  or one third.

  The implementation differs from this in a few details.  Most
  importantly, repetitions are ignored; for input "xxx", M[x,x] equals
  1, not 2.
*/

/*
  Every character is assigned to one of 20 buckets so that the
  co-occurrence matrix requires only 20 * 20 = 400 bits, not
  256 * 256 = 65536 bits or even more if we want the whole Unicode.
  Which character falls in which bucket is arbitrary.

  The second half of the table is a replica of the first half, because of
  laziness.
*/
static const char indexOf[256] = {
    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
//      !   "   #   $   %   &   '   (   )   *   +   ,   -   .   /
    0,  2,  6,  7,  10, 12, 15, 19, 2,  6,  7,  10, 12, 15, 19, 0,
//  0   1   2   3   4   5   6   7   8   9   :   ;   <   =   >   ?
    1,  3,  4,  5,  8,  9,  11, 13, 14, 16, 2,  6,  7,  10, 12, 15,
//  @   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O
    0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  6,  10, 11, 12, 13, 14,
//  P   Q   R   S   T   U   V   W   X   Y   Z   [   \   ]   ^   _
    15, 12, 16, 17, 18, 19, 2,  10, 15, 7,  19, 2,  6,  7,  10, 0,
//  `   a   b   c   d   e   f   g   h   i   j   k   l   m   n   o
    0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  6,  10, 11, 12, 13, 14,
//  p   q   r   s   t   u   v   w   x   y   z   {   |   }   ~
    15, 12, 16, 17, 18, 19, 2,  10, 15, 7,  19, 2,  6,  7,  10, 0,

    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
    0,  2,  6,  7,  10, 12, 15, 19, 2,  6,  7,  10, 12, 15, 19, 0,
    1,  3,  4,  5,  8,  9,  11, 13, 14, 16, 2,  6,  7,  10, 12, 15,
    0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  6,  10, 11, 12, 13, 14,
    15, 12, 16, 17, 18, 19, 2,  10, 15, 7,  19, 2,  6,  7,  10, 0,
    0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  6,  10, 11, 12, 13, 14,
    15, 12, 16, 17, 18, 19, 2,  10, 15, 7,  19, 2,  6,  7,  10, 0
};

/*
  The entry bitCount[i] (for i between 0 and 255) is the number of
  bits used to represent i in binary.
*/
static const char bitCount[256] = {
    0,  1,  1,  2,  1,  2,  2,  3,  1,  2,  2,  3,  2,  3,  3,  4,
    1,  2,  2,  3,  2,  3,  3,  4,  2,  3,  3,  4,  3,  4,  4,  5,
    1,  2,  2,  3,  2,  3,  3,  4,  2,  3,  3,  4,  3,  4,  4,  5,
    2,  3,  3,  4,  3,  4,  4,  5,  3,  4,  4,  5,  4,  5,  5,  6,
    1,  2,  2,  3,  2,  3,  3,  4,  2,  3,  3,  4,  3,  4,  4,  5,
    2,  3,  3,  4,  3,  4,  4,  5,  3,  4,  4,  5,  4,  5,  5,  6,
    2,  3,  3,  4,  3,  4,  4,  5,  3,  4,  4,  5,  4,  5,  5,  6,
    3,  4,  4,  5,  4,  5,  5,  6,  4,  5,  5,  6,  5,  6,  6,  7,
    1,  2,  2,  3,  2,  3,  3,  4,  2,  3,  3,  4,  3,  4,  4,  5,
    2,  3,  3,  4,  3,  4,  4,  5,  3,  4,  4,  5,  4,  5,  5,  6,
    2,  3,  3,  4,  3,  4,  4,  5,  3,  4,  4,  5,  4,  5,  5,  6,
    3,  4,  4,  5,  4,  5,  5,  6,  4,  5,  5,  6,  5,  6,  6,  7,
    2,  3,  3,  4,  3,  4,  4,  5,  3,  4,  4,  5,  4,  5,  5,  6,
    3,  4,  4,  5,  4,  5,  5,  6,  4,  5,  5,  6,  5,  6,  6,  7,
    3,  4,  4,  5,  4,  5,  5,  6,  4,  5,  5,  6,  5,  6,  6,  7,
    4,  5,  5,  6,  5,  6,  6,  7,  5,  6,  6,  7,  6,  7,  7,  8
};

class QCoMatrix
{
public:
    /*
      The matrix has 20 * 20 = 400 entries. This requires 50 bytes, or
      13 words. Some operations are performed on words for more
      efficiency.
    */
    union {
        Q_UINT8 b[52];
        Q_UINT32 w[13];
    };

    QCoMatrix() { memset( b, 0, 52 ); }
    QCoMatrix( const char *text ) {
        char c = '\0', d;
        memset( b, 0, 52 );
        while ( (d = *text) != '\0' ) {
            setCoocc( c, d );
            if ( (c = *++text) != '\0' ) {
                setCoocc( d, c );
                text++;
            }
        }
    }

    void setCoocc( char c, char d ) {
        int k = indexOf[(uchar) c] + 20 * indexOf[(uchar) d];
        b[k >> 3] |= k & 0x7;
    }

    int worth() const {
        int result = 0;
        for ( int i = 0; i < 50; i++ )
            result += bitCount[b[i]];
        return result;
    }

    static QCoMatrix reunion( const QCoMatrix& m, const QCoMatrix& n )
    {
        QCoMatrix p;
        for ( int i = 0; i < 13; i++ )
            p.w[i] = m.w[i] | n.w[i];
        return p;
    }
    static QCoMatrix intersection( const QCoMatrix& m, const QCoMatrix& n )
    {
        QCoMatrix p;
        for ( int i = 0; i < 13; i++ )
            p.w[i] = m.w[i] & n.w[i];
        return p;
    }
};

/*
  Returns an integer between 0 (dissimilar) and 15 (very similar)
  depending on  how similar the string is to \a target.

  This function is efficient, but its results might change in future
  versions of Qt as the algorithm evolves.

  \code
    QString s( "color" );
    a = similarity( s, "color" );  // a == 15
    a = similarity( s, "colour" ); // a == 8
    a = similarity( s, "flavor" ); // a == 4
    a = similarity( s, "dahlia" ); // a == 0
  \endcode
*/
static int similarity( const QString& s1, const QString& s2 )
{
    QCoMatrix m1( s1 );
    QCoMatrix m2( s2 );
    return ( 15 * (QCoMatrix::intersection(m1, m2).worth() + 1) ) /
           ( QCoMatrix::reunion(m1, m2).worth() + 1 );
}

#include <qptrlist.h>

QGPluginManager::QGPluginManager( const QUuid& id, const QStringList& paths, const QString &suffix, bool cs )
    : interfaceId( id ), plugDict( 17, cs ), casesens( cs ), autounload( TRUE )
{
    // Every QLibrary object is destroyed on destruction of the manager
    libDict.setAutoDelete( TRUE );
    for ( QStringList::ConstIterator it = paths.begin(); it != paths.end(); ++it ) {
        QString path = *it;
        addLibraryPath( path + suffix );
    }
}

QGPluginManager::~QGPluginManager()
{
    if ( !autounload ) {
        QDictIterator<QLibrary> it( libDict );
        while ( it.current() ) {
            QLibrary *lib = it.current();
            ++it;
            lib->setAutoUnload( FALSE );
        }
    }
}

void QGPluginManager::addLibraryPath( const QString& path )
{
    if ( !enabled() || !QDir( path ).exists( ".", TRUE ) )
        return;

#if defined(Q_OS_WIN32)
    QString filter = "dll";
#elif defined(Q_OS_MACX)
    QString filter = "dylib";
#elif defined(Q_OS_UNIX)
    QString filter = "so";
#endif

    QStringList plugins = QDir(path).entryList( "*." + filter );
    for ( QStringList::Iterator p = plugins.begin(); p != plugins.end(); ++p ) {
        QString lib = QDir::cleanDirPath( path + "/" + *p );
        if ( libList.contains( lib ) )
            continue;
        libList.append( lib );
    }
}

const QLibrary* QGPluginManager::library( const QString& feature ) const
{
    if ( !enabled() || feature.isEmpty() )
        return 0;

    // We already have a QLibrary object for this feature
    QLibrary *library = 0;
    if ( ( library = plugDict[feature] ) )
        return library;

    // Find the filename that matches the feature request best
    QMap<int, QStringList> map;
    QStringList::ConstIterator it = libList.begin();
    int best = 0;
    int worst = 15;
    while ( it != libList.end() ) {
        if ( (*it).isEmpty() || libDict[*it] ) {
            ++it;
            continue;
        }
        QString basename = QFileInfo(*it).baseName();
        int s = similarity( feature, basename );
        if ( s < worst )
            worst = s;
        if ( s > best )
            best = s;
        map[s].append( basename + QChar(0xfffd) + *it );
        ++it;
    }

    if ( map.isEmpty() )
        return 0; // no libraries to add

    // Start with the best match to get the library object
    QGPluginManager *that = (QGPluginManager*)this;
    for ( int s = best; s >= worst; --s ) {
        QStringList group = map[s];
        group.sort(); // sort according to the base name
        QStringList::ConstIterator git = group.begin();
        while ( git != group.end() ) {
            QString lib = (*git).mid( (*git).find( QChar(0xfffd) ) + 1 );
            QString basename = (*git).left( (*git).find( QChar(0xfffd) ) );
            ++git;

            QStringList sameBasename;
            while( git != group.end() &&
                   basename == (*git).left( (*git).find( QChar(0xfffd) ) )  ) {
                sameBasename << (*git).mid( (*git).find( QChar(0xfffd) ) + 1 );
                ++git;
            }

            if ( sameBasename.isEmpty() ) {
                that->addLibrary( new QComLibrary( lib ) );
            } else {
                QPtrList<QComLibrary> same;
                same.setAutoDelete( TRUE );
                for ( QStringList::ConstIterator bit = sameBasename.begin();
                      bit != sameBasename.end(); ++bit )
                    same.append( new QComLibrary( *bit ) );
                QComLibrary* bestMatch = 0;
                for ( QComLibrary* candidate = same.first(); candidate; candidate = same.next() )
                    if ( candidate->qtVersion() && candidate->qtVersion() <= QT_VERSION
                         && ( !bestMatch || candidate->qtVersion() > bestMatch->qtVersion() ) )
                        bestMatch = candidate;
                if ( bestMatch ) {
                    same.find( bestMatch );
                    that->addLibrary( same.take() );
                }
            }

            if ( ( library = that->plugDict[feature] ) )
                return library;
        }
    }
    return 0;
}

QStringList QGPluginManager::featureList() const
{
    QStringList features;

    if ( !enabled() )
        return features;

    QGPluginManager *that = (QGPluginManager*)this;
    QStringList theLibs = libList;
    QStringList phase2Libs;
    QStringList phase2Deny;

    /* In order to get the feature list we need to add all interesting
      libraries. If there are libraries with the same base name, we
      prioritze the one that fits our Qt version number and ignore the
      others  */
    QStringList::Iterator it;
    for ( it = theLibs.begin(); it != theLibs.end(); ++it  ) {
        if ( (*it).isEmpty() || libDict[*it] )
            continue;
        QComLibrary* library = new QComLibrary( *it );
        if ( library->qtVersion() == QT_VERSION ) {
            that->addLibrary( library );
            phase2Deny << QFileInfo( *it ).baseName();
        } else {
            delete library;
            phase2Libs << *it;
        }
    }
    for ( it = phase2Libs.begin(); it != phase2Libs.end(); ++it  )
        if ( !phase2Deny.contains( QFileInfo( *it ).baseName() ) )
            that->addLibrary( new QComLibrary( *it ) );

    for ( QDictIterator<QLibrary> pit( plugDict ); pit.current(); ++pit )
        features << pit.currentKey();

    return features;
}

bool QGPluginManager::addLibrary( QLibrary* lib )
{
    if ( !enabled() || !lib )
        return FALSE;

    QComLibrary* plugin = (QComLibrary*)lib;
    bool useful = FALSE;

    QUnknownInterface* iFace = 0;
    plugin->queryInterface( interfaceId, &iFace );
    if ( iFace ) {
        QFeatureListInterface *fliFace = 0;
        QComponentInformationInterface *cpiFace = 0;
        iFace->queryInterface( IID_QFeatureList, (QUnknownInterface**)&fliFace );
        if ( !fliFace )
            plugin->queryInterface( IID_QFeatureList, (QUnknownInterface**)&fliFace );
        if ( !fliFace ) {
            iFace->queryInterface( IID_QComponentInformation, (QUnknownInterface**)&cpiFace );
            if ( !cpiFace )
                plugin->queryInterface( IID_QComponentInformation, (QUnknownInterface**)&cpiFace );
        }
        QStringList fl;
        if ( fliFace )
            // Map all found features to the library
            fl = fliFace->featureList();
        else if ( cpiFace )
            fl << cpiFace->name();

        for ( QStringList::Iterator f = fl.begin(); f != fl.end(); ++f ) {
            QLibrary *old = plugDict[*f];
            if ( !old ) {
                useful = TRUE;
                plugDict.replace( *f, plugin );
            } else {
                // we have old *and* plugin, which one to pick?
                QComLibrary* first = (QComLibrary*)old;
                QComLibrary* second = (QComLibrary*)plugin;
                bool takeFirst = TRUE;
                if ( first->qtVersion() != QT_VERSION ) {
                    if ( second->qtVersion() == QT_VERSION )
                        takeFirst = FALSE;
                    else if ( second->qtVersion() < QT_VERSION &&
                              first->qtVersion() > QT_VERSION )
                        takeFirst = FALSE;
                }
                if ( !takeFirst ) {
                    useful = TRUE;
                    plugDict.replace( *f, plugin );
                    qWarning("%s: Discarding feature %s in %s!",
                             (const char*) QFile::encodeName( plugin->library()),
                             (*f).latin1(),
                             (const char*) QFile::encodeName( old->library() ) );
                } else {
                    qWarning("%s: Feature %s already defined in %s!",
                             (const char*) QFile::encodeName( old->library() ),
                             (*f).latin1(),
                             (const char*) QFile::encodeName( plugin->library() ) );
                }
            }
        }
        if ( fliFace )
            fliFace->release();
        if ( cpiFace )
            cpiFace->release();
        iFace->release();
    }

    if ( useful ) {
        libDict.replace( plugin->library(), plugin );
        if ( !libList.contains( plugin->library() ) )
            libList.append( plugin->library() );
        return TRUE;
    }
    delete plugin;
    return FALSE;
}


bool QGPluginManager::enabled() const
{
#ifdef QT_SHARED
    return TRUE;
#else
    return FALSE;
#endif
}

QRESULT QGPluginManager::queryUnknownInterface(const QString& feature, QUnknownInterface** iface) const
{
    QComLibrary* plugin = 0;
    plugin = (QComLibrary*)library( feature );
    return plugin ? plugin->queryInterface( interfaceId, (QUnknownInterface**)iface ) : QE_NOINTERFACE;
}

#endif //QT_NO_COMPONENT

---