InstallOrder.cc

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* InstallOrder.cc
 *
 * Copyright (C) 2005 SUSE Linux Products GmbH
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 * 02111-1307, USA.
 */

// stolen from yast2-packagemanager
/*
   File:       InstallOrder.h
   Purpose:    Determine order for installing packages
   Author:     Ludwig Nussel <lnussel@suse.de>
   Maintainer: Ludwig Nussel <lnussel@suse.de>

/-*/

#include "zypp/solver/detail/InstallOrder.h"
#include "zypp/base/Logger.h"
#include "zypp/base/Iterator.h"
#include "zypp/base/Algorithm.h"

#include "zypp/ResFilters.h"
#include "zypp/ResStatus.h"
#include "zypp/CapAndItem.h"

namespace zypp
{ 

  namespace solver
  { 

    namespace detail
    { 

using namespace std;
using namespace zypp;

#define ITEMNAME(item) (item)->name()
//-----------------------------------------------------------------------------

InstallOrder::InstallOrder( const ResPool & pool, const PoolItemSet & toinstall, const PoolItemSet & installed )
    : _pool( pool )
    , _toinstall( toinstall )
    , _installed( installed )
    , _dirty (true)
    , _numrun (0)
{
    _DEBUG("InstallOrder::InstallOrder(_toinstall " << _toinstall.size() << " items, _installed " << _installed.size() << " items)");
}


//-----------------------------------------------------------------------------

const void
InstallOrder::printAdj (std::ostream& os, bool reversed) const
{
    const Graph& g = (reversed ? _rgraph : _graph);
    os << "digraph pkgdeps {" << endl;
    for (Graph::const_iterator gcit = g.begin(); gcit != g.end(); ++gcit)
    {
        Nodes::const_iterator niit = _nodes.find(gcit->first);
        int order = niit->second.order;
        string name = gcit->first->name();
        os << "\"" << name << "\"" << "[label=\"" << name << "\\n" << order << "\"";
        os << "] " << endl;
        for (PoolItemList::const_iterator scit = gcit->second.begin(); scit != gcit->second.end(); ++scit)
        {
            os << "\"" << name << "\" -> \"" << (*scit)->name() << "\"" << endl;
        }
    }
    os << "}" << endl;
}


//-----------------------------------------------------------------------------

// yea, that stuff is suboptimal. there should be a heap sorted by order
PoolItemList
InstallOrder::computeNextSet()
{
    PoolItemList newlist;

    if (_dirty) startrdfs();

    for (Nodes::iterator it = _nodes.begin(); it != _nodes.end(); ++it)
    {
        if (it->second.order == 0
            && it->second.item)                 // the default Nodes constructor leaves this empty 
        {
            if (isKind<SystemResObject>( it->second.item.resolvable() ))
                continue;

            XXX << "InstallOrder::computeNextSet found " << ITEMNAME(it->second.item) << endl;
        
            newlist.push_back(it->second.item);
        }
    }

    return newlist;
}


// decrease order of every adjacent node
void
InstallOrder::setInstalled(PoolItem_Ref item )
{
    _dirty = true;

    PoolItemList adj = _rgraph[item];

    XXX << "InstallOrder::setInstalled " << ITEMNAME(item) << endl;

    // order will be < 0
    _nodes[item].order--;
    _installed.insert( item );
    _toinstall.erase( item );

    for (PoolItemList::iterator it = adj.begin(); it != adj.end(); ++it)
    {
        NodeInfo& info = _nodes[*it];
        info.order--;
        if (info.order < 0)
        {
            WAR << "order of node " << (*it) << " is < 0" << endl;
        }
    }
}


void
InstallOrder::setInstalled( const PoolItemList & rl )
{
    for (PoolItemList::const_iterator it = rl.begin(); it != rl.end(); ++it)
    {
        setInstalled(*it);
    }
}

//-----------------------------------------------------------------------------

bool
InstallOrder::doesProvide( const Capability requirement, PoolItem_Ref item ) const
{
    CapSet::const_iterator pend = item->dep( Dep::PROVIDES ).end();
    for( CapSet::const_iterator pit = item->dep( Dep::PROVIDES ).begin(); pit != pend; ++pit) {
        if( pit->matches( requirement ) == CapMatch::yes ) {
            return item;
        }
    }
    return PoolItem_Ref();
}


PoolItem_Ref
InstallOrder::findProviderInSet( const Capability requirement, const PoolItemSet & candidates ) const
{
    for( PoolItemSet::const_iterator citer = candidates.begin(); citer != candidates.end(); citer++) {
        if( doesProvide( requirement, *citer ) ) {
            return *citer;
        }
    }

    return PoolItem_Ref();
}

struct CollectProviders
{
    const PoolItem_Ref requestor;
    PoolItemList result;   
    const PoolItemSet & limitto;                // limit search to members of this set

    CollectProviders (const PoolItem_Ref pi, const PoolItemSet & limit)
        : requestor (pi)
        , limitto (limit)
    { }


    bool operator()( const CapAndItem & c_and_i )
    {
        // item provides cap which matches a requirement from info->requestor
        //   this function gets _all_ providers and filter out those which are
        //   either installed or in our toinstall input list
        //
XXX << "info(" << c_and_i.item <<")"<< endl;
        if ((c_and_i.item.resolvable() != requestor.resolvable())       // resolvable could provide its own requirement
            && (limitto.find( c_and_i.item ) != limitto.end()))         // limit to members of 'limitto' set
        {
            XXX << "tovisit " << ITEMNAME(c_and_i.item) << endl;
            result.push_back (c_and_i.item);
        }

        return true;
    }

};

//-----------------------------------------------------------------------------


void
InstallOrder::rdfsvisit (const PoolItem_Ref item)
{
    typedef list<Capability> CapList;
    CapList requires;

    XXX << "InstallOrder::rdfsvisit, visiting " << ITEMNAME(item) << endl;

    NodeInfo& nodeinfo = _nodes[item];

    nodeinfo.visited = true;
    nodeinfo.begintime = _rdfstime;
    _rdfstime++;

    // put prerequires first and requires last on list to ensure
    // that prerequires are processed first

    for (CapSet::const_iterator it = item->dep (Dep::PREREQUIRES).begin(); it != item->dep (Dep::PREREQUIRES).end(); ++it)
    {
        const Capability cap = *it;
        requires.push_back(cap);
    }

    for (CapSet::const_iterator it = item->dep (Dep::REQUIRES).begin(); it != item->dep (Dep::REQUIRES).end(); ++it)
    {
        const Capability cap = *it;
        requires.push_back(cap);
    }

    for (CapList::const_iterator iter = requires.begin(); iter != requires.end(); ++iter)
    {
        const Capability requirement = *iter;
        XXX << "check requirement " << requirement << " of " << ITEMNAME(item) << endl;
        PoolItemList tovisit;

        // _world->foreachProvidingResItem (requirement, collect_providers, &info);
        Dep dep (Dep::PROVIDES);

        // first, look in _installed
        CollectProviders info ( item, _installed );

        invokeOnEach( _pool.byCapabilityIndexBegin( requirement.index(), dep ),
                      _pool.byCapabilityIndexEnd( requirement.index(), dep ),
                      resfilter::ByCapMatch( requirement ),
                      functor::functorRef<bool,CapAndItem>(info) );

        // if not found in _iustalled, look in _toinstall

        if (info.result.empty()) {
            CollectProviders info1 ( item, _toinstall );

            invokeOnEach( _pool.byCapabilityIndexBegin( requirement.index(), dep ),
                          _pool.byCapabilityIndexEnd( requirement.index(), dep ),
                          resfilter::ByCapMatch( requirement ),
                          functor::functorRef<bool,CapAndItem>(info1) );

            tovisit = info1.result;
        }

        for (PoolItemList::iterator it = tovisit.begin(); it != tovisit.end(); ++it)
        {
            const PoolItem_Ref must_visit = *it;
            if (_nodes[must_visit].visited == false)
            {
                nodeinfo.order++;
                _rgraph[must_visit].push_back( item );
                _graph[item].push_back( must_visit );
                rdfsvisit( must_visit );
            }
            else if (_nodes[must_visit].endtime == 0)
            {
                if (must_visit != item)
                {
                    WAR << "** dependency loop: " << ITEMNAME(item) << " -> " << ITEMNAME(must_visit) << endl;
                }
            }
            else
            {
                // filter multiple depends on same item (cosmetic)
                PoolItemList & lrg = _rgraph[must_visit];
                if( find( lrg.begin(), lrg.end(), item) == lrg.end() )
                {
                    nodeinfo.order++;
                    lrg.push_back( item );

                    PoolItemList & lg = _graph[item];
                    if( find( lg.begin(), lg.end(), must_visit ) == lg.end() )
                        lg.push_back( must_visit );
                }
            }
        }
    }
    _topsorted.push_back(item);
    _nodes[item].endtime = _rdfstime;
    _rdfstime++;

    XXX << ITEMNAME(item) << " done" << endl;
}


void
InstallOrder::startrdfs()
{
    _nodes.clear();
    _rgraph.clear();
    _graph.clear();

    _rdfstime = 1;

    _topsorted.clear();

    _numrun++;
    XXX << "run #" << _numrun << endl;

    // initialize all nodes
    for (PoolItemSet::iterator it = _toinstall.begin(); it != _toinstall.end(); ++it)
    {
        PoolItem_Ref item = *it;
        _nodes[item] = NodeInfo (item);
        _rgraph[item] = PoolItemList();
        _graph[item] = PoolItemList();
    }

    // visit all nodes
    for (PoolItemSet::iterator it = _toinstall.begin(); it != _toinstall.end(); ++it)
    {
        const PoolItem_Ref item = *it;
        if (_nodes[item].visited == false)
        {
            XXX << "start recursion on " << ITEMNAME(item) << endl;
            rdfsvisit (item);
        }
    }

    _dirty = false;
}


//-----------------------------------------------------------------------------

const PoolItemList
InstallOrder::getTopSorted() const
{
    return _topsorted;
}


    };// namespace detail
  };// namespace solver
};// namespace zypp

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