ResolverQueue.cc

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 4 -*- */
/* ResolverQueue.cc
 *
 * Copyright (C) 2000-2002 Ximian, Inc.
 * 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.
 */

#include <map>

#include "zypp/base/String.h"
#include "zypp/solver/detail/ResolverQueue.h"
#include "zypp/solver/detail/QueueItemBranch.h"
#include "zypp/solver/detail/QueueItemConflict.h"
#include "zypp/solver/detail/QueueItemEstablish.h"
#include "zypp/solver/detail/QueueItemGroup.h"
#include "zypp/solver/detail/QueueItemInstall.h"
#include "zypp/solver/detail/QueueItemRequire.h"
#include "zypp/solver/detail/QueueItemUninstall.h"
#include "zypp/solver/detail/ResolverContext.h"
#include "zypp/CapSet.h"
#include "zypp/base/Logger.h"

namespace zypp
{ 

  namespace solver
  { 

    namespace detail
    { 

using namespace std;

IMPL_PTR_TYPE(ResolverQueue);

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


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

ostream&
operator<<( ostream& os, const ResolverQueue & resolverqueue)
{
    os << str::form ("Context [%p]", (const void *)resolverqueue._context.get());
    os <<  ", " << resolverqueue._qitems.size() << " Items:" << endl << "\t";
    os << resolverqueue._qitems;
    return os;
}

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

ResolverQueue::ResolverQueue (const ResPool & pool, const Arch & arch, ResolverContext_Ptr context)
    : _context (context)
{
    _XDEBUG("ResolverQueue::ResolverQueue(pool, " << context << ")");
    if (context == NULL)
        _context = new ResolverContext(pool, arch);
}


ResolverQueue::~ResolverQueue()
{
}

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

void
ResolverQueue::addPoolItemToInstall (PoolItem_Ref poolItem)
{
    QueueItemInstall_Ptr qitem;

    if (_context->isPresent (poolItem)
        && poolItem.status().staysInstalled()) {
        WAR << poolItem << " is already installed" << endl;
        return;
    }

    qitem = new QueueItemInstall (_context->pool(), poolItem, poolItem.status().isSoftInstall());
    poolItem.status().setSoftInstall(false);
    qitem->setExplicitlyRequested ();

    addItem (qitem);
}


void
ResolverQueue::addPoolItemToEstablish (PoolItem_Ref poolItem)
{
    QueueItemEstablish_Ptr qitem;

    qitem = new QueueItemEstablish (_context->pool(), poolItem);
    qitem->setExplicitlyRequested ();

    addItem (qitem);
}


void
ResolverQueue::addPoolItemToRemove (PoolItem_Ref poolItem, bool remove_only_mode)
{
    QueueItemUninstall_Ptr qitem;

    if (_context->isAbsent (poolItem))
        return;

    qitem = new QueueItemUninstall (_context->pool(), poolItem, QueueItemUninstall::EXPLICIT, poolItem.status().isSoftUninstall());
    poolItem.status().setSoftUninstall(false);
    if (remove_only_mode)
        qitem->setRemoveOnly ();

    qitem->setExplicitlyRequested ();

    addItem (qitem);
}


void
ResolverQueue::addPoolItemToVerify (PoolItem_Ref poolItem)
{
    if (poolItem.status().staysInstalled()
        || poolItem.status().isToBeInstalled()) {
        // regarding only items which will on the system after commit
        CapSet requires = poolItem->dep (Dep::REQUIRES);
        for (CapSet::const_iterator iter = requires.begin(); iter != requires.end(); ++iter) {
            QueueItemRequire_Ptr qitem = new QueueItemRequire (_context->pool(), *iter);
            qitem->addPoolItem (poolItem);
            addItem (qitem);
        }

        CapSet conflicts = poolItem->dep (Dep::CONFLICTS);
        for (CapSet::const_iterator iter = conflicts.begin(); iter != conflicts.end(); ++iter) {
            QueueItemConflict_Ptr qitem = new QueueItemConflict (_context->pool(), *iter, poolItem);
            addItem (qitem);
        }
    }
}


void
ResolverQueue::addExtraCapability (const Capability & dep)
{
    QueueItemRequire_Ptr qitem = new QueueItemRequire (_context->pool(), dep);
    addItem (qitem);
}


void
ResolverQueue::addExtraConflict (const Capability & dep)
{
    QueueItemConflict_Ptr qitem = new QueueItemConflict (_context->pool(), dep, PoolItem_Ref());
    addItem (qitem);
}


void
ResolverQueue::addItem (QueueItem_Ptr qitem)
{
    _qitems.push_back(qitem);
}


bool
ResolverQueue::isInvalid ()
{
    return _context->isInvalid() || _context->askUser();
}


bool
ResolverQueue::containsOnlyBranches ()
{
    for (QueueItemList::const_iterator iter = _qitems.begin(); iter != _qitems.end(); ++iter) {
        if (!(*iter)->isBranch())
            return false;
    }

    return true;
}

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

static int
qitemlist_max_priority (const QueueItemList & qil)
{
    int max_priority = -1;
    for (QueueItemList::const_iterator iter = qil.begin(); iter != qil.end(); ++iter) {
        if ((*iter)->priority() > max_priority) {
            max_priority = (*iter)->priority();
        }
    }

    return max_priority;
}



bool
ResolverQueue::processOnce ()
{
    QueueItemList new_qitems;
    int max_priority;
    bool did_something = false;

    _XDEBUG("ResolverQueue::processOnce()" << (int) _qitems.size() << " items");
    while ( (max_priority = qitemlist_max_priority (_qitems)) >= 0
            && _context->isValid () ) {

        bool did_something_recently = false;

        for (QueueItemList::iterator iter = _qitems.begin(); iter != _qitems.end() && _context->isValid();) {
            QueueItem_Ptr qitem = *iter;
            _XDEBUG( "=====> 1st pass: [" << *qitem << "]");
            QueueItemList::iterator next = iter; ++next;
            if (qitem && qitem->priority() == max_priority) {
                if (qitem->process (_qitems, _context, new_qitems)) {
                    did_something_recently = true;
                }
                _qitems.erase (iter);
            }
            iter = next;
        }

        if (did_something_recently) {
            did_something = true;
        }
    }

    _qitems = new_qitems;
    _XDEBUG(_qitems.size() << " qitems after first pass");

    /*
       Now make a second pass over the queue, removing any super-branches.
       (If one branch contains all of the possible items of another branch,
       the larger branch can be dropped.
    */

    for (QueueItemList::iterator iter = _qitems.begin(); iter != _qitems.end();) {
        QueueItemList::iterator next = iter; ++next;
        QueueItem_Ptr qitem = *iter;

        _XDEBUG( "=====> 2nd pass: [" << *qitem << "]");
        if (qitem->isBranch()) {
            _XDEBUG("ResolverQueue::processOnce() is branch");
            QueueItemBranch_Ptr branch = dynamic_pointer_cast<QueueItemBranch>(qitem);
            for (QueueItemList::const_iterator iter2 = _qitems.begin(); iter2 != _qitems.end(); ++iter2) {
                _XDEBUG("Compare branch with [" << *(*iter2) << "]");
                if (iter != iter2
                    && branch->contains (*iter2)) {
                    _XDEBUG("Contained within, removing");
                    _qitems.erase (iter);
                    break;
                }
            }
        }
        iter = next;
    }
    if (did_something) {
      _XDEBUG( "did something: " << _qitems.size() << " qitems");
    }
    else {
      _XDEBUG( "did nothing: " << _qitems.size() << " qitems"); 
    }

    return did_something;
}


void
ResolverQueue::process ()
{
    _XDEBUG("----- Processing -----");
    spew ();

    while (_context->isValid ()
                 && ! isEmpty ()
                 && processOnce ()) {
              /* all of the work is in the conditional! */
              spew ();
    }
}


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

ResolverQueue_Ptr
ResolverQueue::copy_queue_except_for_branch (QueueItem_Ptr branch_qitem, QueueItem_Ptr subqitem) const
{
    ResolverContext_Ptr new_context;
    ResolverQueue_Ptr new_queue;
    _XDEBUG("copy_queue_except_for_branch");
    new_context = new ResolverContext (_context->pool(), _context->architecture(), _context);
      
    new_queue = new ResolverQueue (new_context->pool(), new_context->architecture(), new_context);

    QueueItemList qil = _qitems;
    for (QueueItemList::const_iterator iter = qil.begin(); iter != qil.end(); ++iter) {
        QueueItem_Ptr qitem = *iter;
        QueueItem_Ptr new_qitem;

        if (qitem == branch_qitem) {
            new_qitem = subqitem->copy ();

            if (new_qitem->isInstall()) {
                QueueItemInstall_Ptr install_qitem = dynamic_pointer_cast<QueueItemInstall>(new_qitem);

                /* Penalties are negative priorities */
                int penalty;
                Source_Ref src = install_qitem->item()->source();
                penalty = - src.priority();

                install_qitem->setOtherPenalty (penalty);
            }

        } else {

            new_qitem = qitem->copy ();

        }

        new_queue->addItem (new_qitem);
    }

    return new_queue;
}


void
ResolverQueue::splitFirstBranch (ResolverQueueList & new_queues, ResolverQueueList & deferred_queues)
{
    QueueItemBranch_Ptr first_branch = NULL;
    typedef std::map <QueueItem_Ptr, QueueItem_Ptr> DeferTable;
    DeferTable to_defer;

    for (QueueItemList::const_iterator iter = _qitems.begin(); iter != _qitems.end() && first_branch == NULL; ++iter) {
        QueueItem_Ptr qitem = *iter;
        if (qitem->isBranch()) {
            first_branch = dynamic_pointer_cast<QueueItemBranch>(qitem);
        }
    }

    if (first_branch == NULL)
        return;

    QueueItemList possible_qitems = first_branch->possibleQItems();

    /*
       Check for deferrable qitems: if we have two install qitems where the to-be-installed
       poolItems have the same name, then we will defer the lower-priority install if
       one of the following is true:
       (1) Both poolItems have the same version
       (2) The lower-priority channel is a previous version.
    */

    for (QueueItemList::const_iterator iter = possible_qitems.begin(); iter != possible_qitems.end(); ++iter) {
        QueueItemList::const_iterator iter2 = iter;
        for (iter2++; iter2 != possible_qitems.end(); iter2++) {
            QueueItem_Ptr qitem = *iter;
            QueueItem_Ptr qitem2 = *iter2;

            if (qitem->isInstall() && qitem2->isInstall()) {
                PoolItem_Ref r = (dynamic_pointer_cast<QueueItemInstall>(qitem))->item();
                PoolItem_Ref r2 = (dynamic_pointer_cast<QueueItemInstall>(qitem2))->item();
                Source_Ref source = r->source();
                Source_Ref source2 = r2->source();
                int priority, priority2;

                priority = _context->getSourcePriority( source );
                priority2 = _context->getSourcePriority( source2 );

                if (priority != priority2 && r->name() == r2->name()) {
                    if (r->edition().compare(r2->edition()) == 0
                        || (priority < priority2 && r->edition().compare(r2->edition()) < 0)
                        || (priority > priority2 && r->edition().compare(r2->edition()) > 0))
                    {
                        if (priority < priority2)
                            to_defer[qitem] = qitem;
                        else /* if (priority > priority2) */
                            to_defer[qitem2] = qitem2;
                    }
                }
            }
        }
    }

    for (QueueItemList::const_iterator iter = possible_qitems.begin(); iter != possible_qitems.end(); ++iter) {
        ResolverQueue_Ptr new_queue;
        QueueItem_Ptr new_qitem = *iter;

        new_queue = copy_queue_except_for_branch ((QueueItem_Ptr) first_branch, new_qitem);

        DeferTable::const_iterator pos = to_defer.find (new_qitem);
        if (pos != to_defer.end()) {
            deferred_queues.push_back(new_queue);
        } else {
            new_queues.push_back(new_queue);
        }
    }

}


void
ResolverQueue::spew ()
{
    _XDEBUG( "Resolver Queue: " << (_context->isInvalid() ? "INVALID" : "") );

    if (_qitems.empty()) {

        _XDEBUG( "  (empty)" );

    } else {
        for (QueueItemList::const_iterator iter = _qitems.begin(); iter != _qitems.end(); ++iter) {
            _XDEBUG( "  " << *(*iter) );
        }

    }
}

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

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