path: root/ept/debtags/coll/fast.tcc

/*
 * Fast index for tag data
 *
 * Copyright (C) 2005,2006  Enrico Zini <enrico@debian.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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
 */

#ifndef TAGCOLL_COLL_FAST_TCC
#define TAGCOLL_COLL_FAST_TCC

#include <ept/debtags/coll/fast.h>
#include <ept/debtags/coll/set.h>

#include <wibble/operators.h>

using namespace std;
using namespace wibble::operators;

namespace tagcoll {
namespace coll {

template<class ITEM, class TAG> template<typename ITEMS, typename TAGS>
void Fast<ITEM, TAG>::insert(const ITEMS& items, const TAGS& tags)
{
    using namespace wibble::operators;

    if (tags.empty())
        return;

    for (typename ITEMS::const_iterator i = items.begin();
            i != items.end(); ++i)
    {
        typename std::map< ITEM, std::set<TAG> >::iterator iter = this->items.find(*i);
        if (iter == this->items.end())
            this->items.insert(std::make_pair(*i, std::set<TAG>() | tags));
        else
            iter->second |= tags;
    }

    for (typename TAGS::const_iterator i = tags.begin();
            i != tags.end(); ++i)
    {
        typename std::map< TAG, std::set<ITEM> >::iterator iter = this->tags.find(*i);
        if (iter == this->tags.end())
            this->tags.insert(std::make_pair(*i, std::set<ITEM>() | items));
        else
            iter->second |= items;
    }
}

template<class ITEM, class TAG>
void Fast<ITEM, TAG>::insert(const wibble::Singleton<ITEM>& item, const std::set<TAG>& tags)
{
    using namespace wibble::operators;

    if (tags.empty())
        return;

    typename std::map< ITEM, std::set<TAG> >::iterator iter = this->items.find(*item.begin());
    if (iter == this->items.end())
        this->items.insert(std::make_pair(*item.begin(), tags));
    else
        iter->second |= tags;

    for (typename std::set<TAG>::const_iterator i = tags.begin();
            i != tags.end(); ++i)
    {
        typename std::map< TAG, std::set<ITEM> >::iterator iter = this->tags.find(*i);
        if (iter == this->tags.end())
            this->tags.insert(std::make_pair(*i, std::set<ITEM>() | *item.begin()));
        else
            iter->second |= *item.begin();
    }
}

template<class ITEM, class TAG>
void Fast<ITEM, TAG>::insert(const std::set<ITEM>& items, const wibble::Singleton<TAG>& tag)
{
    using namespace wibble::operators;

    for (typename std::set<ITEM>::const_iterator i = items.begin();
            i != items.end(); ++i)
    {
        typename std::map< ITEM, std::set<TAG> >::iterator iter = this->items.find(*i);
        if (iter == this->items.end())
            this->items.insert(std::make_pair(*i, std::set<TAG>() | *tag.begin()));
        else
            iter->second |= *tag.begin();
    }

    typename std::map< TAG, std::set<ITEM> >::iterator iter = this->tags.find(*tag.begin());
    if (iter == this->tags.end())
        this->tags.insert(std::make_pair(*tag.begin(), items));
    else
        iter->second |= items;
}

template<class ITEM, class TAG>
std::set<ITEM> Fast<ITEM, TAG>::getItemsHavingTag(const TAG& tag) const
{
    typename map<TAG, std::set<ITEM> >::const_iterator i = tags.find(tag);
    if (i != tags.end())
        return i->second;
    else
        return std::set<ITEM>();
}

template<class ITEM, class TAG>
std::set<TAG> Fast<ITEM, TAG>::getTagsOfItem(const ITEM& item) const
{
    typename map<ITEM, std::set<TAG> >::const_iterator i = items.find(item);
    if (i != items.end())
        return i->second;
    else
        return std::set<TAG>();
}

template<class ITEM, class TAG>
std::set<ITEM> Fast<ITEM, TAG>::getTaggedItems() const
{
    std::set<ITEM> res;
    for (typename map<ITEM, std::set<TAG> >::const_iterator i = items.begin();
            i != items.end(); i++)
        res |= i->first;
    return res;
}

template<class ITEM, class TAG>
std::set<TAG> Fast<ITEM, TAG>::getAllTags() const
{
    std::set<TAG> res;
    for (typename map<TAG, std::set<ITEM> >::const_iterator i = tags.begin();
            i != tags.end(); i++)
        res |= i->first;
    return res;
}

template<class ITEM, class TAG>
std::vector<TAG> Fast<ITEM, TAG>::getAllTagsAsVector() const
{
    std::vector<TAG> res;
    for (typename map<TAG, std::set<ITEM> >::const_iterator i = tags.begin();
            i != tags.end(); i++)
        res.push_back(i->first);
    return res;
}

#if 0
template<class ITEM, class TAG>
void Fast<ITEM, TAG>::output(Consumer<ITEM, TAG>& consumer) const
{
    for (typename map<ITEM, std::set<TAG> >::const_iterator i = items.begin();
            i != items.end(); i++)
        consumer.consume(i->first, i->second);
}
#endif

template<class ITEM, class TAG> template<typename OUT>
void Fast<ITEM, TAG>::outputReversed(OUT out) const
{
    for (typename std::map<TAG, std::set<ITEM> >::const_iterator i = tags.begin();
            i != tags.end(); ++i)
    {
        *out = make_pair(wibble::singleton(i->first), i->second);
        ++out;
    }
}


template<class ITEM, class TAG>
std::set<TAG> Fast<ITEM, TAG>::getTagsImplying(const TAG& tag) const
{
    // tag1 implies tag2 if the itemset of tag1 is a subset of the itemset of tag2
    std::set<TAG> res;
    std::set<ITEM> itemsToCheck = getItemsHavingTag(tag);
    // TODO: choose which one is the most efficient implementation
#if 0
    // Roughly:
    // O(n[pkgs per tag] * log(nitems) * log(n[items per pkg]) + n[tags per item] * n[items per tag])
    std::set<TAG> tagsToCheck;
    for (std::set<ITEM>::const_iterator i = itemsToCheck.begin();
            i != itemsToCheck.end(); ++i)
        tagsToCheck |= getTags(*i);
    for (std::set<TAG>::const_iterator i = tagsToCheck.begin();
            i != tagsToCheck.end(); ++i)
        if (utils::set_contains(itemsToCheck, getItems(*i)))
            res |= *i;
#else
    // O(ntags * n[items per tag])
    for (typename std::map<TAG, std::set<ITEM> >::const_iterator i = tags.begin();
            i != tags.end(); ++i)
        if (utils::set_contains(itemsToCheck, getItemsHavingTag(i->first)))
            res |= i->first;
#endif
    return res - tag;
}

template<class ITEM, class TAG>
std::set<ITEM> Fast<ITEM, TAG>::getItemsExactMatch(const std::set<TAG>& tags) const
{
    std::set<ITEM> res = this->getItemsHavingTags(tags);
    typename std::set<ITEM>::iterator i = res.begin();
    while (i != res.end())
    {
        typename std::map<ITEM, std::set<TAG> >::const_iterator t = items.find(*i);
        if (t != items.end() && t->second != tags)
        {
            typename std::set<ITEM>::iterator j = i;
            ++i;
            res.erase(j);
        } else
            ++i;
    }
    return res;
}

template<class ITEM, class TAG>
TAG Fast<ITEM, TAG>::findTagWithMaxCardinality(size_t& card) const
{
    card = 0;
    TAG res = TAG();
    for (typename std::map<TAG, std::set<ITEM> >::const_iterator i = tags.begin();
            i != tags.end(); ++i)
        if (i->second.size() > card)
        {
            card = i->second.size();
            res = i->first;
        }
    return res;
}
     
template<class ITEM, class TAG>
void Fast<ITEM, TAG>::removeTag(const TAG& tag)
{
    typename std::map<TAG, std::set<ITEM> >::iterator itag = tags.find(tag);
    for (typename std::set<ITEM>::const_iterator iitemset = itag->second.begin();
            iitemset != itag->second.end(); ++iitemset)
    {
        typename std::map<ITEM, std::set<TAG> >::iterator iitem = items.find(*iitemset);
        iitem->second -= tag;
        if (iitem->second.empty())
            items.erase(iitem);
    }
    tags.erase(itag);
}

template<class ITEM, class TAG>
Fast<ITEM, TAG> Fast<ITEM, TAG>::getChildCollection(const TAG& tag) const
{
    Fast<ITEM, TAG> res;

    typename std::map<TAG, std::set<ITEM> >::const_iterator itag = tags.find(tag);
    for (typename std::set<ITEM>::const_iterator i = itag->second.begin();
            i != itag->second.end(); ++i)
    {
        typename std::map<ITEM, std::set<TAG> >::const_iterator iitem = items.find(*i);
        res.insert(wibble::singleton(*i), iitem->second);
    }

    res.removeTag(tag);
    return res;
}

template<class ITEM, class TAG>
void Fast<ITEM, TAG>::removeTagsWithCardinalityLessThan(size_t card)
{
    typename std::map<TAG, std::set<ITEM> >::const_iterator i = tags.begin();
    while (i != tags.end())
    {
        if (i->second.size() < card)
        {
            typename std::map<TAG, std::set<ITEM> >::const_iterator j = i;
            ++i;
            removeTag(j->first);
        } else
            ++i;
    }
}


#if 0
template<class ITEM, class TAG>
void Fast<ITEM, TAG>::consumeItem(const ITEM& item, const std::set<TAG>& tags)
{
    // Add the tags to the item
    items[item] |= tags;

    // Add the item to the tags
    for (typename std::set<TAG>::const_iterator i = tags.begin(); i != tags.end(); i++)
        this->tags[*i] |= item;
}

template<class ITEM, class TAG>
void Fast<ITEM, TAG>::consumeItems(const std::set<ITEM>& items, const std::set<TAG>& tags)
{
    for (typename std::set<ITEM>::const_iterator i = items.begin(); i != items.end(); i++)
        // Add the tags to the item
        this->items[*i] |= tags;

    for (typename std::set<TAG>::const_iterator i = tags.begin(); i != tags.end(); i++)
        // Add the items to the tag
        this->tags[*i] |= items;
}
#endif

}
}

#include <ept/debtags/coll/base.tcc>

#endif

// vim:set ts=4 sw=4: