FilterSearch.hh

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/*
    Copyright (c) 2002-2009 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
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/**
 * @file FilterSearch.hh
 *
 * Declaration of FilterSearch class.
 *
 * @author Tommi Rantanen 2003 (tommi.rantanen-no.spam-tut.fi)
 * @author Jari Mäntyneva 2005 (jari.mantyneva-no.spam-tut.fi)
 * @note rating: red
 */
 
#ifndef TTA_FILTER_SEARCH_HH
#define TTA_FILTER_SEARCH_HH
 
 
#include <vector>
 
#include "CostDBTypes.hh"
#include "SearchStrategy.hh"
#include "MatchType.hh"
#include "CostDBEntry.hh"
#include "Matcher.hh"
#include "Exception.hh"
 
 
/**
 * Implementation of the queries from the cost database.
 *
 * Using the FilterSearch algorithm requires only a Search() function
 * call.
 *
 * Search is based on filtering non-matching entries out according to
 * information of one field at a time. Thus, it is very generic
 * accepting field changes to entries without touching to the searrch
 * algorithms.
 *
 * Cache and quick filtering is used for optimisation. Cache contains
 * all the results from the previous queries. Quick filtering removes
 * unneccessary entries in linear time in the beginning of the search.
 */
class FilterSearch: public SearchStrategy {
public:
    FilterSearch();
    virtual ~FilterSearch();
 
    SearchStrategy* copy() const;
    CostDBTypes::EntryTable search(
        const CostDBEntryKey& searchKey,
        CostDBTypes::EntryTable components,
        const CostDBTypes::MatchTypeTable& match);
 
private:
    /**
     * Represents a cache entry.
     */
    class Cache {
        friend class FilterSearchTest;
    public:
    Cache(
            CostDBTypes::MatchTypeTable matchingType,
            CostDBEntryKey* key,
            CostDBTypes::EntryTable& entry);
    ~Cache();
        Cache* copy() const;
    bool isEqual(
            CostDBTypes::MatchTypeTable matchingType,
            const CostDBEntryKey* key) const;
    CostDBTypes::EntryTable entries() const;
    private:
        /// Type of match used for these results.
    CostDBTypes::MatchTypeTable matchType_;
        /// Search key of the query for these results.
    CostDBEntryKey* searchKey_;
        /// Resulting database entries. Not owned by this class.
    CostDBTypes::EntryTable entries_;
 
        /// Copying not allowed.
        Cache(const Cache&);
        /// Assignment not allowed.
        Cache& operator=(const Cache&);
    };
 
    /// Table of cache entries.
    typedef std::vector<Cache*> CacheTable;
    /// Table of matcher types.
    typedef std::vector<Matcher*> MatcherTable;
 
    CostDBTypes::EntryTable findFromCache(
        const CostDBEntryKey& searchKey,
        const CostDBTypes::MatchTypeTable& match);
    MatcherTable createMatchers(const CostDBTypes::MatchTypeTable& match);
 
    /// Results of the previous queries.
    CacheTable entryCache_;
    /// Storage for all matchers. They cannot be deleted before search
    /// strategy itself is deleted. Thus, this storage exists to
    /// deallocate the memory reserved by matchers.
    MatcherTable matcherStorage_;
 
    /// Copying not allowed.
    FilterSearch(const FilterSearch&);
    /// Assignment not allowed.
    FilterSearch& operator=(const FilterSearch&);
};
 
#endif