LookupTable.h

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/*
 * Copyright (C) 1996-2019 The Squid Software Foundation and contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.
 */

#ifndef SQUID_LOOKUPTABLE_H_
#define SQUID_LOOKUPTABLE_H_

#include "sbuf/Algorithms.h"
#include "sbuf/SBuf.h"

#include <unordered_map>

template <typename EnumType>
struct LookupTableRecord
{
    const char *name;
    EnumType id;
};

class SBufCaseInsensitiveLess : public std::binary_function<SBuf, SBuf, bool> {
public:
    bool operator() (const SBuf &x, const SBuf &y) const {
        return x.caseCmp(y) < 0;
    }
};

template<typename EnumType, typename RecordType = LookupTableRecord<EnumType>, typename Hasher = CaseInsensitiveSBufHash >
class LookupTable
{
public:
    typedef RecordType Record;

    LookupTable(const EnumType theInvalid, const Record data[]) :
        invalidValue(theInvalid)
    {
        for (auto i = 0; data[i].name != nullptr; ++i) {
            lookupTable[SBuf(data[i].name)] = data[i].id;
        }
    }

    EnumType lookup(const SBuf &key) const {
        auto r = lookupTable.find(key);
        if (r == lookupTable.end())
            return invalidValue;
        return r->second;
    }

private:
    typedef std::unordered_map<const SBuf, EnumType, Hasher> lookupTable_t;
    lookupTable_t lookupTable;
    EnumType invalidValue;
};

#endif /* SQUID_LOOKUPTABLE_H_ */