LookupTable.h

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/*
 * Copyright (C) 1996-2023 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;
};
 
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:
    using lookupTable_t = std::unordered_map<const SBuf, EnumType, Hasher, CaseInsensitiveSBufEqual>;
    lookupTable_t lookupTable;
    EnumType invalidValue;
};
 
#endif /* SQUID_LOOKUPTABLE_H_ */